Adhesive Composition, Liquid Crystal Display, and Disassembly Method Thereof

Abstract

The present invention discloses an adhesive composition, a liquid crystal display and a disassembly method thereof. The adhesive composition includes: 0.1 to 1 part by weight of a plurality of nanoparticles; 50 to 95 parts by weight of an acrylate resin; and 5 to 50 parts by weight of a polyfunctional acrylate or a monomer or oligomer of acrylic acid, and the total weight of the acrylate resin and the polyfunctional acrylate or the monomer or oligomer of acrylic acid is 100 parts by weight, wherein the weight average molecular weight of the acrylate resin is 100,000 to 1,500,000. The shell layer of the nanoparticle covers a partial surface of the core, and an acrylate group is grafted to the surface of the core. The adhesive composition of the present invention has characteristics such as high transmittance, low haze, and resolvability. When recycling or reworking, the adhesive layer can be simply irradiated with near-infrared rays to resolve the glue, so as to achieve the effect of disassembling the liquid crystal display.

Description

Technical Field

[0001] The present invention relates to an adhesive composition, a liquid crystal display, and a disassembly method thereof, and particularly to an adhesive composition that can be debonded after irradiating high-energy near-infrared rays, a liquid crystal display including the adhesive composition, and a method for disassembling the liquid crystal display. Background Art

[0002] Currently, commercially available optical adhesives pursue high adhesion and reliability, so they are designed as permanent curing materials. However, once the optical adhesive is adhered, it cannot be disassembled, and there are problems such as residual glue and damaged polarizers after stripping the adhesive for rework, which need to be discarded.

[0003] In summary, there is an urgent need for a new adhesive layer with characteristics such as high transmittance, low haze, and debondability. Summary of the Invention

[0004] The purpose of the present invention is to provide an adhesive composition with characteristics such as high transmittance, low haze, and debondability, a liquid crystal display including the adhesive composition, and a method for disassembling the liquid crystal display.

[0005] The adhesive composition provided by an embodiment of the present invention includes: 0.1 to 1 part by weight of a plurality of nanoparticles; 50 to 95 parts by weight of an acrylate resin; and 5 to 50 parts by weight of a polyfunctional acrylate or a monomer or oligomer of acrylic acid, and the total weight of the acrylate resin and the polyfunctional acrylate or the monomer or oligomer of acrylic acid is 100 parts by weight, wherein the weight average molecular weight of the acrylate resin is 100,000 to 1,500,000; wherein the nanoparticles have a core, a shell layer, and an acrylate group, the core is selected from silicon oxide, the shell layer is at least one of gold, silver, and copper, the shell layer covers a part of the surface of the core, and the acrylate group is grafted to the surface of the core, wherein the adhesive force of the adhesive composition before irradiating near-infrared rays is 0.5 Kg / in to 1.5 Kg / in, and the adhesive force after irradiating near-infrared rays is 0 to 0.3 Kg / in.

[0006] In some embodiments, the weight ratio of the core to the shell layer is 50:100 to 100:100.

[0007] In some embodiments, the weight ratio of the core to the acrylate group is 60:100 to 110:100.

[0008] In some embodiments, the size of the nanoparticles is 10 nm to 200 nm.

[0009] In some embodiments, the monomer of the acrylate resin includes 50 to 99% by weight of a first monomer with a Tg of -15°C to -70°C, and 1 to 50% by weight of a second monomer with a Tg higher than -15°C.

[0010] In some embodiments, the first monomer includes at least one of ethyl acrylate, 2-ethylhexyl acrylate, butyl acrylate, isooctyl acrylate, isobutyl acrylate, isodecyl acrylate, lauryl acrylate, 2-propylheptyl acrylate, heptadecyl acrylate, tetrahydrofurfuryl acrylate, ethoxyethoxyethyl acrylate, methoxypolyethylene glycol acrylate, isodecyl methacrylate, lauryl methacrylate, isotridecyl methacrylate, and methoxypolyethylene glycol methacrylate.

[0011] In some embodiments, the first monomer includes butyl acrylate and 2-ethylhexyl acrylate.

[0012] In some embodiments, the second monomer includes at least one of vinyl acetate, acrylonitrile, acrylamide, styrene, methyl methacrylate, methyl acrylate, methacrylic acid, acrylic acid, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, and glycidyl methacrylate.

[0013] In some embodiments, the second monomer includes methyl methacrylate, acrylic acid, and 2-hydroxyethyl acrylate.

[0014] In some embodiments, the polyfunctional acrylate or acrylic acid includes at least one of 1,6-hexanediol diacrylate, 1,9-nonanediol diacrylate, 1,10-decanediol diacrylate, neopentyl glycol diacrylate, 2-hydroxy-3-propyl methacrylate, polyethylene glycol diacrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, polypropylene glycol diacrylate, polytetramethylene glycol diacrylate, polyethylene polypropylene glycol diacrylate, dialkylene glycol diacrylate, tricyclodecane dimethanol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, bis-trimethylolpropane tetraacrylate, dipentaerythritol polyacrylate, pentaerythritol polyacrylate, 1,6-hexanediol dimethacrylate, 1,9-nonanediol dimethacrylate, 1,10-decanediol dimethacrylate, and neopentyl glycol dimethacrylate.

[0015] In some embodiments, a thermal initiator is further included.

[0016] In some embodiments, the energy intensity of the near-infrared ray is 1500 mJ / cm 2 to 2500 mJ / cm 2 .

[0017] A liquid crystal display provided by an embodiment of the present invention includes: an upper substrate including a first adhesive layer between a color filter substrate and an upper polarizer; a lower substrate including a second adhesive layer between a thin film transistor substrate and a lower polarizer; and a liquid crystal layer between the color filter of the upper substrate and the thin film transistor substrate of the lower substrate; wherein the first adhesive layer, the second adhesive layer, or both of the above include the above-mentioned adhesive composition.

[0018] A method for disassembling a liquid crystal display provided by an embodiment of the present invention includes: providing the above-mentioned liquid crystal display; separating the upper substrate and the lower substrate; and irradiating the upper substrate, the lower substrate, or both of the above with near-infrared rays to de-bond the first adhesive layer, the second adhesive layer, or both of the above.

[0019] The adhesive composition of the present invention has sufficient adhesive force, and the adhesive force decreases significantly (i.e., it is easy to de-bond) after irradiating with near-infrared rays. When recycling or reworking, it is possible to simply irradiate with near-infrared rays to de-bond the adhesive layer, so as to achieve the effect of disassembling the liquid crystal display. Description of the Drawings

[0020] Figure 1 It is a schematic diagram of a liquid crystal display in an embodiment of the present invention.

[0021] Among them, reference numerals:

[0022] BM: Black matrix

[0023] CF: Color filter

[0024] S: Spacer

[0025] TFT: Thin film transistor

[0026] 100: Liquid crystal display

[0027] 110: Upper substrate

[0028] 111: Color filter substrate

[0029] 113: First adhesive layer

[0030] 115: Upper polarizer

[0031] 117, 127: Glass substrate

[0032] 120: Lower substrate

[0033] 121: Thin film transistor substrate

[0034] 123: Second adhesive layer

[0035] 125: Lower polarizer

[0036] 130: Liquid crystal layer Detailed Description of the Invention

[0037] An adhesive composition provided by an embodiment of the present invention includes: 0.1 to 1 part by weight of a plurality of nanoparticles; 50 to 95 parts by weight of an acrylate resin; and 5 to 50 parts by weight of a polyfunctional acrylate or a monomer or oligomer of acrylic acid, and the total weight of the acrylate resin and the polyfunctional acrylate or the monomer or oligomer of acrylic acid is 100 parts by weight. If the proportion of the nanoparticles is too low, the adhesive composition may have almost no debonding effect after irradiating near-infrared light. If the proportion of the nanoparticles is too high, it may negatively affect the light transmittance and haze of the adhesive composition. If the proportion of the acrylate resin is too low (or the proportion of the polyfunctional acrylate or the monomer or oligomer of acrylic acid is too high), the adhesive force of the adhesive composition may be insufficient. If the proportion of the acrylate resin is too high (or the proportion of the polyfunctional acrylate or the monomer or oligomer of acrylic acid is too low), the debonding effect of the adhesive composition after irradiating near-infrared light may be insufficient.

[0038] In some embodiments, the weight-average molecular weight of the acrylate resin is 100,000 to 1,500,000. If the weight-average molecular weight of the acrylate resin is too low, the adhesiveness is poor and it is easy to debond. If the weight-average molecular weight of the acrylate resin is too high, the viscosity is too high and it is not easy to be photo-debonded.

[0039] In some embodiments, the nanoparticles have a core, a shell, and acrylate groups. For example, the core is silica. If the core is other oxides such as titanium oxide or zirconium oxide, it is not easy to absorb NIR light sources. In some embodiments, the shell is at least one selected from gold, silver, and copper, and the shell covers a partial surface of the core. The acrylate groups are grafted to the surface of the core. In some embodiments, the method of grafting the acrylate groups to the core surface is to use a compound having a siloxanyl group (such as Si-OR, where R is an alkyl group) or a silanol group (such as Si-OH) at one end and an acrylate group at the other end to react with the Si-OH on the core surface. For example, the above compound can be 3-(methacryloyloxy)propyltrimethoxysilane, 3-(methacryloyloxy)propylmethyldiethoxysilane, 3-(methacryloyloxypropyl)triethoxysilane, 3-(acryloyloxy)propyltrimethoxysilane, or a combination of the above. In some embodiments, the weight ratio of the core to the shell is 50:100 to 100:100, 50:100 to 95:100, or 70:100 to 90:100. If the proportion of the shell is too low, the debonding effect of the adhesive composition after irradiating near-infrared light may be insufficient. If the proportion of the shell is too high, the proportion of the acrylate groups grafted to the core surface is too low, resulting in the nanoparticles being unable to be effectively dispersed in the adhesive composition. In some embodiments, the weight ratio of the core to the acrylate groups is 60:100 to 110:100, 70:100 to 100:100, or 90:100 to 100:100. If the proportion of the acrylate groups is too low, the nanoparticles cannot be effectively dispersed in the adhesive composition. If the proportion of the acrylate groups is too high, the proportion of the shell covering the core is too low, resulting in insufficient debonding effect of the adhesive composition after irradiating near-infrared light.

[0040] In some embodiments, the adhesive force of the adhesive composition before irradiating near-infrared light is 0.5 Kg / in to 1.5 Kg / in, and the adhesive force after irradiating near-infrared light is 0 to 0.3 Kg / in. If the adhesive force of the adhesive composition before irradiating near-infrared light is too low, it is not easy to effectively adhere to the layer to be adhered (such as a glass substrate and a polarizer). If the adhesive force of the adhesive composition after irradiating near-infrared light is too high, it means that the adhesive composition is not debonded or is insufficiently debonded, resulting in the adhesive composition remaining on the layer to which it is adhered.

[0041] In some embodiments, the size of the nanoparticles is 10 nm to 200 nm, 50 nm to 200 nm, or 100 nm to 200 nm. If the size of the nanoparticles is too small, it will be difficult to debond the adhesive composition after irradiating near-infrared light. If the size of the nanoparticles is too large, it will negatively affect the light transmittance and haze of the adhesive composition.

[0042] In some embodiments, the monomers of the acrylate resin include 50 to 99 wt% of a first monomer having a glass transition temperature (Tg) of -15°C to -70°C, and 1 to 50 wt% of a second monomer having a Tg higher than -15°C. If the proportion of the first monomer is too low (i.e., the proportion of the second monomer is too high), it is difficult to increase the viscosity and it is not easy to meet the viscosity specification. If the proportion of the first monomer is too high (i.e., the proportion of the second monomer is too low), the viscosity is too high, which will cause difficulty in smoothly completing the debinding.

[0043] In some embodiments, the first monomer includes at least one of ethyl acrylate, 2-ethylhexyl acrylate, butyl acrylate, isooctyl acrylate, isobutyl acrylate, isodecyl acrylate, lauryl acrylate, 2-propylheptyl acrylate, heptadecyl acrylate, tetrahydrofurfuryl acrylate, ethoxyethoxyethyl acrylate, methoxypolyethylene glycol acrylate, isodecyl methacrylate, lauryl methacrylate, isotridecyl methacrylate, and methoxypolyethylene glycol methacrylate. For example, the first monomer includes butyl acrylate and 2-ethylhexyl acrylate.

[0044] In some embodiments, the second monomer includes at least one of vinyl acetate, acrylonitrile, acrylamide, styrene, methyl methacrylate, methyl acrylate, methacrylic acid, acrylic acid, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, and glycidyl methacrylate. For example, the second monomer includes methyl methacrylate, acrylic acid, and 2-hydroxyethyl acrylate.

[0045] It can be understood that the "monomer or oligomer of polyfunctional acrylate or acrylic acid" refers to the monomer of polyfunctional acrylate, the oligomer of polyfunctional acrylate, the monomer of polyfunctional acrylic acid, or the oligomer of polyfunctional acrylic acid. In some embodiments, the polyfunctional acrylate or acrylic acid includes at least one of 1,6-hexanediol diacrylate, 1,9-nonanediol diacrylate, 1,10-decanediol diacrylate, neopentyl glycol diacrylate, 2-hydroxy-3-propyl methacrylate, polyethylene glycol diacrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, polypropylene glycol diacrylate, polytetramethylene glycol diacrylate, polyethylene polypropylene glycol diacrylate, dialkylene glycol diacrylate, tricyclodecane dimethanol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, bis-trimethylolpropane tetraacrylate, dipentaerythritol polyacrylate, pentaerythritol polyacrylate, 1,6-hexanediol dimethacrylate, 1,9-nonanediol dimethacrylate, 1,10-decanediol dimethacrylate, and neopentyl glycol dimethacrylate.

[0046] In some embodiments, the adhesive composition further includes a catalytic amount of a thermal initiator. For example, the thermal initiator can be a peroxide or an azo compound, such as benzoyl peroxide, dioctyl peroxydicarbonate, dimyristyl peroxydicarbonate, dilauroyl peroxide, didecanoyl peroxide, 2,5-dimethyl-2,5-bis(2-ethylhexanoylperoxy)hexane, 1,1,3,3-tetramethylbutyl peroxy-2-ethylhexanoate, t-amyl peroxy-2-ethylhexanoate, t-butyl peroxy-2-ethylhexanoate, t-butyl peroxy diethylacetate, t-butyl peroxyisobutyrate, 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane, azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), or 1,1'-azobis(hexahydrobenzyl cyanide).

[0047] In some embodiments, the energy intensity of the near-infrared light that irradiates the adhesive composition to make it de-bond is 1500 mJ / cm 2 to 2500 mJ / cm 2 . For example, the wavelength of the near-infrared light is 800 nm to 1500 nm. If the energy intensity of the near-infrared light is too low, it is not easy to make the adhesive composition de-bond. If the energy intensity of the near-infrared light is too high, it may damage the object adhered by the adhesive composition (such as a polarizer, a color filter substrate, or a thin film transistor substrate). It should be noted that near-infrared light with a certain energy intensity is required to have the effect of making the adhesive composition de-bond. For example, even if the ambient light contains near-infrared light, generally low-intensity near-infrared light is not easy to make the adhesive composition de-bond, resulting in the failure of the device containing the adhesive composition.

[0048] As Figure 1 shown, a liquid crystal display 100 provided by an embodiment of the present invention includes: an upper substrate 110, including a first adhesive layer 113 located between a color filter substrate 111 and an upper polarizer 115; a lower substrate 120, including a second adhesive layer 123 located between a thin film transistor substrate 121 and a lower polarizer 125; and a liquid crystal layer 130, located between the color filter substrate 111 of the upper substrate 110 and the thin film transistor substrate 121 of the lower substrate 120. In some embodiments, the first adhesive layer 113, the second adhesive layer 123, or both of the above include the above-mentioned adhesive composition. In Figure 1 it, the color filter substrate 111 includes a glass substrate 117 and a color filter CF (including a black matrix BM) formed thereon, and the thin film transistor substrate 121 includes a thin film transistor TFT and a glass substrate 127. In some embodiments, spacers S can be used to separate the upper substrate 110 and the lower substrate 120 to define the thickness of the liquid crystal layer 130. It should be noted that Figure 1The liquid crystal display 100 shown is only for illustration. Those with common general knowledge in this technical field can adopt any known liquid crystal display, and use the adhesive composition of the present invention to adhere the polarizer and the glass substrate to achieve the effects described in the present invention.

[0049] An embodiment of the present invention provides a method for disassembling a liquid crystal display, including: providing Figure 1 the liquid crystal display 100 shown; separating the upper substrate 110 and the lower substrate 120; and irradiating the upper substrate 110, the lower substrate 120, or both with near-infrared rays to de-bond the first adhesive layer 113, the second adhesive layer 123, or both. In this way, the upper polarizer 115, the lower polarizer 125, or both can be separated from the upper substrate 110, the lower substrate 120, or both, with almost no problem of residual adhesive. As can be seen from the above, by using the adhesive composition of the present invention, when recycling or reworking, the adhesive layer can be simply de-bonded by irradiating near-infrared rays to achieve the effect of disassembling the liquid crystal display.

[0050] In some embodiments, the acrylate resin and the multi-functional acrylate or the monomer or oligomer of acrylic acid do not contain epoxy groups or isocyanate groups, so the adhesive composition is easy to de-bond after irradiating with near-infrared rays.

[0051] To make the above content, other purposes, features, and advantages of the present invention more obvious and understandable, the following specifically gives preferred embodiments and, in conjunction with the accompanying drawings, makes a detailed description as follows:

[0052] [Examples]

[0053] Synthesis Example 1

[0054] Take 55 parts by weight of butyl acrylate, 23 parts by weight of 2-ethylhexyl acrylate, 10 parts by weight of methyl methacrylate, 8 parts by weight of acrylic acid, 4 parts by weight of 2-hydroxyethyl acrylate, 0.3 parts by weight of benzoyl peroxide, and mix with 150 parts by weight of ethyl acetate, then heat to 80 °C and stir at 250 rpm for 6 hours to obtain an acrylate resin with a solid content of about 40 wt%, a weight average molecular weight of about 500,000 to 800,000 (GPC analysis, brand: Waters, calibrated with polystyrene as the standard each time), and a viscosity of 6000 cps to 15000 cps (BROOKFIELD viscometer). Coating the above acrylate resin on a PET substrate, and then placing it in an oven at 50 °C for 5 minutes to dry, to obtain a dry film with a thickness of 20 μm to 25 μm. Attach the dry film to a 10 cm * 10 cm stainless steel plate and measure its adhesive force (1.4 Kg / in, measurement standard: JISZO237).

[0055] Synthesis Example 2

[0056] Take 50 g of a 20 wt% SiO2 dispersion (dispersed in water, with an average particle size of 30 ± 6 nm, nano sol purchased from Changchun Petrochemical Company), mix it with 13.5 g of 3-(trimethoxysilyl)-propyl methacrylate and 1.5 g of 3-aminopropyl triethoxysilane, react at 40 °C for 4 hours, then cool to room temperature and continue stirring for 48 hours to obtain a SiO2 core grafted with acrylate (methacrylate) and amino groups on its surface. Then add chloroauric acid (HAuCl4) to the above solution, followed by sodium citrate, and then add NH2OH.HCl to reduce chloroauric acid / Na2CO3 to form a gold shell-coated part of the silica core, that is, SiO2 / Au core-shell composite particles with acrylate grafted on the surface. The weight ratio of the SiO2 core to the Au shell is 80:100, and the weight ratio of the SiO2 core to the grafted acrylate group is 95:100. The average particle size of the nanoparticles is about 150 nm. The above dispersion can be further diluted or concentrated to obtain the desired dispersion concentrations such as 1%, 5%, and 10%.

[0057] Comparative Example 1

[0058] Take 80 g of the acrylate resin of Synthesis Example 1, 20 g of dipentaerythritol hexaacrylate as a polyfunctional acrylate, and 0.5 g of benzoyl peroxide as a thermal initiator, stir evenly for 24 hours, then coat it on a polarizing film by a doctor blade method, and then place it in an oven at 50 °C for 5 minutes to dry to obtain a dry film (i.e., an adhesive composition) with a thickness of 20 μm to 25 μm. The transmittance of the dry film is 92% (measuring method: ultraviolet-visible light spectrometer), and the haze is 0.45% (measuring method: haze meter). Attach the dry film to a 10 cm * 10 cm stainless steel plate and measure the adhesive force (1.2 Kg / in, measurement standard: JISZO237). Irradiate the polarizing film with near-infrared light with a wavelength of 800 nm to 1500 nm, a power of 2 kW, and an intensity of 2000 mJ / cm 2 to release the dry film. The adhesive force of the dry film after release is 1.2 Kg / in, that is, there is no release effect.

[0059] Example 1-1

[0060] Take 80 g of the acrylate resin of Synthesis Example 1, 20 g of dipentaerythritol hexaacrylate as a polyfunctional acrylate, 0.5 g of a dispersion of SiO2 / Au core-shell composite particles grafted with acrylate on the surface of Synthesis Example 2 (containing 1% composite particles), and 0.5 g of benzoyl peroxide as a thermal initiator. After uniformly stirring for 24 hours, it is coated on a polarizing film by a doctor blade method, and then placed in an oven at 50 °C for 5 minutes to dry, so as to obtain a dry film (i.e., an adhesive composition) with a thickness of 20 μm to 25 μm. The transmittance of the dry film is 90% (the measurement method is an ultraviolet-visible spectrometer), and the haze is 0.5% (the measurement method is a haze meter). The dry film is attached to a 10 cm * 10 cm stainless steel plate, and the adhesive force is measured (1.2 Kg / in, the measurement standard is JIS ZO237). The polarizing film is irradiated with near-infrared light with a wavelength of 800 nm to 1500 nm, a power of 2 kW, and an intensity of 2000 mJ / cm 2 to debond the dry film. The adhesive force of the dry film after debonding is 0.2 Kg / in (the measurement standard is JIS ZO237). From the above, it can be seen that the adhesive composition of Example 1-1 has sufficient adhesive force, and the adhesive force decreases significantly after irradiation with high-energy near-infrared light (i.e., it has the near-infrared debonding property).

[0061] Example 1-2

[0062] Take 80 g of the acrylate resin of Synthesis Example 1, 20 g of dipentaerythritol hexaacrylate as a polyfunctional acrylate, 0.5 g of a dispersion of SiO2 / Au core-shell composite particles grafted with acrylate on the surface of Synthesis Example 2 (containing 5% composite particles), and 0.5 g of benzoyl peroxide as a thermal initiator. After uniformly stirring for 24 hours, it is coated on a polarizing film by a doctor blade method, and then placed in an oven at 50 °C for 5 minutes to dry, so as to obtain a dry film (i.e., an adhesive composition) with a thickness of 20 μm to 25 μm. The transmittance of the dry film is 92% (the measurement method is an ultraviolet-visible spectrometer), and the haze is 0.41% (the measurement method is a haze meter). The dry film is attached to a 10 cm * 10 cm stainless steel plate, and the adhesive force is measured (1.2 Kg / in, the measurement standard is JIS ZO237). The polarizing film is irradiated with near-infrared light with a wavelength of 800 nm to 1500 nm, a power of 2 kW, and an intensity of 2000 mJ / cm 2 to debond the dry film. The adhesive force of the dry film after debonding is 0.05 Kg / in (the measurement standard is JIS ZO237). From the above, it can be seen that the adhesive composition of Example 1-2 has sufficient adhesive force, and the adhesive force decreases significantly after irradiation with high-energy near-infrared light (i.e., it has the near-infrared debonding property).

[0063] Example 1-3

[0064] Take 80 g of the acrylate resin of Synthesis Example 1, 20 g of dipentaerythritol hexaacrylate as a polyfunctional acrylate, 0.5 g of a dispersion of SiO2 / Au core-shell composite particles having surface-grafted acrylate of Synthesis Example 2 (containing 10% composite particles), and 0.5 g of benzoyl peroxide as a thermal initiator, and stir them uniformly for 24 hours. Then, coat them on a polarizing film by a doctor blade method, and place them in an oven at 50 °C for 5 minutes to dry, so as to obtain a dry film (i.e., an adhesive composition) with a thickness of 20 μm to 25 μm. The transmittance of the dry film is 91% (the measurement method is an ultraviolet-visible spectrometer), and the haze is 0.48% (the measurement method is a haze meter). Attach the dry film to a 10 cm * 10 cm stainless steel plate, and measure the adhesive strength (0.9 Kg / in, the measurement standard is JIS ZO237). Irradiate the polarizing film with near-infrared light having a wavelength of 800 nm to 1500 nm, a power of 2 kW, and an intensity of 2000 mJ / cm 2 to release the dry film. The adhesive strength after the dry film is released is 0.05 Kg / in (the measurement standard is JIS ZO237). As can be seen from the above, the adhesive compositions of Examples 1-3 have sufficient adhesive strength, and the adhesive strength decreases significantly after irradiating with high-energy near-infrared light (i.e., having the near-infrared release property).

[0065] Comparative Example 2

[0066] Take 80 g of a synthetic resin (purchased from Xinkang Resin HT-6501BS), coat it on a polarizing film by a doctor blade method, and place it in an oven at 50 °C for 5 minutes to dry, so as to obtain a dry film (i.e., an adhesive composition) with a thickness of 20 μm to 25 μm. The transmittance of the dry film is 92% (the measurement method is an ultraviolet-visible spectrometer), and the haze is 0.45% (the measurement method is a haze meter). Attach the dry film to a 10 cm * 10 cm stainless steel plate, and measure the adhesive strength (2.9 Kg / in, the measurement standard is JIS ZO237). Irradiate the polarizing film with near-infrared light having a wavelength of 800 nm to 1500 nm, a power of 2 kW, and an intensity of 2000 mJ / cm 2 to release the dry film. The adhesive strength after the dry film is released is 2.9 Kg / in (the measurement standard is JIS ZO237). As can be seen from the above, the adhesive composition of Comparative Example 2 has sufficient adhesive strength, but the adhesive strength is the same after irradiating with high-energy near-infrared light (i.e., not having the near-infrared release property).

[0067] Comparative Example 3-1

[0068] 80 g of synthetic resin (purchased from Changxing 77688) was coated on the polarizing film by a doctor blade method, and then placed in an oven at 50 °C for 5 minutes to dry, to obtain a dry film (i.e., the adhesive composition) with a thickness of 20 μm to 25 μm. The transmittance of the dry film was 92% (measurement method: ultraviolet-visible spectrometer), and the haze was 0.45% (measurement method: haze meter). The dry film was attached to a 10 cm * 10 cm stainless steel plate, and the adhesive strength was measured (1.5 Kg / in, measurement standard: JIS ZO237). The polarizing film was irradiated with near-infrared light with a wavelength of 800 nm to 1500 nm, a power of 2 kW, and an intensity of 2000 mJ / cm 2 to delaminate the dry film. The adhesive strength of the dry film after delamination was 1.5 Kg / in (measurement standard: JIS ZO237). From the above, it can be seen that the adhesive composition of Comparative Example 3-1 had sufficient adhesive strength, but the adhesive strength was the same after irradiation with high-energy near-infrared light (i.e., it did not have the near-infrared delamination property).

[0069] Comparative Example 3-2

[0070] 80 g of synthetic resin (Changxing 77688) and 20 g of dipentaerythritol hexaacrylate as a polyfunctional acrylate were uniformly stirred for 24 hours, and then coated on the polarizing film by a doctor blade method, and then placed in an oven at 50 °C for 5 minutes to dry, to obtain a dry film (i.e., the adhesive composition) with a thickness of 20 μm to 25 μm. The transmittance of the dry film was 92% (measurement method: ultraviolet-visible spectrometer), and the haze was 0.43% (measurement method: haze meter). The dry film was attached to a 10 cm * 10 cm stainless steel plate, and the adhesive strength was measured (1.3 Kg / in, measurement standard: JIS ZO237). The polarizing film was irradiated with near-infrared light with a wavelength of 800 nm to 1500 nm, a power of 2 kW, and an intensity of 2000 mJ / cm 2 to delaminate the dry film. The adhesive strength of the dry film after delamination was 1.3 Kg / in (measurement standard: JIS ZO237). From the above, it can be seen that the adhesive composition of Comparative Example 3-2 had sufficient adhesive strength, but the adhesive strength was the same after irradiation with high-energy near-infrared light (i.e., it did not have the near-infrared delamination property).

[0071] Comparative Example 3-3

[0072] Take 80 g of synthetic resin (Changxing 77688), 20 g of dipentaerythritol hexaacrylate as a polyfunctional acrylate, 0.5 g of a dispersion of surface-grafted acrylate SiO2 / Au core-shell composite particles of Synthesis Example 2 (containing 1% composite particles), and 0.5 g of benzoyl peroxide as a thermal initiator, and stir them evenly for 24 hours. Then, coat them on a polarizing film by a doctor blade method, and place them in an oven at 50 °C for 5 minutes to dry, so as to obtain a dry film (i.e., an adhesive composition) with a thickness of 20 μm to 25 μm. The transmittance of the dry film is 92% (the measurement method is an ultraviolet-visible spectrometer), and the haze is 0.6% (the measurement method is a haze meter). Attach the dry film to a 10 cm * 10 cm stainless steel plate, and measure the adhesive force (1.2 Kg / in, the measurement standard is JISZO237). Irradiate the polarizing film with near-infrared light with a wavelength of 800 nm to 1500 nm, a power of 2 kW, and an intensity of 2000 mJ / cm 2 to demold the dry film. The adhesive force of the dry film after demolding is 1.2 Kg / in (the measurement standard is JISZO237). As can be seen from the above, the adhesive composition of Comparative Example 3-3 has sufficient adhesive force, but the adhesive force is the same after irradiating with high-energy near-infrared light (i.e., it does not have the near-infrared demolding property). Thus, it can be seen that not all adhesive compositions formed by combining synthetic resins with core-shell composite particles and polyfunctional acrylate monomers have a demolding effect after irradiating with near-infrared light.

[0073] Comparative Example 3-4

[0074] Take 80 g of synthetic resin (Changxing 77688), 20 g of dipentaerythritol hexaacrylate as a polyfunctional acrylate, 0.5 g of a dispersion of surface-grafted acrylate SiO2 / Au core-shell composite particles of Synthesis Example 2 (containing 5% composite particles), and 0.5 g of benzoyl peroxide as a thermal initiator, and stir them evenly for 24 hours. Then, coat them on a polarizing film by a doctor blade method, and place them in an oven at 50 °C for 5 minutes to dry, so as to obtain a dry film (i.e., an adhesive composition) with a thickness of 20 μm to 25 μm. The transmittance of the dry film is 91% (the measurement method is an ultraviolet-visible spectrometer), and the haze is 0.8% (the measurement method is a haze meter). Attach the dry film to a 10 cm * 10 cm stainless steel plate, and measure the adhesive force (1.1 Kg / in, the measurement standard is JISZO237). Irradiate the polarizing film with near-infrared light with a wavelength of 800 nm to 1500 nm, a power of 2 kW, and an intensity of 2000 mJ / cm 2The near-infrared irradiated polarizing film releases the dry film from its adhesion. The adhesion force after the dry film is released from its adhesion is 1.1 Kg / in (the measurement standard is JIS ZO237). From the above, it can be seen that the adhesive compositions of Comparative Examples 3-4 have sufficient adhesion force, but the adhesion force after irradiation with high-energy near-infrared rays is the same (i.e., they do not have the near-infrared releasing property). Thus, it can be known that not all adhesive compositions formed by combining synthetic resins with core-shell composite particles and polyfunctional acrylate monomers have a releasing effect after irradiation with near-infrared rays.

[0075] Comparative Example 3-5

[0076] Take 80 g of synthetic resin (Changxing 77688), 20 g of dipentaerythritol hexaacrylate as the polyfunctional acrylate, 0.5 g of the dispersion of SiO2 / Au core-shell composite particles with surface-grafted acrylate of Synthesis Example 2 (containing 10% composite particles), and 0.5 g of benzoyl peroxide as the thermal initiator, stir evenly for 24 hours, then coat it on the polarizing film by the doctor blade method, and then place it in an oven at 50 °C for 5 minutes to dry to obtain a dry film with a thickness of 20 μm to 25 μm (i.e., the adhesive composition). The transmittance of the dry film is 89% (the measurement method is ultraviolet-visible spectrometer), and the haze is 1.6% (the measurement method is haze measurement). Attach the dry film to a 10 cm * 10 cm stainless steel plate and measure the adhesion force (1.0 Kg / in, the measurement standard is JIS ZO237). Use near-infrared rays with a wavelength of 800 nm to 1500 nm, a power of 2 kW, and an intensity of 2000 mJ / cm 2 The near-infrared irradiated polarizing film releases the dry film from its adhesion. The adhesion force after the dry film is released from its adhesion is 1.0 Kg / in (the measurement standard is JIS ZO237). From the above, it can be seen that the adhesive compositions of Comparative Examples 3-4 have sufficient adhesion force, but the adhesion force after irradiation with high-energy near-infrared rays is the same (i.e., they do not have the near-infrared releasing property). Thus, it can be known that not all adhesive compositions formed by combining synthetic resins with core-shell composite particles and polyfunctional acrylate monomers have a releasing effect after irradiation with near-infrared rays.

[0077] Although the present invention has been disclosed above with several preferred embodiments, it is not intended to limit the present invention. Any person having ordinary knowledge in the technical field to which the present invention pertains may make any changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be determined by the scope of the appended patent application.

Claims

1. An adhesive composition comprising: 0.1 to 1 parts by weight of a plurality of nanoparticles; 50 to 95 parts by weight of a monoacrylate resin; as well as 5 to 50 parts by weight of a multifunctional acrylate monomer, a multifunctional acrylate oligomer, a multifunctional acrylic acid monomer, or a multifunctional acrylic acid oligomer, wherein the total weight of the acrylate resin and the multifunctional acrylate monomer, the multifunctional acrylate oligomer, the multifunctional acrylic acid monomer, or the multifunctional acrylic acid oligomer is 100 parts by weight; The weight average molecular weight of the acrylic resin is 100,000 to 1.5 million; The nanoparticles have a core, a shell, and an acrylate group, wherein the core is silicon oxide, the shell is at least one selected from gold, silver, and copper, the shell covers a portion of the surface of the core, and the acrylate group is grafted to the surface of the core; The adhesive composition has an adhesive strength of 0.5 kg / in to 1.5 kg / in before irradiation with near infrared rays, and an adhesive strength of 0 to 0.3 kg / in after irradiation with the near infrared rays, wherein the energy intensity of the near infrared rays is 1500 mJ / cm 2 Up to 2500 mJ / cm 2 , wherein the weight ratio of the core to the shell is 50:100 to 100:100, wherein the weight ratio of the core to the acrylate group is 60:100 to 110:

100.

2. The adhesive composition according to claim 1, wherein the size of the nanoparticles is 10 nm to 200 nm.

3. The adhesive composition according to claim 1, wherein the monomers of the acrylic resin include 50 to 99 wt% of a first monomer having a Tg of -15°C to -70°C, and 1 to 50 wt% of a second monomer having a Tg higher than -15°C.

4. The adhesive composition according to claim 3, wherein the first monomer comprises at least one of ethyl acrylate, ethylhexyl acrylate, butyl acrylate, isooctyl acrylate, isobutyl acrylate, isodecyl acrylate, lauryl acrylate, 2-propylheptyl acrylate, heptadecyl acrylate, tetrahydrofuranyl acrylate, ethoxyethoxyethyl acrylate, methoxypolyethylene glycol acrylate, isodecyl methacrylate, lauryl methacrylate, isotridecyl methacrylate, and methoxypolyethylene glycol methacrylate. 5 . The adhesive composition according to claim 4 , wherein the first monomer comprises butyl acrylate and ethylhexyl acrylate.

6. The adhesive composition according to claim 3, wherein the second monomer comprises at least one of vinyl acetate, acrylonitrile, acrylamide, styrene, methyl methacrylate, methyl acrylate, methacrylic acid, acrylic acid, hydroxyethyl acrylate, hydroxypropyl acrylate, and glycidyl methacrylate.

7. The adhesive composition according to claim 6, wherein the second monomer comprises methyl methacrylate, acrylic acid, and hydroxyethyl acrylate.

8. The adhesive composition according to claim 1, wherein the monomer of the polyfunctional acrylate or the monomer of the polyfunctional acrylic acid comprises at least one of 1,6 - hexanediol diacrylate, 1,9 - nonanediol diacrylate, 1,10 - decanediol diacrylate, neopentyl glycol diacrylate, 2 - hydroxy - 3 - propyl methacrylate, polyethylene glycol diacrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, polypropylene glycol diacrylate, polytetramethylene glycol diacrylate, polyethylene - polypropylene glycol diacrylate, tricyclodecane dimethanol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, bis - trimethylolpropane tetraacrylate, poly - pentaerythritol polyacrylate, 1,6 - hexanediol dimethacrylate, 1,9 - nonanediol dimethacrylate, 1,10 - decanediol dimethacrylate, and neopentyl glycol dimethacrylate.

9. The adhesive composition according to claim 1, further comprising a thermal initiator.

10. A liquid crystal display, comprising: an upper substrate, comprising a first adhesive layer between a color filter substrate and an upper polarizer; a lower substrate, comprising a second adhesive layer between a thin - film transistor substrate and a lower polarizer; and a liquid crystal layer, located between the color filter substrate of the upper substrate and the thin - film transistor substrate of the lower substrate; wherein the first adhesive layer, the second adhesive layer, or both of the above comprise the adhesive composition according to any one of claims 1 - 9.

11. A method for disassembling a liquid crystal display, comprising: providing the liquid crystal display according to claim 10; separating the upper substrate from the lower substrate; and Irradiate the upper substrate, the lower substrate, or both of them with near-infrared rays to desolve the first adhesive layer, the second adhesive layer, or both of them, wherein the energy intensity of the near-infrared rays is 1500 mJ / cm 2 to 2500 mJ / cm 2 .

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