KR20140111392A - Adhesive composition for optical use and adhesive film comprising the same - Google Patents

Abstract

The present invention relates to an adhesive composition for optical use and an adhesive film including the same and, more specifically, to an adhesive composition which comprises monofunctional acrylic oligomers with a hydroxyl (-OH) group at a terminal end, monofunctional acrylic monomers, isocyanate based cross-linking agents with at least three functional groups and free radical initiators, has excellent durability such as heat resistance, wet heat resistance and the like by excellent cohesive force by high adhesion and cross linking density and is able to manufacture a thick film type adhesive film since an additional solvent is not included, and to an adhesive film including the same.

Description

TECHNICAL FIELD [0001] The present invention relates to a pressure-sensitive adhesive composition for optical use and an adhesive film containing the same. BACKGROUND ART [0002]

The present invention relates to a pressure-sensitive adhesive composition for optical use which is excellent in adhesion and cohesive force and thus has excellent durability and an adhesive film containing the same.

Recently, in the rapidly developing display industry, optically transparent pressure-sensitive pressure-sensitive adhesives are frequently used to mount a touch panel or a touch screen or to obtain high brightness and high permeability.

A touch panel or a touch screen is a device for finding a position coordinate by recognizing a change in a potential difference generated by using a predetermined input means such as a pen or a finger. Specifically, when a certain point on the upper substrate is pressed, an upper electrode formed of a transparent conductive film and a lower electrode formed of a transparent conductive film are brought into contact with each other at a lower portion of the upper substrate, and a potential difference is generated. .

In recent years, the touch panel or the touch screen has been used as a device for inputting information in combination with a display device.

The pressure-sensitive adhesive used for attaching the transparent conductive film of the touch screen or the touch panel has adhesiveness to various substrates, and curl or bubbles are suppressed even when exposed to harsh conditions such as high temperature and high humidity conditions Durability is required.

Generally, acrylic or urethane acrylic pressure-sensitive adhesives are used in order to ensure the visibility of the display, and they require separate thickening processes (thickness: 50 to 1000 mm).

The acrylate-based pressure-sensitive adhesive has a problem that the curing process is too slow and the processability is low. In the case of the urethane acrylate-based pressure-sensitive adhesive, the curing process is quick during the photopolymerization, but the properties such as adhesiveness are lowered relative to the acrylate-based oligomer.

A method of using a urethane acrylate oligomer as a single-walled urethane acrylate-based pressure-sensitive adhesive has been proposed (Korean Patent Publication No. 2005-0021977). However, there is a problem that peeling failure occurs in a heat-resistant condition because adhesive strength is not sufficiently high.

In addition, although a method of using a urethane acrylate-based oligomer having a mutual ability has been proposed (Korean Patent Laid-Open Publication No. 2005-0021977), there is a disadvantage in that the tack property is too low and the cohesive force is too high, .

The present invention provides a pressure-sensitive adhesive composition for optical applications having high adhesion and cohesive force and excellent durability such as heat resistance and anti-wet heat.

In order to accomplish the above object, the present invention provides an optical film comprising a monofunctional urethane acrylate oligomer having a terminal hydroxyl group (-OH), a monofunctional acrylate monomer, an isocyanate crosslinking agent having three or more functional groups and a free radical initiator Sensitive adhesive composition.

The monofunctional urethane acrylate oligomer may include a backbone derived from a polyol having at least one molecular structure selected from the group consisting of polyether, polyester, polyolefin, polyacrylate, and polycarbonate.

Preferably, the monofunctional urethane acrylate oligomer may comprise a backbone derived from a polyol having a molecular structure of polyolefin.

More preferably, the molecular structure of the polyolefin may be polyalkylene glycol.

Wherein the isocyanate-based crosslinking agent is an adduct in which 3 moles of a diisocyanate compound and 1 mole of a polyhydric alcohol compound are reacted; An isocyanurate compound in which 3 moles of a diisocyanate compound is self-condensed; Burette obtained by condensing 1 mole of diisocyanate in diisocyanate urea obtained from 2 moles of 3 moles of diisocyanate compound; Triphenylmethane triisocyanate; And methylene bistriisocyanate. [0033] The term " a "

Preferably, the diisocyanate compound may be tolylene diisocyanate or xylylene diisocyanate.

40 to 80% by weight of a monofunctional urethane acrylate oligomer having a hydroxyl group (-OH) at the terminal, 5 to 55% by weight of a monofunctional acrylate monomer, 0.1 to 5% by weight of an isocyanate crosslinking agent having three or more functional groups, 0.1 to 5% by weight of a radical initiator.

Further, the present invention provides a pressure-sensitive adhesive in which the pressure-sensitive 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.

The pressure-sensitive adhesive composition of the present invention is advantageous not only in adhesion but also in cross-linking density, so that it has excellent cohesive strength and excellent durability such as heat resistance and anti-wet heat. The adhesive force is excellent not only for a plastic material but also for an inorganic material.

Further, since the pressure-sensitive adhesive composition of the present invention does not contain a separate solvent, it is possible to produce a thick-film type pressure-sensitive adhesive film.

The present invention relates to a pressure-sensitive adhesive composition for optical use which is excellent in adhesion and cohesive force and thus has excellent durability and an adhesive film containing the same.

Hereinafter, the present invention will be described in detail.

The pressure-sensitive adhesive composition of the present invention contains a monofunctional urethane acrylate oligomer having a hydroxyl group (-OH) at the terminal, a monofunctional acrylate monomer, an isocyanate crosslinking agent having three or more functional groups, and a free radical initiator.

The monofunctional urethane acrylate oligomer having a hydroxyl group (-OH) at its end serves to maintain viscoelasticity and storage elasticity by imparting physical properties and flexibility of a pressure-sensitive adhesive.

The monofunctional urethane acrylate oligomer is obtained by combining a main chain moiety resulting from the molecular structure of the polyol, a urethane bonding group formed by the reaction of an isocyanate and a polyol, and an acrylate monomer containing an isocyanate to form a reactive group of an acryloyl group at the terminal .

The hydroxyl group (-OH) formed at the terminal can form a hydrogen bond between the urethane acrylate oligomers and binds with an isocyanate crosslinking agent having three or more functional groups, so that the crosslinking density of the pressure-sensitive adhesive composition is increased and the cohesive force can be increased .

The main chain may be derived from a polyol having at least one molecular structure selected from the group consisting of polyethers, polyesters, polyolefins, polyacrylates, and polycarbonates. From the viewpoint of ease of controlling the price and viscosity, it is preferable that the polyolefin is derived from a polyol, a polyether or a polyol having a mixed structure of them. However, the polyol having a molecular structure of polyolefin is preferable for the pressure- It is good.

The monofunctional urethane acrylate oligomer according to the present invention can be prepared by a known method of polymerizing a polyol and a diisocyanate compound. As the polyol, for example, an oligomer having an ether backbone can be prepared by using a cyclic ether monomer such as oxirane such as ethylene oxide, propylene oxide or tetrahydrofuran. Further, an oligomer having an ester main chain can be prepared by using a cyclic ester such as? -Caprolactone or pivalolactone.

When the polyol thus prepared is reacted with a diisocyanate compound, a polyol structure having a urethane bond group can be obtained. Examples of the diisocyanate compound include 1,4-butylene diisocyanate, 1,6-hexamethylene diisocyanate, cyclopentylene-1,3-diisocyanate, 4,4'- dicyclohexylmethane diisocyanate, isophorone diisocyanate , Cyclohexene-1,4-diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4'-methylene bis (phenyl isocyanate), 2,2- , 4'-diisocyanate, p-phenylene diisocyanate, m-phenylenediisocyanate, xylene diisocyanate, 1,4-naphthylene diisocyanate, 1,5-naphthylene diisocyanate 4,4'-diphenyl diisocyanate , Azobenzene-4,4'-diisocyanate, m- or p-tetramethylxylylene diisocyanate, and 1-chlorobenzene-2,4-diisocyanate. .

The polyol and the diisocyanate are reacted in a monomer ratio, and it is preferable to use an equivalent amount or more of polyol in order to leave a hydroxyl group at the terminal.

Further, urethane acrylate oligomer can be prepared by reacting 2-isocyanatoethyl (meth) acrylate having an isocyanate group in order to further link an acryloyl group to the reactant. It is preferable to add isocyanatoalkyl acrylate corresponding to one half of the excess amount of the hydroxyl group equivalent of the excessively added polyol in order to introduce a hydroxyl group at one end and introduce an acrylic group at only the other end.

The monofunctional urethane acrylate oligomer preferably has a glass transition temperature (Tg) of -60 to 0 캜, preferably -60 to -20 캜, in view of tackiness and heat resistance of the pressure-sensitive adhesive. The weight average molecular weight is preferably 1,000 to 40,000, and more preferably 1,000 to 35,000.

Such a monofunctional urethane acrylate oligomer may contain from 40 to 80% by weight, preferably from 50 to 70% by weight. If the content is less than 40% by weight, the viscosity of the pressure-sensitive adhesive composition may be low, and the coating may be difficult. When the content is more than 80% by weight, it may be difficult to control the balance between the viscosity and optical properties of the pressure-sensitive adhesive composition.

The monofunctional acrylate monomer serves to impart durability to the film containing the pressure-sensitive adhesive composition, maintain the viscoelasticity, and adjust the viscosity to improve the coating property of the composition.

Specific examples include ethyl acrylate, methyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, t-butyl acrylate, isobornyl acrylate, isobutyl acrylate, allyl methacrylate, (Meth) acrylate, isodecyl (meth) acrylate, 2-dodecylthioethyl methacrylate, octyl acrylate, isooctyl acrylate, 2-methoxyethyl acrylate, (Meth) acrylate, stearyl (meth) acrylate, tetrapurfuryl (meth) acrylate, isopentyl (meth) acrylate, (Meth) acrylate, octadecyl methacrylate, tetrahydrofuryl acrylate, acrylic acid, cyclohexyl acrylate, and acryloylmorpholine. The book selected one or more may be used.

Preferably, the glass transition temperature (Tg) is 0 ° C or higher, and specifically, one kind selected from the group consisting of acrylomorpholine, acrylic acid, t-butyl acrylate, tetrahydrofuryl methacrylate and cyclohexyl acrylate Or better.

Such a monofunctional acrylate-based monomer may contain 5 to 55% by weight, preferably 5 to 40% by weight. When the content is less than 5% by weight, it may be difficult to expect an increase in adhesion with a plastic material. When the content exceeds 55% by weight, curing shrinkage may be severe or the produced pressure-sensitive adhesive may become hard.

In addition, the polyfunctional acrylate monomer having two or more functional groups may be further included within the scope of the present invention. The polyfunctional acrylate monomer serves to control the curing rate and can be used in an appropriate amount in consideration of the desired curing rate.

Examples of the polyfunctional acrylate monomer include 1,3-butanediol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, ethylene glycol di (Meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, propylene glycol di Acrylate, dipropylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, dicyclopentanedi (meth) acrylate, caprolactone modified dicyclopentenyl (Meth) acrylates such as di (meth) acrylate, di (meth) acrylate modified with ethylene oxide, bis (2-hydroxyethyl) isocyanurate di (Meth) acrylate, dimethylolcyclohexane diacrylate, ethylene oxide modified hexahydrophthalic acid diacrylate, tricyclodecane dimethanol acrylate, neopentyl glycol-modified trimethylolpropane diacrylate Bifunctional monomers such as maleic anhydride, maleic anhydride and maleic anhydride; (Meth) acrylate such as trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol tri (meth) acrylate, propionic acid modified dipentaerythritol tri Trifunctional monomers such as tri (meth) acrylate, tris (2-hydroxyethyl) isocyanurate tri (meth) acrylate, tris (acryloxyethyl) isocyanurate, glycerol tri ; Tetrafunctional monomers such as diglycerin tetra (meth) acrylate, pentaerythritol tetra (meth) acrylate, and ditrimethylol propane tetra (meth) acrylate; Pentafunctional monomers such as propionic acid-modified dipentaerythritol penta (meth) acrylate; And hexafunctional monomers such as dipentaerythritol hexa (meth) acrylate and caprolactone-modified dipentaerythritol hexa (meth) acrylate.

Such polyfunctional acrylate monomers are preferably contained in an amount of 5% by weight or less in the pressure-sensitive adhesive composition.

The isocyanate-based crosslinking agent having three or more functional groups serves to improve the cohesive force by inducing an increase in crosslinking density by bonding with the hydroxyl group (-OH) group of the monofunctional urethane acrylate oligomer.

Wherein the isocyanate-based crosslinking agent is an adduct in which 3 moles of a diisocyanate compound and 1 mole of a polyhydric alcohol compound are reacted; An isocyanurate compound in which 3 moles of a diisocyanate compound is self-condensed; Burette obtained by condensing 1 mole of diisocyanate in diisocyanate urea obtained from 2 moles of 3 moles of diisocyanate compound; Triphenylmethane triisocyanate; And methylene bistriisocyanate. [0033] The term " a "

The diisocyanate compound is selected from the group consisting of tolylene diisocyanate, xylene diisocyanate, 2,4-diphenylmethane diisocyanate, 4,4-diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, tetramethyl xylene diisocyanate and naphthalene Diisocyanate, and diisocyanate. Preferably, it is tolylene diisocyanate or xylylene diisocyanate.

The polyhydric alcohol compound may be trimethylolpropane or the like.

The isocyanate crosslinking agent having three or more such functional groups may contain 0.1 to 5% by weight, preferably 0.2 to 1% by weight. If the content is less than 0.1% by weight, the effect of improving the cohesive strength may be insufficient. If the content is more than 5% by weight, the adhesive strength may be deteriorated due to excessive crosslinking.

The free radical photoinitiator has a function of sufficiently promoting the interior and surface hardening of the pressure-sensitive adhesive, and the type thereof is not particularly limited as long as it is known in the art.

Specific examples of the free radical photoinitiator include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-butyl ether, benzoin isobutyl ether, acetophenone, hydroxydimethylacetophenone, Dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 4-chromenone 2-methyl-1-phenylpropan-1-one, 4-hydroxycyclophenyl ketone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl (2-hydroxyethoxy) phenyl-2- (hydroxy-2-propyl) ketone, benzo Anthraquinone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-t-aminobenzophenone, 4,4'-diethylaminobenzophenone, dichlorobenzophenone, - Butylanthra 2-amino thioxanthone, 2-amino thioxanthone, 2-chlorothioxanthone, 2,4-dimethyl thioxanthone, 2,4-diethyl thioxanthone, benzyldimethyl Ketene, diphenyl ketone benzyl dimethyl ketal, acetophenone dimethyl ketal, p-dimethylaminobenzoic acid ester, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, fluorene, triphenylamine, have. Further, commercially available products such as Darocur 1173, Igacure 184 and Igacure 907 (manufactured by Ciba) can also be used. These may be used alone or in combination of two or more.

The free radical photoinitiator can be used in an appropriate range in consideration of the radiation property, intensity, content of each component, etc. of the light source, and it is preferable that the free radical photoinitiator is contained in an amount of 0.1 to 5% by weight.

The pressure-sensitive adhesive composition of the present invention can be cured to form a pressure-sensitive adhesive. Further, a transparent base film; And an adhesive film formed on at least one side of the transparent base film to form an adhesive 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 not particularly limited as it is used in the art, but is generally photocuring using ultraviolet rays. Generally, after photocuring, thermosetting is performed for 1 to 10 days at room temperature or warming to produce a fully cured pressure-sensitive adhesive.

The light source in the polymerization using ultraviolet rays has a light emission distribution of 400 nm or less, preferably 150 to 400 nm, and more preferably 200 to 380 nm. The light source may be a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, , A black light lamp, a microwave-excited mercury lamp, and a metal halide lamp.

The intensity of the light irradiation can be appropriately adjusted according to the physical properties of the desired pressure-sensitive adhesive, and the amount of accumulated light useful for the activity of the free radical photoinitiator is preferably 10 to 5000 mJ / cm 2, more preferably 200 to 2000 mJ / cm 2. It is preferable to have an appropriate curing reaction time within the above range and to prevent the heat radiated from the lamp and the cohesive force of the cured product produced by heat generation during the polymerization reaction from deteriorating and deterioration of the yellowing or the support.

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 Acrylate series Oligomer

Manufacturing example  One: Single sensory  urethane Acrylate series Oligomer (Containing a hydroxy group at the end, A-1)

100 g of polypropylene glycol was added to a 2 L reactor equipped with a reflux condenser, a thermometer and a stirrer, and the temperature of the solution was raised to 60 DEG C and 0.1 g of dibutyltin dilaurate (DBTDL) was added. 7 g of isophorone diisocyanate was slowly added over 30 minutes using a dropping funnel, and reacted for 4 hours while maintaining the reactor temperature at 60 占 폚. Then, 1 g of 2-methacryloyloxyethyl isocyanate (MOI) was added and reacted at the same temperature for further 4 hours to prepare a monofunctional urethane acrylate oligomer having a hydroxyl group at the terminal.

As a result of IR analysis, no residual NCO peak was observed, and when a part of the reaction product was taken and reacted with additional isophorone diisocyanate, the viscosity was increased. Therefore, the reaction product had a monofunctional Urethane acrylate oligomer.

The monofunctional urethane acrylate oligomer had a weight average molecular weight of 33,000 and a glass transition temperature of -57 캜.

Manufacturing example  2: Bifunctionality  urethane Acrylate series Oligomer (At the end Acrylic group  , A-2)

Except that 2 g of 2-hydroxyethylacrylate (HEA) was used instead of 1 g of 2-methacryloyloxyethyl isocyanate (MOI), 8 g of isophorone diisocyanate was used in place of 1 g of 2-methacryloyloxyethyl isocyanate A bifunctional urethane acrylate oligomer having an acryl group was prepared.

As a result of IR analysis, no residual NCO peak was observed. When a part of the reaction product was taken and reacted with additional isophorodiisocyanate, the viscosity did not increase. Therefore, the reaction product had an acrylic group at both terminals It was confirmed that it was a bifunctional urethane acrylate oligomer.

The monofunctional urethane acrylate oligomer had a weight average molecular weight of 31,000 and a glass transition temperature of -55 占 폚.

Manufacturing example  3: Single sensory  urethane Acrylate series Oligomer (Containing an alkoxy group at the end, A-3)

Except that 1 g of 2-methacryloyloxyethyl isocyanate (MOI) was replaced by 1 g of 2-hydroxyethylacrylate (HEA) and 0.8 g of n-butanol 0.8 g, a monofunctional urethane acrylate oligomer having a terminal butoxy group was prepared.

As a result of the IR analysis, no residual NCO peak was observed, and when a part of the reaction product was taken and reacted with additional isophorodiisocyanate, the viscosity was increased. Therefore, the reaction product had a terminal It was confirmed that the oligomer was a functional urethane acrylate oligomer.

The monofunctional urethane acrylate oligomer had a weight average molecular weight of 31,000 and a glass transition temperature of -57 ° C.

Manufacturing example  4: Single sensory  urethane Acrylate series Oligomer (Containing a hydroxy group at the end, A-4)

A monofunctional urethane acrylate oligomer having a hydroxy group at the terminal was prepared in the same manner as in Preparation Example 1 except that 100 g of polyethylene-propylene copolymerized glycol was used instead of 100 g of polypropylene glycol.

The monofunctional urethane acrylate oligomer had a weight average molecular weight of 35,000 and a glass transition temperature of -37 ° C.

Example  1-6 and Comparative Example  1-6

(1) Pressure-sensitive adhesive composition

As shown in Table 1 below, a pressure-sensitive adhesive composition was prepared by mixing a urethane acrylate oligomer, an acrylate-based monomer, an isocyanate-based crosslinking agent, and a free radical initiator.

division
(weight%) Urethane acrylate oligomer Acrylate series
Monomer Cross-linking agent Free radical initiator A-1 A-2 A-3 A-4 B-1 B-2 B-3 B-4 C-1 C-2 C-3 C-4 Example 1 60 - - - 28 9.5 - - 0.5 - - - 2 Example 2 60 - - - 28 - 9.5 - 0.5 - - - 2 Example 3 60 - - - 28 9.5 - - - 0.5 - - 2 Example 4 - - - 60 28 9.5 - - 0.5 - - - 2 Example 5 45 - - - 43 9.5 - - 0.5 - - - 2 Example 6 75 - - - 13 9.5 - - 0.5 - - - 2 Comparative Example 1 60 - - - 28 10 - - - - - - 2 Comparative Example 2 - 60 - - 28 9.5 - - 0.5 - - - 2 Comparative Example 3 - - 60 - 28 9.5 - - 0.5 - - - 2 Comparative Example 4 60 - - - - - - 37.5 0.5 - - - 2 Comparative Example 5 60 - - - 28 9.5 - - - - 0.5 - 2 Comparative Example 6 60 - - - 28 9.5 - - - - - 0.5 2 B-1: Isobornyl acrylate, Tg = 94 DEG C
B-2: t-Butyl acrylate, Tg = 41 DEG C
B-3: acryloylmorpholine, Tg = 145 DEG C
B-4: Hexanediol diacrylate
C-1: TDI-trimethylolpropane adduct (Nippon Urethanesecoronate-L)
C-2: HDI-trimer (Nippon Urethanesecoronate-HXR)
C-3: Tolylene diisocyanate
C-4: Hexamethylene diisocyanate
Free radical initiator: Ciba, Darocur-1173

(2) Production of adhesive film

The pressure-sensitive adhesive composition prepared in the above (1) was coated on a transparent substrate film coated with a silicone release agent to a thickness of 300 m, and then the same transparent substrate film was laminated thereon. Then, ultraviolet rays at a speed of 600 mJ / And completely cured by irradiation to form a pressure-sensitive adhesive.

Test Example

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

1. Adhesion (N / 25 mm )

① Glass ( Glass ) Adhesion

The base film coated with the releasing agent laminated on the adhesive film was peeled off, and the PET base film which had not been subjected to releasing treatment was laminated. The pressure-sensitive adhesive sheet was cut into a size of 25 mm x 250 mm using a super-cutter, bonded to glass, fixed to the autograft, and peeled at 180 DEG peel at a speed of 300 m / min to measure adhesive strength.

② Triacetylcellulose ( TAC ) Film adhesion

A triacetyl cellulose (TAC) film was adhered to the glass using a double-sided tape to prepare a glass adhered to the TAC film. The substrate film coated with the release agent on the adhesive film prepared above was peeled off and then laminated on the TAC film. The pressure-sensitive adhesive sheet was cut into a size of 25 mm x 250 mm using a super cutter, and the TAC film was adhered to the adhered glass. The pressure-sensitive adhesive sheet was fixed to the autograft, and peeled off at 180 rpm at a rate of 300 m / min.

③ Polyethylene terephthalate ( PET ) Film adhesion

The glass adhered to the PET film was prepared by adhering the PET film to the glass using a double-sided tape. The substrate film on which the releasing agent coated on the adhesive film was peeled off was laminated on a PET film. The adhesive sheet was cut into a size of 25 mm x 250 mm using a super cutter, and the PET film was bonded to the adhered glass. The adhesive sheet was fixed to the autograft, and peeled off at 180 ° PEEL at a rate of 300 m / min.

2. Heat resistance

The substrate film coated with the releasing agent laminated on the pressure-sensitive adhesive film was peeled off, and then laminated on a non-releasable PET (38 um film made by Toray Advanced Materials Co., Ltd.). The pressure-sensitive adhesive sheet was cut into A4 size using a super cutter, bonded to glass, treated at 50 ° C for 20 minutes in an autoclave, and then left in an 80 ° heat-resistant oven for 100 hours.

<Evaluation Criteria>

◎: No defects such as bubbles after heat resistance evaluation.

○: After the heat resistance evaluation, less than 10 bubbles of less than 1um occurred on the outside.

△: 10 or more bubbles of 1um or less occurred on the outer edge after the evaluation of heat resistance.

X: Bubbles and floating occurred after heat resistance evaluation.

3. Humidity Durability

The substrate film coated with the releasing agent laminated on the adhesive film was peeled off and then laminated on the PET film not subjected to releasing treatment. The pressure-sensitive adhesive sheet was cut into A4 size using a super cutter and bonded to glass. The adhesive sheet was treated with an autoclave at 50 DEG C for 20 minutes under a pressure of 5 atm. Then, the pressure-sensitive adhesive sheet was allowed to stand in a humidity oven at 60 DEG C and 60RH% for 100 hours.

<Evaluation Criteria>

◎: No defects such as bubbles after the evaluation of moisture heat resistance.

○: Bubbles less than 1 μm occurred on the outer edge after the evaluation of heat resistance.

Δ: 10 or more bubbles of 1 μm or less occurred on the outer periphery after the evaluation of wet heat resistance.

X: Bubbles and floating occurred after evaluation of heat resistance.

division Adhesive force (N / 25mm) Heat resistance Humidity Durability Glass TAC PET Example 1 25.5 17.6 19.3 ◎ ◎ Example 2 27.3 16.9 18.6 ◎ ◎ Example 3 24.8 17.2 18.3 ◎ ◎ Example 4 23.1 15.3 17.7 ◎ ◎ Example 5 24.8 15.9 17.1 ◎ ◎ Example 6 23.1 14.7 16.7 ◎ ◎ Comparative Example 1 21.0 13.5 15.0 × △ Comparative Example 2 5.7 2.5 3.7 × × Comparative Example 3 18.3 10.2 13.7 △ × Comparative Example 4 1.6 1.7 1.2 × × Comparative Example 5 21.1 14.4 16.9 △ △ Comparative Example 6 20.7 13.6 15.2 ○ ×

As shown in Table 2, the optical pressure-sensitive adhesive compositions for optical use of Examples 1 to 6 according to the present invention were superior in adhesion to glass, TAC and PET as well as adhesion durability such as heat and humidity resistance and heat resistance .

Claims (10)

A pressure-sensitive adhesive composition for optical use comprising a monofunctional urethane acrylate oligomer having a hydroxyl group (-OH) at its end, a monofunctional acrylate monomer, an isocyanate-based crosslinking agent having three or more functional groups, and a free radical initiator.
The polyurethane foam according to claim 1, wherein the monofunctional urethane acrylate oligomer comprises a main chain derived from a polyol having at least one molecular structure selected from the group consisting of polyether, polyester, polyolefin, polyacrylate and polycarbonate Sensitive adhesive composition for optics.
The optical pressure-sensitive adhesive composition for optical use according to claim 2, wherein the monofunctional urethane acrylate oligomer comprises a main chain derived from a polyol having a molecular structure of polyolefin.
The optical pressure-sensitive adhesive composition for optical use according to claim 3, wherein the molecular structure of the polyolefin is polyalkylene glycol.
[Claim 2] The isocyanate-based crosslinking agent according to claim 1, wherein the isocyanate-based crosslinking agent is an adduct in which 3 moles of a diisocyanate compound and 1 mole of a polyhydric alcohol compound are reacted; An isocyanurate compound in which 3 moles of a diisocyanate compound is self-condensed; Burette obtained by condensing 1 mole of diisocyanate in diisocyanate urea obtained from 2 moles of 3 moles of diisocyanate compound; Triphenylmethane triisocyanate; And methylene bistriisocyanate. &Lt; Desc / Clms Page number 24 &gt;
The optical adhesive composition according to claim 5, wherein the diisocyanate compound is tolylene diisocyanate or xylylene diisocyanate.
The thermosetting resin composition according to claim 1, which comprises 40 to 80% by weight of a monofunctional urethane acrylate oligomer having a hydroxyl group (-OH) at its end, 5 to 55% by weight of a monofunctional acrylate monomer, 0.1 to 100% by weight of an isocyanate crosslinking agent having three or more functional groups, 5% by weight, and 0.1 to 5% by weight of a free radical initiator.
A cured pressure-sensitive adhesive composition according to any one of claims 1 to 7.
A transparent base film;
The pressure-sensitive adhesive film according to claim 8, which is formed on one surface of the transparent base film.
The adhesive film according to claim 9, wherein the pressure-sensitive adhesive has a thickness of 25 to 1000 탆.