TW201500495A - Adhesive composition - Google Patents

Abstract

Disclosed is an adhesive composition, wherein the adhesive composition includes an acrylic-based copolymer having an amino group and an acrylic-based copolymer having a carboxyl group, thereby reducing the content of uncross-linked copolymers and enhancing the cohesive force, so that the adhesive composition can maintain the adhesive strength and exhibit excellent reworkability even when being exposed to the high-temperature or high-humidity environment.

Description

Adhesive composition

The present invention relates to an adhesive composition having enhanced cohesion.

When a thin plate having an organic material is attached to an adherend such as glass, ceramic, and metal with an adhesive, disadvantageous conditions such as peeling or curling of the end of the thin plate may occur frequently.

In order to solve these problems, a strong adhesive substance having an improved adhesive performance by increasing the molecular weight of the adhesive component or increasing the crosslinking density is generally used.

In particular, Japanese Patent Publication No. 2002-169017 discloses an adhesive formed by crosslinking a polyfunctional metal chelate compound with an acrylic polymer having an alkyl (meth)acrylic acid as a main structure. An ester monomer unit, and a monomer unit having a carboxyl group. Although the aforementioned adhesives have improved adhesive properties, changes in the shape of the sheet cannot be solved, causing various problems. The change in the shape of the sheet is caused by shrinkage or swelling of a sheet containing an adhesive organic material in the case of high temperature and high humidity.

At the same time, in the manufacturing process of liquid crystal displays and other products, When the light panel is attached to an optical component such as a liquid crystal cell, the polarizing plate may be layered after a predetermined period of time in order to repeatedly use a high unit price liquid crystal cell. Therefore, after the polarizing plate is attached to the liquid crystal cell by the adhesive coated on the polarizing plate, an adhesive which can be relatively easily separated from the liquid crystal cell for a predetermined period of time is required.

Thus, Korean Patent Publication No. 2007-76469 discloses a package An adhesive comprising a diacrylic copolymer and an active energy ray-curable resin, wherein the active energy ray-curable resin is used for enhanced cohesion. In addition, Korean Patent Publication No. 2014-0013916 and No. 2014-0013917 disclose an adhesive composition comprising an acrylic polymer which is a (meth)acrylic acid having a C4 to C10 alkyl group. An ester monomer, a hydroxyl group comprising a copolymerizable monomer, and a copolymer comprising a carboxyl group of a copolymerizable monomer, and further comprising an antistatic agent, the antistatic agent being an ionic compound having a melting point of 30 to 80 ° C, further comprising A trifunctional or higher isocyanate compound, according to the above technique, cohesive force can be improved to exhibit excellent adhesive durability, and re-layering is achievable even after a predetermined period of time (reworkability). However, in recent years, due to the enlargement of the size of the polarizing plate, sufficient durability has become difficult to secure.

Accordingly, the present invention has been made to solve the above problems in the prior art, and an aspect of the present invention is to provide an adhesive having enhanced cohesion. The composition of the composition, wherein the enhanced cohesive force is derived by covalent bonding between an acrylic copolymer and a crosslinking agent and ionic bonding between the acrylic copolymers.

Further, an aspect of the present invention provides an adhesive composition The adhesive composition allows it to be re-layered even after a predetermined period of time, and has excellent durability through the enhanced cohesive force.

In order to achieve this, an acrylic copolymer is provided. An adhesive composition with a crosslinking agent, wherein the acrylic copolymer comprises an acrylic copolymer having an aminoacrylic copolymer and a carboxyl group.

The acrylic copolymer may comprise from 10% to 90% by weight An acrylic copolymer having an amino group and an acrylic copolymer having a carboxyl group in an amount of 10% to 90% by weight.

Here, the monomer for preparing the acrylic copolymer having an amino group may include a mono(meth)acrylate monomer having an alkyl group of 1 to 12 carbon atoms, and at least one monomer is selected from the following Chemical Formula 1 Group of compounds up to 5:

(wherein R1 is hydrogen or monomethyl; and R2 and R3, each independently hydrogen, an alkyl group having 1 to 4 carbon atoms, or a trialkylamine having 1 to 6 carbon atoms), (wherein R1 is hydrogen or monomethyl; R2 and R3, each independently hydrogen or an alkyl group having 1 to 4 carbon atoms; R4 is a hydroxy group or an alkoxy group having 1 to 3 carbon atoms ;1 and n, each being an integer from 1 to 12; and m is an integer of 0 or 1), (wherein R1 is hydrogen or monomethyl; X is O or N of an alkyl group having 1 to 3 carbon atoms), (wherein R1 is hydrogen or monomethyl; and R2 and R3, each independently hydrogen or an alkyl group having from 1 to 4 carbon atoms), (wherein R1 is hydrogen or monomethyl; R4 is a hydroxy group or an alkoxy group having 1 to 3 carbon atoms; R5 is hydrogen, an aliphatic hydrocarbon group having 1 to 4 carbon atoms, halogen, and 1 An alkoxy group to 4 carbon atoms, or an alkylamino group having 1 to 4 carbon atoms; n is an integer of 1 to 12; and m is an integer of 0 or 1.

The group consisting of the at least one monomer selected from the compounds of Chemical Formulas 1 to 5 may be included in 1 to 20 parts by weight per 100 parts of the (meth) acrylate monomer having an alkyl group having 1 to 12 carbon atoms. .

Here, the monomer for preparing the acrylic copolymer having a carboxyl group may include a (meth) acrylate monomer having an alkyl group having 1 to 12 carbon atoms, and at least one monomer is selected from the following chemical formula Groups of compounds from 6 to 14:

The group consisting of the at least one monomer selected from the compounds of Chemical Formulas 6 to 14 may be included in 0.1 to 10 parts by weight per 100 parts of the (meth) acrylate monomer having an alkyl group having 1 to 12 carbon atoms. .

The present invention is directed to polymers having enhanced cohesion.

Hereinafter, the present invention will be described in detail.

An adhesive composition of the invention comprises an acrylic copolymer and a crosslinking agent, wherein the acrylic copolymer comprises an acrylic copolymer having an aminoacrylic copolymer and a carboxyl group.

The adhesive composition of the present invention can exhibit excellent durability because the covalent bonding between the crosslinking agent C and the olefinic copolymer and the ionic bonding between the acrylic copolymers are simultaneously performed, thereby enhancing the adhesive composition. Cohesion.

Here, the acrylic copolymer may contain 10% to 90% by weight of an acrylic copolymer having an amino group, and 10% to 90% by weight of an acrylic copolymer having a carboxyl group.

The improvement of the team cohesive force of the acrylic copolymer having one amino group of less than 10% by weight or more than 90% by weight is less effective, and therefore, sufficient durability improvement (heat resistance and heat and humidity resistance) of the adhesive may not be achieved.

The monomer for preparing the acrylic copolymer having an amino group may include a mono(meth)acrylate monomer having an alkyl group of 1 to 12 carbon atoms, and at least one monomer is selected from the following Chemical Formulas 1 to 5. A group of compounds. Here, the term (meth) acrylate refers to acrylate and methacrylate, and the content of each component is based on the solid content.

[Chemical Formula 1]

(wherein R1 is hydrogen or monomethyl; and R2 and R3, each independently hydrogen, an alkyl group having 1 to 4 carbon atoms, or a trialkylamine having 1 to 6 carbon atoms),

(wherein R1 is hydrogen or monomethyl; R2 and R3, each independently hydrogen or an alkyl group having 1 to 4 carbon atoms; R4 is a hydroxy group or an alkoxy group having 1 to 3 carbon atoms ;1 and n, each being an integer from 1 to 12; and m is an integer of 0 or 1),

(wherein R1 is hydrogen or monomethyl; X is O or N of an alkyl group having 1 to 3 carbon atoms),

(wherein R1 is hydrogen or monomethyl; and R2 and R3, each independently hydrogen or an alkyl group having from 1 to 4 carbon atoms),

(wherein R1 is hydrogen or monomethyl; R4 is a hydroxy group or an alkoxy group having 1 to 3 carbon atoms; R5 is hydrogen, an aliphatic hydrocarbon group having 1 to 4 carbon atoms, halogen, and 1 An alkoxy group to 4 carbon atoms, or an alkylamino group having 1 to 4 carbon atoms; n is an integer of 1 to 12; and m is an integer of 0 or 1.

Examples of the mono(meth)acrylate monomer having an alkyl group of 1 to 12 carbon atoms may include n-butyl (meth) acrylate, 2-butyl (meth) acrylate, t-butyl (Meth) acrylate, 2-ethylhexyl (meth) acrylate, ethyl (meth) acrylate, m-ethyl (meth) acrylate, n-propyl (meth) acrylate, Isopropyl (meth) acrylate, pentyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, decyl (meth) acrylate, hydrazine Base (meth) acrylate, dodecyl (meth) acrylate, and the like. Among them, n-butyl acrylate, 2-ethylhexyl acrylate, and mixtures thereof may be preferred. These may be used singly or in combination of two or more.

At least one monomer selected from the group consisting of the compounds of Chemical Formulas 1 to 5 may be included in the (meth) group having an alkyl group of 1 to 12 carbon atoms. The acrylate monomer is from 1 to 20 parts by weight, more preferably from 2 to 10 parts, per 100 parts. Less than 1 part by weight per 100 parts of the (meth) acrylate monomer may be less effective for cohesiveness, and more than 20 parts by weight per 100 parts of the (meth) acrylate monomer may result Other physical properties of the adhesive are degraded, such as deteriorated moisture resistance due to excessively increased hydrophilicity, excessively increased peeling force of the release film, deteriorated liquid stability, and the like.

For the preparation of the acrylic copolymer having one amino group, except for the group consisting of a (meth) acrylate monomer having an alkyl group of 1 to 12 carbon atoms and at least one monomer selected from the compounds of Chemical Formulas 1 to 5. The monomer of the substance may include a monomer having a monohydroxy group.

The monomer having a hydroxyl group is chemically bonded to supplement the cohesive force or adhesive strength of the adhesive composition, thereby imparting durability and machinability.

Specific examples of the monomer having a monohydroxy group may include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4- Hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 2-hydroxyethylene glycol (meth) acrylate, 2-hydroxy propylene glycol (meth) acrylate, having a 2 to 4 Aminoalkyl hydroxyalkyl glycol (meth) acrylate, 4-hydroxybutyl vinyl ether, 5-hydroxypentyl vinyl ether, 6-hydroxyhexyl vinyl ether, 7-hydroxyl group Heptyl vinyl ether, 8-hydroxyoctyl vinyl ether, 9-hydroxydecyl vinyl ether, 10-hydroxydecyl vinyl ether, and the like. Among them, 4-hydroxybutyl vinyl ether is preferred.

a monomer having a monohydroxy group is contained in having from 1 to 12 carbon atoms A preferred content of the alkyl (meth) acrylate monomer of the alkyl group is from 0.05 to 10 parts by weight per 100 parts by weight, more preferably from 0.1 to 8 parts by weight. Less than 0.05 parts by weight per 100 parts of the (meth) acrylate monomer may reduce the cohesive force of the adhesive, resulting in deterioration of durability. However, more than 10 parts by weight per 100 parts of the (meth) acrylate monomer may lower the adhesive strength adhesive due to a high gel fraction, and there is a problem of durability.

In addition, the acrylic copolymer having an amino group of the present invention can be further One step contains other polymerizable monomers other than the above-mentioned monomers in a range in which the strength of the adhesive does not decrease, for example, 10 parts by weight or less based on the total weight.

The preparation method of the acrylic copolymer having one amino group is not Special restrictions. The acrylic copolymer having an amino group can be produced by, for example, bulk polymerization, solution polymerization, emulsion polymerization, or suspension polymerization, which is commonly used in the prior art. Among them, dissolution polymerization is preferred. Further, a solvent, a polymerization initiator, a chain transfer agent for controlling the molecular weight, and the like can be used, and are usually used at the time of polymerization.

The acrylic copolymer having an amino group has a weight average molecular weight (Mw in terms of polystyrene), preferably 50,000 to 2,000,000, as measured by gel permeation chromatography (GPC), more preferably 400,000 to 2,000,000. If the weight average molecular weight is less than 50,000, the cohesive force between the copolymers is insufficient, causing a problem of durability of the adhesive. If the weight average molecular weight is higher, a large amount of a dilution solvent may be required to ensure processability at the time of coating.

The monomer for preparing an acrylic copolymer having a carboxyl group may comprise a (meth) acrylate monomer having an alkyl group having 1 to 12 carbon atoms, and at least one monomer is selected from the following Chemical Formula 6 Group of compounds up to 14:

At least one monomer selected from the group consisting of the compounds of Chemical Formulas 6 to 14 is contained in 0.1 to 10 parts by weight per 100 parts of the (meth) acrylate monomer having an alkyl group having 1 to 12 carbon atoms. A preferred content is more preferably 2 to 6 parts by weight. Less than 0.1 part by weight per 100 parts of the (meth) acrylate monomer may be less effective for cohesiveness, and more than 10 parts by weight per 100 parts of the (meth) acrylate monomer may be excessive Increased hydrophilicity results in deterioration of moist heat resistance.

The acrylic copolymer having a monocarboxy group of the present invention may include a monomer having a monohydroxy group in addition to at least one monomer selected from the group consisting of the compounds of Chemical Formulas 6 to 14.

Description of a (meth) acrylate monomer having an alkyl group having 1 to 12 carbon atoms, a content of a monomer having a monohydroxy group, and a preparation amount of the copolymer The weight average molecular weight of the method, the copolymer, and the like are the same as those in the acrylic copolymer having an amino group.

According to the present invention, since the crosslinking ratio between the acrylic copolymers is small, the content of the uncrosslinked low molecular weight copolymer is small, thereby reducing the deterioration of durability due to the exuded low molecular weight copolymer, and enhancing the compactness between the copolymers. The cohesive force produced by cross-linking ensures durability.

The crosslinking agent is used to enhance cohesion to improve durability, and is particularly useful for meeting heat resistance and moist heat resistance.

Hydrogen bonds or ionic bonds between polymers may be broken due to moisture absorption under heat and humidity conditions, and a crosslinking agent is used to prevent such breakage.

The crosslinking agent can be reactive with a monohydroxy group or a monocarboxy group. The isocyanate group or epoxy resin crosslinking agent may be used singly or in combination of two or more.

Examples of isocyanates may include diisocyanate compounds such as toluene diisocyanate, xylene diisocyanate, 2,4-diphenylmethane diisocyanate, 4,4-diphenylmethane diisocyanate, cyclohexane diisocyanate, and isophora. a ketone diisocyanate, tetramethyl xylene diisocyanate, and naphthalene diisocyanate; an adduct obtained by reacting a 3 mol of a diisocyanate compound with a 1 mol of a polyhydric alcohol compound, the polyol The compound is, for example, trimethylolpropane or the like, an isocyanurate compound obtained by self-condensation of a 3 mole of a diisocyanate compound, a biuret compound, by 2 moles in 3 moles. Diisocyanate urea obtained from diisocyanate compound The remaining 1 molar diisocyanate compound is obtained by condensation, and a polyfunctional isocyanate compound having a trifunctional group such as triphenylmethane triisocyanate and methylene diisocyanate.

Examples of the epoxy resin may include ethylene glycol diglycidyl ether, Diethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6 - hexanediol diglycidyl ether, polyethylene glycol diglycidyl ether, glycerol diglycidyl ether, glycerol triglycidyl ether, glycerol polydiether, polyglycerol polyglycidyl ether, resorcinol diglycidyl Ether, 2,2-dibromoneopentyl glycol diglycidyl ether, trimethylolpropane triglycidyl ether, pentaerythritol polyglycidyl ether, sorbitol polyglycidyl ether, diglycidyl adipate, Diglycidyl phthalate, tris(glycidyl)isocyanurate, tris(glycidoxyethyl)isocyanurate, 1,3-bis(N,N-diglycidyl) Aminomethylmethyl)cyclohexane, N,N,N',N'-tetraglycidyl-m-xylenediamine, and the like.

The crosslinking agent may be included in an acrylic copolymer having an amino group The content of the acrylic copolymer having a monocarboxy group is 0.1 to 5 parts by weight per 100 parts by weight, preferably 0.2 to 1.0 part by weight. Less than 0.1 part by weight of the crosslinking agent may be less effective for enhancing the cohesive force, and more than 5 parts by weight of the crosslinking agent may deteriorate the strength of the adhesive due to excessively increased cohesive force.

Further, the adhesive composition according to the present invention may further comprise an antistatic agent, and a preferred ionic antistatic agent may be used. Ionic antistatic agent is The ionic salt is composed of an anion and a cation, and the ionic antistatic agent is not particularly limited as long as it can impart ionic conductivity to the adhesive.

In particular, the electrostatic agent antistatic agent may be an ionic salt, Selecting an anion composed of an alkali metal salt, an ammonium salt, a phosphonium salt, and a phosphonium salt; and a cation selected from the group consisting of an inorganic salt, a fluorine-containing organic salt, and an iodide ion composition.

The ionic antistatic agent can be included in the entire acrylic copolymer 0.1 to 5 parts by weight, preferably 0.5 to 3 parts by weight, per 100 parts. Less than 0.1 part by weight of the ionic antistatic agent may result in insufficient antistatic properties, and more than 5 parts by weight of the antistatic agent may fail to ensure durability.

The adhesive composition according to the present invention, in addition to the above ingredients, may Further included additives such as tackifying resins, antioxidants, leveling agents, surface lubricants, dyes, pigments, defoamers, fillers, and light stabilizers to control adhesive strength, cohesion, viscosity, modulus of elasticity, glass Transformation temperature, etc.

Among them, a decane coupling agent is used to improve the adhesion between the adhesive and the substrate. The strength is such that the adhesive composition preferably contains a decane coupling agent. Here, the alkoxydecane contains a monofunctional group, and for example, an amino group, an epoxy group, an ethyl oxime group, a polyolefin diol group, an acryl fluorenyl group, and an alkyl group can be used.

The content of these additives may be in the range in which the effect of the present invention is not impaired. It is properly controlled within the perimeter. For example, in view of the strength and durability of the adhesive, the decane coupling agent may be contained in an acrylic copolymer having an amino group and have one The carboxyl group-containing acrylic copolymer is generally 0.01 to 2 parts by weight, preferably 0.1 to 0.5 parts by weight per 100 parts by weight. Less than 0.01 parts by weight of the decane coupling agent may deteriorate the strength of the adhesive, and more than 2 parts by weight of the decane coupling agent may cause delamination under heat resistant conditions.

The adhesive composition of the present invention can be used as an adhesive for polarized light The board is combined with a liquid crystal cell or used as a surface protective film. Further, the adhesive composition of the present invention can be used for a protective film, a reflective sheet, an adhesive sheet for forming, an adhesive sheet for photography, an adhesive sheet for a landmark, an optical adhesive product, and Electronic products are also used as adhesive sheet products for general use in commercial products.

In the following, although preferred embodiments are provided to aid in understanding this The embodiments provided below are merely illustrative of the invention. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the invention and the scope of the invention.

Preparation Example 1: Acrylic copolymer having an amino group

Preparation Example 1-1

90 parts by weight of n-butyl acrylate, 7 parts by weight of methacrylate, and 3 parts by weight of a monomer mixture of dimethylaminoethyl acrylate are supplied to the reflux and temperature control for promoting nitrogen gas In a one liter reactor of the cooling device, 100 parts by weight of ethyl acetate (acetone), which is a solvent, was fed to the reactor. Thereafter, nitrogen gas was purged for 1 hour to remove oxygen. It was then maintained at a temperature of 62 °C. The mixture was stirred evenly. Next, 0.07 part by weight of azobisisobutyronitrile as a reaction initiator was fed into the reactor, followed by a reaction for 6 hours to prepare an acrylic copolymer having an amino group having a weight average molecular weight of about 1,000,000.

Preparation Example 1-2

The acrylic copolymer having a monoamino group was prepared in the same manner as in the production of Example 1-1 except that dimethylaminoethyl acrylate was substituted with acryloylmorpholine.

Preparation Examples 1-3

In addition to 83 parts by weight of n-butyl acrylate, 7 parts by weight of methacrylate, and 10 parts by weight An acrylic copolymer having an amino group was prepared by the same method as in Preparation Example 1-1 except that the substituted dimethylaminoethyl acrylate was used.

Preparation Examples 1-4

In addition to 83 parts by weight of n-butyl acrylate, 7 parts by weight of methacrylate, and 10 parts by weight An acrylic copolymer having an amino group was prepared by the same method as in Preparation Example 1-1 except that the substituted dimethylaminoethyl acrylate was used.

Preparation Examples 1-5

In addition to 73 parts by weight of n-butyl acrylate, 7 parts by weight of methacrylate, and 20 parts by weight An acrylic copolymer having an amino group was prepared by the same method as in Preparation Example 1-1 except that the substituted dimethylaminoethyl acrylate was used.

Preparation Examples 1-6

An acrylic copolymer having an amino group was prepared by using Example 68 except for 68 parts by weight of n-butyl acrylate, 7 parts by weight of methacrylate, and 25 parts by weight of dimethylaminoethyl acrylate. Prepared in the same manner as in -1.

Preparation Examples 1-7

In addition to 83 parts by weight of n-butyl acrylate, 7 parts by weight of methacrylate, and 10 parts by weight An acrylic copolymer having an amino group was prepared by the same method as in Preparation Example 1-1 except that the substituted dimethylaminoethyl acrylate was used.

Preparation Examples 1-8

In addition to 83 parts by weight of n-butyl acrylate, 7 parts by weight of methacrylate, and 10 parts by weight An acrylic copolymer having an amino group was prepared by the same method as in Preparation Example 1-1 except that the substituted dimethylaminoethyl acrylate was used.

Preparation Example 2: Acrylic copolymer having a carboxyl group

Preparation Example 2-1

89 parts by weight of n-butyl enoate, 7.0 parts by weight of methacrylate, 3.0 parts by weight (Chemical Formula 6), and 1.0 part by weight of a monomer mixture of 4-hydroxybutyl acrylate is fed into a one liter reactor equipped with a cooling device for promoting reflux and temperature control of nitrogen, and is referred to as a solvent 100. Parts by weight of acetone were fed to the reactor. Thereafter, nitrogen gas was purged for 1 hour to remove oxygen, and then maintained at a temperature of 62 °C. The mixture was stirred evenly. Next, 0.07 part by weight of azobisisobutyronitrile as a reaction initiator was fed into the reactor, followed by a reaction for 6 hours to prepare an acrylic copolymer having a carboxyl group having a weight average molecular weight of about 1,000,000.

Preparation Example 2-2

apart from (Chemical Formula 7) used to replace (Chemical Formula 6), an acrylic copolymer having a monocarboxy group was prepared by the same method as in Production Example 2-1.

Preparation Example 2-3

apart from (Chemical Formula 8) used to replace (Chemical Formula 6), an acrylic copolymer having a monocarboxy group was prepared by the same method as in Production Example 2-1.

Preparation Examples 2-4

apart from (Chemical Formula 9) used to replace (Chemical Formula 6), an acrylic copolymer having a monocarboxy group was prepared by the same method as in Production Example 2-1.

Preparation Example 2-5

apart from (Chemical Formula 10) used to replace (Chemical Formula 6), an acrylic copolymer having a monocarboxy group was prepared by the same method as in Production Example 2-1.

Preparation Examples 2-6

apart from (Chemical Formula 11) used to replace (Chemical Formula 6), an acrylic copolymer having a monocarboxy group was prepared by the same method as in Production Example 2-1.

Preparation Examples 2-7

apart from (Chemical Formula 12) used to replace (Chemical Formula 6), an acrylic copolymer having a monocarboxy group was prepared by the same method as in Production Example 2-1.

Preparation Examples 2-8

apart from (Chemical Formula 13) used to replace (Chemical Formula 6), an acrylic copolymer having a monocarboxy group was prepared by the same method as in Production Example 2-1.

Preparation Examples 2-9

apart from (Chemical Formula 14) used to replace (Chemical Formula 6), an acrylic copolymer having a monocarboxy group was prepared by the same method as in Production Example 2-1.

Preparation Example 2-10

In addition to using 91 parts by weight of n-butyl acrylate, 7.0 parts by weight of methacrylate, and 1.0 part by weight (Chemical Formula 6), and 1.0 part by weight of hydroxyethyl acrylate, an acrylic copolymer having a monocarboxy group was prepared by the same method as in Production Example 2-1.

Preparation Example 2-11

In addition to using 82 parts by weight of n-butyl acrylate, 7.0 parts by weight of methacrylate, and 10.0 parts by weight (Chemical Formula 6), and 1.0 part by weight of hydroxyethyl acrylate, an acrylic copolymer having a monocarboxy group was prepared by the same method as in Production Example 2-1.

Preparation Examples 2-12

In addition to using 77 parts by weight of n-butyl acrylate, 7.0 parts by weight of methacrylate, and 15.0 parts by weight With 1.0 part by weight of hydroxyethyl acrylate, an acrylic copolymer having a monocarboxy group was prepared by the same method as in Production Example 2-1.

Examples 1 to 23 and Comparative Examples 1 to 2

An adhesive composition having a solid content of 15% was prepared by mixing according to the ingredients of the composition shown in Table 1 below, followed by dilution with ethyl acetate. Each of the above-prepared adhesive compositions was coated on a release film coated with a ruthenium release agent to have a thickness of 25 μm. It was then dried at 100 ° C for 1 minute to form an adhesive layer.

The adhesive layer thus formed was attached to a 185 μm-thick iodine-based polarizing plate by an attaching treatment to produce an adhesive-attached polarizing plate.

Test example

The characteristics of the adhesive-attached polarizing plate manufactured from the above Examples and Comparative Examples were measured by the following methods, and the results are shown in Table 2, respectively.

Heat resistance / heat and humidity resistance

The release film is removed from the adhesive attached to the polarizing plate, and then the Corning glass allows bonding to the surface layer of the adhesive. After that, the obtained structures were each placed at 80 ° C and 60 ° C / 90 RH% for 300 hours, and then the appearance was confirmed.

<Evaluation basis>

Confirm three or more bubbles and stratification: ×

Confirm two or fewer bubbles and stratification: ○

No recognition of bubbles and delamination: ◎

Reworkability

The adhesive is attached to the polarizing plate and cut into 25 width and length. Mm × 100 mm, and then the release film was peeled off. The polarizing plate was laminated to a Corning #1737 substrate by a pressure of 0.25 MPa, and then placed in an autoclave at 5 atmospheres and 50 ° C for 20 minutes to prepare an evaluation sample. The sample was placed in an oven at 50 ° C heat resistance and taken out after 5 hours. Next, the sample was kept at room temperature for 120 hours and then peeled off at a rate of 1.3 cm/s. The sample was placed in an oven under heat and humidity conditions of 60 ° C and 90% RH and removed therefrom after four hours. Next, the sample was kept at room temperature for 120 hours and then peeled off at a rate of 1.3 cm/s.

<Evaluation basis>

- Significant delamination in the case where the adhesive is not left on the glass substrate and the polarizing plate is not broken: ○

- For heat-resistant conditions or wet heat-resistant conditions, the adhesive is kept on the panel or the polarizing plate is torn during the peeling process: ×

Table 2 demonstrates that adhesive compositions Examples 1-23, included,

An acrylic copolymer having an amino group in accordance with the present invention The polymer and the acrylic copolymer having a monocarboxy group have excellent heat resistance and moist heat resistance while maintaining reworkability equivalent to or higher than the reworkability in Comparative Examples 1 and 2.

The adhesive composition of the present invention has enhanced cohesive force by covalent bonding between the acrylic copolymer and the crosslinking agent and ionic bonding between the acrylic copolymers. The adhesive composition of the present invention can have excellent durability even when exposed to an environment of high temperature or high humidity to maintain adhesive strength and display reworkability equivalent to or higher than conventionally achieved reworkability.

Claims (6)

An adhesive composition comprising an acrylic copolymer and a crosslinking agent, wherein the acrylic copolymer comprises an acrylic copolymer having an amino group, and an acrylic copolymer having a carboxyl group. The adhesive composition according to claim 1, wherein the acrylic copolymer comprises 10% to 90% by weight of an acrylic copolymer having an amino group, and 10% to 90% by weight of a carboxyl group. Acrylic copolymer. The adhesive composition according to claim 1, wherein the monomer for preparing the acrylic copolymer having an amino group comprises a mono(meth)acrylate having an alkyl group of 1 to 12 carbon atoms. a group of at least one monomer selected from the compounds of the following Chemical Formulas 1 to 5: (wherein R1 is hydrogen or monomethyl; and R2 and R3, each independently hydrogen, an alkyl group having 1 to 4 carbon atoms, or a trialkylamine having 1 to 6 carbon atoms), (wherein R1 is hydrogen or monomethyl; R2 and R3, each independently hydrogen or an alkyl group having 1 to 4 carbon atoms; R4 is a hydroxy group or an alkoxy group having 1 to 3 carbon atoms ;1 and n, each being an integer from 1 to 12; and m is an integer of 0 or 1), (wherein R1 is hydrogen or monomethyl; X is O or N of an alkyl group having 1 to 3 carbon atoms), (wherein R1 is hydrogen or monomethyl; and R2 and R3, each independently hydrogen or an alkyl group having from 1 to 4 carbon atoms), (wherein R1 is hydrogen or monomethyl; R4 is a hydroxy group or an alkoxy group having 1 to 3 carbon atoms; R5 is hydrogen, an aliphatic hydrocarbon group having 1 to 4 carbon atoms, halogen, and 1 An alkoxy group to 4 carbon atoms, or an alkylamino group having 1 to 4 carbon atoms; n is an integer of 1 to 12; and m is an integer of 0 or 1. The adhesive composition according to claim 3, wherein the group consisting of the at least one monomer selected from the compounds of Chemical Formulas 1 to 5 is contained in an alkyl group having from 1 to 12 carbon atoms. The acrylate monomer is from 1 to 20 parts by weight per 100 parts. The adhesive composition according to claim 1, wherein the monomer for preparing the acrylic copolymer having a carboxyl group comprises an alkyl (meth)acrylate having 1 to 12 carbon atoms. a monomer, and a group of at least one monomer selected from the compounds of Chemical Formulas 6 to 14 below: [Chemical Formula 10] The adhesive composition of claim 5, wherein the group consisting of the at least one monomer selected from the compounds of Chemical Formulas 6 to 14 is contained in an alkyl group having 1 to 12 carbon atoms (methyl group) The acrylate monomer is 0.1 to 10 parts by weight per 100 parts.