KR20190086851A - Adhesive composition, adhesive sheet, optical member and image display device produced using the same - Google Patents

Abstract

According to the present invention, an adhesive composition comprises: an acrylic polymer; and at least one diluted monomer, wherein a photodegradable photopolymerization initiator is present in an amount of 0.6 wt% or less based on 100 w% of the composition, and the number of bubbles by the following evaluation method is equal to or lower than 1.0 in number/cm^2. The evaluation method of the number of generated bubbles comprises the steps of: bonding PET (7 cm × 7 cm) having a thickness of 100 μm to both surfaces of an adhesive sheet (5 cm × 5 cm, 100 μm in thickness) formed with the adhesive composition; performing an autoclave process on the adhesive sheet for 20 minutes at a temperature of 50°C under the pressure of 5 atm; and analyzing, with the naked eye, an image measured by using an optical microscope so as to confirm the number of bubbles in each unit area. According to the present invention, the adhesive composition enables manufacturing of an adhesive sheet having a smaller number of generated bubbles for each unit area.

Description

TECHNICAL FIELD [0001] The present invention relates to a pressure-sensitive adhesive composition, a pressure-sensitive adhesive sheet, an optical member and a display device using the pressure-

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure-sensitive adhesive composition, a pressure-sensitive adhesive sheet, an optical member and a display device using the same.

2. Description of the Related Art In recent years, an input device that uses a touch panel or the like in combination with various display devices such as a liquid crystal display (LCD) has been widely used. For example, a touch panel is installed in a mobile terminal such as a smart phone or a tablet.

In the manufacture of such display devices and input devices, an optically clear adhesive (OCA) is used for bonding various optical members. Specifically, the optical pressure-sensitive adhesive sheet is used as a pressure-sensitive adhesive film for interlayer adhesion for laminating components in an optical display device, adhesion of a touch screen of a cellular phone, and the like.

Generally, the adhesive sheet is bonded to an optical member such as a window cover glass, and then subjected to a high-temperature and high-pressure autoclave process in order to further increase adhesion to the member (substrate). Therefore, the pressure-sensitive adhesive sheet should be free from sticking or peeling, and the occurrence of bubbles and the like should be suppressed even when the pressure-sensitive adhesive sheet is exposed to severe conditions such as high temperature, high humidity, high temperature,

Korean Patent Laid-Open Publication No. 2016-0076974 relates to an adhesive film and a display member comprising the same, which is formed of a pressure-sensitive adhesive composition comprising a monomer mixture comprising (meth) acrylate having a hydroxyl group and a comonomer, Discloses a pressure-sensitive adhesive film having a recovery force (%) of 40% to 99% and a bubble generation area (%) of 0% by a measuring method.

However, in the above literature, the measurement of the bubble generation area is performed under the anti-wet heat condition. Even when exposed to severe conditions such as high temperature and high pressure of the thick film adhesive of 50 탆 or more, the pressure- There is not.

Therefore, development of a pressure-sensitive adhesive composition capable of producing a pressure-sensitive adhesive sheet in which generation of bubbles is suppressed even when exposed to severe conditions such as high temperature and high pressure of thick film pressure sensitive adhesive of 50 탆 or more is required.

Korean Patent Publication No. 2016-0076974 (Jul.

An object of the present invention is to provide a pressure-sensitive adhesive composition which is capable of producing a pressure-sensitive adhesive sheet having bubbling water, in particular, less bubble generation after autoclave treatment.

The present invention also provides a pressure-sensitive adhesive sheet having a small amount of air bubbles per unit area, an optical member including the pressure-sensitive adhesive sheet, and a display device.

The present invention relates to an acrylic polymer; And at least one diluent monomer, wherein the content of the photopolymerizable photopolymerization initiator is 0.6% by weight or less based on 100% by weight of the entire composition, and the number of bubbles in the following evaluation method is 1.0 / cm ² or less.

[Evaluation method of bubble generation water]

PET (7 cm × 7 cm) having a thickness of 100 μm was bonded to both sides of a pressure sensitive adhesive sheet (5 cm × 5 cm, thickness: 100 μm) formed of the pressure-sensitive adhesive composition, autoclaved at 50 ° C./5 atm for 20 minutes, And the number of bubbles per unit area is confirmed.

The present invention also provides a pressure-sensitive adhesive sheet comprising a cured product of the above-mentioned pressure-sensitive adhesive composition.

The present invention also provides an optical member including the above-mentioned pressure-sensitive adhesive sheet.

Further, the present invention provides a display device including the optical member described above.

The pressure-sensitive adhesive composition according to the present invention has an advantage that it is possible to produce a pressure-sensitive adhesive sheet having a small number of bubbles per unit area after the autoclave treatment.

Further, the pressure-sensitive adhesive sheet according to the present invention is advantageous in that the number of bubbles per unit area is small, and the optical member and the display device including the pressure-sensitive adhesive sheet described above have an advantage of excellent durability.

Hereinafter, the present invention will be described in more detail.

When a member is referred to as being " on "another member in the present invention, this includes not only when a member is in contact with another member but also when another member exists between the two members.

Whenever a part is referred to as "including " an element in the present invention, it is to be understood that it may include other elements as well, without departing from the other elements unless specifically stated otherwise.

≪ Pressure sensitive adhesive composition &

One aspect of the present invention relates to an acrylic polymer composition comprising: an acrylic polymer; And at least one diluting monomer, wherein the content of the photodegradable photopolymerization initiator is 0.6% by weight or less based on 100% by weight of the entire composition, and the number of bubbles in the following evaluation method is 1.0 / cm ² or less.

[Evaluation method of bubble generation water]

PET (7 cm × 7 cm) having a thickness of 100 μm was bonded to both sides of a pressure sensitive adhesive sheet (5 cm × 5 cm, thickness: 100 μm) formed of the pressure-sensitive adhesive composition, autoclaved at 50 ° C./5 atm for 20 minutes, And the number of bubbles per unit area is confirmed.

In the present invention, "bubbles" may have a diameter of several hundreds 탆 or less, specifically several tens to several hundreds of 탆, more specifically, of 50 to 500 nm. The "diameter" is a value representing the particle size, that is, the size of the bubble, and may be a length value of the longest line among the lines passing through the center of the bubble, and a measurement method used in the art can be used. For example, it can be measured using an optical profiler, a scanning electron microscope (SEM), or the like.

While not wishing to be bound by theory, when the pressure-sensitive adhesive sheet is subjected to autoclave treatment at a high temperature and a high pressure, for example, at 50 DEG C / 5 atm, water, volatile compounds, decomposition products of the photodegradable photopolymerization initiator, And the discharged gas causes air bubbles. Further, in the process of returning to normal temperature and normal pressure after the autoclave treatment, the external gas permeates into the pressure-sensitive adhesive sheet to induce bubbles, and in particular, the more volatile substances, the easier the penetration of air into the cross- .

However, the pressure-sensitive adhesive composition according to the present invention has a problem that the content of the photo-decomposable photopolymerization initiator is 0.6% by weight or less based on 100% by weight of the entire composition, and therefore occurs after the autoclave treatment There is an advantage that the number of bubbles is very small.

Specifically, the number of bubbles generated may be 0.5 / cm ² or less.

The acrylic polymer is not limited thereto, but may be polymerized using, for example, a (meth) acrylic monomer.

Specifically, the (meth) acrylic monomer is at least one monomer selected from the group consisting of n-butyl (meth) acrylate, 2-butyl (meth) acrylate, Ethyl (meth) acrylate, ethyl (meth) acrylate, methyl (meth) acrylate, n-propyl (meth) acrylate, (Meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, 2-methylbutyl (Meth) acrylate, isoamyl (meth) acrylate, isoamyl (meth) acrylate, n-decyl (meth) acrylate, isodecyl (Meth) acrylate, dodecyl (meth) acrylate, 2-dodecylthioethyl (meth) Acrylate, 2-methoxyethyl (meth) acrylate, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, (Meth) acrylate, stearyl (meth) acrylate, phenoxyethyl (meth) acrylate, tetrapurfuryl (meth) acrylate, tetrahydrofuryl Monofunctional monomers such as acrylonitrile, acrylonitrile, methacrylonitrile, acrylonitrile, acrylonitrile, Butanediol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, Ethylene glycol di (meth) acrylate, bisphenol A-ethylene glycol diacrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, (Meth) acrylate, propylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, neopentyl glycol di Acrylate, dicyclopentanyl di (meth) acrylate, caprolactone modified dicyclopentenyl di (meth) acrylate, ethylene oxide modified di (meth) acrylate, bis (2-hydroxyethyl) isocyanurate di Methacrylate , Di (acryloxyethyl) isocyanurate, allyl cyclohexyl di (meth) acrylate, dimethylol dicyclopentane diacrylate, ethylene oxide modified hexahydrophthalic acid diacrylate, tricyclodecane dimethanol acrylate, neo Bifunctional monomers such as pentyl glycol-modified trimethylol propane diacrylate and adamantanedicarylate; (Meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol tri (meth) acrylate, propionic acid modified trimethylol propane tri Trifunctional monomers such as (meth) acrylate, tris (2-hydroxyethyl) isocyanurate tri (meth) acrylate, tris (acryloxyethyl) isocyanurate and glycerol tri (meth) acrylate; Quaternary functional monomers such as diglycerin tetra (meth) acrylate, pentaerythritol tetra (meth) acrylate, ditrimethylol propane tetra (meth) acrylate and tetramethylol propane tetra (meth) acrylate; Pentafunctional monomers such as dipentaerythritol penta (meth) acrylate and propionic acid-modified dipentaerythritol penta (meth) acrylate; And hexafunctional monomers such as dipentaerythritol hexa (meth) acrylate and caprolactone-modified dipentaerythritol hexa (meth) acrylate.

The acrylic polymer may have a weight average molecular weight of 300,000 to 800,000, preferably 50 to 70. [ When the weight average molecular weight of the acrylic polymer is within the above range, viscosity required for coating the pressure-sensitive adhesive composition can be easily controlled.

In another embodiment of the present invention, the acrylic polymer may be contained in an amount of 10 to 50% by weight, preferably 20 to 40% by weight based on 100% by weight of the total of the pressure-sensitive adhesive composition. When the acrylic polymer is contained within the above range, the cohesive force of the pressure-sensitive adhesive composition is maximized and the moisture permeability is low even under high-temperature and high-humidity conditions, thereby making it possible to produce a pressure-sensitive adhesive composition having excellent durability.

The polymerization method of the acrylic polymer is not limited to the present invention. When the acrylic polymer is polymerized in the thermal decomposition, the thermal initiator may include, for example, one or more peroxide compound and at least one azo compound, although the thermal initiator is not limited thereto.

The azo compound may be at least one selected from the group consisting of 2,2'-azobis (2-methylbutyronitrile), 2,2'-azobis (isobutyronitrile), 2,2'-azobis (4-methoxy-2,4-dimethylvaleronitrile), and the peroxide compound may be 2,5-dimethyl-2,5-di (tert-butylperoxy) -hexane, dicumyl peroxide, and di (tert-butylperoxy-isopropyl) -benzene, and the content thereof is not limited to the present invention.

When the acrylic polymer is polymerized using a photopolymerization initiator, the sum of the content of the photopolymerization initiator used in the polymerization and the content of the photopolymerization initiator contained in the pressure-sensitive adhesive composition described below is 0.6% by weight or less based on 100% .

In the pressure-sensitive adhesive composition according to the present invention, the content of the photopolymerizable photopolymerization initiator is 0.6% by weight or less, preferably 0.5% by weight or less, based on 100% by weight of the entire composition.

The photopolymerizable photopolymerization initiator may be at least one selected from the group consisting of benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-butyl ether, benzoin isobutyl ether, acetophenone, 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 Propion-1-one, oligo [2-hydroxy-2-methyl-1- (4- (1-methylvinyl) phenyl) propane (Hydroxy-2-propyl) ketone, benzophenone, p-phenylbenzophenone, 4,4-diaminobenzophenone, 4,4'- Diethylaminobenzophenone, dichlorobenzophenone, anthraquinone 2-methylanthraquinone, 2-ethyl anthraquinone, 2-t-butyl anthraquinone, 2-amino anthraquinone, 4-dimethylthioxanthone, 2,4-diethylthioxanthone, benzyldimethylketal, diphenylketone benzyldimethylketal, acetophenone dimethylketal, p-dimethylaminobenzoic acid ester, 2,4,6-trimethylbenzoyldiphenyl Phosphine oxide (TPO), fluorene, triphenylamine, carbazole, and the like. These may be used alone or in combination of two or more.

The pressure-sensitive adhesive composition according to the present invention has an advantage that a pressure-sensitive adhesive sheet having a bubble count of 1.0 / cm ² or less can be produced because the content of the photopolymerizable photopolymerization initiator is 0.6% by weight or less based on 100% by weight of the entire composition.

In the present invention, the diluted monomer is a component which can impart durability to the pressure-sensitive adhesive composition and maintain the storage modulus, and can be easily coated by diluting the pressure-sensitive adhesive composition of the non-solvent type and adjusting the viscosity thereof.

The diluent monomer may be specifically a (meth) acrylic monomer, and the above-mentioned contents may be applied to the (meth) acrylic monomer.

The diluent monomer may be contained in an amount of 50 to 90% by weight, preferably 60 to 80% by weight, based on 100% by weight of the entirety of the pressure-sensitive adhesive composition. In this case, Do.

The pressure-sensitive adhesive composition according to the present invention comprises the acrylic polymer; And further adding a photodegradable photopolymerization initiator to an acrylic syrup containing at least one or more diluting monomers. Specifically, the pressure-sensitive adhesive composition may be formed by adding a photopolymerization initiator to an acrylic syrup in which a (meth) acrylic monomer, a polymer thereof, and an acrylic polymer and a diluting monomer are dissolved, but is not limited thereto.

The pressure-sensitive adhesive composition may further comprise a thiol-based molecular weight modifier. The thiol-based molecular weight modifier can promote the termination and initiation of chain growth upon radical polymerization of the acrylic compound to control the degree of radical polymerization of the acrylic polymer and control the molecular weight of the acrylic polymer. Preferably, a bifunctional or multifunctional thiol molecular weight modifier may be used.

For example, the thiol-based molecular weight modifier may be selected from the group consisting of 2-ethylhexyl 3-mercaptopropionate, n-octyl 3-mercaptopropionate, methoxybutyl 3-mercaptopropionate, tetraethylene glycol bis (3-mercaptopropionate), trimethylolpropane tris (3-mercaptopropionate), pentaerythritol tetrakis (3-mercaptopropionate), tris [(3-mercaptopropionyloxy) Isocyanurate, etc. These may be used alone or in combination of two or more.

The pressure-sensitive adhesive composition may further include additional agents within the range in which the above-described photocuring property is not deteriorated. For example, solvents, silane coupling agents, light stabilizers, antifoaming agents, fillers. Lubricants, surfactants, corrosion inhibitors, and the like may be appropriately included depending on the characteristics of the object.

<Adhesive sheet>

Another aspect of the present invention relates to a pressure-sensitive adhesive sheet comprising a cured product of the pressure-sensitive adhesive composition described above.

In another embodiment of the present invention, the number of bubbles in the pressure-sensitive adhesive sheet according to the following evaluation method is 1.0 / cm ² or less.

[Evaluation method of bubble generation water]

PET (7 cm x 7 cm) having a thickness of 100 mu m was bonded to both sides of the pressure-sensitive adhesive sheet (5 cm x 5 cm, thickness 100 m), autoclaved at 50 DEG C / 5 atm for 20 minutes and then measured with an optical microscope The image is visually analyzed to confirm the number of bubbles per unit area.

The pressure-sensitive adhesive sheet according to the present invention has an advantage of excellent visibility because the number of bubbles per unit area is 1.0 / cm ² or less.

The method for producing the pressure-sensitive adhesive sheet is not particularly limited. For example, the pressure-sensitive adhesive sheet may be prepared by coating the pressure-sensitive adhesive composition on one release film by a known coating method such as a barcoater, an air knife, a gravure, a reverse roll, a kiss roll, a spray, a blade, a die coater, a casting, Method, and bonding the remaining one release film, followed by photopolymerization and curing.

&Lt; Optical member and display device >

Another aspect of the present invention relates to an optical member including the above-mentioned pressure-sensitive adhesive sheet. Specifically, the adhesive sheet may be an optical adhesive film (OCA).

The optical member may be, for example, a touch panel, a window, a polarizing plate, a color filter, a retardation film, an elliptically polarizing film, a reflection film, an antireflection film, a compensation film, a brightness enhancement film, Film, a plastic LCD substrate, a transparent electrode such as indium tin oxide (ITO), fluorinated tin oxide (FTO), aluminum doped zinc oxide (AZO), carbon nanotube (CNT), Ag nanowire, and graphene Film and the like.

The method of manufacturing the optical member can be easily manufactured by a person having ordinary skill in the art to which the present invention belongs.

Another aspect of the present invention relates to a display device including the optical member described above. The display device is not limited thereto as long as it includes an optical member including the above-described pressure sensitive adhesive sheet, and may be, for example, a touch panel, an OLED display, or the like.

Hereinafter, the present invention will be described in detail by way of examples to illustrate the present invention. However, the embodiments according to the present disclosure can be modified in various other forms, and the scope of the present specification is not construed as being limited to the above-described embodiments. Embodiments of the present disclosure are provided to more fully describe the present disclosure to those of ordinary skill in the art. In the following, "%" and "part" representing the content are by weight unless otherwise specified.

Manufacturing example : ( Meta ) Acrylate  Manufacture of syrups

Manufacturing example  One.

50 parts by weight of 2-ethylhexyl acrylate (2-EHA) monomer, 30 parts by weight of isobornyl acrylate (IBOA) monomer, 30 parts by weight of N-butyl acrylate 10% by weight of 5-hydroxypentyl acrylate (NBMAA) and 10% by weight of 5-hydroxypentyl acrylate (5-HPA) monomer were poured into the flask, and nitrogen gas was purged for 1 hour to remove oxygen. And then kept at 80 캜. When the monomer mixture was uniformly mixed and the total weight of the monomer mixture was 100 parts by weight, 0.25 parts by weight of 1-hydroxy-cyclohexyl-phenyl-ketone was added as a photoinitiator. Thereafter, the mixture was stirred and irradiated with UV using a UV lamp (15 mW) to prepare an acrylic syrup having a polymer conversion of 25%.

Manufacturing example  2 to 5

(Meth) acrylate syrup was prepared in the same manner as in Preparation Example 1, but with the composition shown in Table 1 below.

Experimental Example  1. Evaluation of weight average molecular weight and molecular weight distribution

The weight average molecular weight and molecular weight distribution of the (meth) acrylate syrup prepared in Preparation Examples 1 to 5 were measured using GPC under the following conditions. At this time, for the production of the calibration curve, the measurement results were converted using standard polystyrene of the Agilent system, and the results are shown in Table 1 below.

 <Conditions for measuring weight average molecular weight>

Meter: Agilent GPC (Agilent 1200 series, USA)

Column: Two PL Mixed B connections

Column temperature: 40 ° C

Eluent: tetrahydrofuran

Flow rate: 1.0 mL / min

Concentration: ~ 1 mg / mL (100 μL injection)

division (Meth) acrylate monomer (% by weight) Photodegradable photopolymerization initiator
(Parts by weight) Polymer
Conversion Rate
(%) Weight average
Molecular Weight
(Unit: million) 2-EHA IBOA NBMAA 4-HCMA 5-HPA Production Example 1 (A1) 50 30 10 - 10 0.25 25 53 Production Example 2 (A2) 50 30 20 - - 0.25 26 60 Production Example 3 (A3) 50 30 5 15 - 0.25 25 62 Production Example 4 (A4) 50 30 10 10 - 0.25 25 65 Production Example 5 (A5) 50 30 10 - 10 0.5 25 53 2-EHA: 2-ethylhexyl acrylate
IBOA: isobornyl acrylate
NBMAA: N-butoxymethyl acrylamide
4-HCMA: 4-hydroxymethylcyclohexylmethyl acrylate
5-HPA: 5-hydroxypentyl acrylate
Photo-decomposable photopolymerization initiator: 1-hydroxycyclohexyl phenyl ketone

Example  1 to 4 and Comparative Example  1-3.

The pressure-sensitive adhesive composition was prepared by mixing the (meth) acrylate syrup and the photodegradable photopolymerization initiator prepared in the above Preparation Example in the composition shown in Table 2 below.

By coating the thickness of the pressure-sensitive adhesive composition prepared above onto a silicone release agent-coated release film so that the 150㎛ and bonding the mold release film on the UV lamp (UVA based ^{10mW / cm 2, 400mJ / cm} 2) by irradiating the pressure-sensitive adhesive Sheet.

Example Comparative Example One 2 3 4 One 2 3 (Meth) acrylate syrup (parts by weight) Kinds A1 A2 A3 A4 A1 A1 A5 content 100 100 100 100 100 100 100 Photodegradable photopolymerization initiator
(Parts by weight) ¹⁾ 0.25 0.3 0.3 0.25 0.5 1.0 0.25 Number of bubbles / 25 cm ² 0.21 0.35 0.23 0.4 1.45 2.52 2.11 Durability (85 ℃, 85%) ○ ○ Ⓞ ○ △ × × 1) 2,2-dimethoxy-2-phenylacetophenone

Experimental Example  2. Number of bubbles

PET (7 cm x 7 cm) having a thickness of 100 mu m was bonded to both sides of the pressure sensitive adhesive sheet (5 cm x 5 cm, thickness 150 m) produced in Examples and Comparative Examples and autoclaved at 50 DEG C / 5 atm for 20 minutes, The image measured with a microscope (Optical Microscope, manufactured by Olympus) was visually analyzed, and the number of bubbles per unit area was confirmed, and the results are shown in Table 2 above.

Experimental Example  3: Durability evaluation

The release sheet on one side of the pressure-sensitive adhesive sheet prepared in Examples and Comparative Examples was peeled off, and the pressure-sensitive adhesive sheet prepared by corona-treating the 40 mu m-thick cycloolefin (COP) film and the pressure-sensitive adhesive surface was cut to a size of 90 mm x 170 mm The release film adhered to the other surface was peeled off and attached to a glass substrate (110 mm x 190 mm x 0.7 mm) to prepare a specimen. At this time, the applied pressure was 5 kg / cm ^2, and the clean room work was performed so that bubbles or foreign matter would not be generated.

After standing for 100 hours at a temperature of 85 캜 and a relative humidity of 85% RH, the occurrence of bubbles or partial peeling was observed. The evaluation criteria are as follows, and the results are shown in Table 2 above.

<Evaluation Criteria>

◎: No bubble or partial peeling

○: Less than 5 bubbles or partial peeling

?: Bubbles or partial peeling 5 or more, less than 10

X: 10 or more bubbles or partial peeling

As shown in Table 2, in Examples 1 to 4, in which the content of the total photopolymerizable photopolymerization initiator according to the present invention was 0.6% by weight or less based on 100% by weight of the entire composition, the photopolymerization initiator of Comparative Example 1 The bubble count after the warm-pressing treatment is less than 1.0 / cm ² , and the durability is excellent.

Claims (7)

Acrylic polymers; And
At least one diluent monomer,
Wherein the content of the photodegradable photopolymerization initiator is 0.6% by weight or less based on 100% by weight of the entire composition,
Wherein the number of bubbles according to the following evaluation method is 1.0 / cm ² or less:
[Evaluation method of bubble generation water]
PET (7 cm × 7 cm) having a thickness of 100 μm was bonded to both sides of a pressure sensitive adhesive sheet (5 cm × 5 cm, thickness: 100 μm) formed of the pressure-sensitive adhesive composition, autoclaved at 50 ° C./5 atm for 20 minutes, And the number of bubbles per unit area is confirmed. The method according to claim 1,
Wherein the acrylic polymer is contained in an amount of 10 to 50% by weight based on 100% by weight of the total of the pressure-sensitive adhesive composition. The method according to claim 1,
Wherein the diluent monomer is contained in an amount of 50 to 90% by weight based on 100% by weight of the total of the pressure-sensitive adhesive composition. A pressure-sensitive adhesive sheet comprising a cured product of the pressure-sensitive adhesive composition according to any one of claims 1 to 3. 5. The method of claim 4,
Wherein the pressure-sensitive adhesive sheet has a bubble count of 1.0 number / cm ² or less by the following evaluation method:
[Evaluation method of bubble generation water]
PET (7 cm x 7 cm) having a thickness of 100 mu m was bonded to both sides of the pressure-sensitive adhesive sheet (5 cm x 5 cm, thickness 100 m), autoclaved at 50 DEG C / 5 atm for 20 minutes and then measured with an optical microscope The image is visually analyzed to confirm the number of bubbles per unit area. An optical member comprising a pressure-sensitive adhesive sheet according to claim 5. A display device comprising the optical member according to claim 6.