KR102473652B1 - Protection film for display window - Google Patents

Abstract

The protective film for a display window according to the present invention includes a base film and an adhesive layer formed on the base film, the adhesive layer is attached to a surface having a water contact angle of 115 ° or less, and then left at a temperature of 60 ° C for 72 hours. It has a characteristic that peeling of 5 mm or less occurs in Through this, the protective film for a display window according to the present invention has stable adhesion to the display window surface having a high water contact angle to prevent contamination, and can provide a protective film with excellent adhesion and reliability even when bent or bent.

Description

Protective film for display window {PROTECTION FILM FOR DISPLAY WINDOW}

The present invention relates to a protective film for a display window, and more specifically, to a protective film applied to a curved display window having a high water contact angle, which has stable adhesion to the surface of a display window having a high water contact angle, so that even when bent or bent, adhesion and It relates to a protective film for a display window having excellent reliability.

Recently, changes in the display market have been made rapidly, and very various types of displays are being used in various devices. As one of various displays, a touch screen display is used in various fields because a user can use the screen itself as an input interface without using a separate input device. In addition, since a mobile device does not need to have a separate input interface through a touch screen display, a touch screen display is being used very actively.

In particular, in the case of the mobile market, the touch screen display has become the standard of the smartphone form factor as the touch method has begun to be applied in the keypad type keyboard input method. With the development of these smartphones, the mobile market has expanded exponentially, and with the spread of touch screens, they have gone beyond being used in mobile devices such as smartphones and have begun to replace the role of mouse and keyboard, which are the existing PC input interfaces. As it begins to be widely used in vehicles and home appliances, its usage is expanding at a rapid pace.

Due to the expansion of the touch area, the problem of contamination from the outside has begun to emerge in the case of a window substrate (glass or film) located on the outermost layer of a display, including a mobile. In particular, the above-mentioned problems are more prominent as the size of the display increases. In order to prevent this, various additional treatments are performed on the surface of the window substrate that comes into contact with the outside. Anti Finger Printing (AFP) is one of several additional treatments to prevent contamination. Anti-fingerprint coating is a method that utilizes the property of preventing contaminants from adhering to the outside by increasing the water contact angle. When such an anti-fingerprint coating is applied, surface contamination generated from a user's finger or other objects can be reduced.

However, due to the nature of the anti-fingerprint coating, which prevents contaminants from sticking to the outside by increasing the water contact angle, in the case of a protective film that must be attached to the surface of the anti-fingerprint coating, the low water contact angle causes the peel force value along with the zipping noise. The width of the maximum-minimum value of is increased) phenomenon occurs, making it difficult to attach stably. In addition, recently, when a flexible display is used and the display shape is curved or folded, the protective film is detached when the display does not have stable adhesion.

Japanese Laid-open Patent No. 2011-532061

The present invention has been made to solve the above-mentioned problems, and the problem to be solved by the present invention is to prevent contamination and damage of the display surface in the manufacturing process and distribution process in the protective film, a high water contact angle to prevent contamination It is intended to provide a protective film for a display window having a stable adhesive force on the display surface.

The above and other objects and advantages of the present invention will become apparent from the following description of preferred embodiments.

The above object includes a base film and an adhesive layer formed on the base film, and after attaching the adhesive layer to a surface with a water contact angle of 115 ° or less, peeling of 5 mm or less in the curvature evaluation performed after leaving it at 60 ° C for 72 hours It is achieved by the protective film for the display window generated.

Preferably, the peel force measured after attaching the adhesive layer to the surface having a water contact angle of 115° or less and then leaving it for 30 minutes may be 150 to 400 gf/inch.

Preferably, the adhesive layer may include a first silicone adhesive, a second silicone adhesive having higher adhesive strength than the first silicone adhesive, and a tackifier.

Preferably, the content ratio of the second silicone pressure sensitive adhesive to the first silicone pressure sensitive adhesive may be 1:1.5 to 4.

Preferably, it may include 1 to 30 parts by weight of the tackifier based on 100 parts by weight of the first silicone pressure-sensitive adhesive.

Preferably, the first silicone pressure-sensitive adhesive may include an MQ resin.

Preferably, the second silicone pressure-sensitive adhesive may include at least one organosiloxane polymer having a vinyl functional group according to Formula 1.

(Formula 1)

R ₁ R ₂ ViSiO (R ₃ R ₄ SiO) _n SiR ₅ R ₆ Vi

Here, R ₁ , R ₂ , R ₃ , R ₄ , R ₅ and R ₆ are C1-6 alkyl groups or phenyl groups, which may be the same or different, and R ₁ , R ₂ , R ₃ , R ₄ , R ₅ and The alkyl group represented by R ₆ may be any one of methyl, ethyl, propyl, butyl, pentyl, hexyl, cyclopentyl and cyclohexyl, and n is an integer of 1 or greater.

Preferably, the tackifier may include one or more organohydrogensilicon compounds according to formula (2).

(Formula 2)

-(R ₇ HSiO) _n -

Here, R ₇ is a C1-6 alkyl group or a phenyl group, the alkyl group represented by R ₇ may be any one of methyl, ethyl, propyl, butyl, pentyl, hexyl, cyclopentyl, and cyclohexyl, and n is an integer of 1 or more.

Preferably, the adhesive layer may further include a hydrosilylation catalyst.

Preferably, the thickness of the adhesive layer may be 20 to 120 μm.

Preferably, when a member having a water contact angle of 115° or less, a display substrate, a display adhesive layer, and a release film are sequentially laminated on the adhesive layer, the peeling force may satisfy Equation 1 below.

(Equation 1)

X/Y ≥ 2

Here, X is the surface peeling force of the member having a water contact angle of 115 ° or less with the adhesive layer, and Y is the peeling force between the display adhesive layer and the release film.

The protective film for a display window according to the present invention has stable adhesion to the display window surface having a high water contact angle to prevent contamination, and has effects such as excellent adhesion and reliability even when bent or bent.

However, the effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description below.

1 is a configuration diagram of a protective film for a display window according to an embodiment of the present invention.
2 is a view showing an example of attaching a protective film for a display window according to an embodiment of the present invention to a display window.
3 is a view showing a test member in which a surface having a water contact angle of 110 ° and a substrate are laminated on a protective film for a display window according to an embodiment of the present invention.
Figure 4 is a view for explaining the evaluation of the curvature of the protective film for a display window according to an embodiment of the present invention.

With reference to the accompanying drawings, embodiments of the present invention will be described in detail so that those skilled in the art can easily carry out the present invention. However, the present invention may be embodied in many different forms and is not limited to the embodiments described herein.

In the drawings, the thickness is shown enlarged to clearly express the various layers and regions. Like reference numerals have been assigned to like parts throughout the specification. When a part such as a layer, film, region, plate, etc. is said to be “on” another part, this includes not only the case where it is “directly on” the other part, but also the case where there is another part in between. Conversely, when a part is said to be "directly on" another part, it means that there is no other part in between.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In case of conflict, the present specification, including definitions, will control. Also, although methods and materials similar or equivalent to those described herein may be used in the practice or testing of the present invention, suitable methods and materials are described herein.

1 is a configuration diagram of a protective film for a display window according to an embodiment of the present invention. Referring to FIG. 1 , the protective film for a display window according to an embodiment of the present invention includes a base film 110 and an adhesive layer 120, and may further include an adhesive protective film 130.

The base film 110 serves as a support layer for the adhesive tape and may include an adhesive layer and a material having adhesion. For example, the base film 110 may include a plastic material such as a polyester-based material such as polyethylene terephthalate (PET), a polycarbonate-based material, a polyolefin-based material, or a polyimide-based material. In addition, more specifically, the base film 110 may include polyester-based polymers such as polyethylene terephthalate and polyethylene naphthalate, poly(meth)acrylic polymers such as polymethyl methacrylate; It may include a base film such as polystyrene-based polymers or copolymers such as polystyrene and poly(acrylonitrile-styrene) copolymers (AS resins), or/and polycarbonate-based polymers. In addition, the base film 110 may be formed of polyethylene, polypropylene, a polyolefin-based polymer having a cyclo or norbornene structure, a polyolefin-based copolymer such as an ethylene-propylene copolymer, a polyvinyl chloride-based polymer, nylon, or an aromatic polyamide. Polyamide-based polymer, polyimide-based polymer, polysulfone-based polymer, polyethersulfone-based polymer, poly(ether-ether) ketone-based polymer, polyphenylene sulfide-based polymer, polyvinyl alcohol-based polymer, polyvinylidene chloride-based polymer , polyvinyl butyral-based polymers, polyallylate-based polymers, polyoxymethylene-based polymers, epoxy-based polymers, polyurethane-based polymers, poly(acrylic-urethane)-based polymers, and thermosetting curable resins or ultraviolet curable resins such as silicone-based polymers. may be included, and may be used alone or in combination.

In addition, the base film 110 may further include an additive material such as an ultraviolet absorber capable of absorbing ultraviolet rays or an antioxidant to suppress browning of the ultraviolet absorber according to a necessary purpose.

In one embodiment, the adhesive layer 120 may include a first silicone adhesive, a second silicone adhesive, and a tackifier. The second silicone adhesive may have higher adhesive strength than the first silicone adhesive.

In one embodiment, the content ratio of the second silicone adhesive to the first silicone adhesive in the adhesive layer 120 is preferably 1:1.5 to 4. That is, it is preferable that the second silicone pressure sensitive adhesive is 150 to 400 parts by weight based on 100 parts by weight of the first silicone pressure sensitive adhesive.

At this time, when the content of the second silicone adhesive is less than 150 parts by weight, the adhesive strength is low and the peeling force is low, so zipping does not occur, but peeling occurs during reliability evaluation, and when it exceeds 400 parts by weight, the content of hard-type silicone is excessive As a result, zipping occurs and peeling occurs during repeated bending.

In one embodiment, the adhesive layer 120 may include 1 to 30 parts by weight of a tackifier based on 100 parts by weight of the first silicone pressure-sensitive adhesive. At this time, when the content of the tackifier is less than 1 part by weight, the effect of imparting adhesion of the tackifier is insufficient, and when it is greater than 30 parts by weight, the adhesive force by the tackifier does not increase.

In one embodiment, the first silicone adhesive included in the adhesive layer 120 has lower adhesive strength than the second silicone adhesive and may include an MQ resin. MQ resins include resins with R3SiO _1/2 (M units) and SiO _4/2 (Q units), where each R is a predetermined alkyl group, such as a methyl group. However, other aliphatic groups having up to about 20 carbon atoms may be used in place of the methyl group without departing from the scope of the present invention. Also, the molar ratio of M units:Q units may range from about 0.6:1 to 4:1. In addition, the MQ resin may contain up to 5% by weight of silanol functionality, although less than about 1% by weight may alternatively be used.

In one embodiment, the second silicone adhesive included in the adhesive layer 120 includes one or more organosiloxane polymers having a vinyl functional group. One or more organosiloxane polymers having a vinyl functional group are organosiloxane polymers endblocked with a vinyl functional group represented by Formula 1 below. These components may also contain additional vinyl functional groups. These two or more organosiloxane polymers can adjust the viscosity and degree of curing after coating by varying the molecular weight.

(Formula 1)

R ₁ R ₂ ViSiO (R ₃ R ₄ SiO) _n SiR ₅ R ₆ Vi

Here, R ₁ , R ₂ , R ₃ , R ₄ , R ₅ and R ₆ are C1-6 alkyl groups or phenyl groups, which may be the same or different, and R ₁ , R ₂ , R ₃ , R ₄ , R ₅ and The alkyl group represented by R ₆ may be any one of methyl, ethyl, propyl, butyl, pentyl, hexyl, cyclopentyl and cyclohexyl, and n is an integer of 1 or greater.

In addition, the weight average molecular weight of the compound of Formula 1 is preferably 25,000 to 200,000, because in this case, folding and bending properties are good.

In one embodiment, the tackifier included in the adhesive layer 120 includes one or more organic hydrogen silicon compounds. The at least one organohydrogensiloxane compound is a compound represented by Formula 2 and includes at least one cross-linked organohydrogensiloxane compound having an average of 2 or more Si-H bonds per molecule. Organohydrogensiloxane compounds suitable for use in the present invention may be linear, branched, or cyclic molecules, and any mixture or combination thereof.

(Formula 2)

-(R ₇ HSiO) _n -

Here, R ₇ is a C1-6 alkyl group or a phenyl group, the alkyl group represented by R ₇ may be any one of methyl, ethyl, propyl, butyl, pentyl, hexyl, cyclopentyl, and cyclohexyl, and n is an integer of 1 or more.

In one embodiment, the adhesive layer 120 may further include a hydrosilylation catalyst to increase the reaction rate. The hydrosilylation catalyst may include any catalyst known to one skilled in the art to be useful for catalyzing a hydrosilylation reaction. As an example, the hydrosilylation catalyst is preferably a platinum group metal-containing catalyst. By definition, a platinum group metal refers to the ruthenium, rhodium, palladium, osmium, iridium, and platinum metals, as well as any mixtures or complexes thereof. The platinum group metal may include solid or hollow particles, a layer deposited on a carrier such as silica gel or powdered charcoal, or an organometallic compound or complex. Some examples of platinum-containing catalysts include chloroplatinic acid in hexahydrate form or anhydrous form, and platinum-containing catalysts obtained by reacting chloroplatinic acid or this chloroplatinum with an aliphatic unsaturated organosilicon compound. One specific example of a hydrosilylation catalyst, among many examples, is 1,3 diethenyl-1,1,2,2-tetramethyldi, diluted with a vinyl endblocked polymer, having a platinum concentration of about 5,200 ppm. Preferred is the Pt 4000 catalyst (Dow Corning Corporation), described as a platinum complex of siloxanes.

As an example, a release film coated with fluorine silicon may be used as the adhesive protective film 130 .

As described above, in the protective film for a display window manufactured using the first silicone adhesive, the second silicone adhesive, and the tackifier, after removing the adhesive protective film 130, the adhesive layer 120 has a water contact angle of 115° or less. After attaching to the surface, it is preferable that peeling of 5 mm or less occurs in the bending evaluation after being left at a temperature of 60 ° C. for 72 hours. This is because the protective film is easily peeled off from the display window and cannot properly protect the display window when peeling of more than 5 mm occurs in the curvature evaluation.

In addition, after removing the adhesive protective film 130, the adhesive layer 120 is attached to the surface having a water contact angle of 115 ° or less, and then the peel force measured after leaving for 30 minutes is preferably 150 to 400 gf / inch. If the measured adhesive force of the adhesive layer 120 is less than 150 gf/inch, peeling may occur on the curved substrate, and if it has an adhesive force of more than 400 gf/inch, the window layer may be destroyed when peeled from the window layer due to the high adhesive force. do.

In one embodiment, the thickness of the adhesive layer 120 is preferably 20 to 120㎛. If the thickness of the adhesive layer 120 is less than 20 μm, it is not possible to form an adhesive force of 500 gf / inch or more due to the low thickness on the surface at a water contact angle of 110 °, and if it exceeds 120 μm, cost and time in manufacturing the adhesive tape It can be said to be uneconomical.

2 is a view showing an example of attaching a protective film for a display window according to an embodiment of the present invention to a display window.

Referring to FIG. 2 , a protective film for a display window according to the present invention is attached to the surface of the display window to protect the display in the process of manufacturing and distributing/transporting a device including the display window. According to such an example, in the protective film for a display window including the base film 110 and the adhesive layer 120, a member having a water contact angle of 115 ° or less on the surface of the adhesive layer 120 (display window, 10), Through a structure in which the display substrate 20, the display adhesive layer 30, and the release film 40 are sequentially laminated, a member (display window 10) having a water contact angle of 115° or less is protected. A member having a water contact angle of 115 ° or less (display window, 10) means a display window having a water contact angle of 115 ° or less among display windows used in various devices, and the display substrate 20 is a member having a water contact angle of 115 ° or less (display window , 10), the display adhesive layer 30 is a component for bonding and fixing a member (display window, 10) having a water contact angle of 115 ° or less, and the release film 40 is the display adhesive layer 30 It is a configuration to protect the At this time, the adhesive layer 120 and the member having a water contact angle of 115 ° or less (display window, 10) and the peel force between the display adhesive layer 30 and the release film 40 are preferably according to Equation 1.

(Equation 1)

X/Y ≥ 2

Here, X is the surface peeling force of the member having a water contact angle of 115 ° or less with the adhesive layer, and Y is the peeling force between the display adhesive layer and the release film.

At this time, when the peel force ratio described in Equation 1 is less than 2, a process problem occurs in that the adhesive protective film is peeled off when the release film is peeled off in a subsequent process.

Hereinafter, the present invention will be described in more detail through examples. These examples are intended to explain the present invention in more detail, and the scope of the present invention is not limited to these examples.

[Example]

[ Example One]

MQ resin (trade name 810, Wacker Co.) as the first silicone adhesive, at least one organosiloxane polymer having a vinyl functional group (trade name 815, Wacker Co.) as the second silicone adhesive, and organohydrogen silicon compound (trade name HITACK, Wacker Co.) as a tackifier ) at a weight ratio of 1:2:0.01 and stirred at room temperature for 2 hours to sufficiently mix.

Also, as a catalyst, 0.5 g of a platinum complex of 1,3 diethenyl-1,1,2,2-tetramethyldisiloxane diluted with a vinyl endblocked polymer having a platinum content of 5,200 ppm was added to this mixture to make a total of 100 g. to form an adhesive layer composition that matches the

Next, the prepared adhesive composition was coated on a PET film (trade name: XD500P, Toray Advanced Materials) having a thickness of 50 μm to a thickness of 30 μm after drying, and dried and cured in an oven at 140° C. for 3 minutes. Thereafter, an adhesive protective film was laminated on the prepared adhesive layer to prepare a multilayer protective film having a structure of adhesive protective film/adhesive layer/PET base film.

[Example 2]

A protective film was prepared in the same manner as in Example 1, except that the mixing ratio of the MQ resin, the organosiloxane polymer, and the organohydrogen silicon compound was 1:2:0.3.

[Example 3]

A protective film was prepared in the same manner as in Example 1, except that the mixing ratio of the MQ resin, the organosiloxane polymer, and the organic hydrogen silicon compound was 1:3:0.01, and the thickness after drying was 20 μm.

[Example 4]

A protective film was prepared in the same manner as in Example 3, except that the mixing ratio of the MQ resin, the organosiloxane polymer, and the organohydrogen silicon compound was 1:3:0.3.

[Example 5]

A protective film was prepared in the same manner as in Example 1, except that the thickness of the adhesive layer was 120 μm after drying.

[Example 6]

A protective film was prepared in the same manner as in Example 1, except that the mixing ratio of the MQ resin, the organosiloxane polymer, and the organohydrogen silicon compound was 1:1.5:0.3.

[Example 7]

A protective film was prepared in the same manner as in Example 1, except that the mixing ratio of the MQ resin, the organosiloxane polymer, and the organosiloxane compound was 1:4:0.3.

[Comparative Example]

[Comparative Example 1]

A protective film was prepared in the same manner as in Example 1, except that the mixing ratio of the MQ resin, the organosiloxane polymer, and the organosiloxane compound was 0:1:0.3, and the thickness of the adhesive layer was coated to be 50 μm after drying.

[Comparative Example 2]

A protective film was prepared in the same manner as in Comparative Example 1, except that the mixing ratio of the MQ resin, the organosiloxane polymer, and the organohydrogen silicon compound was 0:1:0.

[Comparative Example 3]

A protective film was prepared in the same manner as in Comparative Example 1, except that the mixing ratio of the MQ resin, the organosiloxane polymer, and the organohydrogen silicon compound was 1:4.1:0.01.

[Comparative Example 4]

A protective film was prepared in the same manner as in Comparative Example 1, except that the mixing ratio of the MQ resin, the organosiloxane polymer, and the organohydrogen silicon compound was 1:1.4:0.01.

[Comparative Example 5]

A protective film was prepared in the same manner as in Comparative Example 1, except that the mixing ratio of the MQ resin, the organosiloxane polymer, and the organohydrogen silicon compound was 3:1:0.01.

[Comparative Example 6]

A protective film was prepared in the same manner as in Example 1, except that the mixing ratio of the MQ resin, the organosiloxane polymer, and the organosiloxane compound was 1:4:0.01, and the thickness of the adhesive layer was coated to be 19 μm after drying.

[Comparative Example 7]

A protective film was prepared in the same manner as in Example 1, except that the mixing ratio of the MQ resin, the organosiloxane polymer, and the organohydrogen silicon compound was 1:2:0.005.

For the films prepared in Examples 1 to 7 and Comparative Examples 1 to 7, physical properties were evaluated through the following experimental examples, and the results are shown in Table 1.

[Experimental example]

(1) Peel force (gf/25㎜)

As shown in FIG. 2, after removing the adhesive protective film from the prepared protective film, attaching the surface 210 having a water contact angle of 110 ° to the surface of the adhesive layer 120, and then cutting it into a size of 25 mm * 15 cm to prepare a sample. 180 degree peel test at a speed of 5 mm/sec (0.3 m/min) using a Texture Analyzer (TAXplus/50, SMS Co.) at the time when 30 minutes have elapsed after attaching the surface 210 with a water contact angle of 110 ° ( Peel test) was used to measure the peel strength.

(2) Zipping evaluation

As shown in FIG. 3, after removing the adhesive protective film from the prepared protective film, attaching the surface 210 having a water contact angle of 110 ° and the base material 220 to the surface of the adhesive layer 120, and then having a size of 25 mm * 15 cm. A sample was prepared by cutting, and 5 mm/sec (0.3 m/min) while measuring the peel force by the 180-degree peel test method, the average value of the highest and lowest values in the adhesive force measurement section ±50gf/inch or more non-periodically or periodically 10% of the measured length The presence or absence of zipping in the above section was evaluated.

○: No zipping

X: zipping occurs

(3) Bending evaluation

A sample was prepared by cutting the protective film prepared as shown in FIG. 3 into a size of 500 mm X 500 mm, and when the sample was folded using an automatic bending evaluation machine, Foldy-100 (Flexigo), it was folded 200,000 times at a distance of 5 mm. Stretching was repeated, and the presence or absence of peeling before and after bending was evaluated.

○: No peeling

X: Exfoliation occurs

(4) evaluation of flexion

A sample was prepared by cutting the protective film prepared as shown in FIG. 3 into 200 mm * 20 mm, and polycarbonate, which is an adherend, was attached to the prepared examples and comparative examples as shown in FIG. 310), make a bend in the bending resistance evaluation jig 320 with a width of 180 mm, install the specimen, leave it at 60 ° C for 72 hours, and then put it into evaluation conditions to measure the peeled distance.

No. 1
silicon 2nd
silicon cohesion
granting agent adhesive layer
Thickness (㎛) Peel force
(gf/25㎜) zipping
evaluation bending
evaluation flexion evaluation
(mm) Example 1 One 2 0.01 30 175 ○ ○ 4 Example 2 One 2 0.3 30 155 ○ ○ 5 Example 3 One 3 0.01 20 162 ○ ○ 4 Example 4 One 3 0.3 20 157 ○ ○ 4 Example 5 One 2 0.01 120 348 ○ ○ 2 Example 6 One 1.5 0.3 30 177 ○ ○ 5 Example 7 One 4 0.3 30 165 ○ ○ 4 Comparative Example 1 0 One 0.3 50 250 X X 24 Comparative Example 2 0 One 0 50 20 X X 48 Comparative Example 3 One 4.1 0.01 50 165 X X 21 Comparative Example 4 One 1.4 0.01 50 78 X X 25 Comparative Example 5 3 One 0.01 50 18 ○ X 52 Comparative Example 6 One 4 0.01 19 98 ○ X 25 Comparative Example 7 One 2 0.005 30 121 X X 22

As shown in Table 1, in Examples 1 to 7, adhesive strength was 150 to 400 gf / inch, and no zipping phenomenon occurred, so good results were obtained in bending evaluation and bending evaluation. As such, it can be confirmed that the protective film for a display window according to the present invention has excellent physical properties in a flexible substrate having a water contact angle of 115 ° or less.

On the other hand, through Comparative Examples 1 to 7 outside the configuration of the present invention, it can be seen that defects occur in bending evaluation and bending evaluation of substrates having a water contact angle of 115 ° or less when the adhesive force is lower than 150 gf / inch or zipping occurs.

More specifically, Comparative Example 1 not including the first silicone adhesive showed that zipping occurred and defects occurred in bending evaluation and bending evaluation, and Comparative Example 2 containing only the second silicone adhesive had very low adhesive strength. It can be seen that zipping occurs and defects occur in bending evaluation and bending evaluation.

In addition, it can be seen that Comparative Example 3 with an excessive amount of the second silicone adhesive causes zipping and defects in bending evaluation and bending evaluation, and Comparative Example 4 with a small amount of the second silicone adhesive has very low adhesive strength, It can be seen that Comparative Example 5, in which the first silicone adhesive is excessive, has very low adhesive strength and defects occur in bending evaluation and bending evaluation.

In addition, Comparative Example 6 having a thin adhesive layer has very low adhesive strength and it can be seen that defects occur in bending evaluation and bending evaluation, and Comparative Example 7 lacking a tackifier has a very low adhesive strength in all of the zipping evaluation, bending evaluation, and bending evaluation. It can be seen that defects occur.

Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concept of the present invention defined in the following claims are also made according to the present invention. falls within the scope of the rights of

10: display window
20: display substrate
30: display adhesive layer
40: release film
110: base film
120: adhesive layer
130: adhesive protective film
210: water contact angle 110° surface
220: base
310: Final evaluation specimen for evaluation of flexural resistance
320: jig for evaluating bending resistance

Claims (11)

base film; and
an adhesive layer formed on the base film;
Including,
After attaching the adhesive layer to the surface with a water contact angle of 115 ° or less, peeling of 5 mm or less occurs in the bending evaluation performed after leaving it at 60 ° C for 72 hours,
After attaching the adhesive layer to a surface having a water contact angle of 115 ° or less, the peel force measured after leaving for 30 minutes is 150 to 400 gf / inch, a protective film for a display window. delete According to claim 1,
The adhesive layer includes a first silicone adhesive, a second silicone adhesive having a higher adhesive strength than the first silicone adhesive, and a tackifier, a protective film for a display window. According to claim 3,
The content ratio of the second silicone pressure-sensitive adhesive to the first silicone pressure-sensitive adhesive is 1: 1.5 to 4, a protective film for a display window. According to claim 3,
A protective film for a display window comprising 1 to 30 parts by weight of the tackifier based on 100 parts by weight of the first silicone pressure-sensitive adhesive. According to claim 3,
The first silicone pressure-sensitive adhesive is a protective film for a display window comprising an MQ resin. According to claim 3,
The second silicone pressure-sensitive adhesive includes at least one organosiloxane polymer having a vinyl functional group according to Formula 1,
(Formula 1)
R ₁ R ₂ ViSiO (R ₃ R ₄ SiO) _n SiR ₅ R ₆ Vi
Here, R ₁ , R ₂ , R ₃ , R ₄ , R ₅ and R ₆ are C1-6 alkyl groups or phenyl groups, which may be the same or different, and R ₁ , R ₂ , R ₃ , R ₄ , R ₅ and The alkyl group represented by R ₆ may be any one of methyl, ethyl, propyl, butyl, pentyl, hexyl, cyclopentyl and cyclohexyl, and n is an integer of 1 or more, a protective film for a display window. According to claim 3,
The tackifier comprises one or more organohydrogen silicon compounds according to Formula 2,
(Formula 2)
-(R ₇ HSiO) _n -
Here, R ₇ is a C1-6 alkyl group or a phenyl group, and the alkyl group represented by R ₇ may be any one of methyl, ethyl, propyl, butyl, pentyl, hexyl, cyclopentyl, and cyclohexyl, and n is an integer of 1 or more. Protective film for windows. According to claim 3,
The adhesive layer further comprises a hydrosilylation catalyst, a protective film for a display window. According to claim 1,
The thickness of the adhesive layer is 20 to 120㎛, a protective film for a display window. According to claim 1,
When a member having a water contact angle of 115 ° or less, a display substrate, a display adhesive layer, and a release film are sequentially laminated on the adhesive layer, the peel force satisfies Equation 1 below,
(Equation 1)
X/Y ≥ 2
Here, X is the surface peeling force of the member having a water contact angle of 115 ° or less with the adhesive layer, and Y is the peeling force between the display adhesive layer and the release film. Protective film for display windows.

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