KR20130066488A - Adhesive composition for optical use - Google Patents

Abstract

PURPOSE: An adhesive composition for optical use is provided to improve durability and antistatic performance under high temperature or high temperature and high humidity environment. CONSTITUTION: An adhesive composition for optical use contains 30-80wt% of monofunctional urethane acrylate-based oligomer, 5-60wt% of monofunctional (meth)acrylate monomer, 0.1-10wt% of photopolymerization initiator, and 0.01-20wt% of compound including a compound represented by chemical formula 1. The compound includes one or more selected from PF6^-, (CF3SO2)2N^-, CF3COO^-, NO3^-, CH3COO^-, BF4^-, CF3SO3^-, and (NC)2N^-.

Description

Optical adhesive composition {ADHESIVE COMPOSITION FOR OPTICAL USE}

The present invention relates to an optical pressure-sensitive adhesive composition capable of simultaneously satisfying durability and antistatic properties under high temperature or high temperature / humidity environment while maintaining adhesive force.

Various image display devices including liquid crystal display devices (LCDs) are digital devices that transmit information of a specific content as well as various small devices such as mobile phones, portable game consoles, car navigation systems, digital cameras, small music or video players, and the like. As information display (DID), its use is expanding to advertisement, interior, electronic blackboard, three-dimensional image display, and the like.

As the use of the image display device is expanded, various functional materials such as a touch screen panel for inputting various information, a polymer film having good impact resistance to prevent the display panel from being damaged by an external environment such as weather change or shock, or It is required to be provided with a protective plate such as a glass plate.

This functional material or protective plate is bonded onto the display panel using an adhesive sheet. The adhesive sheet is a thick film type adhesive, unlike a thin film type adhesive used for laminating various optical films including a polarizing plate, and is usually a solvent type or a solventless type containing an acrylate oligomer or a urethane acrylate oligomer between two substrate films. It is a structure in which the adhesive layer formed by photopolymerization hardening of an adhesive composition is interposed.

However, static electricity is generated during the process of bonding the functional material or the protective plate using the adhesive sheet, and the generated static electricity is not only a problem of surface contamination by foreign matter adsorption, a problem of staining due to damage of the display panel, but also a breakage of the thin film transistor line. There is a risk of causing. In addition, static electricity may be generated from an external display device.

In order to solve this, the pressure-sensitive adhesive composition containing an alkali metal salt and an ionic liquid in a liquid state at room temperature was used as the ionic compound. These compounds can lower the adhesive physical properties, and under high temperature or high temperature and high humidity environment, the ionic compounds can migrate to the surface or outflow, which can cause degradation of durability and antistatic properties over time.

The present invention is to provide a pressure-sensitive adhesive composition for optics that can simultaneously satisfy the durability and antistatic properties under high temperature or high temperature and high humidity environment while maintaining the adhesive force.

In order to achieve the above object, the present invention is 30 to 80% by weight of a monofunctional urethane acrylate oligomer, 5 to 60% by weight of a monofunctional (meth) acrylate monomer, 0.1 to 10% by weight of a photoinitiator and Formula 1 as a cation To provide an optical pressure-sensitive adhesive composition containing 0.01 to 20% by weight of a compound containing.

Compound comprising the formula (I) with cations are ^{_{PF 6 -, (CF 3 SO}} 2) 2 N -, CF 3 COO -, NO 3 -, CH 3 COO -, BF 4 -, CF 3 SO 3 - and (NC ) At least one selected from ₂ N ^- as an anion.

Preferably, the compound including Formula 1 as a cation may include PF ₆ ^- or (CF ₃ SO ₂ ) ₂ N ^- as an anion.

The monofunctional urethane acrylate oligomer may have a weight average molecular weight of 5,000 to 30,000.

The monofunctional urethane acrylate oligomer may have a viscosity (25 ° C.) of 10,000 to 300,000 cPs.

The present invention also provides an optical pressure-sensitive adhesive of the adhesive composition is cured.

The present invention also relates to a transparent substrate film; And a pressure-sensitive adhesive formed on one surface of the transparent base film.

The pressure-sensitive adhesive may have a thickness of 25 to 1000 mu m.

Optical pressure-sensitive adhesive composition according to the present invention can maintain the adhesive force and the surface migration or outflow of the ionic compound under high temperature or high temperature and high humidity environment is suppressed to improve the durability and antistatic properties.

The present invention relates to an optical pressure-sensitive adhesive composition capable of simultaneously satisfying durability and antistatic properties under high temperature or high temperature / humidity environment while maintaining adhesive force.

Hereinafter, the present invention will be described in detail.

The optical adhesive composition of this invention contains the monofunctional urethane acrylate oligomer, the monofunctional (meth) acrylate monomer, the photoinitiator, and the compound containing the following general formula (1) as a cation.

[Formula 1]

The urethane acrylate oligomer is a component for imparting the physical properties of the pressure-sensitive adhesive, and generally, a urethane acrylate oligomer is made using polyester polyol and polyether polyol. Among them, polyether polyol is preferred in order to have high molecular weight and low viscosity, and it is particularly preferable to prepare a urethane (meth) acrylate oligomer with polypropylene glycol having a molecular weight of 800 to 4,500 as a main chain.

Moreover, it is preferable that the urethane (meth) acrylate oligomer of this invention is a monofunctional urethane (meth) acrylate oligomer which is not polyfunctional. In the case of using a polyfunctional urethane (meth) acrylate oligomer, the tacky of the surface of the pressure-sensitive adhesive layer is reduced and the cohesive force is excessively high, so that the expression of the adhesive physical properties is not easy.

The monofunctional urethane (meth) acrylate oligomer is a polymer obtained by the reaction of a polypropylene glycol, an isocyanate compound and a hydroxyl group-containing (meth) acrylate monomer having a molecular weight of 800 to 4,500. Polypropylene glycol has an effect of controlling the viscosity of the pressure-sensitive adhesive composition to lower the hydrogen bond between the urethane bonds when the oligomerization containing a methyl group, it is advantageous in terms of cost and low cost.

It is preferable that polypropylene glycol has a molecular weight of 800-4,500. When the molecular weight is less than 800, the viscosity of the oligomer may be increased in the process of high molecular weight oligomer, and when the molecular weight is greater than 4,500, the polypropylene glycol portion, which is a soft segment (amorphous), is too large in the oligomer molecule. Can fall and the durability of heat and moisture resistance becomes weak.

The kind of isocyanate type compound is not specifically limited, For example, isophorone diisocyanate, 2, 4- toluene diisocyanate, 2, 6- toluene diisocyanate, 1, 4- butylene diisocyanate, 1, 6- hexamethylene diisocyanate, Lysine diisocyanate, trimethylhexamethylene diisocyanate, 2,2-bis-4'-propane isocyanate, 6-isopropyl-1,3-phenyldiisocyanate, bis (2-isocyanate ethyl) -fumarate, 1,6- Hexane diisocyanate, 4,4'- diphenylene diisocyanate, 3,3'- dimethylphenylene diisocyanate, 3,3'- dimethyl-4,4'- diphenylmethane diisocyanate, p-phenylenedi isocyanate, m- Phenylene diisocyanate, 1,4-naphthalene diisocyanate, 1,5-naphthalene diisocyanate, 1,4- xylene diisocyanate, 1,3- xylene diisocyanate, cyclopentylene-1,3-diisocyanate Y, 4,4'-dicyclohexylmethane diisocyanate, cyclohexene-1,4-diisocyanate, 4,4'-methylenebis (phenylisocyanate), 2,2-diphenylpropane-4,4'-di Isocyanate, azobenzene-4,4'-diisocyanate, tetramethylxylene diisocyanate, 1-chlorobenzene-2,4-diisocyanate or oligomers thereof and the like, and isophorone diisocyanate, 1,6- Hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, etc. are preferable. These can be used individually or in mixture of 2 or more types.

The kind of the hydroxy group-containing (meth) acrylate monomer is not particularly limited, and for example, hydroxyethyl (meth) acrylate, hydroxybutyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxypentyl (meth) Acrylate, hydroxyhexyl (meth) acrylate, hydroxyethylene glycol (meth) acrylate, hydroxypropylene glycol (meth) acrylate, hydroxybutyl vinyl ether, and the like, among which hydroxyethyl (meth) ) Acrylates are preferred. These can be used individually or in mixture of 2 or more types.

The manufacturing method of a monofunctional urethane (meth) acrylate oligomer is not specifically limited, A conventional one-shot method, a prepolymer method, etc. can be used. For example, the one-shot method mixes polypropylene glycol, a (meth) acrylate monomer having a hydroxy group, and a primary alcohol, and then reacts the isocyanate-based compound with an excess of an isocyanate-based compound in an appropriate equivalent ratio, preferably in order to improve the reaction efficiency. It is a method of manufacturing a monofunctional urethane (meth) acrylate oligomer. In addition, in the prepolymer method, a polypropylene glycol and an isocyanate compound are mixed and reacted with an isocyanate group [-NCO] of the polypropylene glycol and an isocyanate compound to obtain a prepolymer having a urethane bond, and then (meth) acryl having a hydroxy group therein. It is a method for producing a monofunctional urethane (meth) acrylate oligomer by reacting a solution in which a rate monomer and a primary alcohol are mixed in an equivalent ratio of 1: 1.

It is preferable that the number of urethane bonds of the monofunctional urethane (meth) acrylate oligomer is 3 to 15. When the number of urethane bonds is less than 3, it may be difficult to manufacture a uniform composition and the cohesion may be weakened, and when the number of the urethane bonds is greater than 15, the cohesion may be too high and the initial tackiness may be worsened. At this time, the number of urethane bonds can be adjusted in consideration of the molecular weight of polypropylene glycol and the weight average molecular weight of the monofunctional urethane (meth) acrylate oligomer to be prepared.

The weight average molecular weight of the monofunctional urethane (meth) acrylate oligomer affects the adhesion and viscosity. Usually, the smaller the weight average molecular weight, the lower the viscosity but the lower the adhesive strength. On the contrary, the larger the weight average molecular weight, the better the adhesive strength but the viscosity. Becomes higher. In the present invention, the weight average molecular weight is particularly preferably 5,000 to 30,000, more preferably 10,000 to 30,000. If the weight average molecular weight is less than 5,000, the viscosity is too low, the coating property is not good and it is difficult to obtain the effect of the use of the diluent monomer, if it is over 30,000, the viscosity is too high, poor handling.

In addition, the viscosity of the monofunctional urethane (meth) acrylate oligomer is preferably 10,000 to 300,000 cPs, more preferably 10,000 to 150,000 cPs. If the viscosity is less than 10,000 cPs, it is difficult to control the proper coating viscosity using the diluent monomer, and if it is more than 300,000 cPs, it may be difficult to control the adhesion and durability by using excessive diluent monomer to obtain a suitable viscosity.

The monofunctional urethane (meth) acrylate oligomer is preferably contained in 30 to 80% by weight, more preferably 40 to 75% by weight in 100% by weight of the total pressure-sensitive adhesive composition. If the content is less than 30% by weight, the viscosity of the pressure-sensitive adhesive composition is poor, coating property is not good, if it is more than 80% by weight, the viscosity is high, the processability may be lowered, and may be difficult to apply for optical.

The (meth) acrylate monomer is a monomer having a functional group capable of crosslinking with a monofunctional urethane (meth) acrylate oligomer while controlling the viscosity of the pressure-sensitive adhesive composition that is solventless.

The kind of the monofunctional (meth) acrylate monomer is not particularly limited, and for example, n-butyl (meth) acrylate, 2-butyl (meth) acrylate, t-butyl (meth) acrylate, isobutyl (meth) acryl Latex, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, ethyl (meth) acrylate, methyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, Pentyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, 2-methylbutyl (meth) acrylate, n-nonyl (meth) acrylate, isononyl (meth) acrylate , Isoamyl (meth) acrylate, n-decyl (meth) acrylate, isodecyl (meth) acrylate, octadecyl (meth) acrylate, isobornyl (meth) acrylate, 4-methyl-2-pentyl ( Meta) acrylate, dodecyl (meth) acrylate, 2-dodecylthio Ethyl (meth) acrylate, lauryl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 2-methoxyethyl (meth) acrylate, hydroxyethyl (meth) acrylate, hydroxypropyl ( Meth) acrylate, hydroxybutyl (meth) acrylate, allyl (meth) acrylate, stearyl (meth) acrylate, phenoxyethyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, acrylo Ilmorpholine etc. are mentioned. These can be used individually or in mixture of 2 or more types.

In addition, bifunctional (meth) acrylate monomers, trifunctional (meth) acrylate monomers, or mixtures thereof may be mixed with a monofunctional (meth) acrylate monomer within a range that does not impair the effects of the present invention. have. As the bifunctional (meth) acrylate monomer, 1,3-butanedioldi (meth) acrylate, 1,4-butanedioldi (meth) acrylate, 1,6-hexanedioldi (meth) acrylate, ethylene glycol di (Meth) acrylate, bisphenol A- ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, propylene glycol di (Meth) acrylate, dipropylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, dicyclopentanyldi (meth) acrylate, caprolactone modified dish Clopentenyl di (meth) acrylate, ethylene oxide modified phosphate di (meth) acrylate, bis (2-hydroxyethyl) isocyanurate di (meth) acrylate, di (acryloxyethyl) isocyanu Acrylate, allylated cyclohexyldi (meth) acrylate, dimethyloldicyclopentanedi (meth) acrylate, ethylene oxide modified hexahydrophthalic acid di (meth) acrylate, tricyclodecanedimethanol (meth) acrylate, neopentyl Glycol modified trimethylolpropanedi (meth) acrylate, adamantanedi (meth) acrylate, and the like. As the trifunctional (meth) acrylate monomer, trimethylolpropane tri (meth) acrylate, dipentaerythritol tri (meth) acrylate, propionic acid-modified dipentaerythritol tri (meth) acrylate, pentaerythritol tree (Meth) acrylate, propylene oxide modified trimethylolpropane tri (meth) acrylate, tris (2-hydroxyethyl) isocyanurate tri (meth) acrylate, tris (acryloxyethyl) isocyanurate, glycerol Tri (meth) acrylate etc. are mentioned. These can be used individually or in mixture of 2 or more types.

The monofunctional (meth) acrylate monomer is preferably included at 5 to 60% by weight in 100% by weight of the total pressure-sensitive adhesive composition, more preferably 10 to 50% by weight, most preferably 20 to 45% by weight. It is good. If the content is less than 5% by weight, the curing rate may be lowered, and if it is more than 60% by weight, curing shrinkage may occur seriously and the coatability may be reduced.

A photoinitiator is a component for fully advancing hardening of the surface as well as the inside of the coated adhesive composition, If it is known in the art, the kind is not specifically limited. Specifically, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-butyl ether, benzoin isobutyl ether, acetophenone, hydroxydimethylacetophenone, dimethylaminoacetophenone, Dimethoxy-2-phenylacetophenone, 3-methylacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 4-chronolocetophenone, 4, 4-dimethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 4-hydroxycyclophenylketone, 1-hydroxycyclohexylphenylketone, 2-methyl-1- [4 -(Methylthio) phenyl] -2-morpholino-propan-1-one, 4- (2-hydroxyethoxy) phenyl-2- (hydroxy-2-propyl) ketone, benzophenone, p-phenyl Benzophenone, 4,4-diaminobenzophenone, 4,4'-diethylaminobenzophenone, dichlorobenzophenone, anthraquinone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-t-butylanthraquinone, 2-aminoanthraquinone, 2-meth Tyl thioxanthone, 2-ethyl thioxanthone, 2-chloro thioxanthone, 2,4-dimethyl thioxanthone, 2,4-diethyl thioxanthone, benzyl dimethyl ketal, diphenyl ketone benzyl dimethyl ketal, acetophenone Dimethyl ketal, p-dimethylaminobenzoic acid ester, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, fluorene, triphenylamine, carbazole and the like. Further, commercially available products such as Darocur 1173, Irgacure 184, Irgacure 907, Irgacure 1700 and TPO-L (BASF) can also be used. These can be used individually or in combination of 2 or more types.

The photopolymerization initiator is preferably included in 0.1 to 10% by weight in 100% by weight of the total pressure-sensitive adhesive composition, more preferably 0.1 to 5% by weight. When the content is less than 0.1% by weight, the curing rate may be slow and sufficient curing may be difficult to proceed, and when the content is more than 10% by weight, the molecular weight of the polymer to be photopolymerized may be reduced, thereby reducing durability.

Compound containing Formula 1 as a cation is polymerized (meth) acrylate group of the main chain and the cation of the pressure-sensitive adhesive during the curing process of the pressure-sensitive adhesive composition is not phase separated. If the cations are bound to the backbone of the cured pressure sensitive adhesive, the probability that the anions will also phase separate due to electrical attraction with the cations is significantly reduced.

Since the compound is an ionic liquid having high electrical conductivity, it has antistatic properties, and as described above, there is no phase separation phenomenon, thereby improving durability.

At this time, the curing rate is measured to confirm the main chain and polymerization degree of the compound and the pressure-sensitive adhesive, the curing rate measurement can be confirmed by the double bond consumption rate using FT-IR.

The compounds as the anion ^{_{PF 6 -, (CF 3 SO}} 2) 2 N - from ^{_{-, CF 3 COO -, NO}} 3 -, CH 3 COO -, BF 4 -, CF 3 SO 3 - and (NC) ₂ N It may include one or more selected, it is preferable to include PF ₆ ^- or (CF ₃ SO ₂ ) ₂ N ^- in terms of antistatic properties and manufacturing cost.

The compound containing Formula 1 as a cation is preferably included in 0.01 to 20% by weight in 100% by weight of the total pressure-sensitive adhesive composition, more preferably 0.1 to 20% by weight. If the content is less than 0.01% by weight it may be difficult to obtain an antistatic effect, when the content is more than 20% by weight may increase the content of the relatively monofunctional acrylate monomer may be reduced durability.

The adhesive composition of the present invention can be cured to form an adhesive. In addition, transparent substrate film; An adhesive film may be formed by including the adhesive formed on one surface of the transparent base film.

The pressure-sensitive adhesive may have a thickness of 25 to 1000 mu m.

The transparent base film is not particularly limited as it is excellent in transparency, mechanical strength, thermal stability, moisture barrier property, isotropy and the like.

The curing is used in the art, but is not particularly limited, photocuring using ultraviolet light is generally.

In the polymerization using ultraviolet rays, the light source has a light emission distribution having a wavelength of 400 nm or less, preferably 150 to 400 nm, and more preferably 200 to 380 nm. , Black light lamps, microwave-excited mercury lamps and metal halide lamps.

The intensity of the light irradiation can be appropriately adjusted according to the required physical properties of the pressure-sensitive adhesive, the amount of accumulated light useful for the activity of the free radical photoinitiator is preferably 10 to 5000mJ / ㎠, more preferably 200 to 800mJ / ㎠. It is preferable to have an appropriate curing reaction time within the above range, and do not cause a decrease in cohesion, yellowing or deterioration of the support of the cured product produced by heat radiated from the lamp and exotherm during the polymerization reaction.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the present invention. Such variations and modifications are intended to be within the scope of the appended claims.

Manufacturing example : urethane ( Meta ) Acrylate Oligomer

A 10 L four-necked flask equipped with a thermometer and a stirring device and capable of refluxing nitrogen was immersed in an oil bath, and 3038 g of polypropylene glycol (Sannix PP-4000, Samyang Chemical) with a molecular weight of 4,000 was placed in this flask. 337 g and 0.3 g of dibutyl tin dilaurate as urethane-forming catalysts were added, followed by stirring at a reaction temperature of 60 ° C. for 2 hours to obtain a urethane prepolymer. After the reaction temperature was lowered to 40 ° C., 0.3 g of dibutyltin dilaurate, a urethaneization catalyst, and 0.5 g of 2,6-t-butyl-4-methylphenol (BHT), a polymerization inhibitor, were added thereto. A mixture of 56 g of butanol and 88 g of 2-hydroxyethyl acrylate (Osaka Organic Chemical Co., Ltd.) was reacted with a slow dropwise addition for 30 minutes. The reaction temperature was then raised to 70 ° C. and stirred to obtain a monofunctional urethane acrylate oligomer having a weight average molecular weight of 26,600.

Example  One

(1) pressure-sensitive adhesive composition

67% by weight of the urethane (meth) acrylate oligomer of Preparation Example 1, 15% by weight of acryloyl morpholine and 15% by weight of isobornyl acrylate, 2.0% by weight of photopolymerization initiator Tarocure 1173, bis ( A pressure-sensitive adhesive composition was prepared by mixing 1.0% by weight of a compound consisting of trifluoromethanesulfonyl) imide.

 (2) adhesive film

After curing on one transparent film coated with a silicone release agent on a polyethylene terephthalate (PET) film, the pressure-sensitive adhesive composition of the above (1) is coated so that the thickness is 300 μm, and then the same transparent film is bonded on the pressure-sensitive adhesive layer. , Ultraviolet (600 mJ / cm 2) was irradiated at a rate of 4 m / min and completely cured.

Example  2 to 8 and Comparative example  1 to 4

To carry out the same as in Example 1, to prepare a pressure-sensitive adhesive film using the composition of Table 1.

division
(weight%) Monofunctional
Urethane acrylate oligomer Uniluminescent (meta)
Acrylate
Monomer Photopolymerization
Initiator Cation of Formula 1
Containing
compound Antistatic agent A-1 A-2 B-1 B-2 B-3 C-1 C-2 Example 1 67 15 15 2 One - - - - Example 2 65 15 15 2 3 - - - - Example 3 68 10 10 2 10 - - - - Example 4 63 7.5 7.5 2 20 - - - - Example 5 68 10 10 2 - 10 - - - Example 6 68 10 10 2 - - 10 - - Example 7 67.9 15 15 2 0.1 - - - - Example 8 67.99 15 15 2 0.01 - - - - Comparative Example 1 68 10 10 2 - - - 10 - Comparative Example 2 68 10 10 2 - - - - 10 Comparative Example 3 67.995 10 10 2 0.005 - - - - Comparative Example 4 48 10 10 2 30 - - - - A-1: Isobonylacrylate
A-2: Acrylomorpholine
B-1: [2- (methacryloyloxy) ethyl] -N, N, N-trimethylammonium bis (trifluoromethylsulfonyl) imide
B-2: [2- (methacryloyloxy) ethyl] -N, N, N-trimethylammonium trifluoromethanesulfonate
B-3: [2- (methacryloyloxy) ethyl] -N, N, N-trimethylammonium hexafluorophosphate
C-1: 1-octyl-4-methylpyridinium hexafluorophosphate
C-2: bis (trifluoromethanesponyl) imide lithium salt, HQ115 product, 3M company
Photopolymerization initiator: Tarocure 1173, BASF

Test Example

Physical properties of the pressure-sensitive adhesive composition and pressure-sensitive adhesive film prepared in Examples and Comparative Examples were measured by the following method, and the results are shown in Table 2 below.

1. Adhesion (N / 25㎜)

The prepared pressure-sensitive adhesive film was cut into a size of 25 mm × 250 mm using a super cutter, and then the release film was peeled off, bonded to a glass plate, and a specimen was prepared. The prepared specimen was fixed to a universal testing machine (UTM), and then peeled at 180 ° at a speed of 300 m / min to measure adhesion to glass. At this time, the adhesive force means the adhesive force of the surface irradiated with ultraviolet rays.

In addition, the adhesion to the triacetyl cellulose (TAC) film was measured in the same manner as above.

2. Hayes

The prepared pressure-sensitive adhesive film was left in a -40 ° C oven and an 80 ° C oven for 100 hours, respectively, to visually observe haze generation due to crystallinity, and evaluated based on the following criteria.

 <Evaluation Criteria>

○: no crystalline, no haze

×: crystallinity, haze occurs

3. Adhesive durability (heat resistant and Wet heat )

The prepared pressure-sensitive adhesive film was cut to A4 size using a super cutter, and one transparent film was peeled off, and then bonded to a glass plate. The conjugate was treated in an autoclave for 20 minutes at 50 ° C. and 5 atmospheres to prepare a specimen. Heat-resistant durability was left for 100 hours in the specimen at 80 ℃ oven, heat-resistant durability was left for 100 hours in 60 ℃ and 90% RH oven, and then whether bubbles or peeling occurred on the bonding surface of the glass plate and the adhesive layer It was observed visually and evaluated based on the following criteria.

<Evaluation Criteria>

○: no bubble or peeling phenomenon at the joint surface

△: Some bubbles or peeling phenomenon on the joining surface

X: There are many bubbles and peeling phenomenon in the joining surface

4. Surface resistivity

Using the surface resistivity measuring instrument (MCP-HT450, manufactured by Mitsuishi Chemical Co., Ltd.), three points of the adhesive film were measured 10 times, respectively, and the average values were represented.

5. Double bond consumption rate (%)

The extent to which the unsaturated C-C double bonds in the ethylenically unsaturated groups of the urethane acrylate oligomer component and the acrylate monomeric component were consumed as a function of time during curing was measured using Fourier transform infrared spectroscopy techniques (FT-IR).

Evaluation instrument: FT-IR

Measuring method: measuring the extinction level of an unsaturated C-C double bond signal at about 810 cm

Percentage Consumption is the percentage of double bonds lost during UV irradiation, with a value of 0% before irradiation.

6. Gel fraction  Measure(%)

Measure the weight of the adhesive of 10cm × 10cm size, seal it in a 250 mesh metal mesh, dip it in ethyl acetate, and leave it for 3 days, then leave it in an oven at 80 ℃ for 1 hour to dry the solvent and measure the dry weight The gel fraction of Formula 1 was calculated.

division Adhesion (N / 25㎜) Hayes durability Surface resistivity
(Ω / □) Double bond
Consumption rate (%) Gel fraction
(%) Example 1 22.4 0.3 ○ 3.8 × 10 ¹⁰ 99 82 Example 2 20.5 0.4 ○ 2.1 × 10 ¹⁰ 99 83 Example 3 24.3 0.5 ○ 1.2 × 10 ¹⁰ 99 82 Example 4 25.8 0.5 ○ 3.4 × 10 ⁹ 99 84 Example 5 21.7 0.6 ○ 1.9 × 10 ¹⁰ 99 83 Example 6 22.5 0.5 ○ 1.3 × 10 ¹⁰ 99 85 Example 7 23.2 0.4 ○ 6.47 × 10 ¹⁰ 99 83 Example 8 24.4 0.4 ○ 1.17 × 10 ¹¹ 99 83 Comparative Example 1 12.6 0.8 × 2.3 × 10 ¹⁰ 99 72 Comparative Example 2 15.6 1.3 × 2.8 × 10 ¹⁰ 99 70 Comparative Example 3 20.3 0.3 ○ 5.3 × 10 ¹² 99 84 Comparative Example 4 24.7 0.9 △ 6.2 × 10 ⁸ 99 83

As shown in Table 2, Examples 1 to 8 of the monofunctional urethane acrylate oligomer, a monofunctional (meth) acrylate monomer, a photopolymerization initiator and a compound containing a chemical formula 1 as a cation according to the present invention in a specific amount The pressure-sensitive adhesive film using the pressure-sensitive adhesive composition was confirmed to be excellent in adhesion, durability and haze as well as antistatic properties.

Specifically, in Examples 1 to 8, the compound containing Formula 1 as a cation was combined with the main chain of the pressure sensitive adhesive to maintain the double bond consumption rate and the gel fraction value almost the same. It can be seen that the fraction has decreased.

In addition, Comparative Examples 1 and 2 using an antistatic agent (ionic liquid) not fixed to the main chain had low adhesion, durability and haze due to the surface migration of the ionic liquid.

In addition, Comparative Examples 3 and 4 in which the compound containing Formula 1 as a cation were included in trace amounts and excessive amounts, respectively, did not satisfy the antistatic property and durability.

Claims (8)

30 to 80% by weight of monofunctional urethane acrylate oligomer, 5 to 60% by weight of monofunctional (meth) acrylate monomer, 0.1 to 10% by weight of photopolymerization initiator, and 0.01 to 20% by weight of compound containing formula 1 as cation Optical pressure-sensitive adhesive composition.
[Formula 1]

The method according to claim 1, the compound comprising the formula (I) with cations are ^{_{PF 6 -, (CF 3 SO}} 2) 2 N -, CF 3 COO -, NO 3 -, CH 3 COO -, BF 4 -, CF 3 SO Optical adhesive composition containing at least one selected from ₃ ^- and (NC) ₂ N ^- as an anion.
The optical pressure-sensitive adhesive composition of claim 1, wherein the compound containing Formula 1 as a cation comprises PF ₆ ^- or (CF ₃ SO ₂ ) ₂ N ^- as an anion.
The optical pressure-sensitive adhesive composition of claim 1, wherein the monofunctional urethane acrylate oligomer has a weight average molecular weight of 5,000 to 30,000.
The optical pressure-sensitive adhesive composition of claim 4, wherein the monofunctional urethane acrylate oligomer has a viscosity (25 ° C) of 10,000 to 300,000 cPs.
Optical adhesive which the adhesive composition of any one of Claims 1-5 hardened | cured.
A transparent base film;
Adhesive film comprising the pressure-sensitive adhesive of claim 6 formed on one surface of the transparent base film.
The pressure-sensitive adhesive film of claim 7, wherein the pressure-sensitive adhesive has a thickness of 25 to 1000㎛.