Adhesive sheet for display

Abstract

Disclosed is an adhesive sheet for a display, which has excellent foreign matter covering characteristics by satisfying a high initial adhesive force to glass, a low room temperature modulus, and a high adhesive force under high temperature and high humidity. The adhesive sheet according to the present invention is characterized by having a peel force of 1700 gf / 25 mm or more and a room temperature modulus of 0.07 MPa to 0.15 MPa as measured by adhering the adhesive sheet to glass and peeling the adhesive sheet at 180 DEG C at a speed of 5 mm per second after one hour.

Description

Technical Field

[0001] The present invention relates to an adhesive sheet for a display having excellent foreign matter covering characteristics. Background Art

[0002] An integrated circuit (driver integrated circuit (IC)), which is called a chip, is made of a semiconductor material such as silicon. After being formed as small parts of transistors in silicon, they are connected together through interconnections laminated on the silicon surface.

[0003] When an integrated circuit (driver integrated circuit) is mounted on a polyimide film, an adhesive sheet is attached to the surfaces of the polyimide film and the integrated circuit, and the mounting is performed by heating and pressing simultaneously. Therefore, a high-temperature adhesive force of the adhesive sheet is required.

[0004] However, the commonly used adhesive sheet has a hard structure based on butyl acrylate, so there are the following problems: the adhesive force decreases due to the high mounting temperature, resulting in a lifting phenomenon, and due to the lifting phenomenon, air bubbles are generated around the integrated circuit.

[0005] Moreover, the adhesive sheet also has an unfavorable condition in terms of bending characteristics due to its hard structure.

[0006] Therefore, it is necessary to develop an adhesive sheet having excellent characteristics in covering foreign matters such as air bubbles around the integrated circuit. Summary of the Invention

[0007] An object of the present invention is to provide an adhesive sheet for a display, which has excellent foreign matter covering characteristics by satisfying a high initial adhesive force to glass, a low room temperature modulus, and a high adhesive force under high temperature and high humidity.

[0008] Moreover, an object of the present invention is to provide an adhesive sheet for a display having excellent bending characteristics and heat resistance.

[0009] Another object of the present invention is to provide a display component including an adhesive sheet having excellent foreign matter covering characteristics.

[0010] The object of the present invention is not limited to the above-mentioned objects. Other objects and advantages of the present invention not mentioned can be understood from the following description and more clearly understood through the embodiments of the present invention. And it is obvious that the objects and multiple advantages of the present invention can be achieved by the methods and combinations disclosed in the claims of the invention.

[0011] The adhesive sheet of the present invention is characterized in that the peeling force measured by attaching the adhesive sheet to glass and peeling it at a speed of 5 mm per second at 180° after 1 hour is 1700 gf / 25 mm or more, and the room temperature modulus is 0.07 MPa to 0.15 MPa.

[0012] The peel strength of the adhesive sheet to the polyimide film, measured by attaching one side of the adhesive sheet to the polyimide film and leaving it at 25 °C for 24 hours and then peeling it at a rate of 300 mm per minute under conditions of 60 °C and 90% humidity, can be 300 gf / 25 mm or more.

[0013] The peel strength of the adhesive sheet, measured by attaching the adhesive sheet to glass and peeling it at 180° at a rate of 5 mm per second after 24 hours, can be 1800 gf / 25 mm or more.

[0014] The light transmittance measured according to ASTM D 1003 (a standard established by the American Society for Testing and Materials) can be 90% or more, and the haze can be 1.0% or less.

[0015] The adhesive sheet may contain an acrylic resin and a curing agent.

[0016] The acrylic resin may contain an unsubstituted linear or branched (meth)acrylic acid alkyl ester monomer having 1 to 20 carbon atoms, a nitrogen-containing monomer, and an ethylenic monomer having a carboxyl group, and the ethylenic monomer having a carboxyl group may contain acrylic acid (AA) and β-carboxyethyl acrylate (β-CEA).

[0017] In this case, the unsubstituted linear or branched (meth)acrylic acid alkyl ester monomer having 1 to 20 carbon atoms contains 2-ethylhexyl acrylate (2-EHA) and butyl acrylate (BA), and the content of 2-ethylhexyl acrylate may be greater than the content of butyl acrylate.

[0018] Based on the total amount of 100 weight percentages, the acrylic resin may contain 2 to 5 weight percentages of the nitrogen-containing monomer and 4.5 to 10.5 weight percentages of the ethylenic monomer having a carboxyl group.

[0019] The ethylenic monomer having a carboxyl group may contain 1.5 to 4.5 weight percentages of acrylic acid and 3 to 6 weight percentages of β-carboxyethyl acrylate.

[0020] Based on 100 parts by weight of the acrylic resin, the adhesive sheet may contain 0.5 to 1.5 parts by weight of the curing agent.

[0021] The display component of the present invention is characterized by including a polyimide film; an integrated circuit mounted on the polyimide film; and the adhesive sheet disposed on the polyimide film on which the integrated circuit is mounted.

[0022] The adhesive sheet for a display of the present invention has an excellent effect of covering foreign matters by satisfying a high initial adhesion to glass, a low room temperature modulus, and a high adhesion under high temperature and high humidity.

[0023] Moreover, the adhesive sheet for a display has excellent bending characteristics and heat resistance.

[0024] In addition, a display component including the adhesive sheet of the present invention has excellent foreign matter covering characteristics.

[0025] In addition to the above effects, specific effects of the present invention will be described together when explaining the following specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A picture showing improved foreign matter covering characteristics according to Embodiment 1 of the present invention.

[0027] Figure 2 A picture showing improved heat resistance due to excellent high-temperature compression characteristics according to Embodiment 1 of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0028] The above objects, features, and advantages will be described in detail with reference to the accompanying drawings hereinafter, so that those of ordinary skill in the art to which the present invention pertains can easily implement the technical idea of the present invention. When explaining the present invention, if it is determined that a detailed description of a well-known technology related to the present invention may unnecessarily obscure the gist of the present invention, the detailed description will be omitted. Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals are used to denote the same or similar structural elements.

[0029] Hereinafter, providing any structure "above (or below)" a structural element or "on (or under)" a structural element means that the any structure is provided in contact with the upper surface (or lower surface) of the structural element, and other structures may be interposed between the structural element and the any structure provided "on (or under)" the structural element.

[0030] Moreover, when it is described that a certain structural element is "connected", "coupled", or "joined" to another structural element, the plurality of structural elements may be directly connected or joined to each other, but it should be understood that other structural elements may be "interposed" between the structural elements, or the structural elements may be "connected", "coupled", or "joined" through other structural elements.

[0031] Hereinafter, an adhesive sheet for a display according to some embodiments of the present invention will be described.

[0032] The adhesive sheet for a display of the present invention contains N-vinylpyrrolidone (NVP) and β-carboxyethyl acrylate (β-CEA) in the monomer composition of the acrylic resin constituting the adhesive sheet, so that the initial peel strength (after 1 hour of adhesion) to glass can be ensured to be 1700 gf / 25 mm or more, and high adhesive strength can be ensured at low room temperature modulus and high temperature and high humidity.

[0033] Therefore, when an integrated circuit (driver integrated circuit (IC)) is mounted on a polyimide film, the adhesive sheet for a display of the present invention has an excellent effect of covering foreign matters.

[0034] The adhesive sheet of the present invention is characterized in that the peel strength measured by attaching the adhesive sheet to glass and peeling it at a speed of 5 mm per second at 180° after 1 hour is 1700 gf / 25 mm or more, and the room temperature modulus is 0.07 MPa to 0.15 MPa.

[0035] Preferably, the peel strength of the adhesive sheet for a display after attaching it to glass for 1 hour can be 1700 to 3000 gf / 25 mm, more preferably 1800 to 2500 gf / 25 mm, and further preferably 1850 to 2300 gf / 25 mm.

[0036] And, preferably, the room temperature modulus of the adhesive sheet for a display can be 0.09 to 0.14 MPa.

[0037] By satisfying the high initial adhesive strength to glass and low room temperature modulus, the adhesive sheet has an effect of being beneficial to ensuring the foreign matter covering property of the adhesive sheet.

[0038] Regarding the peel strength of the adhesive sheet after 24 hours, the peel strength measured by attaching the adhesive sheet to glass and peeling it at a speed of 5 mm per second at 180° after 24 hours can be 1800 gf / 25 mm or more, preferably 1800 to 3000 gf / 25 mm, and more preferably 1900 to 2500 gf / 25 mm.

[0039] The peel strength of the adhesive sheet after 24 hours satisfies 1800 gf / 25 mm or more, so that the cut part of the attached adhesive sheet can be prevented from floating up, and the expansion of bubbles generated by foreign matters can be prevented. On the contrary, when the peel strength of the adhesive sheet after 24 hours is less than 1800 gf / 25 mm, the problems mentioned above may occur.

[0040] Regarding the adhesive force of the adhesive sheet under high temperature and high humidity conditions, the peeling force from the polyimide film measured by attaching one side of the adhesive sheet to the polyimide film and leaving it at 25°C for 24 hours and then peeling at a rate of 300 mm per minute under the conditions of 60°C and 90% can be 300 gf / 25 mm or more, preferably 310 - 600 gf / 25 mm, and more preferably 310 - 550 gf / 25 mm.

[0041] The adhesive sheet also satisfies high adhesive force under high temperature and high humidity conditions, thereby preventing the phenomenon of bubbles generated around the integrated circuit when the integrated circuit (driver integrated circuit (IC)) is mounted on the polyimide film due to the lifting of the adhesive sheet.

[0042] In the case where the adhesive sheet is applied as an optical component, the light transmittance measured according to ASTM D 1003 can be 90% or more, and the haze can be 1.0% or less.

[0043] Preferably, the light transmittance can be 91% or more, and the haze can be 0.9% or less.

[0044] By satisfying the light transmittance and haze of the adhesive sheet, excellent transparency can be ensured.

[0045] In order to ensure excellent foreign matter covering properties, such an adhesive sheet is preferably formed from a composition having a soft monomer structure, and the adhesive sheet can be a cured product of a composition containing an acrylic resin and a curing agent.

[0046] The acrylic resin may contain an unsubstituted linear or branched (meth)acrylic acid alkyl ester monomer having 1 - 20 carbon atoms, a nitrogen-containing monomer, and an ethylenic monomer having a carboxylic acid group.

[0047] The unsubstituted linear or branched (meth)acrylic acid alkyl ester monomer having 1 - 20 carbon atoms forms the backbone of the adhesive sheet, and the glass transition temperature of the adhesive sheet can be adjusted by adjusting the ratio of 2-ethylhexyl acrylate and butyl acrylate in the constituent monomers. Ultimately, the unsubstituted linear or branched (meth)acrylic acid alkyl ester monomer having 1 - 20 carbon atoms is the main monomer determining the room temperature modulus.

[0048] From this viewpoint, the unsubstituted linear or branched (meth)acrylic acid alkyl ester monomer having 1 - 20 carbon atoms contains 2-ethylhexyl acrylate and butyl acrylate, and the content of 2-ethylhexyl acrylate can be greater than the content of butyl acrylate.

[0049] Preferably, relative to the total amount of 100% by weight, the acrylic resin may contain 45 to 55% by weight of 2-ethylhexyl acrylate and 35 to 45% by weight of butyl acrylate. More preferably, it may contain 46 to 50% by weight of 2-ethylhexyl acrylate and 38 to 44% by weight of butyl acrylate. By containing 45 to 55% by weight of 2-ethylhexyl acrylate and 35 to 45% by weight of butyl acrylate, it is beneficial to ensure a low room temperature modulus and prevent the generation of bubbles after thermocompression bonding.

[0050] If the acrylic resin does not contain 2-ethylhexyl acrylate and the butyl acrylate content exceeds 45% by weight, or the butyl acrylate content is less than 35% by weight, there will be problems of low initial adhesion (after 1 hour of adhesion) to glass or high room temperature modulus.

[0051] Nitrogen-containing monomers generally include: primary amino group-containing monomers such as aminomethyl (meth)acrylate and aminoethyl (meth)acrylate; secondary amino group-containing monomers such as tert-butylaminoethyl (meth)acrylate; and tertiary amino group-containing monomers such as ethylaminoethyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, and diethylaminoethyl (meth)acrylate, etc.

[0052] However, in the present invention, monomers are selected that can enhance the heat resistance characteristics in an alicyclic form while enhancing the adhesion characteristics through a polar structure. From this perspective, the nitrogen-containing monomers used in the present invention impart heat resistance and adhesion by preventing the generation of bubbles after thermocompression bonding, and the monomers may include N-vinylpyrrolidone represented by Structural Formula 1.

[0053] Structural Formula 1:

[0054]

[0055] Ethylenically unsaturated monomers having a carboxylic acid group include acrylic acid and β-carboxyethyl acrylate, which have reaction sites for reacting with a curing agent.

[0056] β-carboxyethyl acrylate can be represented by the following Structural Formula 2.

[0057] Structural Formula 2:

[0058]

[0059] In the present invention, by simultaneously containing a nitrogen monomer and β-carboxyethyl acrylate with a low glass transition temperature, a low room temperature modulus of the adhesive sheet can be ensured.

[0060] Relative to a total of 100 weight percentages, the acrylic resin may contain 2 to 5 weight percentages of nitrogen-containing monomers and 4.5 to 10.5 weight percentages of ethylenic monomers having a carboxylic acid group.

[0061] Preferably, it may contain 6 to 8 weight percentages of ethylenic monomers having a carboxylic acid group, wherein it may contain 1.5 to 4.5 weight percentages of acrylic acid and 3 to 6 weight percentages of β-carboxyethyl acrylate.

[0062] If the nitrogen-containing monomer is less than 2 weight percentages, there is a problem of reduced adhesion to glass and adhesion under high temperature and high humidity. On the contrary, if the nitrogen-containing monomer exceeds 5 weight percentages, there is a problem that the room temperature modulus becomes too high.

[0063] Moreover, if the acrylic resin does not contain β-carboxyethyl acrylate but contains a high content of acrylic acid, it results in the room temperature modulus becoming too high.

[0064] Preferably, a curing agent having a crosslinked structure is introduced, and the crosslinked structure imparts appropriate cohesion to the adhesive sheet.

[0065] The curing agent reacts with functional groups such as hydroxyl groups and carboxyl groups introduced into the acrylic resin to form a crosslinked structure. Therefore, it is preferable to contain an isocyanate curing agent or an epoxy curing agent because of their high reactivity with hydroxyl groups or carboxyl groups and easy introduction of a crosslinked structure.

[0066] As the isocyanate curing agent, a polyisocyanate having 2 or more isocyanate groups per molecule is used. As the polyisocyanate curing agent, for example, it may include lower aliphatic polyisocyanates such as butene diisocyanate and hexamethylene diisocyanate; alicyclic isocyanates such as cyclopentyl diisocyanate, cyclohexyl diisocyanate, and isophorone diisocyanate; aromatic isocyanates such as 2,4-toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, and xylylene diisocyanate; and one or more of isocyanate adducts such as trimethylolpropane / toluene diisocyanate trimer adduct (e.g., "Coronate L" prepared by Tosoh Corporation), trimethylolpropane / hexamethylene diisocyanate trimer adduct (e.g., "Coronate HL" prepared by Tosoh Corporation), trimethylolpropane adduct of xylylene diisocyanate (e.g., "Takenate D110N" prepared by Mitsui Chemicals, Inc.), and isocyanurate of hexamethylene diisocyanate (e.g., "Coronate HX" prepared by Tosoh Corporation).

[0067] As an epoxy-based curing agent, a polyfunctional epoxy compound having two or more epoxy groups per molecule is used. The epoxy groups of the epoxy-based curing agent may include glycidyl groups. As the epoxy-based curing agent, for example, it may include one or more of N,N,N',N'-tetraglycidyl-m-xylenediamine, diglycidylaniline, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, 1,6-hexanediol diglycidyl ether, neopentyl glycol diglycidyl ether, ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, sorbitol polyglycidyl ether, glycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, polyglycerol polyglycidyl ether, dehydrated sorbitol polyglycidyl ether, trimethylolpropane polyglycidyl ether, adipic acid diglycidyl ester, phthalic acid diglycidyl ester, triglycidyl-tris(2-hydroxyethyl)isocyanurate, resorcinol diglycidyl ether, and bisphenol-S-diglycidyl ether.

[0068] With respect to 100 parts by weight of the acrylic resin, the adhesive sheet may contain 0.5 to 1.5 parts by weight of the curing agent. The content of the curing agent satisfies 0.5 to 1.5 parts by weight, so that the room temperature aging time of the adhesive sheet can be shortened and the adhesive strength can be improved.

[0069] If the content of the curing agent exceeds 1.5 parts by weight, there is a problem of reduced adhesive strength under high temperature and high humidity conditions.

[0070] The display component of the present invention is characterized by including a polyimide film; an integrated circuit mounted on the polyimide film; and an adhesive sheet provided on the polyimide film on which the integrated circuit is mounted.

[0071] In the present invention, the adhesive sheet has a flexible structure formed from a nitrogen-containing monomer and an ethylenic monomer having a carboxyl group. Therefore, even at a high mounting temperature, the adhesive strength can be maintained or improved, thereby preventing the lifting phenomenon generated around the integrated circuit. Thus, the problem of air bubble generation in the adhesive sheet can be solved, and excellent foreign matter covering characteristics can be obtained. And due to the soft structure of the adhesive sheet, excellent bending characteristics can be obtained.

[0072] Specific examples of the adhesive sheet for a display are observed as follows.

[0073] 1. Manufacture of the Adhesive Sheet for a Display

[0074] Examples and Comparative Examples

[0075] Prepare the adhesive sheet composition according to Tables 1 to 3.

[0076] Manufacture the adhesive sheet from the adhesive sheet composition and record the results in Tables 1 to 3.

[0077] Evaluation and Results

[0078] Peeling force after adhering to glass for 1 hour

[0079] Cut the adhesive sheets for displays of the said examples and comparative examples into a width of 1 inch. After removing the release film, adhere them to the glass with a clean surface. After 1 hour, measure the peeling force of the adhesive sheet (unit: gf / 25 mm) by peeling at 180° at a speed of 5 mm per second.

[0080] Peeling force after adhering to glass for 24 hours (hr)

[0081] Cut the adhesive sheets for displays of the said examples and comparative examples into a size of 25 mm × 200 mm. After removing the release film, adhere them to the glass with a clean surface. After 24 hours, measure the peeling force of the adhesive sheet (unit: gf / 25 mm) by peeling at 180° at a speed of 5 mm per second.

[0082] Peeling force of polyimide (PI) film under high temperature / high humidity (60 °C, 90%)

[0083] Cut the adhesive sheets for displays of the said examples and comparative examples into a width of 25 mm × 200 mm, then remove the release film. Use a 2 kg hand roller to adhere one side of the adhesive sheet to the polyimide film (thickness: 50 μm) at a speed of 3 m / min. After adhesion, place it at room temperature (25 °C) for 24 hours. Install the polyimide (PI) film on the lower fixture and the adhesive sheet on the upper fixture. Under the conditions of a temperature of 60 °C and a humidity of 90%, perform a "T" - shaped peel at a speed of 300 mm per minute to measure the peeling force of the adhesive sheet (unit: gf / 25 mm).

[0084] Modulus at room temperature (25 °C)

[0085] Apply the compositions of the examples and comparative examples respectively on a heavy release liner (SKC HT&M, RT81N) with a peeling force of 100 gf. At room temperature, laminate a light release liner (SKC, SG31) with a peeling force of 30 gf on the upper part of the heavy release liner coated with the composition using a roller laminator. Then, cure at a temperature of 50 °C for 48 hours to manufacture a shear storage modulus measurement sample with an adhesive layer having a thickness of 1 mm.

[0086] Punch the manufactured measurement sample into a circle with a diameter of 8 mm. After removing the light release liner, adhere it to a parallel plate with a diameter of 8 mm and remove the heavy release liner.

[0087] Afterwards, using a rheometer (TA instrument, ARES G2) as the modulus measurement device, under the conditions of an axial force of 0.5 N, a start temperature of -40 °C, an end temperature of 200 °C, a ramp rate of 10 °C / min, a strain of 1%, and a frequency of 1 Hz, the room temperature storage modulus was measured. After repeating this process a total of 5 times, the average value was calculated.

[0088] Foreign matter covering property

[0089] To simulate foreign matter in the adhesive sheets for displays of the above-described examples and comparative examples, a black circular dot with a diameter of 300 μm and a height of 5 μm was placed on the glass surface, with the direction of the dot in contact with the adhesive surface. After attaching it at a speed of 3 m / min using a 2 kg hand roller, after 7 days, the maximum size of the entire bubble including the dot was measured by microscope to evaluate the size.

[0090] If the bubble size is large, it is judged that the foreign matter covering property is poor; if the bubble size is small, it is judged that the foreign matter covering property is excellent. (O (800 μm or less, excellent), △ (exceeding 800 to less than 1000 μm, medium), X (1000 μm or more, poor))

[0091] Thermal press bonding property

[0092] The release film was removed from the adhesive sheets manufactured in the above-described examples and comparative examples, and samples were taken by attaching them to a polyimide film (polyimide advanced material; GF300 Grade). Each sample was placed in a press bonding device, the temperature of the lower plate was fixed at 60 °C, the temperature of the upper plate was set to change at 10 °C intervals between 150 and 300 °C, and the temperature at which bubbles were generated in the press bonded portion was measured. When placing the sample, the attached polyimide film was positioned above, and a 200 μm Teflon sheet and a wafer with a thickness of 500 μm were cut into 5 mm × 5 mm sizes and placed on the sample. During press bonding, the pressure of the press bonding device was set to 5 kg / cm 2 , and the pressure was applied to the same position as much as possible.

[0093] After the high-temperature press bonding evaluation, the temperature at which bubbles were generated (the temperature at which defects occurred) was recorded. If bubbles were generated at a temperature of 220 °C or lower, it was preliminarily judged as "poor (X)"; if bubbles were generated at a temperature exceeding 220 °C, it was preliminarily judged as "good (○)".

[0094] Light transmittance and haze

[0095] By the ASTM D 1003 method, the haze and light transmittance of the adhesive sheet for displays after peeling off the release liner film were measured using a haze meter (NDH7000).

[0096] Table 1

[0097]

[0098] Referring to Table 1, Examples 1 to 5 all satisfied the composition and composition ratio of the present invention, showing high adhesion to glass and low room temperature modulus, and also excellent adhesion under high temperature and high humidity conditions.

[0099] Therefore, the foreign matter covering characteristics of Examples 1 to 5 were excellent.

[0100] Table 2

[0101]

[0102]

[0103] Referring to Table 2, in Example 6, the content of the curing agent exceeded 1.5 parts by weight, and the adhesion under high temperature and high humidity conditions was low.

[0104] In Comparative Example 7, as the vinyl monomer having a carboxylic acid group that does not contain β-carboxyethyl acrylate and only contains acrylic acid alone, the room temperature modulus showed an excessively high value.

[0105] In Comparative Examples 8 and 9, the content of N-vinylpyrrolidone as the nitrogen-containing monomer was less than 2 wt%, the adhesion to glass and the adhesion under high temperature and high humidity conditions showed low values, and the size of the band-shaped bubbles was 1000 μm or more, resulting in poor foreign matter covering characteristics.

[0106] In Comparative Example 10, the content of N-vinylpyrrolidone as the nitrogen-containing monomer exceeded 5 wt%, and the room temperature modulus showed an excessively high value.

[0107] Table 3

[0108]

[0109]

[0110] In the past, a hard structure based on butyl acrylate was used, resulting in poor foreign matter covering characteristics and bending characteristics.

[0111] However, in the present invention, as the unsubstituted linear or branched (meth)acrylic acid alkyl ester monomer having 1 to 20 carbon atoms, 2-ethylhexyl acrylate and butyl acrylate are included, and within the range of 45 to 55 wt% of 2-ethylhexyl acrylate and 35 to 45 wt% of butyl acrylate, by adding more 2-ethylhexyl acrylate than butyl acrylate, the soft characteristics of the adhesive sheet are exhibited.

[0112] In Comparative Example 11, the content of butyl acrylate is less than 35 wt%, and the content of N-vinylpyrrolidone as the nitrogen-containing monomer exceeds 5 wt%, resulting in an excessively high room temperature modulus.

[0113] In Comparative Example 12, as the unsubstituted linear or branched (meth)acrylic acid alkyl ester monomer having 1 to 20 carbon atoms, only butyl acrylate is included alone, and as the ethylenically unsaturated monomer having a carboxyl group, only acrylic acid is included alone, and 15 wt% of ethyl acrylate is included. In Comparative Example 12, the initial adhesion to glass and the adhesion under high temperature and high humidity conditions are too low, and the room temperature modulus shows an excessively high value. And the size of the strip-shaped bubbles is 1000 μm or more, resulting in poor foreign matter covering characteristics and generating bubbles after thermocompression bonding.

[0114] In Comparative Example 13, the contents of acrylic acid and β-carboxyethyl acrylate as the ethylenically unsaturated monomers having a carboxyl group respectively exceed the specified contents, resulting in a high room temperature modulus.

[0115] In Comparative Example 14, the content of β-carboxyethyl acrylate as the ethylenically unsaturated monomer having a carboxyl group exceeds 6 wt%, resulting in a low room temperature modulus.

[0116] Figure 1 A picture showing that the foreign matter covering characteristics are improved according to Example 1 of the present invention.

[0117] Refer to Figure 1 , when the adhesive sheet is attached to the foreign matter adsorbed on the display panel, the generation of bubbles is minimized due to the low storage elastic modulus. And, due to the high adhesion after attaching the adhesive sheet, the problem that the size of the bubbles generated due to the foreign matter adsorbed on the display panel expands over time is solved.

[0118] Figure 2 A picture showing that the heat resistance is improved due to the excellent high temperature compression characteristics according to Example 1 of the present invention.

[0119] Refer to Figure 2 , during high temperature compression bonding, no deformation due to pressing appears on the surface. And, when confirmed with the naked eye, it is confirmed that even at a high mounting temperature, due to the high adhesion of the adhesive sheet, no bubbles are generated due to floating at high temperature around the integrated circuit.

[0120] As described above, the present invention has been illustrated with reference to the accompanying drawings. However, the present invention is not limited to the embodiments and the drawings disclosed in this specification. Obviously, those of ordinary skill in the technical field to which the present invention pertains can make various modifications within the scope of the technical idea of the present invention. Moreover, even if the effects of the structure according to the present invention are not explicitly described and explained in the above description of the embodiments of the present invention, the effects predictable from the corresponding structure should also be recognized.

Claims

1. An adhesive sheet, characterized in that: The peeling force measured by attaching the adhesive sheet to glass and peeling it off at 180° at a speed of 5 mm per second after 1 hour was 1700 gf / 25 mm or more, and the room temperature modulus was 0.07 MPa to 0.15 MPa.

2. The adhesive sheet according to claim 1, characterized in that The peeling force to the polyimide film measured by attaching one side of the adhesive sheet to the polyimide film and leaving it at 25° C. for 24 hours and then peeling it at 60° C. and 90% at a speed of 300 mm per minute is 300 gf / 25 mm or more.

3. The adhesive sheet according to claim 1, characterized in that The peeling force measured by attaching the adhesive sheet to glass and peeling it off at 180° at a speed of 5 mm per second after 24 hours was 1800 gf / 25 mm or more.

4. The adhesive sheet according to claim 1, characterized in that The light transmittance measured according to ASTM D 1003 is 90% or more, and the haze is 1.0% or less.

5. The adhesive sheet according to claim 1, characterized in that The adhesive sheet includes an acrylic resin and a curing agent.

6. The adhesive sheet according to claim 5, characterized in that The acrylic resin comprises an unsubstituted linear or branched (meth)acrylic acid alkyl ester monomer having 1 to 20 carbon atoms, a nitrogen-containing monomer, and a vinyl monomer having a carboxylic acid group. The vinyl monomer having a carboxylic acid group includes acrylic acid and β-carboxyethyl acrylate.

7. The adhesive sheet according to claim 6, characterized in that The unsubstituted linear or branched (meth) alkyl acrylate monomer having 1 to 20 carbon atoms includes 2-ethylhexyl acrylate and butyl acrylate. The content of 2-ethylhexyl acrylate is greater than that of butyl acrylate.

8. The adhesive sheet according to claim 6, characterized in that The acrylic resin includes 2 to 5 weight percent of a nitrogen-containing monomer and 4.5 to 10.5 weight percent of a vinyl monomer having a carboxylic acid group, relative to a total amount of 100 weight percent. 9 . The adhesive sheet according to claim 8 , wherein the vinyl monomer having a carboxylic acid group comprises 1.5 to 4.5 weight percent of acrylic acid and 3 to 6 weight percent of β-carboxyethyl acrylate.

10. The adhesive sheet according to claim 5, characterized in that The adhesive sheet includes 0.5 to 1.5 parts by weight of a curing agent based on 100 parts by weight of the acrylic resin.

11. A display component, characterized in that: include: Polyimide film; an integrated circuit mounted on the polyimide film; as well as The adhesive sheet according to claim 1, which is provided on the polyimide film on which the integrated circuit is mounted.

Images