KR102258167B1 - Adhesive composition and protective sheet prepared from the same - Google Patents

Abstract

According to the embodiments of the present invention, the pressure-sensitive adhesive composition includes a urethane-based resin and a solvent formed from a polyol and an isocyanate-based compound, and an equivalent ratio of the hydroxy group of the polyol and the isocyanate group of the polyfunctional isocyanate compound in a predetermined range (OH/NCO ). The pressure-sensitive adhesive composition can be effectively applied, for example, as a low-adhesion protective sheet for an image display device.

Description

Adhesive composition and protective sheet manufactured therefrom TECHNICAL FIELD [ADHESIVE COMPOSITION AND PROTECTIVE SHEET PREPARED FROM THE SAME}

The present invention relates to a pressure-sensitive adhesive composition and a protective sheet prepared therefrom, and more particularly, to a pressure-sensitive adhesive composition comprising an adhesive resin and a protective sheet prepared therefrom.

In manufacturing an image display device such as a liquid crystal display (LCD) device, an organic light emitting display (OLED) device, or the like, the surfaces of various structures may be protected with an adhesive sheet before, for example, a subsequent processing process or a subsequent bonding process.

The adhesive sheet may be peeled off again to perform a subsequent process, and during peeling, static electricity may be generated, causing disturbance in the operation of the structure or the display channel. Therefore, the pressure-sensitive adhesive sheet needs to have an appropriate antistatic performance.

In addition, when the adhesive force or peeling force of the pressure-sensitive adhesive sheet is excessively increased, when the pressure-sensitive adhesive sheet is peeled, a display structure such as an OLED device may be damaged, and a residue of the adhesive component may be generated.

In addition, it is preferable that the pressure-sensitive adhesive sheet stably maintains durability and stain resistance on the structure for a long period of time.

Korean Patent Laid-Open Publication No. 2004-0030919 (2004.04.09) discloses a method of manufacturing a pressure-sensitive adhesive layer having a low surface resistivity by using an organic salt as an antistatic agent, but the organic salt is expensive and has sufficient adhesive properties. May not be secured.

Japanese Laid-Open Patent No. 1994-128539 (1994.05.10) discloses a method of providing antistatic properties by mixing polyether polyol and one or more alkali metal salts, but the above-described adhesive properties may not be sufficiently secured. .

Korean Patent Publication No. 2004-0030919 Japanese Laid-Open Patent No. 1994-128539

An object of the present invention is to provide a pressure-sensitive adhesive composition capable of manufacturing a protective sheet having improved folding properties, low-adhesion properties, and mechanical stability.

One object of the present invention is to provide a protective sheet having improved folding properties, low adhesive properties, and mechanical stability.

1.Contains a urethane-based resin and a solvent formed from a polyol and a polyfunctional isocyanate compound, and the equivalent ratio (OH/NCO) of the hydroxy group of the polyol and the isocyanate group of the polyfunctional isocyanate compound is 1.5 to 4, a pressure-sensitive adhesive composition.

2. In the above 1, the hydroxy group of the polyol and the equivalent ratio (OH/NCO) of the isocyanate group of the polyfunctional isocyanate compound is 2 to 4, the pressure-sensitive adhesive composition.

3. In the above 1, wherein the polyol has a weight average molecular weight of 2,500 or less, the pressure-sensitive adhesive composition.

4. The pressure-sensitive adhesive composition of the above 1, wherein the polyol comprises at least one selected from the group consisting of polycarbonate polyol, polyester polyol, polyether polyol, and polycaprolactone polyol.

5. In the above 1, wherein the polyfunctional isocyanate compound is a polyfunctional alicyclic isocyanate compound, the pressure-sensitive adhesive composition

6. In the above 1, wherein the polyfunctional isocyanate compound is that the isocyanate groups are arranged asymmetrically, the pressure-sensitive adhesive composition.

7. In the above 1, the content of the urethane-based resin is 40 to 60% by weight of the total weight of the pressure-sensitive adhesive composition, the pressure-sensitive adhesive composition.

8. The pressure-sensitive adhesive composition of the above 1, further comprising an antistatic agent.

9. In the above 8, wherein the antistatic agent comprises a salt of a metal cation and a fluorine-containing anion, the pressure-sensitive adhesive composition.

10. In the above 9, wherein the fluorine-containing anion contains (bis) fluorine sulfonyl imide anion, the pressure-sensitive adhesive composition.

11. Formed from the pressure-sensitive adhesive composition according to any one of the above 1 to 10, a protective sheet.

12. The protective sheet according to 11 above, which is provided for protecting the surface of the display element of the display panel.

The pressure-sensitive adhesive composition according to the embodiments of the present invention satisfies the ratio (OH/NCO) of a predetermined hydroxy group and an isocyanate group, and damages and adhesion of the object due to improved folding and low-adhesion properties upon peeling. Component residue can be prevented. In addition, since it has improved aging stability, air bubbles, peeling, etc. can be prevented, and stable durability can be maintained for a long period of time.

In addition, the pressure-sensitive adhesive composition according to exemplary embodiments may be applied to, for example, an organic light-emitting display (OLED) panel, thereby providing a protective sheet having improved low-adhesion and folding characteristics.

1 to 3 are cross-sectional views illustrating a display panel or an image display device to which a protective sheet is applied according to exemplary embodiments.

According to embodiments of the present invention, the pressure-sensitive adhesive composition includes a urethane-based resin and a solvent formed from a polyol and a polyfunctional isocyanate compound, and the equivalent ratio of the hydroxy group of the polyol and the isocyanate group of the polyfunctional isocyanate compound (OH/NCO) May be about 1.5 to 4. The pressure-sensitive adhesive composition can be effectively applied, for example, as a low-adhesion protective sheet for an image display device.

Hereinafter, embodiments of the present invention will be described in detail.

<Adhesive composition>

The pressure-sensitive adhesive composition according to embodiments of the present invention may include a urethane-based resin and a solvent.

The urethane-based resin may be obtained by curing a polyol and an isocyanate-based compound.

Non-limiting examples of the polyol include polycarbonate polyol, polyester polyol, polyether polyol, polycaprolactone polyol, and the like. These may be used alone or in combination of two or more.

For example, the polycarbonate polyol may include a condensate of a polyol compound and a carbonic acid diester-based compound. The polyol compound is ethylene glycol, diethylene glycol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, 2-butyl-2-ethyl-1,3- Propanediol, 2,4-diethyl-1,5-pentanediol, 1,2-hexanediol, 1,6-hexanediol, 1,8-octane diol, 1,9-nonanediol, 2-methyl-1 ,8-octane diol, 1,8-decane diol, octadecane diol, etc. are mentioned. These may be used alone or in combination of two or more.

The carbonic acid diester-based compound may include dimethyl carbonate, diethyl carbonate, diisopropyl carbonate, dibutyl carbonate, ethyl butyl carbonate, ethylene carbonate, propylene carbonate, and the like. These may be used alone or in combination of two or more.

In addition, the polycarbonate polyol may include a copolymer of the condensate and an additional compound. The additional compound may include, for example, a carboxyl group-containing compound, a hydroxy group-containing compound, an ester-based compound, and the like.

The polyester polyol may include, for example, a condensation product of the above-described polyol compound and an organic acid-based compound.

For example, the organic acid-based compound is succinic acid, adipic acid, pimelic acid, azelaic acid, sebacic acid, 1,12-dodecane diacid, 1,14-tetradecane diacid, terephthalic acid, phthalic acid, isophthalic acid, 1, 4-naphthalene dicarboxylic acid or an anhydride thereof. These may be used alone or in combination of two or more.

The polyether polyol may include, for example, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, and the like.

The polycaprolactone polyol may include, for example, a polyester diol formed through ring-opening polymerization of ε-caprolactone.

In some embodiments, the urethane-based resin may be formed or polymerized as a polyol, preferably including polycarbonate polyol and/or polycaprolactone polyol, more preferably polycarbonate polyol. Therefore, due to the three-dimensional molecular structure of the sp2 hybrid orbitals of the above-described polyols, it is predicted that the low-adhesive properties and folding properties of the pressure-sensitive adhesive composition can be further improved, and damage and residues of the object can be prevented during re-peel. However, it is limited to this theory and should not be interpreted.

In some embodiments, the polyol may include a multifunctional polyol having a weight average molecular weight (Mw) of 2,500 or less, preferably 1,500 to 2,500, and preferably a difunctional polyol, and accordingly, the pressure-sensitive adhesive composition has low-adhesive properties. And the folding characteristics are further strengthened to prevent residues during the re-peeling process and to suppress damage to the object.

The polyfunctional isocyanate compound may include a polyfunctional isocyanate compound that can be used in the urethanization reaction, for example, a polyfunctional aliphatic isocyanate compound, a polyfunctional alicyclic isocyanate, a polyfunctional aromatic isocyanate compound, and the like. These may be used alone or in combination of two or more.

Examples of the polyfunctional aliphatic isocyanate compound include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, 1,2-propylene diisocyanate, 2,3-butylene diisocyanate, 1,3 -Butylene diisocyanate, dodecamethylene diisocyanate, 2,4,4-trimethyl hexamethylene diisocyanate, etc. are mentioned.

Examples of the polyfunctional alicyclic isocyanate compound include 3-isocyanate methyl-3,5,5-trimethylcyclohexyl isocyanate, 1,3-cyclopentane diisocyanate, 1,3-cyclohexane diisocyanate, and 1,4-cyclohexane Diisocyanate, methyl-2,4-cyclohexane diisocyanate, methyl-2,6-cyclohexane diisocyanate, 4,4'-methylenebis (cyclohexyl isocyanate), 1,4-bis (isocyanate methyl) cyclohexane, 1,4-bis(isocyanate methyl) cyclohexane. 4,4'-dicyclohexylmethane diisocyanate, etc. are mentioned.

Examples of the polyfunctional aromatic isocyanate compound include 1,3-phenylene diisocyanate, 4,4'-diphenyl diisocyanate, 1,4-phenylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4 -Tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4'-toluidine diisocyanate, 4,4'-diphenyl ether diisocyanate, and the like.

In some embodiments, the polyfunctional isocyanate compound may preferably be a polyfunctional alicyclic isocyanate compound, and when the polyfunctional alicyclic isocyanate compound is formed, a urethane-based resin with a polyol has a high reaction rate, and is formed therefrom. It is good to be able to effectively prevent the yellowing of the adhesive layer or the protective sheet.

In some embodiments, the polyfunctional isocyanate-based compound may have isocyanate groups arranged asymmetrically. For example, a plurality of isocyanate groups contained in the polyfunctional isocyanate-based compound may be asymmetrically disposed within the molecular structure, so that each isocyanate group may be bonded to a different polyol molecule, so that a urethane-based resin can be easily formed, The hydroxy group of the polyol and the equivalent ratio (OH/NCO) of the isocyanate group of the polyfunctional isocyanate compound can be easily satisfied in the range described below, thereby further improving the folding and low-adhesion properties of the protective sheet made of the pressure-sensitive adhesive composition. have. As a non-limiting example of a polyfunctional isocyanate compound in which isocyanate groups are arranged asymmetrically, isophorone diisocyanate is mentioned.

According to exemplary embodiments, the equivalent ratio (OH/NCO) of the hydroxy group of the polyol and the isocyanate group of the polyfunctional isocyanate compound may be about 1.5 to 4, and accordingly, the urethane formed from the polyol and the polyfunctional isocyanate compound By controlling the degree of crosslinking of the series resin, a protective sheet having excellent low-adhesion properties and folding properties can be implemented. When the urethane-based resin is formed from the polyol and the polyfunctional isocyanate compound, the conversion (yield) may be maintained at, for example, about 90% or more, and the hydroxyl groups contained in the polyol are unreacted according to the equivalent ratio. Or, it may react with an isocyanate group to form a urethane bond.

When the equivalence ratio is less than about 1.5, the protective sheet to be manufactured becomes too stiff to reduce the folding property, thereby causing damage to the object, and the stability over time may be deteriorated. When the equivalence ratio is greater than about 4, for example, unreacted polyol may increase, resulting in bubbles and poor peeling during coating, and durability of the manufactured protective sheet may be reduced.

In some embodiments, the equivalence ratio may be preferably about 2 to 4, and a desired low-adhesion property and folding property may be preferably implemented in the equivalence ratio range. Etc. can be effectively prevented.

The urethane-based resin may be included in an amount of about 40 to 60% by weight based on the total weight of the pressure-sensitive adhesive composition.

When the content of the urethane-based resin is less than about 40% by weight, mechanical durability or adhesion of the pressure-sensitive adhesive composition or protective sheet may be excessively deteriorated, and stability over time may also be deteriorated. When the content of the urethane-based resin exceeds about 60% by weight, it is difficult to realize the low-adhesion property, and the specific resistance increases, so that antistatic properties may also be deteriorated. Preferably, the content of the urethane-based resin may be about 45 to 60% by weight.

In some embodiments, the urethane-based resin may further include a catalyst to promote curing or crosslinking reaction of the polyol and the isocyanate-based compound.

The catalyst may include an organometallic compound in consideration of compatibility with polyols. Non-limiting examples of the catalyst include iron acetyl acetonate, iron 2-ethylhexanoate, dibutyl tin dichloride, dibutyl tin oxide, dibutyl tin dilaurate, dibutyl tin diacetate, dibutyl tin Sulfide, tributyl tin methoxide, tributyl tin acetate, triethyl tin ethoxide, tributyl tin ethoxide, dioctyl tin oxide, dioctyl tin dilaurate, tributyl tin chloride, tributyl tin trichloroacetate, di Butyl titanium dichloride, tetrabutyl titanate, butoxy titanium trichloride, zirconium naphthenate, zirconium acetylacetonate, and the like. These may be used alone or in combination of two or more.

In one embodiment, a polymerization inhibitor may be used to prevent an increase in adhesive strength due to an increase in the molecular weight of the urethane-based resin. The polymerization inhibitor may include, for example, a hydroquinone-based compound.

The solvent is widely used in the field of an adhesive composition, and may include an organic solvent having excellent compatibility with the urethane-based resin. For example, an organic solvent such as toluene, xylene, methyl ether ketone, polyethylene glycol methyl ether acetate, or the like may be used.

The solvent may be included in a residual amount excluding the urethane-based resin and an antistatic agent, or a residual amount excluding the urethane-based resin, the antistatic agent, and additional agents described below.

The pressure-sensitive adhesive composition according to some embodiments may further include an antistatic agent in addition to the above-described components.

The antistatic agent may include a metal-containing ionic solid. In example embodiments, the antistatic agent may include a fluorine anion solid.

In this case, the antistatic agent may include a salt of a metal cation and a fluorine-containing anion. Examples of the metal cations include alkali metal cations such as lithium cations.

In some embodiments, the fluorine-containing anion may include a (bis) fluor sulfonyl imide anion.

By using the above-described fluorine anion solid, excellent resistance properties and antistatic properties can be implemented even with a small amount. In some embodiments, the antistatic agent may be included in an amount of about 0.01 to 1% by weight based on the total weight of the pressure-sensitive adhesive composition.

When the content of the antistatic agent is less than about 0.01% by weight, sufficient antistatic properties may not be implemented. When the content of the antistatic agent exceeds about 1% by weight, precipitation, bubbles, or peeling of the antistatic agent may be caused. Preferably, in one embodiment, the antistatic agent may be used in an amount of about 0.01 to 0.03% by weight.

In addition, by using the solid salt containing the (bis) fluorosulfonyl imide anion, compatibility with the urethane-based resin containing a polyol may be improved. In addition, it is possible to prevent side effects such as leakage and denaturation in a high-temperature/high-humidity environment that occur when the liquid ionic compound is used.

In some embodiments, the pressure-sensitive adhesive composition may further include an additional agent within a range that does not degrade low-adhesion properties and folding properties.

For example, the pressure-sensitive adhesive composition may further include additional agents such as a solvent, an antioxidant, a corrosion inhibitor, a leveling agent, a surface lubricant, a dye, a pigment, an antifoaming agent, a filler, and a light stabilizer.

The additional agent may be included in an amount of about 0.01% by weight or less based on the total weight of the pressure-sensitive adhesive composition.

As described above, since the pressure-sensitive adhesive composition according to exemplary embodiments has improved low-adhesion properties and folding properties, it is possible to prevent damage to the object and the occurrence of adhesive component residues during re-peeling, and to reduce the incidence of defects such as bubble generation during coating It can be significantly lowered. In addition, when applied as a protective sheet, stability over time and mechanical reliability required for application can be properly secured.

<Protection sheet, display panel, image display device>

1 to 3 are cross-sectional views illustrating a display panel or an image display device to which a protective sheet is applied according to exemplary embodiments.

Referring to FIG. 1, the pressure-sensitive adhesive composition may be applied on at least one surface of the base layer 60 to form the pressure-sensitive adhesive layer 70 through, for example, a drying and/or curing process. The pressure-sensitive adhesive composition may be formed through a coating method such as roll coating, gravure coating, reverse coating, spray coating, air knife coating, and die coater.

The base layer 60 may include, for example, plastic, paper, metal film, nonwoven fabric, or the like. In one embodiment, the base layer 60 may include a plastic film such as a polyester resin, a polaramide resin, a polyimide resin, a polyolefin resin, a polyethylene terephthalate (PET) resin, or the like.

Accordingly, a protective sheet in which the base layer 60 and the adhesive layer 70 are stacked may be manufactured, and the protective sheet may have low adhesion and folding characteristics through the adhesive composition.

In some embodiments, the base layer 60 may be formed on the upper and lower surfaces of the adhesive layer 70, respectively. For example, formed on the lower surface of the adhesive layer 70 After removing the base layer 60, the exposed surface of the adhesive layer 70 may be attached to the display panel 50. Accordingly, the protective sheet may be provided as a surface protective sheet of the display panel 50.

The display panel 50 may include, for example, a thin film transistor (TFT) substrate and a display device (eg, an OLED device or an LCD device) formed on the TFT substrate.

Referring to FIG. 2, in order to laminate an additional optical member or functional layer on the display panel 50, the protective sheet may be peeled off from the display panel 50.

As described above, since the pressure-sensitive adhesive composition has excellent antistatic properties and low-adhesion peeling properties, it can be peeled off without damaging the display elements of the display panel 50. In addition, since the pressure-sensitive adhesive composition has improved stability over time, it is possible to protect the display panel 50 by blocking the occurrence of lift and air bubbles after being attached to the display panel 50.

Referring to FIG. 3, a functional structure 80 may be stacked on one surface of the display panel 50 from which the protective sheet is peeled off. The functional structure 80 may include an optical structure such as a polarizing plate, a retardation film, a hard coating layer, and a window film. In some embodiments, the functional structure 80 may include a touch sensor or a touch screen panel.

As described with reference to FIGS. 1 to 3, when the protective sheet is directly applied to the display panel 50, in order to prevent operation disturbance or damage of the display element due to static electricity or adhesive residue, for example, for a polarizing plate. An improved low-adhesion property compared to the protective sheet may be required.

Accordingly, a protective sheet having improved folding properties and low-adhesion properties can be prepared and applied by using the pressure-sensitive adhesive composition satisfying the equivalent ratio or content of the functional groups according to exemplary embodiments.

Hereinafter, experimental examples including specific examples and comparative examples are presented to aid in understanding of the present invention, but this is only illustrative of the present invention and does not limit the scope of the appended claims, and the scope and technology of the present invention It is obvious to those skilled in the art that various changes and modifications to the embodiments are possible within the scope of the spirit, and it is natural that such modifications and modifications fall within the appended claims.

Examples and Comparative Examples

In a 3L 4-neck flask equipped with an electronic stirrer, heating mentle, cooling tube and temperature controller, a polyfunctional isocyanate compound, a polyfunctional polyol, a catalyst, a polymerization inhibitor, an antistatic agent, and a solvent were prepared in Table 1 below (indicated in parts by weight). Was put into. Specifically, while stirring the isocyanate compound, the polyol, and the polymerization inhibitor, the reaction temperature was increased to 40° C. by self-heating, and when the temperature was kept constant, the catalyst was added and the temperature was gradually raised to 70° C. to react for 6 hours. ^{When the 2250cm- 1} peak, which is the characteristic peak of NCO in FT-IR, disappeared, the reaction was terminated to prepare a urethane-based resin, and an antistatic agent was added to prepare an adhesive composition

The prepared adhesive composition was coated on one side of a PET film (75 μm), dried in an oven at 80° C. for 2 minutes, and then a silicone release-treated PET film (50 μm) was bonded onto the coating layer to form a protective sheet with an adhesive layer of 75 μm. Was prepared.

Example Comparative example One 2 3 4 5 6 One 2 3 Polyol (A) A-1 400 600 - - 300 - 200 100 - A-2 - - 400 600 - - - - 1000 A-3 - - - - - 400 - - - Isocyanate
Series compound (B) B-1 22 22 - - 22 22 22 22 - B-2 - - 26 26 - - - - 22 Catalyst (C) 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 Polymerization inhibitor (D) 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 Antistatic agent (E) 12 12 12 12 12 12 12 12 12 Solvent (F) 435 635 440 635 435 435 235 135 1035 OH/NCO equivalent ratio 2 3 2 3 1.5 2 One 0.5 5 A-1: Polycarbonate polyol (weight average molecular weight (Mw) = 2,000)
A-2: Polycaprolactone polyol (Mw=2,000)
A-3: Polyethylene glycol (Mw=2,000)
B-1: isophorone diisocyanate (IPDI, Mw=220)
B-2: 4,4'-dicyclohexylmethane diisocyanate (Mw=262)
C: dibutyl tin diraulate
D: methoxy hydroquinone
E: lithium bisfluorosulfonylimide
F: methyl ethyl ketone

Experimental example

(1) glass peeling force

The protective sheets of Examples and Comparative Examples were cut to a size of 25 mm×250 mm using a super cutter. Thereafter, the release film (PET film) was peeled and a specimen bonded to a glass plate was prepared. The specimen was fixed to a universal testing machine (UTM) and then ^{peeled at 180°} at a rate of 300 mm/min to measure the peel force on the glass.

(2) liner peeling force

The protective sheets of Examples and Comparative Examples were cut to a size of 25 mm×250 mm using a super cutter to prepare a specimen. The release film of the prepared specimen was partially peeled off, fixed on a universal testing machine (UTM), and peeled at 180° at a speed of 300 mm/min to measure the peel force.

(3) Surface resistivity

Using a surface resistivity meter (MCP-HT450, manufactured by Mitsuishi Chemical), three points of the adhesive layer included in the protective sheet were measured 10 times each, and the surface resistivity was measured with the average value.

(4) Durability over time

After cutting the protective sheets of Examples and Comparative Examples to be 300mm x 220mm, ^{a pressure of 5kg/cm 2} was applied to Corning's #1737 glass, and a specimen was prepared by bonding to prevent bubbles or foreign matters from occurring. After the specimen was left in an oven at 60° C. for 7 days, the occurrence of air bubbles or peeling was observed, and durability over time was evaluated according to the following criteria.

<Evaluation criteria>

Ⓞ: No air bubbles or peeling.

○: Bubbles or peeling <5

△: 5 ≤ bubbles or peeling <10

×: 10 ≤ bubbles or peeling

The evaluation results are shown in Table 2 below.

Referring to Table 2, it can be seen that the optical laminate made of the pressure-sensitive adhesive composition satisfying the OH/NCO equivalent ratio according to the above-described exemplary embodiments has excellent low-adhesion properties and folding properties, and excellent durability over time. .

However, it can be seen that in Comparative Examples 1 to 3 out of the OH/NCO equivalent ratio range according to the embodiments, low-adhesion characteristics and folding characteristics are not substantially implemented, and durability is very deteriorated.

50: display panel
60: base layer
70: adhesive layer
80: functional structure

Claims (12)

It includes a urethane-based resin and a solvent formed from a polyol and a polyfunctional isocyanate compound,
The equivalent ratio (OH/NCO) of the hydroxy group of the polyol and the isocyanate group of the polyfunctional isocyanate compound is 1.5 to 4,
The polyol is a bifunctional polyol having a weight average molecular weight of 2,500 or less, the pressure-sensitive adhesive composition.
The pressure-sensitive adhesive composition according to claim 1, wherein an equivalent ratio (OH/NCO) of the hydroxy group of the polyol and the isocyanate group of the polyfunctional isocyanate compound is 2 to 4.
delete The pressure-sensitive adhesive composition of claim 1, wherein the polyol comprises at least one selected from the group consisting of polycarbonate polyol, polyester polyol, polyether polyol, and polycaprolactone polyol.
The pressure-sensitive adhesive composition according to claim 1, wherein the polyfunctional isocyanate compound is a polyfunctional alicyclic isocyanate compound
The pressure-sensitive adhesive composition of claim 1, wherein the polyfunctional isocyanate compound has isocyanate groups asymmetrically arranged.
The method according to claim 1, wherein the content of the urethane-based resin is 40 to 60% by weight of the total weight of the pressure-sensitive adhesive composition, the pressure-sensitive adhesive composition.
The pressure-sensitive adhesive composition of claim 1, further comprising an antistatic agent.
The pressure-sensitive adhesive composition of claim 8, wherein the antistatic agent comprises a salt of a metal cation and a fluorine-containing anion.
The pressure-sensitive adhesive composition according to claim 9, wherein the fluorine-containing anion contains a (bis) fluor sulfonyl imide anion.
A protective sheet formed from the pressure-sensitive adhesive composition according to any one of claims 1, 2 and 4 to 10.
The protective sheet according to claim 11, which is provided for protecting a surface of a display element of a display panel.

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