TWI826970B - Resin composition and optically clear adhesive - Google Patents

Abstract

The present invention provides an adhesive composition and an optical adhesive. The adhesive composition has excellent wettability and light resistance through a combination and content ratio of monomers having a specific glass transition temperature and normal temperature surface tension, and can cover step height differences. ) and foreign matter (defect); the above-mentioned optical adhesive can cover the foreign matter (defect) located between the laminate layers of the display or transparent electrode product.

Description

Adhesive compositions and optical adhesives

The present invention relates to an adhesive composition and an optical adhesive formed using the adhesive composition.

Optical adhesive (OCA, Optically Clear Adhesive) is an adhesive inserted to join functional layers constituting display products or products containing transparent electrodes (hereinafter, transparent electrode products). In order to achieve functions, the optical adhesive The adhesion of the adhesive is important. In particular, the functional layer may be made of two or more different materials or members. Even in this case, it is required to have excellent adhesion on both sides. In Patent Document 1, an optical adhesive is known that utilizes a partially polymerized acrylic resin to ensure excellent adhesion to a glass substrate.

Bubbles may occur in display products or transparent electrode products containing optical adhesives due to various reasons such as foreign matter contained in the glass substrate or seeping into the process, gas generated in the optical adhesive or polarizing plate, and thermal shrinkage of the polarizing plate. The generation or floating phenomenon between laminate layers (합지층). In particular, the generation of bubbles or the floating phenomenon between laminated layers mainly occurs because foreign matter (defect) located between the laminated layers of a display product or a transparent electrode product acts as a nucleus.

The existing optical adhesive with high cross-link density and glass transition temperature exhibits excellent stability in high-temperature, high-temperature/high-humidity, and thermal shock evaluations by introducing an excess of cross-linking agent and highly thermally stable monomer. , but the generation of bubbles or floating between laminate layers obviously occurs.

Therefore, there is a demand for optical adhesives that are stable and can prevent the generation of bubbles or floating between laminated layers. [Existing technical documents] 〔Patent documents〕

(Patent Document 1) Korean Patent Publication No. 10-2016-0105354

The object of the present invention is to provide an adhesive composition and an optical adhesive that can solve the above problems.

Another object of the present invention is to provide an adhesive composition for forming an optical adhesive that is excellent in wettability and light resistance and can cover steps and defects.

In addition, an object of the present invention is to provide an adhesive composition for forming an optical adhesive that satisfies basic physical properties such as durability and adhesive force and can minimize the generation of bubbles or the floating phenomenon between laminated layers. .

In addition, an object of the present invention is to provide an optical adhesive that can cover a defect between laminated layers of a display product or a transparent electrode product.

The term "normal temperature" used in the present invention refers to the temperature in a natural state without special heating or cooling, and may refer to any temperature in the range of about 10°C to 30°C, for example, about 15°C or above, or about 18°C or above , a temperature above about 20℃ or above about 23℃, or below about 27℃.

The term "surface tension" used in the present invention is a force acting in a direction that minimizes the surface of a liquid substance, and can be determined by a surface tension meter using a platinum ring and in accordance with the ISO 304 standard. measured value. In addition, the term "normal temperature surface tension" used in the present invention may be a value measured according to the above method in a normal temperature environment. In addition, here, normal temperature may be specifically about 25°C.

The term "substituted" used in the present invention means that a hydrogen atom bonded to a carbon atom of a compound is replaced by another substituent. The substituted position is a position where a hydrogen atom can be substituted, that is, a position where a substituent can be substituted. There is no particular limitation. When two or more substituents are substituted, the above substituents may be the same or different from each other.

The term "substituent" used in the present invention refers to an atom or atomic group that replaces one or more hydrogen atoms on the parent chain of hydrocarbons. In this case, in the present invention, the carbon in the parent chain of the hydrocarbon bonded to the above substituent is defined as a substituted carbon. In addition, the substituents are described below, but are not limited thereto. As long as there is no special description in the present invention, the above-mentioned substituents may be further substituted by the substituents described below or may not be substituted by any substituent.

Unless otherwise stated, the term "alkyl or alkylene" used in the present invention may have 1 to 20 carbon atoms, or 1 to 16 carbon atoms, or 1 to 12 carbon atoms, or 1 to 12 carbon atoms. 8. Or a linear or branched chain alkyl or alkylene group with 1 to 6 carbon atoms; or a carbon number of 3 to 20, or a carbon number of 3 to 16, or a carbon number of 3 to 12, or a carbon atom A cyclic alkyl group or alkylene group having 3 to 8 carbon atoms or 3 to 6 carbon atoms. Here, the cyclic alkyl group or alkylene group includes an alkyl group or alkylene group that only exists in a ring structure and an alkyl group or alkylene group that contains a ring structure. For example, cyclohexyl and methylcyclohexyl are both equivalent to cyclic alkyl groups.

Unless otherwise stated, the term "alkenyl or alkenylene" used in the present invention may have 2 to 20 carbon atoms, or 2 to 16 carbon atoms, or 2 to 12 carbon atoms, or 2 to 20 carbon atoms. 8. Or a linear or branched non-cyclic alkenyl or alkenylene group having 2 to 6 carbon atoms; or having 3 to 20 carbon atoms, or 3 to 16 carbon atoms, or 3 to 12 carbon atoms, or A cyclic alkenyl or alkenylene group having 3 to 8 carbon atoms or 3 to 6 carbon atoms. Here, when an alkenyl group or alkenylene group containing a ring structure is included, it corresponds to a cyclic alkenyl group or alkenylene group.

Unless otherwise stated, the term "alkynyl or alkynylene" used in the present invention may have a carbon number of 2 to 20, or a carbon number of 2 to 16, or a carbon number of 2 to 12, or a carbon number of 2 to 8. Or a linear or branched chain acyclic alkynyl or alkynylene group with 2 to 6 carbon atoms; or a carbon number of 3 to 20, or a carbon number of 3 to 16, or a carbon number of 3 to 12 , or a cyclic alkynyl group or alkynylene group having 3 to 8 carbon atoms, or 3 to 6 carbon atoms. Here, when an alkynyl group or alkynylene group containing a ring structure is included, it corresponds to a cyclic alkynyl group or alkynylene group.

The above-mentioned alkyl group, alkylene group, alkenyl group, alkenylene group, alkynyl group, and alkynylene group may be optionally substituted by one or more substituents. In this case, the substituent may be at least one selected from the group consisting of halogen (chlorine (Cl), iodine (I), bromine (Br), fluorine (F)), aryl group, heteroaryl group, ether group, carbonyl group, carboxyl group and hydroxyl group. , but is not limited to this.

The term "aryl" used in the present invention refers to an aromatic ring obtained by removing one hydrogen from an aromatic hydrocarbon ring, and the aromatic hydrocarbon ring may include a monocyclic or polycyclic ring. The number of carbon atoms of the above-mentioned aryl group is not particularly limited, but unless otherwise stated, it may be 6 to 30 carbon atoms, or 6 to 26 carbon atoms, or 6 to 22 carbon atoms, or 6 to 20 carbon atoms. , or an aryl group having 6 to 18 carbon atoms, or an aryl group having 6 to 15 carbon atoms. In addition, the term "arylene group" used in the present invention refers to a group having two bonding positions on an aryl group, that is, a divalent group. Except that each of them is a divalent group, the above description of the aryl group can be applied.

The term "heteroaryl" used in the present invention refers to an aromatic ring containing one or more heteroatoms other than carbon. Specifically, the above-mentioned heteroatoms may contain one or more selected from nitrogen (N), oxygen (O) ), sulfur (S), selenium (Se), and tellurium (Te) atoms. In this case, the atoms constituting the ring structure of the heteroaryl group can be called ring atoms. Furthermore, heteroaryl groups may contain monocyclic or polycyclic rings. The number of carbon atoms of the above-mentioned heteroaryl group is not particularly limited, but unless otherwise stated, it may be 2 to 30 carbon atoms, or 2 to 26 carbon atoms, or 2 to 22 carbon atoms, or 2 to 2 carbon atoms. 20. Either a heteroaryl group having 2 to 18 carbon atoms, or a heteroaryl group having 2 to 15 carbon atoms. In other examples, the number of ring atoms of the heteroaryl group is not particularly limited, but may be a heteroaryl group having 5 to 30, 5 to 25, 5 to 20, 5 to 15, 5 to 10, or 5 to 8 ring atoms.

In addition, the term "heteroaryl group" used in the present invention refers to a group having two bonding positions on the heteroaryl group, that is, a divalent group. Except that each of them is a divalent group, the above description of the heteroaryl group can be applied.

The term "acrylate compound" used in the present invention means acrylic acid, methacrylic acid, a derivative of acrylic acid, or a derivative of methacrylic acid. In addition, the term "(meth)acrylyl group" used in the present invention means an acrylyl group or a methacrylyl group.

In one example of the present invention, the adhesive composition includes a copolymer obtained by copolymerizing two or more monomers. The above-mentioned monomers may include monomers with a surface tension at room temperature greater than 30 mN/m and a surface tension at room temperature of 30 mN/m. The following monomers.

In addition, in an example of the present invention, the normal temperature surface tension of the copolymer of the adhesive composition may be 30 mN/m or less, 29.5 mN/m or less, 29 mN/m or less, 28.5 mN/m or less, or 28 mN/m or less, In other examples, the normal-temperature surface tension of the copolymer of the adhesive composition may be 20 mN/m or more, 21 mN/m or more, 22 mN/m or more, or 23 mN/m or more.

The ambient surface tension of the adhesive composition can be affected by the ambient surface tension of the included copolymer. In one example of the present invention, the normal temperature surface tension of the adhesive composition may be 30 mN/m or less, 29.5 mN/m or less, 29 mN/m or less, 28.5 mN/m or less, or 28 mN/m or less. In other examples, The normal-temperature surface tension of the above-mentioned adhesive composition may be 20 mN/m or more, 21 mN/m or more, 22 mN/m or more, or 23 mN/m or more. When the normal temperature surface tension of the adhesive composition satisfies the above range, the normal temperature surface tension of the copolymer contained in the adhesive composition may also satisfy the above range.

In one example of the present invention, the monomer contained in the adhesive composition may satisfy the following general formula 1.

[General formula 1]

3≤A/B×100≤30

In General Formula 1, A represents the weight of a monomer with a surface tension at room temperature greater than 30 mN/m, and B represents the weight of a monomer with a surface tension at room temperature of 30 mN/m or less.

In addition, the value of A/B×100 in General Formula 1 may be 3 or more, 3.5 or more, 4 or more, 4.5 or more, 5 or more, 5.5 or more, or 6 or more. In other examples, A/B in General Formula 1 above may be The value of B×100 may be 30 or less, 28 or less, 26 or less, 24 or less, or 22 or less. In addition, the value of A/B×100 in the above-mentioned general formula 1 may be within a range formed by appropriately selecting the upper limit and the lower limit listed above.

When the value of A/B×100 in General Formula 1 satisfies the above range, an adhesive composition can be formed that is excellent in wettability and light resistance and can cover steps and defects.

In one example of the present invention, the monomers contained in the adhesive composition may further include monomers with a glass transition temperature greater than 10°C and monomers with a glass transition temperature below 10°C.

In an example of the present invention, the glass transition temperature of the copolymer of the adhesive composition may be -25°C or below, -26°C or below, -27°C or below, -28°C or below, -29°C or below, -30°C or below. , below -31°C, below -32°C, below -33°C, or below -34°C. In other examples, the glass transition temperature of the copolymer of the above-mentioned adhesive composition can be above -50°C, above -49.5°C, -49℃ or above or -48.5℃ or above.

The glass transition temperature of the adhesive composition can be affected by the glass transition temperature of the included copolymers. In an example of the present invention, the glass transition temperature of the adhesive composition can be -25°C or below, -26°C or below, -27°C or below, -28°C or below, -29°C or below, -30°C or below, -31 ℃ below, -32 ℃ below, -33 ℃ below or -34 ℃ below, in other examples, the glass transition temperature of the above-mentioned adhesive composition can be -50 ℃ above, -49.5 ℃ above, -49 ℃ above or - Above 48.5℃. When the glass transition temperature of the adhesive composition satisfies the above range, the glass transition temperature of the copolymer contained in the adhesive composition may also satisfy the above range.

In one example of the present invention, the monomer included in the adhesive composition may satisfy the following general formula 2.

[General formula 2]

1≤C/D×100≤22

In General Formula 2, C represents the weight of a monomer with a glass transition temperature greater than 10°C, and D represents the weight of a monomer with a glass transition temperature of 10°C.

In addition, the value of C/D×100 in General Formula 2 may be 1 or more, 1.5 or more, 2 or more, 2.5 or more, 3 or more, 3.5 or more, 4 or more, 4.5 or more, 5 or more, 5.5 or more, or 6 or more. In other examples, the value of C/D×100 in General Formula 2 may be 22 or less, 21 or less, 20 or less, 19 or less, or 18 or less. In addition, the value of C/D×100 in the above-described general formula 2 may be within a range formed by appropriately selecting the upper and lower limits listed above.

When the value of C/D×100 in General Formula 2 satisfies the above range, an adhesive composition having appropriate storage modulus and tensile modulus can be formed.

In another example of the present invention, the adhesive composition includes a copolymer obtained by copolymerizing two or more monomers. The normal temperature surface tension of the copolymer is 30 mN/m or less, and the glass transition temperature may be -25°C or less. .

In another example of the present invention, the normal temperature surface tension of the copolymer of the adhesive composition can be 30 mN/m or less, 29.5 mN/m or less, 29 mN/m or less, 28.5 mN/m or less, or 28 mN/m or less, among others. In an example, the normal-temperature surface tension of the copolymer of the adhesive composition may be 20 mN/m or more, 21 mN/m or more, 22 mN/m or more, or 23 mN/m or more.

The ambient surface tension of the adhesive composition can be affected by the ambient surface tension of the included copolymer. In one example of the present invention, the normal temperature surface tension of the adhesive composition may be 30 mN/m or less, 29.5 mN/m or less, 29 mN/m or less, 28.5 mN/m or less, or 28 mN/m or less. In other examples, The normal-temperature surface tension of the above-mentioned adhesive composition may be 20 mN/m or more, 21 mN/m or more, 22 mN/m or more, or 23 mN/m or more. When the normal temperature surface tension of the adhesive composition satisfies the above range, the normal temperature surface tension of the copolymer contained in the adhesive composition may also satisfy the above range.

In addition, the glass transition temperature of the copolymer of the adhesive composition may be -25°C or lower, -26°C or lower, -27°C or lower, -28°C or lower, -29°C or lower, -30°C or lower, -31°C or lower, -32°C or below, -33°C or -34°C. In other examples, the glass transition temperature of the copolymer of the above-mentioned adhesive composition may be -50°C or above, -49.5°C or above, -49°C or - Above 48.5℃.

The glass transition temperature of the adhesive composition can be affected by the glass transition temperature of the included copolymers. In an example of the present invention, the glass transition temperature of the adhesive composition can be -25°C or below, -26°C or below, -27°C or below, -28°C or below, -29°C or below, -30°C or below, -31 ℃ below, -32 ℃ below, -33 ℃ below or -34 ℃ below, in other examples, the glass transition temperature of the above-mentioned adhesive composition can be -50 ℃ above, -49.5 ℃ above, -49 ℃ above or - Above 48.5℃. When the glass transition temperature of the adhesive composition satisfies the above range, the glass transition temperature of the copolymer contained in the adhesive composition may also satisfy the above range.

In another example of the present invention, the monomers contained in the adhesive composition may include at least one of a first monomer or a second monomer, and the above-mentioned first monomer includes a monomer with a surface tension greater than 30 mN/m at room temperature and Monomers with a surface tension of 30 mN/m or less at room temperature; the above-mentioned second monomers include monomers with a glass transition temperature greater than 10°C and monomers with a glass transition temperature below 10°C.

The above-mentioned first monomer can satisfy the following general formula 1.

[General formula 1]

3≤A/B×100≤30

In General Formula 1, A represents the weight of a monomer with a surface tension at room temperature greater than 30 mN/m, and B represents the weight of a monomer with a surface tension at room temperature of 30 mN/m or less.

In addition, the value of A/B×100 in General Formula 1 may be 3 or more, 3.5 or more, 4 or more, 4.5 or more, 5 or more, 5.5 or more, or 6 or more. In other examples, A/B in General Formula 1 above may be The value of B×100 may be 30 or less, 28 or less, 26 or less, 24 or less, or 22 or less. In addition, the value of A/B×100 in the above-mentioned general formula 1 may be within a range formed by appropriately selecting the upper limit and the lower limit listed above.

When the value of A/B×100 in General Formula 1 satisfies the above range, an adhesive composition can be formed that is excellent in wettability and light resistance and can cover steps and defects.

The above-mentioned second monomer may satisfy the following general formula 2.

[General formula 2]

1≤C/D×100≤22

In General Formula 2, C represents the weight of a monomer with a glass transition temperature greater than 10°C, and D represents the weight of a monomer with a glass transition temperature of 10°C or less.

In addition, the value of C/D×100 in General Formula 2 may be 1 or more, 1.5 or more, 2 or more, 2.5 or more, 3 or more, 3.5 or more, 4 or more, 4.5 or more, 5 or more, 5.5 or more, or 6 or more. In other examples, the value of C/D×100 may be 22 or less, 21 or less, 20 or less, 19 or less, or 18 or less. In addition, the value of C/D×100 in the above-described general formula 2 may be within a range formed by appropriately selecting the upper and lower limits listed above.

When the value of C/D×100 in General Formula 2 satisfies the above range, an adhesive composition having appropriate storage modulus and tensile modulus can be formed.

In another example of the present invention, the monomers included in the adhesive composition may include monomers with a glass transition temperature greater than 10° C. and a surface tension at room temperature greater than 30 mN/m, which is equivalent to a surface tension at room temperature of the first monomer greater than 30 mN. /m monomer or a monomer whose glass transition temperature of the second monomer is greater than 10°C.

Relative to the total weight of the monomer, the above-mentioned monomer with a glass transition temperature greater than 10°C and a surface tension at room temperature greater than 30 mN/m may contain more than 0.5% by weight, more than 0.75% by weight, more than 1% by weight, more than 1.25% by weight, or more than 1.5% by weight. or 1.75% by weight or more. In other examples, the above-mentioned monomer with a glass transition temperature greater than 10° C. and a surface tension at room temperature greater than 30 mN/m may contain 18% by weight or less, 17% by weight or less, or 16% by weight relative to the total weight of the monomer. % or less or 15% by weight or less. In addition, the above-mentioned monomers with a glass transition temperature greater than 10° C. and a normal temperature surface tension greater than 30 mN/m may be included in the range formed by appropriately selecting the upper and lower limits listed above.

In addition, in another example of the present invention, the monomers contained in the adhesive composition may further include monomers with a glass transition temperature of 10° C. or less and a surface tension at room temperature of 30 mN/m or less, which is equivalent to the first monomer. A monomer with a surface tension of 30 mN/m or less at room temperature or a monomer with a glass transition temperature of the second monomer of 10°C or less.

Relative to 100 parts by weight of the monomer with a glass transition temperature greater than 10°C and a surface tension at room temperature greater than 30mN/m, the above-mentioned monomer with a glass transition temperature below 10°C and a surface tension at room temperature below 30mN/m may contain more than 450 parts by weight, 475 parts by weight or more, 500 parts by weight or more, 525 parts by weight or more, 550 parts by weight or more or 575 parts by weight or more, in other examples, relative to 100 monomers with a glass transition temperature greater than 10°C and a surface tension at room temperature greater than 30mN/m Parts by weight, the above-mentioned monomer with a glass transition temperature of 10°C or less and a surface tension of 30 mN/m or less at room temperature may include 6000 parts by weight or less, 5800 parts by weight or less, 5600 parts by weight or less, 5400 parts by weight or less, 5200 parts by weight or less, 5000 parts by weight or less or 4800 parts by weight or less. In addition, the monomer having a glass transition temperature of 10° C. or less and a surface tension at room temperature of 30 mN/m or less may be included in the range formed by appropriately selecting the upper and lower limits listed above.

The adhesive composition contains monomers with a glass transition temperature greater than 10°C and a surface tension at room temperature greater than 30mN/m and/or monomers with a glass transition temperature below 10°C and a surface tension at room temperature below 30mN/m that meet the above content range. When used, excellent wettability and light resistance can be ensured.

In one example of the present invention, the adhesive composition may include a specific compound group, which means that the adhesive composition may include one or more compounds that satisfy the above-mentioned specific compound group. For example, the fact that the adhesive composition contains a chain alkyl acrylate compound containing a compound represented by the following Chemical Formula 1 means that the above-mentioned adhesive composition may contain one or more structures satisfying the compound represented by the following Chemical Formula 1 compound of.

In one example of the present invention, the monomer whose normal-temperature surface tension is 30 mN/m or less in the adhesive composition may include a chain alkyl acrylate compound.

The term "chain alkyl acrylate compound" used in the present invention may mean an acrylate compound containing a chain alkyl group. Here, the chain alkyl group may refer to a linear alkyl group or a branched alkyl group.

The above-mentioned chain alkyl group may be a straight chain or branched chain having 1 to 30 carbon atoms, or 1 to 25 carbon atoms, or 1 to 20 carbon atoms, or 1 to 15 carbon atoms, or 1 to 10 carbon atoms. alkyl chain.

The normal-temperature surface tension of the chain alkyl acrylate compound may be 30 mN/m or less, 29 mN/m or less, 28 mN/m or less, 27 mN/m or less, 26 mN/m or less, or 25 mN/m or less.

In addition, the glass transition temperature of the chain alkyl acrylate compound may be -20°C or lower, -30°C or lower, -40°C or lower, or -50°C or lower.

The above-mentioned chain alkyl acrylate compound may include one or more compounds represented by the following Chemical Formula 1.

[Chemical formula 1]

In Chemical Formula 1, L ₁ is a linear alkylene group having 1 to 14 carbon atoms or a branched alkylene group having 2 to 14 carbon atoms, and R ₁ and R ₂ may each independently be hydrogen, A linear alkyl group having 1 to 6 carbon atoms or a branched alkyl group having 2 to 6 carbon atoms.

In addition, in other examples, L ₁ may be a linear alkylene group having 1 or more, 2 or more, 3 or more, 4 or more, 5 or more, 6 or more, or 7 or more carbon atoms, or a linear alkylene group having 2 or more carbon atoms, or 3 or more. A branched alkylene group of more than 4, 4 or more, 5 or more, 6 or more or 7 or more. In another example, L ₁ may be a linear or branched alkylene group having 14 or less, 13 or less, 12 or less, 11 or less, 10 or less, 9 or less, or 8 or less carbon atoms. L ₁ may be a linear or branched alkylene group having a number of carbon atoms within a range formed by appropriately selecting the upper limit and lower limit of the number of carbon atoms listed above.

In addition, in other examples, R ₁ and R ₂ may each independently be hydrogen, a linear alkyl group having 1 to 4 carbon atoms, or a branched alkyl group having 2 to 4 carbon atoms. In other examples, , R ₁ and R ₂ may each independently be hydrogen or a linear alkyl group having 1 to 2 carbon atoms.

The normal temperature surface tension of the compound represented by the above-mentioned Chemical Formula 1 may be 30 mN/m or less, 29 mN/m or less, 28 mN/m or less, 27 mN/m or less, 26 mN/m or less, or 25 mN/m or less.

In addition, the glass transition temperature of the compound represented by the above-mentioned Chemical Formula 1 may be -20°C or lower, -30°C or lower, -40°C or lower, or -50°C or lower.

Examples of the compound represented by the above Chemical Formula 1 include isobutyl acrylate, isodecyl acrylate, isooctyl acrylate, ethyl acrylate, butyl acrylate, and 2-ethylhexyl acrylate. Specially limited to this.

In an example of the present invention, the chain alkyl acrylate compound may contain 55% by weight or more, 57.5% by weight or more, 60% by weight or more, or 62.5% by weight relative to the total weight of the monomers with a surface tension of 30 mN/m or less at room temperature. % or more or 65% by weight or more. In other examples, the chain alkyl acrylate compound may contain 98% by weight or less, 97% by weight or less, or 96% by weight relative to the total weight of the monomers with a surface tension of 30 mN/m or less at room temperature. % or less or less than 95% by weight. In addition, the above-mentioned chain alkyl acrylate compound may be included in a range formed by appropriately selecting the upper limit and lower limit listed above.

In another example of the present invention, the chain alkyl acrylate compound may contain 55% by weight or more, 57.5% by weight or more, 60% by weight or more, or 62.5% by weight relative to the total weight of the monomers with a surface tension of 30 mN/m or less at room temperature. % or more or 65% by weight or more. In other examples, the chain alkyl acrylate compound may contain 70% by weight or less, 69% by weight or less, or 68% by weight relative to the total weight of the monomers with a surface tension of 30 mN/m or less at room temperature. %the following. In addition, the above-mentioned chain alkyl acrylate compound may be included in a range formed by appropriately selecting the upper limit and lower limit listed above.

In one example of the present invention, the monomer whose normal-temperature surface tension is 30 mN/m or less in the adhesive composition may include a hydroxyl-containing acrylate compound.

The room-temperature surface tension of the above-mentioned hydroxyl-containing acrylate compound may be 30 mN/m or less, 29 mN/m or less, or 28 mN/m or less.

Moreover, the glass transition temperature of the said chain alkyl acrylate compound may be 0 degreeC or less, -5 degreeC or less, -10 degreeC or less, or -15 degreeC or less.

The above-mentioned hydroxyl-containing acrylate compound is not particularly limited as long as it is an acrylate compound having a hydroxyl group and satisfying the above-mentioned physical properties.

The above-mentioned hydroxyl-containing acrylate compound may include one or more compounds represented by the following Chemical Formula 2.

[Chemical formula 2]

In Chemical Formula 2, L ₂ may be a straight-chain alkylene group having 1 to 10 carbon atoms, a branched alkylene group having 2 to 10 carbon atoms, a straight-chain alkylene group having 2 to 10 carbon atoms, or Branched alkenylene group or linear or branched alkynylene group having 2 to 10 carbon atoms.

In addition, in one example, L ₂ may be a linear alkylene group having 1 or more, 2 or more, 3 or more, or 4 or more carbon atoms. In other examples, L ₂ may be 10 or less or 9 carbon atoms. A straight-chain alkylene group below, 8 or below, 7 or below, 6 or below, or 5 or below. L ₂ may be a linear alkylene group having a number of carbon atoms within a range formed by appropriately selecting the upper limit and lower limit of the number of carbon atoms listed above.

In another example, L ₂ may be a branched alkylene group having 2 or more, 3 or more, or 4 or more carbon atoms; a linear or branched alkenylene group; or a linear or branched alkenylene group. Chain alkynylene group, in other examples, L ₂ can be a branched alkylene group with carbon atoms of 10 or less, 9 or less, 8 or less, 7 or less, 6 or less, or 5 or less; linear or branched Chain alkenylene; or linear or branched alkynylene. L ₂ may be a branched alkylene group, a linear or branched alkenylene group, or a branched alkylene group having a number of carbon atoms within a range formed by appropriately selecting the upper limit and lower limit of the number of carbon atoms listed above, or Linear or branched alkynylene group.

The normal-temperature surface tension of the compound represented by the above-mentioned Chemical Formula 2 may be 30 mN/m or less, 29 mN/m or less, or 28 mN/m or less.

In addition, the glass transition temperature of the compound represented by the above-mentioned Chemical Formula 2 may be 0°C or lower, -5°C or lower, -10°C or lower, or -15°C or lower.

Examples of the compound represented by the above Chemical Formula 2 include 2-hydroxyethyl acrylate, 4-hydroxybutyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxy-1-methylethyl acrylate, and the like. If the above physical properties are satisfied, It is not particularly limited to this.

In one example of the present invention, the hydroxyl-containing acrylate compound may contain 1 wt% or more, 2 wt% or more, 3 wt% or more, or 4 wt% relative to the total weight of the monomer with a surface tension of 30 mN/m or less at room temperature. or 5 wt% or more. In other examples, the hydroxyl-containing acrylate compound may contain 40 wt% or less, 38.5 wt% or less, or 37 wt% or less based on the total weight of the monomer with a normal temperature surface tension of 30 mN/m or less. Or less than 35.5% by weight. Furthermore, the above-mentioned hydroxyl-containing acrylate compound may be included in a range formed by appropriately selecting the upper and lower limits listed above.

In another example of the present invention, the hydroxyl-containing acrylate compound may contain 30 wt% or more, 30.5 wt% or more, 31 wt% or more, or 31.5 wt% relative to the total weight of the monomer with a normal temperature surface tension of 30 mN/m or less. As mentioned above, in other examples, the hydroxyl-containing acrylate compound may contain 40% by weight or less, 38.5% by weight or less, 37% by weight or less, or 35.5% by weight or less based on the total weight of the monomer with a surface tension of 30 mN/m or less at room temperature. . Furthermore, the above-mentioned hydroxyl-containing acrylate compound may be included in a range formed by appropriately selecting the upper and lower limits listed above.

In one example of the present invention, the monomer whose normal temperature surface tension is 30 mN/m or less in the adhesive composition may include a chain alkyl acrylate compound and a hydroxyl-containing acrylate compound.

In this case, the weight ratio (P/R) of the chain alkyl acrylate compound (P) and the hydroxyl-containing acrylate compound (R) may be 1 or more, 1.2 or more, 1.4 or more, 1.6 or more, or 1.8 or more, and may be Under 20, under 19.5, under 19 or under 18.5. In addition, the weight ratio (P/R) of the above-mentioned chain alkyl acrylate compound (P) and the hydroxyl-containing acrylate compound (R) may be included in a range formed by appropriately selecting the upper and lower limits listed above.

In other examples, the weight ratio (P/R) of the chain alkyl acrylate compound (P) and the hydroxyl-containing acrylate compound (R) may be 1 or more, 1.2 or more, 1.4 or more, 1.6 or more, or Above 1.8, it can be below 3.6, below 3.2, below 2.8 or below 2.4. In addition, the weight ratio (P/R) of the above-mentioned chain alkyl acrylate compound (P) and the hydroxyl-containing acrylate compound (R) may be included in a range formed by appropriately selecting the upper and lower limits listed above.

When the weight ratio (P/R) of the above-mentioned chain alkyl acrylate compound (P) and the hydroxyl-containing acrylate compound (R) satisfies the above range, it has appropriate stability and can also prevent the generation of bubbles or lamination. Floating phenomenon between layers.

In one example of the present invention, the monomer whose normal temperature surface tension is greater than 30 mN/m of the adhesive composition may include a cyclic alkyl acrylate compound.

The room-temperature surface tension of the above-mentioned cyclic alkyl acrylate compound may be greater than 30 mN/m, 31 mN/m or more, 32 mN/m or more, or 33 mN/m or more.

In addition, the glass transition temperature of the above-mentioned cyclic alkyl acrylate compound may be 50°C or higher, 55°C or higher, 60°C or higher, 65°C or higher, 70°C or higher, or 75°C or higher.

The above-mentioned cyclic alkyl acrylate compound may be an acrylate compound as long as it has a cyclic alkyl group and satisfies the above-mentioned physical properties. For example, there are isobornyl (meth)acrylate, cyclohexyl (meth)acrylate, and (meth)acrylate. ) 3,3,5-trimethylcyclohexyl acrylate, tert-butylcyclohexyl (meth)acrylate, etc., and their types are not particularly limited.

In one example of the present invention, the cyclic alkyl acrylate compound may comprise 10 to 100 wt%, 15 to 100 wt%, or 20 to 100 wt% relative to the total weight of the monomer with a surface tension greater than 30 mN/m at room temperature.

In one example of the present invention, the monomers whose normal-temperature surface tension is less than 30 mN/m of the adhesive composition include hydroxyl-containing acrylate compounds, and the monomers whose normal-temperature surface tension of the adhesive composition is greater than 30 mN/m may include Cyclic alkyl acrylate compounds. Here, the hydroxyl-containing acrylate compound and the cyclic alkyl acrylate compound are the same as above.

In one example of the present invention, the weight ratio (R/Q) of the above-mentioned hydroxyl-containing acrylate compound (R) and the cyclic alkyl acrylate compound (Q) may be 1.2 or more, 1.3 or more, 1.4 or more, or 1.5 or more. , above 1.6, above 1.7 or above 1.8, and can be below 10, below 9, below 8, below 7 or below 6. In addition, the weight ratio (R/Q) of the above-mentioned hydroxyl-containing acrylate compound (R) and the cyclic alkyl acrylate compound (Q) may be included in a range formed by appropriately selecting the upper and lower limits listed above.

When the weight ratio (R/Q) of the above-mentioned hydroxyl-containing acrylate compound (R) and the cyclic alkyl acrylate compound (Q) satisfies the above range, basic required physical properties such as durability and adhesive force are satisfied, and bubbles can be formed at the same time. The generation or lifting between laminate layers is minimized.

In one example of the present invention, the monomer whose normal temperature surface tension is greater than 30 mN/m of the adhesive composition may include an acrylate compound containing a cyclic ether group.

The room-temperature surface tension of the above-mentioned cyclic ether group-containing acrylate compound may be greater than 30 mN/m, 30.5 mN/m or more, or 31 mN/m or more.

In addition, the glass transition temperature of the above-mentioned cyclic ether group-containing acrylate compound may be 10°C or lower, 5°C or lower, 0°C or lower, -5°C or lower, or -10°C or lower.

The above-mentioned cyclic ether group-containing acrylate compound may include one or more compounds represented by the following Chemical Formula 3.

[Chemical formula 3]

In Chemical Formula 3, R ₃ may be hydrogen or a linear alkyl group having 1 to 20 carbon atoms. In addition, L ₃ and L ₄ may each independently be a single bond or a linear alkylene group having 1 to 20 carbon atoms. In addition, L ₅ may be a single bond or a linear alkylene group having 1 to 8 carbon atoms. In addition, Q may be an oxygen atom or a carbon atom.

In addition, in other examples, L ₃ and L ₄ in Chemical Formula 3 may each independently be 1 to 20 carbon atoms, 1 to 16 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms, or A linear alkylene group having 2 to 8 atoms or 2 to 6 carbon atoms or 2 to 4 carbon atoms. In addition, L ₅ may be a single bond or a linear alkylene group having 1 to 4 carbon atoms. For example, L 5 may be a single bond.

In addition, the sum of the numbers of carbon atoms present in L ₄ and L ₅ in Chemical Formula 3 may be in the range of 1 to 8. The total number of carbon atoms may be 7 or less, 6 or less, 5 or less, 4 or less, or 3 or less, or 1 or more, 2 or more, or 3 or more. The sum of the number of carbon atoms of the above-mentioned L ₄ and _{L 5} is the number of carbon atoms of the alkylene group of the above-mentioned L ₅ when L ₅ is an alkylene group and L 4 is a single bond. When L ₅ is an alkylene group and L When ₄ is also an alkylene group, it is the sum of the number of carbon atoms of the alkylene group of L ₅ and the number of carbon atoms of the alkylene group of L ₄ . In addition, when a substituent is present in the above-mentioned alkylene group, the number of carbon atoms present in the substituent is not included in the above-mentioned "and".

The normal-temperature surface tension of the compound represented by the above-mentioned Chemical Formula 3 may be greater than 30 mN/m, 30.5 mN/m or more, or 31 mN/m or more.

In addition, the glass transition temperature of the compound represented by the above-mentioned Chemical Formula 3 may be 10°C or lower, 5°C or lower, 0°C or lower, -5°C or lower, or -10°C or lower.

The compound represented by the above-mentioned Chemical Formula 3 can be exemplified by oxiranyl (meth)acrylate, oxetanyl (meth)acrylate, (meth)acrylate Tetrahydrofuranyl (meth)acrylate, tetrahydro-2H-pyranyl (meth)acrylate, ethylene oxide (meth)acrylate ester (oxiranylmethyl (meth)acrylate, or glycidyl (meth)acrylate), oxetanylethyl (meth)acrylate (oxetanylethyl (meth)acrylate) and tetrahydrofuran methyl (meth)acrylate ( or tetrahydrofurfuryl (meth)acrylate), etc., as long as they satisfy the above-mentioned physical properties, they are not particularly limited thereto.

In one example of the present invention, when the acrylate compound containing a cyclic ether group is included in the adhesive composition, it can be included in an amount of 35% by weight or more and 40% by weight based on the total weight of the monomer with a surface tension greater than 30 mN/m at room temperature. Weight % or more, 45 weight % or more, 50 weight % or more, 55 weight % or more or 60 weight % or more, in other examples, containing a cyclic ether group based on the total weight of the monomer with a surface tension greater than 30 mN/m at room temperature. The acrylate compound may comprise 80% by weight or less, 75% by weight or less, 70% by weight or less, or 65% by weight or less. Furthermore, the above-mentioned cyclic ether group-containing acrylate compound may be included in a range formed by appropriately selecting the upper and lower limits listed above.

In one example of the present invention, the monomer whose normal temperature surface tension is greater than 30 mN/m of the adhesive composition may include an acrylate compound containing a cyclic ether group and a compound containing an acrylamide group.

The room-temperature surface tension of the above-mentioned acrylamide group-containing compound may be greater than 30 mN/m, 33 mN/m or more, 35 mN/m or more, or 37 mN/m or more.

In addition, the glass transition temperature of the acrylamide group-containing compound may be 80°C or higher, 90°C or higher, 100°C or higher, or 110°C or higher.

The above-mentioned acrylamide group-containing compound only needs to be a compound having an acrylamide group and satisfying the above-mentioned physical properties. For example, there are N,N-dimethylacrylamide, N,N-methylethylacrylamide and N,N-diethyl acrylamide and the like are not particularly limited in type.

In one example of the present invention, the acrylamide group-containing compound may comprise 10 parts by weight or more, 15 parts by weight or more, 20 parts by weight or more, or 25 parts by weight relative to 100 parts by weight of the acrylate compound containing a cyclic ether group. or 30 parts by weight or more, and in other examples, it may include 90 parts by weight or less, 80 parts by weight or less, 70 parts by weight or less, 60 parts by weight or less, 50 parts by weight or less, or 40 parts by weight or less.

In one example of the present invention, in order to utilize active energy rays for curing, the adhesive composition may further include a photoinitiator. Here, the photoinitiator can be selected taking into consideration the high absorptivity near the emission spectrum of active energy rays and the compatibility between the above-mentioned compounds. In order to quickly cure the adhesive composition, the above-mentioned active energy rays are preferably ultraviolet rays. .

The photoinitiator may be one or more selected from benzophenone initiators and α-hydroxyketone initiators, and α-hydroxyketone initiators are preferably selected. Specifically, the photoinitiator can include 1-hydroxy-cyclohexylphenyl ketone (1-hydroxy-cyclohexylphenyl ketone), 2-hydroxy-4'-(2-hydroxyethoxy) among α-hydroxyketone initiators )-2-methylpropiophenone (2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone) and 1-hydroxy-1-methylethyl phenyl ketone ), but not limited to this.

In addition, the content of the photoinitiator is not particularly limited as long as the adhesive composition can be appropriately cured. However, it may be 0.01% by weight or more, 0.015% by weight or more, 0.02% by weight or more based on the total weight of the adhesive composition. 0.025% by weight or more. In other examples, it may be 0.05% by weight or less, 0.04% by weight or less, or 0.03% by weight or less.

The adhesive composition containing a photoinitiator can be cured by active energy rays, and as mentioned above, the active energy rays can be ultraviolet rays. The amount of ultraviolet light may be 5 J/cm ² or more, 6 J/cm ² or more, 7 J/cm ² or more, 8 J/cm ² or more, 9 J/cm ² or more, or 10 J/cm ² or more. In other examples, it may be 20 J/cm 2 or more. /cm ² or less, 18J/cm ² or less, 16J/cm ² or less, 14J/cm ² or less or 12J/cm ² or less. The curing time refers to the time until the adhesive composition is completely cured, and may differ depending on the thickness of the adhesive composition, the amount of light of the above-mentioned ultraviolet rays, and the like.

If necessary, the adhesive composition according to the present invention may further include a leveling agent, an adhesion-imparting agent, a coupling agent, a viscosity regulator, and the like. For example, a viscosity modifier, such as a plasticizer, a thixotropic agent, a diluent or a dispersant, may be further included in order to increase or decrease the viscosity, or to adjust the viscosity according to shear force. Thixotropic agents can adjust the viscosity of the adhesive composition in response to shear forces. Examples of thixotropic agents that can be used include fumed silica, bentonite, and the like. As long as the diluent or dispersant is commonly used to reduce the viscosity of the adhesive composition and can exhibit the above-mentioned effects, different types known in the art can be used without limitation.

In addition, the adhesive composition may have the above-mentioned structure, and may be a solvent-based composition, an aqueous composition, or a solvent-free composition. However, when considering the convenience of the manufacturing process, the solvent-free type may be suitable.

In addition, the adhesive composition can be formed by mixing each component listed above, and the mixing order is not particularly limited as long as all required components are included.

In one example of the present invention, the film may be the cured product of the above-mentioned adhesive composition itself, or may contain the cured product of the above-mentioned adhesive composition. In addition, the film may have at least one or more physical properties among the following physical properties, and may be used as an optically clear adhesive (OCA).

In one example of the present invention, the film is used as an optical adhesive for a display product or a transparent electrode product, thereby covering defects located between laminated layers of the display product or transparent electrode product, thereby preventing the formation of bubbles. .

Each of the following physical properties is independent, so that any physical property does not take priority over other physical properties, and the film can satisfy at least one or two or more of the following physical properties. A film satisfying at least one or more of the following physical properties is produced by combining each component of the adhesive composition.

The normal temperature adhesive force of the film can be above 0.7kg/inch, above 0.75kg/inch or above 0.8kg/inch. The above-mentioned normal temperature adhesive force can be a value measured by adhering the cured product of the above-mentioned adhesive composition to a PET (polyethylene terephthalate, polyterephthalate) film, using an adhesive force measuring device, and measuring the cured product at 300 mm/min. The peeling speed and 180° peeling angle are values obtained by measuring the above PET film at room temperature. In addition, normal temperature at this time may mean about 25°C.

In addition, the tensile modulus of the film may be 0.002kgf/mm ² or more, 0.003kgf/mm ² or more, 0.004kgf/mm ² or more, 0.005kgf/mm ² or more, or 0.006kgf/mm ² or more. In other examples, It can be 0.012kgf/mm ² or less, 0.011kgf/mm ² or less, 0.01kgf/mm ² or less, or 0.009kgf/mm ² or less. Furthermore, the tensile modulus of the above-described film may be within a range formed by appropriately selecting the upper and lower limits listed above. In this case, the tensile modulus can be defined as σ/ε, where σ is tensile stress/cross-sectional area, and ε can be the value from the strain at which the film breaks to the gauge length (initial strain)/gauge length.

In addition, the normal temperature storage modulus of the film may be 0.1 MPa or less, and the 80°C storage modulus may be 0.055 MPa or less. That is, the normal temperature storage modulus of the film is 0.1 MPa or less and the 80°C storage modulus may be 0.055 MPa or less.

The storage modulus at room temperature of the above-mentioned film may be 0.1MPa or less, 0.09MPa or less, 0.08MPa or less, 0.07MPa or less, or 0.06MPa or less. In other examples, the room-temperature storage modulus of the above-mentioned film may be 0.02MPa or more, 0.025 MPa or above, 0.03MPa or above, 0.035MPa or above, 0.04MPa or above or 0.045MPa or above. In addition, the normal temperature at this time may mean about 25° C., and the normal temperature storage modulus of the film may be within a range formed by appropriately selecting the upper and lower limits listed above.

In addition, the 80°C storage elastic modulus of the above-mentioned film may be 0.055MPa or less, 0.0525MPa or less, or 0.05MPa or less. In other examples, the 80°C storage elastic modulus of the above-mentioned film may be 0.005MPa or more, 0.0075MPa or more, or 0.01 MPa or above or 0.0125MPa or above. Furthermore, the 80° C. storage modulus of the above film may be within a range formed by appropriately selecting the upper and lower limits listed above.

When the tensile modulus and storage modulus (normal temperature and 80°C) of the film meet the above ranges, excellent stability can be ensured in high temperature, low temperature, thermal shock and high temperature/high humidity evaluations.

The wet-time measured for the film according to the wettability evaluation process described below may be 60 seconds or less.

[Wettability evaluation process]

1) The adhesive composition is placed between the first light-peel release film and the heavy-peel release film so as to have a predetermined thickness, and the adhesive composition is cured to produce a cured product sample.

2) Remove the first light-peel release film from the cured product sample, and attach the second light-peel release film to the top of the cured product sample from which the first light-peel release film has been removed so as to overlap from the end of the cured product sample to 0.2cm in the length direction. One surface of the cured product sample of the release film was peeled off to prepare an evaluation sample.

3) On one surface of the above-mentioned glass substrate, gently place the above-mentioned evaluation sample in such a manner that the second light-peel release film is in contact with the above-mentioned glass substrate, and place the exposed portion where the second light-peel release film is not attached, The cured product sample was adhered so as to be in contact with the above-mentioned glass substrate from the end to 0.2 cm in the longitudinal direction.

4) From the point in time when the exposed part of the evaluation sample is in contact with the glass substrate from the end to approximately 0.5 cm in the length direction until the time when the exposed part is in contact with the glass substrate from the end to approximately 2 cm in the length direction The time elapsed until the point of material contact is measured as wet-time.

After laminating the film and polarizing plate, no bubbles can be generated even when exposed to a light amount of about 830 to 1000W/ ^m for about 500 hours.

At this time, the polarizing plate is not particularly limited as long as it is a polarizing plate mainly used in this field, and may have a protective film, TAC (tri-acetyl-cellulose, triacetyl cellulose) film, PVA (poly vinyl alcohol, polyethylene). Alcohol film), TAC film, PSA (pressure sensitive adhesives, pressure-sensitive adhesive) film and release film are sequentially laminated structures.

In one example of the present invention, the display or the transparent electrode may include the above-mentioned film as an adhesive layer. In addition, the display may include a transparent electrode containing a film.

Displays (or display products) or transparent electrode products (displays containing transparent electrodes) contain a film that covers foreign matter and therefore satisfy basic required physical properties such as durability and adhesion while preventing the generation of air bubbles or floating between laminated layers. Minimize occurrences. Here, the display can be exemplified by a CRT (cathode ray tube) display; a PDP (plasma display panel), an LCD (liquid crystal display), an LED (light emitting diode) display; and an OLED (organic display). emitting diode (organic light-emitting diode) display and quantum dot (quantum dot) display, but are not limited thereto. In addition, an example of a transparent electrode product is a display containing a transparent electrode formed on a transparent rigid substrate such as a glass substrate, and PET (polyethylene terephthalate), PES ( Electrode material with high conductivity and high transmittance in the visible light region on flexible substrates such as polyether sulfone (polyether sulfone) and PEN (Polyethylene naphthalate).

The present invention can provide an optical adhesive-forming adhesive composition that is excellent in wettability and light resistance and can cover steps and defects.

The present invention can provide an adhesive composition for forming an optical adhesive that satisfies basic physical properties such as durability and adhesive force and can minimize the generation of bubbles or floating phenomena between laminated layers.

In addition, the present invention can provide a film capable of covering defects located between laminated layers of a display product or a transparent electrode product.

The present invention will be described below using Examples and Comparative Examples, but the scope of the present invention is not limited by the contents presented below.

＜Measurement method of physical properties＞

1. Tensile modulus measurement method

The adhesive composition is placed between the release films with a thickness of 200µm, and is cured by light curing using an ultraviolet lamp under a light intensity of 9 to 11J/ ^cm2 . Cut into a width of 2.5cm and a length of 7cm (gauge length 3.5cm) and thickness 200µm, thereby producing a measurement sample. Then, deform the above-mentioned sample in the length direction at a speed of 300mm/min until it breaks, and measure the strain (strain (Δl), unit: mm) and tensile stress (tensile stress (F), unit: kgf) at this time. And the tensile modulus (unit: kgf/mm ² ) was calculated.

Here, the tensile modulus is defined as σ/ε. σ is defined as F/A, F (Tensile stress) is the tensile stress, and A is the cross-sectional area. ε is defined as △l/l, △l is the difference between the strain at which the sample is broken and the gauge length (initial strain) value, and l is the gauge length.

The adhesive composition was placed between the light-peel release film and the heavy-peel release film with a thickness of 200 µm, and photocuring was performed using an ultraviolet lamp at a light amount of 9 to 11 J/cm ² solidify. After curing, the cured product sample was cut into a width of 2.5cm, a length of 11cm, and a thickness of 325µm.

Remove the light-peel release film of the cured product sample, and attach a PET (polyethylene terephthalate, polyethylene terephthalate) film with a width of 2.5 cm or more, a length of 25 cm, and a thickness of 75 µm to the light-peel release film. face. The cured product sample with the PET film attached was cut into a width of 2.5cm, a length of 25cm, and a thickness of 350µm.

Then, the heavy-peel release film of the cut cured product sample was removed, so that the surface of the heavy-peel release film and the glass substrate with a width of 12.5 cm, a length of 12.5 cm, and a thickness of 700 µm (Corning Incorporated, product name: The above-mentioned cut cured product sample was attached to one surface of Eagle XG glass. A roller of about 2 kg was used to attach the glass substrate to the cut cured sample, and after attachment, it was left at room temperature for about 30 minutes.

Then, the above-mentioned PET film was controlled by an adhesion measuring device (Dayuan Technology Co., Ltd., model name: TW-D2000) and peeled off at a peeling speed of 300mm/min and a peeling angle of 180° at room temperature, thereby measuring the adhesion. . Through repeated experiments, the measured adhesion force is expressed as an average value.

2. Wetability evaluation method-wet-time measurement

Next, the wettability evaluation process was carried out under normal temperature and normal humidity conditions.

The adhesive composition was placed in a thickness of 200 µm between a first light release release film having a width of 42.0 cm, a length of 1000 cm and a thickness of 50 µm and a heavy release release film having a width of 42.0 cm, a length of 1000 cm and a thickness of 75 µm. Then, the above-mentioned adhesive composition was cured by photocuring at a light amount of 9 to 11 J/cm ² using an ultraviolet lamp, and cut into a width of 2 cm, a length of 4 cm, and a thickness of 325 µm, thereby manufacturing Cured product sample.

The first light-peel release film was removed, and a second light-peel release film with a width of 2.0 cm, a length of 4.0 cm, and a thickness of 50 µm was attached to the removed film so as to overlap from the end of the cured product sample to 0.2 cm in the length direction. One surface of the cured product sample of the first lightly peeled release film was removed to prepare an evaluation sample. That is, in the evaluation sample, the heavy peeling release film was attached to the entire one surface of the cured product sample, and the second light peeling release film was overlapped and attached to the other surface from the end of the cured product sample to 0.2 cm in the length direction. The portion without overlap has a structure in which the cured product sample is exposed.

On one surface of a glass substrate (Corning Incorporated, product name: Eagle Place the above evaluation sample gently so that it touches the material.

Then, the evaluation sample was attached so as to be in contact with the glass substrate from the end of the exposed cured product sample to 0.2 cm in the longitudinal direction. That is, the exposed cured material sample of the evaluation sample was attached so as to be in contact with the above-mentioned glass substrate from the end to about 0.2 cm.

From the time when the exposed part of the evaluation sample is attached in contact with the above-mentioned glass substrate from the end to about 0.5 cm in the length direction until the time when the above-mentioned exposed part is in contact with the above-mentioned glass substrate from the end to 2 cm in the length direction The time elapsed until the point of contact was measured as wet-time.

Based on the measured elapsed time, the wettability was evaluated according to the following standards.

PASS: The elapsed time (wet-time) is 60 seconds or less

NG: The elapsed time (wet-time) is greater than 60 seconds

3. Lightfastness evaluation method

The adhesive composition was placed between the light-peel release film and the heavy-peel release film with a thickness of 200 µm, and photocuring was performed using an ultraviolet lamp at a light amount of 9 to 11 J/cm ² solidify. After curing, the cured product sample was cut into a width of 10cm, a length of 10cm, and a thickness of 325µm.

The light-peel release film of the cured product sample was removed, and the above-mentioned cured product sample was attached to a glass substrate with a width of 10 cm, a length of 10 cm, and a thickness of 700 µm in contact with the surface from which the light-peel release film was removed (Corning Incorporated, Product name: One surface of Eagle XG glass. A roller of approximately 2 kg was used to adhere the glass substrate to the cured product sample.

Prepare protective film, TAC (tri-acetyl-cellulose, triacetyl cellulose) film, PVA (poly vinyl alcohol, polyvinyl alcohol film), TAC film, PSA (pressure sensitive adhesives, pressure-sensitive adhesive) film and detachable film. For a polarizing plate with a structure of sequentially stacked mold films, a width of 10cm, a length of 10cm and a thickness of 258µm, remove the protective film.

The re-peelable release film of the cured product sample adhered to the glass base material is removed, and the TAC film surface of the polarizing plate from which the protective film is removed is brought into contact with the surface from which the re-peelable release film has been removed. stacked samples.

Then, in a vacuum lamination equipment (MRK Company, product name: M-Tool vacuum laminator & autoclave) that can create a vacuum environment of about 97 kPa, the glass substrate of the laminated sample is oriented Place it on the bottom and remove the release film of the polarizing plate to expose the PSA film. Place a glass substrate (Corning, product name: Eagle XG glass) with a width of 10cm, a length of 10cm and a thickness of 700µm on the exposed surface. The PSA film was left at a temperature of about 40° C. for about 30 seconds, and a laminated sample of the above-mentioned glass substrate and the release film from which the polarizing plate was removed was laminated.

That is, the laminated laminated sample has a structure in which the glass substrate, the polarizing plate from which the protective film and the release film are removed, the cured adhesive composition, and the glass base material are laminated in this order.

After lamination, an autoclave operation is performed for about 15 minutes at a temperature of about 50° C. and a pressure of about 0.5 MPa. Then, use a light generating device (Philips Company, product name: Arenavision MVF403) to expose to a light amount of about 830 to 1000W/ ^m2 for about 500 hours. At this time, the light generated in the above light generating device first interacts with the layer. Press the laminated sample into contact with the glass substrate.

Then, it was confirmed whether bubbles were generated between the glass base material and the cured adhesive composition, and the light resistance was evaluated according to the following standards.

PASS: No bubbles are generated

NG: generate bubbles

4. Measurement method of storage modulus based on temperature

The adhesive composition was placed between the release films so as to have a thickness of 200 µm, and was cured by photocuring using an ultraviolet lamp at a light intensity of 9 to 11 J/cm ² to form a cured product. The above-mentioned cured products were adhered to each other and made into a thickness of 1 mm. The above-mentioned cured product was cut into a diameter of 8 mm and a thickness of 1 mm, thereby producing a disk-shaped measurement sample.

A rotational rheometer (TA Company, product name: ARES-G2) was used to apply 1% strain (strain) and a rotation speed of 1Hz to the above-mentioned measurement samples, and the storage temperature was measured in the temperature range of -50°C to 120°C. Energy modulus. In the process of heating from -50°C to 120°C, the heating rate is 5°C per minute.

In addition, the normal temperature storage modulus is based on the storage modulus at 25°C.

Example 1

The weight ratio of the monomer (T1) with a glass transition temperature (Tg) greater than 10°C and the monomer (T2) with a glass transition temperature below 10°C is 15:85 (T1:T2), and the surface tension at room temperature is greater than 30mN/m An adhesive composition was produced such that the weight ratio of the monomer (S1) and the monomer (S2) with a surface tension at room temperature of 30 mN/m or less was 15:85 (S1:S2).

Specifically, isodecyl acrylate (IDA, isodecyl acrylate), isobornyl acrylate (IBOA, isobornyl acrylate), 2-hydroxyethyl acrylate (2-HEA, 2-hydroxyethyl acrylate) and butyl acrylate (BA, butyl acrylate) was evenly mixed at a weight ratio of 24:15:27:34 (IDA:IBOA:2-HEA:BA), and 0.03 parts by weight of photoinitiator (Ciba, IRGCURE) was added to 100 parts by weight of the above mixture. 184), thereby producing an adhesive composition.

Example 2

The weight ratio of the monomer (T1) with a glass transition temperature (Tg) greater than 10°C and the monomer (T2) with a glass transition temperature below 10°C is 7:93 (T1:T2), and the surface tension at room temperature is greater than 30mN/m An adhesive composition was produced such that the weight ratio of the monomer (S1) and the monomer (S2) with a surface tension at room temperature of 30 mN/m or less was 18:82 (S1:S2).

Specifically, butyl acrylate (BA, butyl acrylate), isobornyl acrylate (IBOA, isobornyl acrylate), tetrahydrofurfuryl acrylate (THFA, tetrahydrofurfuryl acrylate), 2-ethylhexyl acrylate (2-EHA, 2-ethylhexyl acrylate) and 2-hydroxyethyl acrylate (2-HEA, 2-hydroxyethyl acrylate) in a weight ratio of 20:7:11:34:28 (BA:IBOA:THFA:2-EHA:2-HEA) The mixture was uniformly mixed, and 0.03 parts by weight of a photoinitiator (IRGCURE 184 from Ciba) was added to 100 parts by weight of the above mixture to prepare an adhesive composition.

Example 3

The weight ratio of the monomer (T1) with a glass transition temperature (Tg) greater than 10°C and the monomer (T2) with a glass transition temperature below 10°C is 2:98 (T1:T2), and the surface tension at room temperature is greater than 30mN/m An adhesive composition was produced such that the weight ratio of the monomer (S1) and the monomer (S2) with a surface tension at room temperature of 30 mN/m or less was 5:95 (S1:S2).

Specifically, 2-ethylhexyl acrylate (2-EHA), 2-hydroxyethyl acrylate (2-HEA), N,N-dimethylacrylamide (DMAA), isobornyl acrylate (IBOA) ) and tetrahydrofurfuryl acrylate (THFA) are uniformly mixed in a weight ratio of 90:5:1:1:3 (2-EHA:2-HEA:DMAA:IBOA:THFA), relative to 100 parts by weight of the above mixture, 0.03 parts by weight of photoinitiator (IRGCURE 184 from Ciba Corporation) was added to prepare an adhesive composition.

Comparative example 1

The weight ratio of the monomer (T1) with a glass transition temperature (Tg) greater than 10°C and the monomer (T2) with a glass transition temperature below 10°C is 19:81 (T1:T2), and the surface tension at room temperature is greater than 30mN/m An adhesive composition was produced such that the weight ratio of the monomer (S1) and the monomer (S2) with a surface tension at room temperature of 30 mN/m or less was 24:76 (S1:S2). Specifically, 2-ethylhexyl acrylate (2-EHA), 2-hydroxyethyl acrylate (2-HEA), N,N-dimethylacrylamide (DMAA), isostearyl acrylate ( ISTA), isobornyl acrylate (IBOA) and tetrahydrofurfuryl acrylate (THFA) with a weight of 39:17:5:20:14:5 (2-EHA:2-HEA:DMAA:ISTA:IBOA:THFA) The mixture was mixed uniformly and 0.18 parts by weight of a photoinitiator (IRGCURE 184 from Ciba) was added to 100 parts by weight of the above mixture to prepare an adhesive composition.

Comparative example 2

The weight ratio of the monomer (T1) with a glass transition temperature (Tg) greater than 10°C and the monomer (T2) with a glass transition temperature below 10°C is 24:76 (T1:T2), and the surface tension at room temperature is greater than 30mN/m An adhesive composition was produced such that the weight ratio of the monomer (S1) and the monomer (S2) with a surface tension at room temperature of 30 mN/m or less was 37:63 (S1:S2).

Specifically, 2-ethylhexyl acrylate (2-EHA), 2-hydroxyethyl acrylate (2-HEA), N,N-dimethylacrylamide (DMAA), isostearyl acrylate ( ISTA), isobornyl acrylate (IBOA) and tetrahydrofurfuryl acrylate (THFA) with a weight of 33:14:12:17:12:12 (2-EHA:2-HEA:DMAA:ISTA:IBOA:THFA) The mixture was mixed uniformly and 0.15 parts by weight of a photoinitiator (IRGCURE 184 from Ciba) was added to 100 parts by weight of the above mixture to prepare an adhesive composition.

Comparative example 3

The weight ratio of the monomer (T1) with a glass transition temperature (Tg) greater than 10°C and the monomer (T2) with a glass transition temperature below 10°C is 19:81 (T1:T2), and the surface tension at room temperature is greater than 30mN/m An adhesive composition was produced such that the weight ratio of the monomer (S1) and the monomer (S2) with a surface tension at room temperature of 30 mN/m or less was 24:76 (S1:S2).

Specifically, 2-ethylhexyl acrylate (2-EHA), 2-hydroxyethyl acrylate (2-HEA), N,N-dimethylacrylamide (DMAA), isostearyl acrylate ( ISTA), isobornyl acrylate (IBOA) and tetrahydrofurfuryl acrylate (THFA) with a weight of 39:17:5:20:14:5 (2-EHA:2-HEA:DMAA:ISTA:IBOA:THFA) The mixture was mixed uniformly and 0.03 parts by weight of a photoinitiator (IRGCURE 184 from Ciba) was added to 100 parts by weight of the above mixture to prepare an adhesive composition.

Comparative example 4

The weight ratio of the monomer (T1) with a glass transition temperature (Tg) greater than 10°C and the monomer (T2) with a glass transition temperature below 10°C is 24:76 (T1:T2), and the surface tension at room temperature is greater than 30mN/m An adhesive composition was produced such that the weight ratio of the monomer (S1) and the monomer (S2) with a surface tension at room temperature of 30 mN/m or less was 30:70 (S1:S2).

Specifically, 2-ethylhexyl acrylate (2-EHA), 2-hydroxyethyl acrylate (2-HEA), N,N-dimethylacrylamide (DMAA), isobornyl acrylate (IBOA) ) and tetrahydrofurfuryl acrylate (THFA) are uniformly mixed in a weight ratio of 49:21:6:18:6 (2-EHA:2-HEA:DMAA:IBOA:THFA), relative to 100 parts by weight of the above mixture, 0.03 parts by weight of photoinitiator (IRGCURE 184 from Ciba Corporation) was added to prepare an adhesive composition.

The physical properties measured in the above Examples and Comparative Examples are shown in Table 1 below.

Table 1 distinguish Glass transition temperature (℃) Surface tension at room temperature (mN/m) Tensile modulus (kgf/mm ² ) Storage modulus at room temperature (MPa) 80℃ storage modulus (MPa) Adhesion (kg/inch) Wetting time (seconds) Lightfastness evaluation Example 1 -35 29.3 0.009 0.046 0.052 0.8 PASS 30~50 PASS Example 2 -36 27 0.006 0.060 0.048 1 Pass 20~40 PASS Example 3 -48 25.7 0.005 0.025 0.015 0.9 Pass 10~20 PASS Comparative example 1 -17 34.6 0.021 0.156 0.070 3.6 NG>300 NG Comparative example 2 -12 32.8 0.050 0.314 0.056 5.2 NG>300 NG Comparative example 3 -20 35.4 0.021 0.159 0.088 2.7 NG>300 NG Comparative example 4 -32 31.2 0.012 0.072 0.070 1 NG 60~100 NG

Referring to Table 1, the glass transition temperature in Examples 1 to 3 was -25°C or lower, and the surface tension at room temperature was 30 mN/m or lower.

In contrast, Comparative Examples 1 to 3 were unable to satisfy the glass transition temperature of -25°C or lower, and the normal temperature surface tensions in Comparative Examples 1 to 4 all showed values larger than 30 mN/m.

In addition, referring to Table 1, Examples 1 to 3 have a tensile modulus in the range of 0.002 to 0.012 kgf/mm ² , but Comparative Examples 1 to 4 are shown to have a tensile modulus of 0.012 kgf/mm ² or more.

In addition, referring to Table 1, Examples 1 to 3 show that the storage modulus at normal temperature is 0.1 MPa or less, and the storage modulus at 80° C. is 0.055 MPa or less. Referring to FIGS. 1 and 2 , the storage modulus values according to temperature of Examples 1 and 2 can be confirmed.

On the contrary, in Comparative Examples 1 to 3, the storage elastic modulus at normal temperature all showed a value larger than 0.1 MPa, and the storage elastic modulus at 80° C. showed a value larger than 0.055 MPa. Referring to FIGS. 3 and 4 , the storage modulus values according to temperature of Comparative Example 1 and Comparative Example 3 can be confirmed.

In addition, referring to Table 1, the wet-time in Examples 1 to 3 was 60 seconds or less, and all showed PASS in the wettability evaluation. On the contrary, in Comparative Examples 1 to 4, the wetting time showed a value larger than 60 seconds, and all showed NG in the wettability evaluation.

In addition, referring to Table 1, Examples 1 to 3 did not generate bubbles in the light resistance evaluation and all showed PASS. Figures 5 and 6 show the light resistance evaluation results of Examples 1 and 2. Referring to the above-mentioned Figures 5 and 6, it can be seen that no bubbles are generated even if foreign matter (defect) is present.

On the contrary, in Comparative Examples 1 to 4, bubbles were generated in the light resistance evaluation, and all were displayed as NG. Figures 7 to 10 show the light resistance evaluation results of Comparative Examples 1 to 4. Referring to the above-mentioned FIGS. 7 to 10, it can be seen that bubbles are generated with the foreign matter (defect) as the center.

without

Figure 1 shows the temperature-dependent storage modulus (Storage Modulus), loss modulus (Loss Modulus) and tangent value (tan δ) of the cured product of the adhesive composition according to Example 1 at -50°C to 120°C. Graph showing temperature range in °C. Figure 2 shows the temperature-dependent storage modulus (Storage Modulus), loss modulus (Loss Modulus) and tangent value (tan δ) of the cured product of the adhesive composition according to Example 2 at -50°C to 120 Graph showing temperature range in °C. Figure 3 shows the temperature-dependent storage modulus (Storage Modulus), loss modulus (Loss Modulus) and tangent value (tan δ) of the cured product of the adhesive composition according to Comparative Example 1 at -50°C to 120°C. Graph showing temperature range in °C. Figure 4 shows the temperature-dependent storage modulus (Storage Modulus), loss modulus (Loss Modulus) and tangent value (tan δ) of the cured product of the adhesive composition according to Comparative Example 3 at -50°C to 120°C. Graph showing temperature range in °C. 5 is a photograph showing the relationship between the glass substrate and the cured adhesive composition after light resistance evaluation of the adhesive composition according to Example 1. 6 is a photograph showing the relationship between the glass substrate and the cured adhesive composition after light resistance evaluation of the adhesive composition according to Example 2. 7 is a photograph showing the relationship between the glass base material and the cured adhesive composition after light resistance evaluation of the adhesive composition according to Comparative Example 1. 8 is a photograph showing the relationship between the glass base material and the cured adhesive composition after light resistance evaluation of the adhesive composition according to Comparative Example 2. 9 is a photograph showing the relationship between the glass substrate and the cured adhesive composition after light resistance evaluation of the adhesive composition according to Comparative Example 3. 10 is a photograph showing the relationship between the glass base material and the cured adhesive composition after light resistance evaluation of the adhesive composition according to Comparative Example 4.

Claims (18)

An adhesive composition comprising a copolymer obtained by copolymerizing two or more monomers, wherein the monomers include monomers with a surface tension at room temperature greater than 30 mN/m and monomers with a surface tension at room temperature of less than 30 mN/m; The monomers with surface tension at room temperature below 30 mN/m include hydroxyl-containing acrylate compounds, and the monomers with room temperature surface tension greater than 30 mN/m include cyclic alkyl acrylate compounds; the hydroxyl-containing acrylate compound R and the The weight ratio R/Q of the cyclic alkyl acrylate compound Q is in the range of 1.2 to 10; the monomer satisfies the following general formula 1:

In general formula 1, A represents the weight of a monomer with a surface tension at room temperature greater than 30 mN/m, B represents the weight of a monomer with a surface tension at room temperature below 30 mN/m; and the copolymer has a surface tension at room temperature of 30 mN/m. the following. The adhesive composition according to claim 1, wherein the monomers include monomers with a glass transition temperature greater than 10°C and monomers with a glass transition temperature below 10°C, and the glass transition temperature of the copolymer is -25°C or below. The adhesive composition according to claim 2, wherein the monomer satisfies the following general formula 2:

In General Formula 2, C represents the weight of a monomer with a glass transition temperature greater than 10°C, and D represents the weight of a monomer with a glass transition temperature of 10°C or less. The adhesive composition according to claim 1, wherein the monomer with a normal temperature surface tension of 30 mN/m or less contains a chain alkyl acrylate compound. The adhesive composition according to claim 4, wherein the glass transition temperature of the chain alkyl acrylate compound is -20°C or lower. The adhesive composition according to claim 4, wherein the chain alkyl acrylate compound includes more than one compound represented by the following chemical formula 1:

In Chemical Formula 1, L ₁ is a linear alkylene group having 1 to 14 carbon atoms or a branched alkylene group having 2 to 14 carbon atoms, and R ₁ and R ₂ are each independently hydrogen or carbon. A linear alkyl group having 1 to 6 atoms or a branched alkyl group having 2 to 6 carbon atoms. The adhesive composition according to claim 1, wherein the glass transition temperature of the hydroxyl-containing acrylate compound is 0° C. or lower. The adhesive composition according to claim 1, wherein the hydroxyl-containing acrylate compound includes more than one compound represented by the following chemical formula 2:

In Chemical Formula 2, L ₂ is a linear alkylene group having 1 to 10 carbon atoms, a branched alkylene group having 2 to 10 carbon atoms, or a linear or branched alkylene group having 2 to 10 carbon atoms. A chain alkenylene group or a linear or branched alkynylene group having 2 to 10 carbon atoms. The adhesive composition according to claim 1, wherein the monomer with a surface tension greater than 30 mN/m at room temperature includes a cyclic alkyl acrylate compound. The adhesive composition according to claim 9, wherein the glass transition temperature of the cyclic alkyl acrylate compound is 50° C. or higher. The adhesive composition according to claim 1, wherein the monomer with a normal temperature surface tension greater than 30 mN/m includes an acrylate compound containing a cyclic ether group. The adhesive composition according to claim 11, wherein the glass transition temperature of the cyclic ether group-containing acrylate compound is 10° C. or lower. The adhesive composition according to claim 11, wherein the acrylate compound containing a cyclic ether group includes one or more compounds represented by the following chemical formula 3:

In Chemical Formula 3, R ₃ is hydrogen or a linear alkyl group having 1 to 20 carbon atoms, and L ₃ and L ₄ are each independently a single bond or a linear alkylene group having 1 to 20 carbon atoms. , L ₅ is a single bond or a linear alkylene group having 1 to 8 carbon atoms, and Q is an oxygen atom or a carbon atom. A film containing a cured product of the adhesive composition according to claim 1. The film according to claim 14, wherein the normal temperature adhesive force of the film is more than 0.7kg/inch, or the tensile modulus is in the range of 0.002 to 0.012kgf/ ^mm2 , or the normal temperature storage modulus is less than 0.1MPa And the storage modulus at 80°C is below 0.055MPa. An adhesive composition comprising a copolymer obtained by copolymerizing two or more monomers; wherein the monomers include at least one of a first monomer or a second monomer, and the first monomer includes a normal temperature surface Monomers with a tension greater than 30 mN/m and monomers with a surface tension below 30 mN/m at room temperature; the second monomer includes monomers with a glass transition temperature greater than 10°C and monomers with a glass transition temperature below 10°C; at room temperature Monomers with a surface tension of less than 30 mN/m include hydroxyl-containing acrylate compounds; monomers with a surface tension greater than 30 mN/m at room temperature include cyclic alkyl acrylate compounds; the hydroxyl-containing acrylate compound R and the cyclic The weight ratio R/Q of the alkyl acrylate compound Q is in the range of 1.2 to 10; the first monomer satisfies the following general formula 1, and the second monomer satisfies the following general formula 2:

In general formula 1, A represents the weight of the monomer with a surface tension at room temperature greater than 30 mN/m, B represents the weight of the monomer with a surface tension at room temperature less than 30 mN/m, and in general formula 2, C represents the glass transition temperature greater than 10 °C, D represents the weight of the monomer with a glass transition temperature of 10 °C or less; and the normal temperature surface tension of the copolymer is 30 mN/m or less, and the glass transition temperature is -25 °C or less. The adhesive composition according to claim 16, wherein the monomer with a glass transition temperature greater than 10° C. and a surface tension at room temperature greater than 30 mN/m is included in the range of 0.5 to 18% by weight relative to the total weight of the monomer. The adhesive composition according to claim 18, wherein the monomer with a glass transition temperature of 10°C or less and a surface tension at room temperature of 30mN/m or less is compared to a monomer with a glass transition temperature of more than 10°C and a surface tension at room temperature of more than 30mN/m. 100 parts by weight of the monomer is included in the range of 450 to 5500 parts by weight.