KR20140136162A - Pressure-sensitive adhesive composition for optical use - Google Patents

Abstract

The present invention relates to a pressure-sensitive adhesive composition for optical applications, and more particularly, to a pressure-sensitive adhesive composition for optical pressure-sensitive adhesive compositions which comprises a monofunctional urethane acrylate oligomer having an alkoxysilane group at the terminal thereof; Monofunctional acrylate monomers; And a free radical initiator, it is excellent in the adhesive force (room temperature and warming) to the inorganic material and is excellent in durability such as heat resistance and anti-wet heat, and does not contain any additional solvent. Therefore, Sensitive pressure-sensitive adhesive composition.

Description

PRESSURE-SENSITIVE ADHESIVE COMPOSITION FOR OPTICAL USE

The present invention relates to a pressure-sensitive adhesive composition for optical applications having excellent adhesion to an inorganic material, excellent durability such as heat resistance and anti-wet heat.

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 suppresses the occurrence of curl or bubbles even when exposed to harsh conditions such as high temperature and high humidity conditions, Durability is required.

In general, an acrylic or urethane acrylic pressure-sensitive adhesive is used to ensure the visibility of the display. Such a pressure-sensitive adhesive requires a separate thickening step (thickness: 50 to 1000 mm), and there is a problem that durability such as physical properties and heat resistance is deteriorated as an adhesive layer such as an adhesive force under severe conditions.

In this regard, Korean Patent Laid-Open Publication No. 2012-72163 discloses a pressure-sensitive adhesive composition containing a urethane (meth) acrylate copolymer having a hydroxyl group and a vinyl group at a terminal thereof to improve reworkability, To solve the cost increase problem. However, the above method has a problem that the adhesion failure under severe conditions is so low that the peeling failure can not be sufficiently suppressed.

An object of the present invention is to provide a pressure-sensitive adhesive composition for optical applications having excellent adhesion to an inorganic material, excellent durability such as heat resistance and anti-wet heat.

In order to accomplish the above object, the present invention provides a process for producing an oligomer comprising a monofunctional urethane acrylate oligomer having an alkoxysilane group at the terminal; Monofunctional acrylate monomers; And a pressure-sensitive adhesive composition for optical use containing a free radical initiator.

The alkoxysilane group of the monofunctional urethane acrylate oligomer may be derived from an alkoxysilane compound having at least one nucleophilic substituent selected from the group consisting of a hydroxyl group, a carboxyl group, a thiol group and an amino group.

The alkoxysilane compound having a nucleophilic substituent may be at least one selected from the group consisting of formulas (1) to (16).

40 to 80% by weight of a monofunctional urethane acrylate oligomer having an alkoxysilane group at the terminal; 5 to 55% by weight monofunctional acrylate monomer; And from 0.1 to 5% by weight of a free radical initiator.

INDUSTRIAL APPLICABILITY The pressure-sensitive adhesive composition of the present invention has an excellent adhesive strength (room temperature and warming) to an inorganic material (particularly, glass) and an excellent durability such as heat resistance and anti-wet heat.

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 applications having excellent adhesion to an inorganic material, excellent durability such as heat resistance and anti-wet heat.

Hereinafter, the present invention will be described in detail.

The pressure-sensitive adhesive composition for optical use of the present invention comprises a monofunctional urethane acrylate oligomer having an alkoxysilane group at the terminal; Monofunctional acrylate monomers; And a free radical initiator. Here, the oligomer generally means a low molecular weight polymer compound having a weight average molecular weight (Mw) of 1,000 to 40,000, preferably 1,000 to 35,000.

The monofunctional urethane acrylate oligomer having an alkoxysilane group at the end thereof basically imparts physical properties and flexibility of a pressure-sensitive adhesive to maintain viscoelasticity and storage elastic modulus.

If the urethane acrylate oligomer is polyfunctional, the surface tackiness is poor and the cohesive strength is too high, so that the appearance of the adhesive property is not easy. In the case of having an alkoxy group at the terminal instead of the ionic functional group, the adhesive force is not sufficiently high, so that peeling failure may occur under heat-resistant conditions. In the case of having a hydroxy group, the adhesive strength is increased, I will not.

The monofunctional urethane acrylate oligomer of the present invention is preferably polymerized by containing a polyol, a diisocyanate compound and an alkoxysilane compound having a nucleophilic substituent.

Specifically, the monofunctional urethane acrylate oligomer having an alkoxysilane group at the terminal thereof has a main chain portion derived from a polyol, the monofunctional urethane acrylate oligomer, A urethane bonding group formed by the reaction of a diisocyanate and a polyol; One end of the acrylate monomer having a hydroxyl group has a reactive group of an acryloyl group and the other end thereof has an alkoxysilane group.

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 easiness of controlling the price and viscosity, it is preferable to be derived from a polyol having a polyester, polyether or a mixed structure thereof.

The urethane linking group can be produced 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.

The diisocyanate compound may be 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 , At least one aliphatic diisocyanate compound selected from the group consisting of azobenzene-4,4'-diisocyanate, m- or p-tetramethylxylene diisocyanate and 1-chlorobenzene-2,4- Is recommended.

Usually, the polyol and the diisocyanate compound are reacted at an equivalent ratio, and it is preferable to use an excessive amount of the diisocyanate compound to form an isocyanate group at the terminal. More preferably, it is used in an amount of 1.01 to 1.1 equivalents based on 1 equivalent of the polyol.

 At one end, a urethane acrylic oligomer is prepared by reacting 2-hydroxyethyl (meth) acrylate with an acrylate monomer having a hydroxyl group to form a reactive group of an acryloyl group. At this time, it is preferable to control the content of the acrylate monomer having a hydroxyl group so that it can react with the half of the residual amount of the diisocyanate compound remaining after the reaction with the polyol.

In addition, the amount corresponding to the other half of the residual amount of the diisocyanate compound performs the reaction using an alkoxysilane compound having a nucleophilic substituent.

The alkoxysilane compound having nucleophilic substitution may be one having at least one nucleophilic substituent selected from the group consisting of a hydroxyl group, a thiol group, an amino group, and a carboxyl group.

Preferably, it is at least one selected from the group consisting of formulas (1) to (16).

[Chemical Formula 1]

(2)

(3)

[Chemical Formula 4]

[Chemical Formula 5]

[Chemical Formula 6]

(7)

[Chemical Formula 8]

[Chemical Formula 9]

[Chemical formula 10]

(11)

[Chemical Formula 12]

[Chemical Formula 13]

[Chemical Formula 14]

[Chemical Formula 15]

[Chemical Formula 16]

It is preferable that the monofunctional urethane acrylate oligomer having an alkoxysilane group at the terminal thereof maintains a glass transition temperature (Tg) of -60 to 50 캜, preferably -60 to 20 캜.

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.

(Meth) acrylate, ethyl acrylate, butyl acrylate, isobutyl acrylate, allyl methacrylate, 2-ethoxyethyl (meth) acrylate, isodecyl (Meth) acrylate, hydroxypropyl (meth) acrylate, hydroxypropyl (meth) acrylate, 2-ethylhexyl acrylate, Acrylate, stearyl (meth) acrylate, tetrapurfuryl (meth) acrylate, phenoxyethyl (meth) acrylate, isobutyl (meth) acrylate, Octadecyl methacrylate, isobonyl (meth) acrylate, tetrahydrofuryl acrylate, acryloylmorpholine and the like can be used. In consideration of the glass transition temperature, it is preferable to use acrylic acid such as isobonyl (meth) acrylate, acrylomorpholine, acrylic acid, t-butyl acrylate, tetrahydrofurfuryl methacrylate, lauryl ( _C12 ) acrylate and cyclohexyl acrylate It is preferable to use at least one selected from the group consisting of

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

In addition, the present invention may further include a bifunctional or higher acrylate-based monomer within a range that does not deviate from the intended effect. The bifunctional or higher acrylate monomers serve to control the curing rate, and it is preferable to use an appropriate amount in consideration of the object of the present invention and the curing rate within the control range.

Examples of the acrylate monomer having two or more functional groups include 1,3-butanediol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, (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) acrylate, di (meth) acrylate, ethylene oxide modified di (meth) acrylate, 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.

It is preferable that such bifunctional or higher functional acrylate monomer is contained in an amount of 5 wt% or less in 100 wt% of the whole composition.

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 may be used in an appropriate range in consideration of the radiation property, intensity, content of each component, etc. of the light source, and is preferably contained in an amount of 0.1 to 5% by weight based on the total content (100% by weight) of the pressure-sensitive adhesive composition.

The pressure-sensitive adhesive composition of the present invention can be cured to form a pressure-sensitive adhesive. Further, a transparent base film; The pressure-sensitive adhesive may include the pressure-sensitive adhesive formed on one side of the transparent substrate film.

The pressure-sensitive adhesive may have a thickness of 5 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 and the like.

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

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

100 g of polypropylene diol was charged into a 2 L reactor equipped with a reflux condenser, a thermometer and a stirrer. After raising the temperature of the solution to 60 DEG C, 0.1 g of DBTDL (dibutyltin dilaurate) was added. 8 g of isophorone diisocyanate was slowly added over 30 minutes using a dropping funnel, and the reaction was carried out for 4 hours while maintaining the temperature of the reactor at 60 占 폚. A part of the above reaction product was taken and it was confirmed by IR analysis that the residual NCO peak was observed and that it was an oligomer containing a terminal NCO group. Subsequently, 1 g of 4-hydroxybutyl acrylate (4HBA) and 1.24 g of a compound represented by the formula (9) (3-aminopropyltrimethoxysilane) were added to the reaction product and reacted at the same temperature for further 4 hours. A part of the reaction product was taken and it was confirmed by IR analysis that no residual NCO peak was observed and that the peak of hydrogen attached to the side of the carbon adjacent to the amine of 3-aminopropyltrimethoxysilane disappeared in NMR, It was confirmed that the oligomer was a functional urethane acrylate oligomer.

Manufacturing example  2

(3-aminopropyltrimethoxysilane) was used in the same manner as in Preparation Example 1, except that 1.36 g of the compound of Formula 5 (3-thiolpropyltrimethoxysilane) was used instead of 1.24 g of the compound of Formula 9 A functional urethane acrylate oligomer was prepared.

Manufacturing example  3

(3-aminopropyltriethoxysilane) was used in place of the 1.24 g of the compound of the formula 9 (3-aminopropyltrimethoxysilane), 1.53 g of 3- A functional urethane acrylate oligomer was prepared.

Manufacturing example  4

(3-hydroxypropyltrimethoxysilane) was used in place of 1.24 g of the compound represented by the formula (9) to obtain a compound having an alkoxysilane group at the terminal thereof A monofunctional urethane acrylate oligomer was prepared.

Manufacturing example  5

The procedure of Preparation Example 1 was repeated, except that 1.35 g of the compound of Formula 13 (2-carboxypropyltrimethoxysilane) was used instead of 1.24 g of the compound of Formula 9 (3-aminopropyltrimethoxysilane) A functional urethane acrylate oligomer was prepared.

compare Manufacturing example  One: Bifunctionality  urethane Acrylate series Oligomer

100 g of polypropylene diol was charged into a 2 L reactor equipped with a reflux condenser, a thermometer and a stirrer. After raising the temperature of the solution to 60 DEG C, 0.1 g of DBTDL (dibutyltin dilaurate) was added. 8 g of isophorone diisocyanate was slowly added thereto for 30 minutes using a dropping funnel and reacted for 4 hours while maintaining the temperature of the reactor at 60 ° C. After that, 2-hydroxyethyl acrylate (HEA) were added and reacted at the same temperature for an additional 4 hours.

A part of the reaction product was taken and the residual NCO peak was not observed as a result of the IR analysis. When a part of the reaction product was taken and reacted with isophorodiisocyanate, the viscosity did not increase. The resulting compound had an acrylic group It was confirmed that it was a bifunctional urethane acrylate oligomer.

compare Manufacturing example  2: at the end Butoxy group  Have Single sensory  urethane Acrylate series Oligomer

Except that 2 g of 2-hydroxyethyl acrylate (HEA) and 0.8 g of n-butanol were used instead of 2 g of 2-hydroxyethylacrylate (HEA) to give a butoxy group at the terminal A monofunctional urethane acrylate oligomer was prepared.

A part of the reaction product is taken and IR analysis shows that no residual NCO peak is observed and that when a part of the reaction product is taken and reacted with isophorodiisocyanate, the viscosity is not increased, resulting in a compound having a butoxy group at the terminal It was confirmed that the oligomer was a functional urethane acrylate oligomer.

compare Manufacturing example  3: having a hydroxy group at the terminal Single sensory  urethane Acrylate series Oligomer

Hydroxyethyl acrylate (HEA) was prepared in the same manner as in Comparative Preparation Example 1 except that 7 g of isophorone diisocyanate was used instead of 8 g of isophorone diisocyanate to prepare a urethane oligomer having a hydroxyl group at the terminal, 1g of 2-methacryloyloxyethyl isocyanate (MOI) was used instead of 2g to prepare a monofunctional urethane acrylate oligomer having a hydroxyl group at the terminal.

A part of the reaction product is taken and the residual NCO peak is not observed as a result of the IR analysis. When a part of the reaction product is taken and reacted with isophorodiisocyanate, the viscosity of the resulting product is increased. The resulting compound is a monofunctional urethane Acrylate oligomer.

Example  One

(1) Pressure-sensitive adhesive composition

20 g of isobornyl acrylate (Tg = 94 占 폚), 20 g of t-butyl acrylate (Tg = 41 占 폚), 60 g of a free radical photoinitiator (product of Ciba Company, Darocur-1173) as monofunctional diluent monomer, Were mixed to prepare a pressure-sensitive adhesive composition.

(2) Production of adhesive film

The pressure-sensitive adhesive composition prepared in the above (1) was coated on a transparent base film coated with a silicone release agent to a thickness of 50 m, irradiated with ultraviolet rays at a velocity of 4 m / min (600 mJ / cm 2) The laminate was then irradiated with ultraviolet light at a speed of 4 m / min (600 mJ / cm 2) to prepare a fully cured pressure-sensitive adhesive film.

Example  2 to 9 and Comparative Example  1 to 4

A pressure-sensitive adhesive composition and a pressure-sensitive adhesive film were prepared in the same manner as in Example 1, except that the composition shown in Table 1 below was used.

division
(g) Urethane acrylate oligomer Monofunctional acrylate series
Monomer Free radical
Initiator Silane
Coupling agent Manufacturing example Comparative Manufacturing Example A-1 A-2 A-3 Example 1 Production Example 1 (60) - 20 20 - 2 - Example 2 Production Example 2 (60) - 20 20 - 2 - Example 3 Production Example 3 (60) - 20 20 - 2 - Example 4 Production Example 4 (60) - 20 20 - 2 - Example 5 Production Example 5 (60) - 20 20 - 2 - Example 6 Production Example 1 (60) - 20 - 20 2 - Example 7 Production Example 1 (60) - - 20 20 2 - Example 8 Production Example 1 (45) - 20 20 - 2 - Example 9 Production Example 1 (75) - 20 20 - 2 - Comparative Example 1 - Comparative Preparation Example 1 (60) 20 20 - 2 - Comparative Example 2 - Comparative Preparation Example 2 (60) 20 20 - 2 - Comparative Example 3 - Comparative Preparation Example 3 (60) 20 20 - 2 - Comparative Example 4 - Comparative Preparation Example 3 (60) 20 20 2 0.5 A-1: Isobornyl acrylate, Tg = 94 DEG C
A-2: t-Butyl acrylate, Tg = 41 DEG C
A-3: acrylomorpholine, Tg = 145 DEG C
Free radical photoinitiator: Ciba, Darocur-1173
Silane coupling agent: glycidoxypropyltrimethoxysilane (Shin-Etsu, KBM403)

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. Glass ( Glass ) Adhesion (N / 25 mm )

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 an autoclave, peeled at 180 ° PEEL at a speed of 300 m / min and then adhered at room temperature (25 ° C) ) Were measured.

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 and bonded to glass. The adhesive sheet was treated with an autoclave at 50 ° C for 20 minutes under a pressure of 5 atm, and then left in a 90 ° heat oven for 250 hours.

◎: 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 left in a humidity oven at 60 DEG C and 60RH% for 100 hours.

◎: 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 GLASS Adhesion (N / 25mm) Heat resistance Humidity Durability Room temperature Warming Example 1 18.4 37.5 ◎ ◎ Example 2 16.9 38.3 ○ ◎ Example 3 19.1 39.1 ○ ◎ Example 4 18.3 36.6 ○ ◎ Example 5 19.3 33.7 ○ ◎ Example 6 17.8 36.6 ◎ ◎ Example 7 19.2 37.8 ◎ ◎ Example 8 14.2 32.1 ◎ ◎ Example 9 18.4 34.5 ◎ ◎ Comparative Example 1 5.2 7.2 ○ × Comparative Example 2 18.5 21.6 × △ Comparative Example 3 20.7 23.7 △ × Comparative Example 4 15.3 17.2 × ×

As shown in Table 2, according to the present invention, a monofunctional urethane acrylate oligomer having an alkoxysilane group at the terminal thereof; Monofunctional acrylate monomers; And the free radical initiator of Examples 1 to 9 were superior to those of Comparative Examples 1 to 4 in terms of adhesiveness, heat resistance, and heat and humidity resistance.

Claims (4)

A monofunctional urethane acrylate oligomer having an alkoxysilane group at the terminal; Monofunctional acrylate monomers; And a free radical initiator.
[3] The method according to claim 1, wherein the alkoxysilane group of the monofunctional urethane acrylate oligomer is derived from an alkoxysilane compound having at least one nucleophilic substituent selected from the group consisting of a hydroxyl group, a carboxyl group, a thiol group and an amino group, Composition.
The pressure-sensitive adhesive composition for optical use according to claim 2, wherein the alkoxysilane compound having nucleophilic substitution is at least one selected from the group consisting of the compounds represented by formulas (1) to (16)
[Chemical Formula 1]

(2)

(3)

[Chemical Formula 4]

[Chemical Formula 5]

[Chemical Formula 6]

(7)

[Chemical Formula 8]

[Chemical Formula 9]

[Chemical formula 10]

(11)

[Chemical Formula 12]

[Chemical Formula 13]

[Chemical Formula 14]

[Chemical Formula 15]

[Chemical Formula 16]

[4] The composition of claim 1, further comprising 40 to 80% by weight of a monofunctional urethane acrylate oligomer having an alkoxysilane group at the terminal; 5 to 55% by weight monofunctional acrylate monomer; And 0.1 to 5% by weight of a free radical initiator.