KR102031798B1 - Adhesive composition, adhesive sheet, optical member and image display device produced using the same - Google Patents

Abstract

Pressure-sensitive adhesive composition according to the invention is an acrylic polymer; And at least one dilution monomer; wherein the acrylic polymer has a Fedor's solubility parameters of 10 (cal / cm ³ ) ^0.5 or less, calculated by the following Formula 1, and the weight average solubility of the dilution monomer: The absolute value of the difference between the parameter and the solubility parameter of the acrylic polymer is 1.0 (cal / cm ³ ) ^0.5 or less.
[Equation 1]
∑ (SP _i × M _i )
(In Formula 1, SP _i is the solubility parameter of each monomer constituting the acrylic polymer,
M _i is the weight ratio of each monomer to the total weight of 100 monomers constituting the acrylic polymer).
The pressure-sensitive adhesive composition according to the present invention is not only excellent in washability, but also has an advantage of being able to produce an adhesive sheet having excellent adhesion and a low haze value.

Description

Adhesive composition, adhesive sheet, optical member and display device manufactured using the same {ADHESIVE COMPOSITION, ADHESIVE SHEET, OPTICAL MEMBER AND IMAGE DISPLAY DEVICE PRODUCED USING THE SAME}

The present invention relates to an adhesive composition, an adhesive sheet manufactured using the same, an optical member, and a display device.

BACKGROUND ART In the field of portable electronic devices such as mobile phones and portable information terminal devices, pressure-sensitive adhesives are used for fixing between various members. As the adhesive, OCR (optically clear resin), which is a liquid adhesive, and OCA (optically clear adhesive), a sheet-like adhesive, are used.

In particular, the OCR-type adhesive has been used in the manufacture of various electronic devices, because it is easy to remove using ethanol and the like, and thus it is easy to recover optical members used in defective products that may occur in electronic device manufacturing. In the case of the adhesive, there is a problem in that the adhesive force is insufficient to be applied to a flexible image display device, which has recently been in the spotlight, and in order to solve such a problem, the use of an OCA-type adhesive having excellent adhesive force has recently increased.

Japanese Patent Laid-Open Publication No. 2009-256607 relates to an acrylic pressure sensitive adhesive, an acrylic pressure sensitive adhesive layer, an acrylic pressure sensitive adhesive tape or sheet, which includes a) containing at least 50% by weight of an alkyl (meth) acrylate having an alkyl group having 1 to 20 carbon atoms as a monomer unit. In the acrylic adhesive containing the acrylic polymer and b) tackifying resin, 15 weight% or more of the two types of monomer units in which a) acrylic polymer has a difference of solubility parameter (SP value) becomes 0.2 (MPa) ^1/2 or more, respectively It is an acrylic polymer containing.

Korean Patent Laid-Open Publication No. 2006-0045721 relates to a pressure-sensitive adhesive composition for an optical member, a pressure-sensitive adhesive layer for an optical member, and a method for manufacturing the same, an optical member with pressure-sensitive adhesive, and an image display device, wherein the main monomer units constituting the (meth) acrylic polymer When the solubility parameter (SP value) of the homopolymer is δ1 [(J / cm ³ ) ^1/2 ], the solubility that the difference (Δδ = δ1-δ2) of the solubility parameter (SP value) becomes +1.7 to +5 Disclosed is a content of the pressure-sensitive adhesive composition for an optical member comprising a poor solvent having a parameter (SP value) δ 2 [(J / cm ³ ) ^1/2 ] of 20 to 60% by weight of the total amount of the organic solvent. Doing.

However, there is a problem that deterioration in detergency may occur when the monomer having a large solubility parameter is added in an excessive amount, and in the case of using a solvent type polymer, there is a problem in that thick film production is difficult.

Therefore, there is a demand for development of a pressure-sensitive adhesive composition which is excellent in adhesion and excellent in cleanability without affecting the production of a thick film.

Japanese Patent Laid-Open No. 2009-256607 (2009.11.05.) Republic of Korea Patent Publication No. 2013-0141340 (2013.12.26.)

An object of this invention is to provide the adhesive composition which is excellent in adhesive force and excellent in washability.

In addition, the present invention is to provide a pressure-sensitive adhesive sheet excellent in cleanability, low haze value, excellent heat resistance and heat and moisture resistance, and an optical member and a display device including the same.

The present invention is an acrylic polymer; And at least one dilution monomer; wherein the acrylic polymer has a Fedor solubility parameter of 10 (cal / cm ³ ) ^0.5 or less, calculated by the following formula 1, and the weight average solubility of the dilution monomer: It provides an adhesive composition wherein the absolute value of the difference between the parameter and the solubility parameter of the acrylic polymer is 1.0 (cal / cm ³ ) ^0.5 or less.

[Equation 1]

∑ (SP _i × M _i )

In Formula 1, SP _i is the solubility parameter of each monomer constituting the acrylic polymer,

M _i is the weight ratio of each monomer with respect to the total weight of 100 monomers constituting the acrylic polymer.

Moreover, this invention provides the adhesive sheet containing the hardened | cured material of the adhesive composition mentioned above.

In addition, the present invention provides an optical member including the adhesive sheet described above.

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

The pressure-sensitive adhesive composition according to the invention has the advantage of excellent washability.

In addition, the pressure-sensitive adhesive sheet prepared by using the pressure-sensitive adhesive composition according to the present invention has the advantage of excellent cleanability, low haze value, the optical member and the display device including the above-mentioned pressure-sensitive adhesive sheet is excellent in optical properties, heat resistance and There is an advantage that the reliability of the heat-and-moisture resistance is excellent.

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

In the present invention, when a member is located "on" another member, this includes not only when one member is in contact with another member but also when another member exists between the two members.

In the present invention, when a part "includes" a certain component, this means that it may further include other components, without excluding the other components unless otherwise stated.

<Adhesive Composition>

One aspect of the invention is an acrylic polymer; And at least one dilution monomer; wherein the acrylic polymer has a Fedor solubility parameter of 10 (cal / cm ³ ) ^0.5 or less, calculated by the following formula 1, and the weight average solubility of the dilution monomer: It is related with the adhesive composition whose absolute value of the difference of a parameter and the solubility parameter of the said acrylic polymer is 1.0 (cal / cm <^3> ) ^0.5 or less.

[Equation 1]

∑ (SP _i × M _i )

In Formula 1, SP _i is the solubility parameter of each monomer constituting the acrylic polymer,

M _i is the weight ratio of each monomer with respect to the total weight of 100 monomers constituting the acrylic polymer.

The acrylic polymer is not particularly limited as long as the Fedor solubility parameter calculated by the above formula 1 is 10 (cal / cm ³ ) ^0.5 or less.

Specifically, the acrylic polymer may be polymerized using a (meth) acrylic monomer.

Specifically, the (meth) acrylic monomers are n-butyl (meth) acrylate, 2-butyl (meth) acrylate, t-butyl (meth) acrylate, isobutyl (meth) acrylate, hexyl (meth) acrylic Latex, cyclohexyl (meth) acrylate), N-vinylpyrrolidone, 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) acrylic Elate, isononyl (meth) acrylate, isoamyl (meth) acrylate, n-decyl (meth) acrylate, isodecyl (meth) acrylate, isobornyl (meth) acrylate, 4-methyl-2-pentyl (Meth) acrylate, dodecyl (meth) acrylate, 2-dodecylthioethyl (meth) a Relate, 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, tetraperfuryl (meth) acrylate, tetrahydrofuryl (meth) acrylic Monofunctional monomers such as acrylate and acryloyl morpholine; 1,3-butanedioldi (meth) acrylate, 1,4-butanedioldi (meth) acrylate, 1,6-hexanedioldi (meth) acrylate, 2-butyl-2-ethyl-1,3-propane Diol diacrylate, 1,9-nonanediol diacrylate, ethylene glycol di (meth) acrylate, bisphenol A-ethylene glycol diacrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) Acrylate, tetraethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylic Dicyclopentanyldi (meth) acrylate, caprolactone modified dicyclopentenyldi (meth) acrylate, ethylene oxide modified phosphate di (meth) acrylate, bis (2-hydroxyethyl) isocyanurate di ( Meta) acrylate , Di (acryloxyethyl) isocyanurate, allylated cyclohexyldi (meth) acrylate, dimethyloldicyclopentanediacrylate, ethylene oxide modified hexahydrophthalic acid diacrylate, tricyclodecane dimethanol acrylate, neo Difunctional monomers such as pentyl glycol modified trimethylolpropanediacrylate and adamantanediacrylate; Trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol tri (meth) acrylate, propionic acid modified trimethylolpropane tri (meth) acrylate, propylene oxide modified trimethylolpropane tree Trifunctional monomers such as (meth) acrylate, tris (2-hydroxyethyl) isocyanurate tri (meth) acrylate, tris (acryloxyethyl) isocyanurate, and glycerol tri (meth) acrylate; Tetrafunctional monomers such as diglycerin tetra (meth) acrylate, pentaerythritol tetra (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, and tetramethylolpropane tetra (meth) acrylate; 5-functional monomers, such as dipentaerythritol penta (meth) acrylate and propionic acid modified dipentaerythritol penta (meth) acrylate; Hexafunctional monomers, such as dipentaerythritol hexa (meth) acrylate and caprolactone modified dipentaerythritol hexa (meth) acrylate, etc. are mentioned.

The acrylic polymer according to the present invention has a Fedor solubility parameter of 10 (cal / cm ³ ) ^0.5 or less, specifically 1 (cal / cm ³ ) ^0.5 to 9.9 (cal / cm ³ ) ^0.5 , more specifically, calculated by Equation 1 above. 5 (cal / cm ³ ) ^0.5 to 9.8 (cal / cm ³ ) may be ^0.5 or less.

When the acrylic polymer whose Fedor solubility parameter calculated by the said Formula 1 satisfy | fills the said range is used, the adhesive composition excellent in washability and this adhesive sheet can be obtained.

Although not wishing to be limited by theory, when using an acrylic polymer in which the solubility parameter is calculated to a value satisfying the above range, the solubility with a solvent included in the cleaning liquid increases, so that the adhesive composition is excellent and thus the pressure-sensitive adhesive composition There is an advantage of easy removal of the pressure-sensitive adhesive sheet formed.

In one embodiment of the present invention, the acrylic polymer may have a weight average molecular weight of 300,000 to 800,000, preferably 40 to 700,000. When the weight average molecular weight of the acrylic polymer is in the above range, it is preferable because there is an advantage that it is easy to adjust the viscosity required when coating the pressure-sensitive adhesive composition.

In another embodiment of the present invention, the acrylic polymer may be included in 10 to 50 parts by weight, preferably 20 to 40 parts by weight based on 100 parts by weight of the total pressure-sensitive adhesive composition. When the acrylic polymer is included in the above range, the cohesive force of the pressure-sensitive adhesive composition is maximized, and it is possible to prepare a pressure-sensitive adhesive composition having excellent heat resistance and moisture heat resistance even under conditions of high temperature and high humidity.

In the present invention, the dilution monomer is a component that can make coating easy by providing durability to the pressure-sensitive adhesive composition and maintaining the storage modulus, and diluting the solvent-free pressure-sensitive adhesive composition to adjust the viscosity.

The dilution monomer may specifically be a (meth) acrylic monomer, and if the absolute value of the difference between the weight average solubility parameter of the dilution monomer and the solubility parameter of the acrylic polymer satisfies 1.0 (cal / cm ³ ) ^0.5 or less, the As the (meth) acrylic monomer, the above-described contents may be applied.

Preferably, the difference between the weight average solubility parameter of the dilution monomer and the solubility parameter of the acrylic polymer may be 1.0 (cal / cm ³ ) ^0.5 or less. Specifically, the difference between the weight average solubility parameter of the dilution monomer and the solubility parameter of the acrylic polymer may be 0.1 (cal / cm ³ ) ^0.5 or more and 0.9 (cal / cm ³ ) ^0.5 or less.

In the present invention, the solubility parameter can be obtained by calculating Fedors (Polymer Eng. & Sic.), Vol. 14, No. 2 (1974), pp148-154, that is, through the following equation. have.

In the above formula, Δe _i is the evaporation energy of 25 ° C. attributable to the atom or group, and Δv _i is the molar volume of 25 ° C.

Solubility parameters of the method for calculating the Fedors of the representative monomers are shown in Table 1 below.

Monomer SP Acrylamide 17.19 Acrylic acid 14.04 2-hydroxyethyl acrylate 13.31 Acrylonitrile 13.11 2-hydroxypropyl acrylate 12.44 N-vinyl-2-pyrrolidone 12.32 2-phenoxyethyl acrylate 11.79 Glycidyl acrylate 11.32 Methyl acrylate 10.58 Tetrahydrofuryl acrylate 10.53 Methoxymethyl acrylate 10.43 N-octyl acrylamide 10.33 Ethyl acrylate 10.20 Cyclohexyl acrylate 10.16 Methoxyethyl acrylate 10.16 Ethoxyethyl acrylate 9.96 n-propyl acrylate 9.95 n-butyl acrylate 9.77 Ethyl methacrylate 9.72 i-propyl acrylate 9.72 Isobonyl Acrylate 9.71 Amyl acrylate 9.63 i-butyl acrylate 9.57 n-hexyl acrylate 9.52 n-heptyl acrylate 9.43 n-octyl acrylate 9.35 n-nonyl acrylate 9.29 Methoxytripropylene glycol acrylate 9.26 n-decyl acrylate 9.24 2-ethylhexyl acrylate 9.22 n-undecyl acrylate 9.19 Lauryl acrylate 9.15 n-tridecyl acrylate 9.11 t-butyl acrylate 9.05 Stearyl acrylate 8.88

When the difference between the weight average solubility parameter of the dilution monomer and the solubility parameter of the acrylic polymer satisfies the above range, the compatibility of the dilution monomer and the acrylic polymer is excellent and has a low haze value, thereby providing excellent optical performance and heat resistance. And it has the advantage that the adhesive sheet excellent in the reliability of moisture-and-heat resistance can be obtained.

The diluent monomer may be included in an amount of 50 to 90 parts by weight, preferably 60 to 80 parts by weight, based on 100 parts by weight of the entire pressure-sensitive adhesive composition, and in this case, it is preferable because there is an advantage that can be easily adjusted to the required viscosity when coating the pressure-sensitive adhesive composition. .

In another embodiment of the present invention, the pressure-sensitive adhesive composition may further include a photopolymerization initiator.

For example, the photopolymerization initiator may be benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-butyl ether, benzoin isobutyl ether, acetophenone, hydroxydimethylacetophenone, dimethylamino Acetophenone, 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, oligo [2-hydroxy-2-methyl-1- (4- (1-methylvinyl) phenyl) propanone] , 4- (2-hydroxyethoxy) phenyl-2- (hydroxy-2-propyl) ketone, benzophenone, p-phenylbenzophenone, 4,4-diaminobenzophenone, 4,4'-diethyl Aminobenzophenone, dichlorobenzophenone, anthraquinone, 2-methyl Traquinone, 2-ethylanthraquinone, 2-t-butylanthraquinone, 2-aminoanthraquinone, 2-methylthioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethyl thi Oxanthone, 2,4-diethyl thioxanthone, benzyldimethyl ketal, diphenyl ketone benzyl dimethyl ketal, acetophenone dimethyl ketal, p-dimethylaminobenzoic acid ester, 2,4,6-trimethylbenzoyldiphenylphosphine oxide ( TPO), fluorene, triphenylamine, carbazole and the like. These may be used alone or in combination of two or more.

The photopolymerization initiator may be included in an amount of 0.1 to 5 parts by weight, preferably 0.5 to 5 parts by weight, and more preferably 0.5 to 2 parts by weight, based on 100 parts by weight of the total acrylic syrup including the acrylic polymer and the diluent monomer. When the photopolymerization initiator is included in the above range, the photocuring rate produced by the pressure-sensitive adhesive composition is slowed, and the phenomenon in which the initial durability of the pressure-sensitive adhesive sheet is reduced can be suppressed, and the phenomenon in which transparency due to yellowing is lowered can be suppressed. .

The pressure-sensitive adhesive composition may further include a thiol-based molecular weight regulator. The thiol-based molecular weight modifier may promote termination and initiation of chain growth during radical polymerization of the acrylic compound, thereby controlling the degree of radical polymerization of the acrylic polymer and the like and controlling the molecular weight of the acrylic polymer. Preferably a bifunctional or higher polyfunctional thiol molecular weight regulator can be used.

For example, the thiol-based molecular weight modifier is 2-ethylhexyl 3-mercaptopropionate, n-octyl 3-mercaptopropionate, methoxybutyl 3-mercaptopropionate, tetraethylene glycol bis (3-mer Captopropionate), trimethylolpropane tris (3-mercaptopropionate), pentaerythritol tetrakis (3-mercaptopropionate), tris [(3-mercaptopropionyloxy) -ethyl]- Isocyanurate, and the like, and these may be used alone or in combination of two or more thereof.

The pressure-sensitive adhesive composition may further include additional agents within a range in which the above-described photocuring properties are not degraded. For example, a solvent, a silane coupling agent, a light stabilizer, an antifoamer, and a filler. Components such as lubricants, surfactants, corrosion inhibitors and the like may be appropriately included depending on the characteristics of the object.

Pressure-sensitive adhesive composition according to the invention the acrylic polymer; And it may be formed by further adding a photopolymerization initiator to the acrylic syrup containing at least one dilution monomer.

The pressure-sensitive adhesive composition according to the present invention comprises an acrylic polymer having a Fedor's solubility parameters of 10 (cal / cm ³ ) ^0.5 or less, calculated by the formula 1 above, and the weight average solubility parameter of the dilution monomer and the acrylic since the absolute value of the difference between the solubility parameter of the polymer is to satisfy 1.0 (cal / cm ^{3) 0.5} or less are possible as well as the cleaning property Good manufacturing of pressure-sensitive adhesive sheet having a low haze value. Moreover, the adhesive sheet which is excellent in washing property and excellent in adhesive force can be obtained.

<Adhesive sheet>

Another aspect of this invention relates to the adhesive sheet containing the hardened | cured material of the adhesive composition mentioned above. The adhesive sheet according to the present invention is an acrylic polymer; And at least one dilution monomer; wherein the acrylic polymer has a Fedor solubility parameter of 10 (cal / cm ³ ) ^0.5 or less, calculated by the following formula 1, and the weight average solubility of the dilution monomer: Since the absolute value of the difference between the parameter and the solubility parameter of the acrylic polymer is manufactured by using the pressure-sensitive adhesive composition of 1.0 (cal / cm ³ ) ^0.5 or less, it is excellent in adhesive force and has excellent cleaning property and has a small haze value.

[Equation 1]

∑ (SP _i × M _i )

In Formula 1, SP _i is the solubility parameter of each monomer constituting the acrylic polymer,

M _i is the weight ratio of each monomer with respect to the total weight of 100 monomers constituting the acrylic polymer.

Specifically, the pressure-sensitive adhesive sheet has an adhesive force to the alkali glass of 30N / 25mm or more, the washability may be 50 times or less.

The alkali glass may be, for example, soda glass, boric silicate glass, or the like, but is not limited thereto, and may be understood in terms of ordinary terms in the art.

The adhesive force indicates the degree to which the adhesive sheet is adhered to the alkali glass, and may be measured as follows. For example, the release film of one side of the adhesive sheet is peeled off and corona treated and bonded to the 38 μm PET film and the adhesive side, and the specimen is cut to have a width of 25 mm and a length of 100 mm. Subsequently, the release film adhered to the PET / adhesive layer composition was peeled off, and the adhesive sheet was attached to the soda glass using a roller of 2 kg according to JIS Z 0237, followed by autoclave (50 ° C., 5 atm). The adhesive sheet was pressed for 20 minutes and stored for 1 hour in a constant temperature and humidity condition (23 ° C., 50% RH) by using autograph (AG-1S, SHIMADZU), and the adhesive sheet was 300 mm / min from soda glass. The adhesive force can be measured while peeling at a peeling speed of and a peeling angle of 180 degrees.

In the present invention, the "cleaning time of 50 times or less" may mean that the number of cleaning times when washing by the following washing method is 50 or less round trips.

The cleaning method comprises the steps of: i) fabricating a sample by bonding the pressure sensitive adhesive sheet to a glass substrate by exposing the pressure sensitive adhesive sheet on at least one surface of the glass substrate for 20 minutes in an autoclave at 50 ° C. and 5 atm; Ii) the sample Fixing to a sample stage of a film friction tester (Linear Crockmeter), fixing a microfiber wiper to a jig to apply a load to the sample stage, and then wetting ethanol to the sample and the microfiber wiper; And iii) abutting the ethanol-soaked sample and the microfiber wiper with each other, and then adjusting the load applied to the sample to be 1 kg in total, thereby reciprocating the sample stage on which the sample is placed so that the adhesive sheet on the sample is perfectly It may include the step of measuring the number of reciprocating motions when removed as the number of cleaning.

The amount of ethanol used in step ii) is not particularly limited in the present invention because it is variously applicable conditions depending on the size of the sample and the thickness of the adhesive sheet, but at least enough to sufficiently wet the sample and the microfiber wiper to be applied. Preferably the amount of is applied. As an example, the size of the adhesive sheet is 15 × In the case of 15mm, about 2ml of ethanol may be used for the adhesive sheet, and 5-10ml of ethanol may be used for the microfiber wiper, but is not limited thereto.

The manufacturing method of the said adhesive sheet is not specifically limited. For example, the pressure-sensitive adhesive sheet is a method of coating the pressure-sensitive adhesive composition on a release film, such as a bar coder, air knife, gravure, reverse roll, kiss roll, spray, blade, die coater, casting, spin coating, etc. After coating using the method, the remaining one release film can be bonded, and then formed by photopolymerization curing.

The pressure-sensitive adhesive sheet according to the present invention has the advantage of excellent adhesive strength and excellent cleaning properties and low haze value.

<Optical member and display device>

Another aspect of the present invention relates to an optical member comprising 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 elliptical polarizing film, a reflective film, an antireflection film, a compensation film, a brightness enhancement film, an alignment film, a light diffusion film, a glass scattering prevention film, and a surface protection film. Transparent electrodes such as films, plastic LCD substrates, indium tin oxide (ITO), fluorinated tin oxide (FTO), aluminum dopped zinc oxide (AZO), carbon nanotube (CNT), Ag nanowires, and graphene A film etc. are mentioned.

The manufacturing method of the optical member can be easily manufactured by those skilled in the art to which the present invention pertains.

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 the optical member including the adhesive sheet described above, and may be referred to as a touch panel, an OLED display, or the like.

Hereinafter, the present invention will be described in detail with reference to Examples. However, embodiments according to the present disclosure may be modified in various other forms, and the scope of the present specification is not to be interpreted as being limited to the embodiments described below. The embodiments of the present specification are provided to more fully describe the present specification to those skilled in the art. In addition, "%" and "part" which show content below are a basis of weight unless there is particular notice.

Preparation Example: Preparation of (meth) acrylate Syrup

Preparation Example 1

Monomer mixture consisting of 50% by weight of 2-ethylhexyl acrylate (2-EHA) monomer and 50% by weight of isobonyl acrylate (IBOA) monomer in a 1 L reactor equipped with a refrigeration system for easy reflux of nitrogen gas After purging nitrogen gas for 1 hour to remove oxygen, it was maintained at 80 ℃. After the monomer mixture was uniformly mixed, when the total weight of the monomer mixture was 100 parts by weight, 0.5 part by weight of 1-hydroxy-cyclohexyl-phenyl-ketone was added as a photopolymerization initiator. After stirring, and irradiated with UV lamp (10mW) to prepare an acrylic syrup of 40% conversion, 10 parts by weight of 2-ethylhexyl acrylate (2-EHA) monomer, isobornyl acrylate with respect to 100 parts by weight of acrylic syrup 15 parts by weight of (IBOA) monomer and 10 parts by weight of 2-hydroxyethyl acrylate (2-HEA) were further added to prepare an acrylic syrup of Preparation Example 1.

Preparation Examples 2 to 10

To carry out the same as in Preparation Example 1, to prepare a (meth) acrylate syrup in the composition of Table 2.

division Solubility
parameter Preparation Example 1
(A1) Preparation Example 2
(A2) Preparation Example 3
(A3) Preparation Example 4
(A4) Preparation Example 5
(A5) Preparation Example 6
(A6) Preparation Example 7
(A7) Preparation Example 8
(A8) Preparation Example 9
(A9) Preparation Example 10
(A10) (Meth) acrylate
syrup Acrylic polymer LA 9.15 - 10 - 13 10 - 20 10 15 - 2-EHA 9.22 15 10 20 - - 13 - - - 10 IBOA 9.71 15 - - - 20 10 10 - 5 10 CHA 10.16 - 10 20 10 - - - 10 - - NVP 12.32 - - - - - - - 10 10 - 2-HEA 13.31 - - - 2 - 2 - - - 5 ratio(%) 30 30 40 25 30 25 30 30 35 25 Dilution
Monomer LA 9.15 - 20 - 30 20 - 30 30 10 - 2-EHA 9.22 30 30 20 - - 35 - - - 15 IBOA 9.71 33 - - - 30 30 10 - 20 10 CHA 10.16 - 10 30 30 - - - 20 20 - NVP 12.32 - 10 10 - 15 - 30 - 15 30 2-HEA 13.31 7 - - 15 5 10 20 20 - 20 ratio(%) 70 70 60 75 70 75 70 70 65 75 Molecular Weight (Mw) 740,000 610,000 470,000 680,000 700,000 650,000 650,000 620,000 580,000 700,000 Photopolymerization initiator 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 LA: lauryl acrylate
2-EHA: 2-ethylhexyl acrylate
IBOA: Isobonylacrylate
CHA: cyclohexyl acrylate
NVP: N-vinylpyrrolidone
2-HEA: 2-hydroxyethyl acrylate
Photopolymerization Initiator: Hydroxy Cyclohexylphenyl Ketone

Preparation of Pressure-Sensitive Adhesive Compositions: Examples 1-6 and Comparative Examples 1-4

The pressure-sensitive adhesive composition was prepared by mixing the content of the (meth) acrylate syrup and the photopolymerization initiator of the preparation example in the composition of Table 2 below.

The pressure-sensitive adhesive composition prepared above was coated on a release film coated with a silicone release agent to have a thickness of 150 μm, the release film was bonded thereon, and cured through a TL lamp (UVV) to prepare an adhesive sheet.

Example Comparative example One 2 3 4 5 6 One 2 3 4 (Meth) acrylate syrup
(Parts by weight) Kinds A1 A2 A3 A4 A5 A6 A7 A8 A9 A10 content 100 100 100 100 100 100 100 100 100 100 Photoinitiator ^{1 )} (part) 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 Acrylic polymer
Solubility constant (cal / cm ³ ) ^0.5 9.47 9.51 9.69 9.89 9.52 9.74 9.34 10.54 10.30 10.23 Dilution Monomer
Solubility constant (cal / cm ³ ) ^0.5 9.86 9.78 10.21 10.39 10.37 9.96 10.59 10.63 10.36 11.62 △ Solubility constant (cal / cm ³ ) ^0.5 0.40 0.27 0.52 0.50 0.84 0.22 1.25 0.08 0.06 1.38 adhesiveness N / 25mm 35.5 32.8 32.4 42.1 33.2 38.6 21.2 25.4 33.5 34.6 Detergency time 30 22 25 27 38 20 150 170 180 200 Haze % 0.3 0.4 0.3 0.3 0.3 0.4 1.5 0.3 0.3 3.2 durability Heat resistance Ⓞ ○ ○ ○ ○ Ⓞ × ○ ○ × Moisture and Heat Resistance Ⓞ ○ ○ ○ ○ Ⓞ × × × × 1) 2,2-dimethoxy-1,2-diphenylethanone

Experimental Example  1. Measurement of adhesion

Peel off the release film on one side of the adhesive sheet prepared in the above Examples and Comparative Examples and corona treated and bonded to 38㎛ PET film and pressure-sensitive adhesive and then cut to 25 mm in width, 100 mm in length to prepare a specimen It was. Subsequently, the release film adhered to the PET / adhesive layer composition was peeled off, and the adhesive sheet was attached to the soda glass using a roller of 2 kg according to JIS Z 0237, followed by autoclave (50 ° C., 5 atm). The adhesive sheet was pressed for 20 minutes and stored for 1 hour in a constant temperature and humidity condition (23 ° C., 50% RH) by using autograph (AG-1S, SHIMADZU), and the adhesive sheet was 300 mm / min from soda glass. The adhesive force was measured while peeling at a peeling rate of 180 ° and a peeling angle of 180 °, and the results are shown in Table 3 above.

Experimental Example 2. Cleanability Evaluation

The pressure-sensitive adhesive sheets prepared in Examples and Comparative Examples were evaluated in the following order.

I) At least one surface of the glass substrate was treated with an adhesive sheet (15 mm × 15 mm) for 20 minutes in an autoclave of 50 ° C. and 5 atm, and then the adhesive sheet was bonded to the glass substrate to prepare a sample.

Ii) the sample After fixing to a sample stage of a film friction tester (Linear Crockmeter), a microfiber wiper was fixed to a jig to apply a load to the sample stage, the sample and the microfiber wiper was sufficiently wetted with ethanol. At this time, about 2ml of ethanol was used for the adhesive sheet surface, and about 8ml of ethanol was used for the microfiber wiper surface.

Iii) the ethanol-soaked sample and the microfiber wiper are brought into contact with each other, and then fixed by adjusting the load of the jig to 1 kg and reciprocating the sample stage to completely remove the adhesive layer on the sample. The number of times was measured, and the results are shown in Table 3 above.

Experimental Example 3. Haze Measurement

The adhesive sheets prepared in Examples and Comparative Examples were cut into 3 cm × 3 cm sizes, and then bonded to 4 cm × 4 cm glass using a haze meter (HZ-1, manufactured by Suga Test Instrument Co., Ltd.). Measurements were made in accordance with JIS K 7361-1. The results are shown in Table 2 above.

Experimental Example 4. Evaluation of durability (heat resistance, heat resistance)

Peeling the release film on one side of the adhesive sheet prepared in Examples and Comparative Examples, and cut the adhesive sheet prepared by corona treatment and bonding to a 40 μm cycloolefin (COP) -based film and the adhesive surface to a size of 90 mm × 170 mm The release film attached to the other side was peeled off and then attached to a glass substrate (110 mm × 190 mm × 0.7 mm) to prepare a specimen. At this time, the applied pressure was 5kg / ㎠ and the clean room work so as not to generate bubbles or foreign matter.

The heat resistance characteristics were observed whether bubbles or peeling occurred after being left for 500 hours at a temperature of 100 ℃, the moisture heat resistance characteristics of bubbles or partial peeling after leaving for 500 hours under the conditions of 85 ℃ temperature and 85% RH Whether or not was observed. Evaluation criteria are as follows, and the results are shown in Table 3 above.

<Evaluation Criteria>

Ⓞ: no bubble or partial peeling

○: less than 5 bubbles or partial peeling

△: 5 or more bubbles or partial peeling, less than 10

×: 10 or more bubbles or partial peelings

Referring to Table 3, the acrylic polymer is prepared using the pressure-sensitive adhesive composition according to the present invention satisfying the Fedor solubility parameter according to the present invention, the difference between the weight average solubility parameter of the dilution monomer and the solubility parameter of the acrylic polymer. It can be seen that the pressure-sensitive adhesive sheets of Examples 1 to 6 are superior in the washability, optically transparent, and excellent in adhesive strength than those of the pressure-sensitive adhesive sheets of Comparative Examples 1 to 4. Moreover, it turns out that the durability of heat resistance and moisture-and-moisture heat resistance is excellent.

Claims (9)

Acrylic polymers; And
At least one dilution monomer;
The acrylic polymer has a Fedor solubility parameter of 1 (cal / cm ³ ) ^0.5 to 9.9 (cal / cm ³ ) ^0.5 calculated by Equation 1 below,
It contains the hardened | cured material of the adhesive composition whose absolute value of the difference of the weight average solubility parameter of the said dilution monomer and the solubility parameter of the said acrylic polymer is 1.0 (cal / cm <^3> ) ^0.5 or less,
Adhesive sheet with adhesive strength of 30 N / 25 mm or more to alkali glass:
[Equation 1]
∑ (SP _i × M _i )
(In Formula 1, SP _i is the solubility parameter of each monomer constituting the acrylic polymer,
M _i is the weight ratio of each monomer to the total weight of 100 monomers constituting the acrylic polymer). The method of claim 1,
The acrylic polymer has a weight average molecular weight of 300,000 to 800,000 adhesive sheet. The method of claim 1,
The adhesive sheet whose difference of the weight average solubility parameter of the said dilution monomer and the solubility parameter of the said acrylic polymer is 1.0 (cal / cm <^3> ) ^0.5 or less. The method of claim 1,
The acrylic polymer is a pressure-sensitive adhesive sheet containing 10 to 50 parts by weight based on 100 parts by weight of the total pressure-sensitive adhesive composition. The method of claim 1,
The dilution monomer is an adhesive sheet containing 50 to 90 parts by weight based on 100 parts by weight of the total pressure-sensitive adhesive composition. The method of claim 1,
The pressure-sensitive adhesive composition is a pressure-sensitive adhesive sheet further comprising a photopolymerization initiator. delete An optical member comprising the adhesive sheet according to any one of claims 1 to 6. A display device comprising the optical member according to claim 8.