CN115362234A - optical stack - Google Patents

Abstract

The invention aims to reduce the number of processes and necessary components in the manufacturing process of a self-luminous display device such as a Mini/Micro LED display device with improved anti-reflection function, anti-glare function and contrast. The optical laminate (10) of the present invention comprises a substrate (1) and a pressure-sensitive adhesive layer (2) containing a colorant. The substrate (1) is provided with an antireflection treatment and/or an antiglare treatment (3) on one surface (1 a). The antireflection treatment and/or the antiglare treatment (3) is preferably an antiglare layer. The optical laminate (10) of the present invention is formed by laminating an adhesive layer (2) on the surface (1 b) of a substrate (1) on the side not subjected to an antireflection treatment and/or an antiglare treatment.

Description

optical stack

technical field

The present invention relates to an optical laminate suitable for encapsulating light-emitting elements of self-luminous display devices such as Mini/Micro LEDs.

Background technique

In recent years, self-luminous display devices represented by Mini/Micro LED display devices (Mini/MicroLight Emitting Diode Display, Mini/Micro Light Emitting Diode Display devices) have been designed as next-generation display devices. The Mini/Micro LED display device is basically composed of a substrate on which many tiny LED light-emitting elements (LED chips) are arranged at a high density as a display panel. Covering components such as panels.

There are several types of self-luminous display devices such as Mini/Micro LED display devices, such as white backlight method, white light-emitting color filter method, and RGB method. In the white light-emitting color filter method and RGB method, in order to prevent the For the reflection of metal wiring arranged on the substrate, metal oxides such as ITO, etc., a black packaging material may be used (see, for example, Patent Documents 1 to 3). Among them, in the RGB-type Mini/Micro LED display device in which LED chips are arranged, the above-mentioned black packaging material can also help prevent RGB color mixing and improve contrast.

prior art literature

patent documents

Patent Document 1: Japanese Patent Laid-Open No. 2019-204905

Patent Document 2: Japanese Patent Laid-Open No. 2017-203810

Patent Document 3: Japanese PCT Publication No. 2018-523854

Contents of the invention

The problem to be solved by the invention

Liquid curable resins and binders containing black colorants (dye, pigment) are used as the black sealing material. In the case of using a liquid curable resin containing a black colorant, there is a problem that unevenness in blackness occurs due to unevenness in thickness. In addition, compared with dyes, pigments are often selected due to their excellent heat resistance and weather resistance. However, in the case of using a liquid curable resin in which pigments are dispersed, in addition to the above-mentioned thickness unevenness, there may also occur Problems such as uneven filling when liquid curable resin is filled, and uneven dispersion of pigments during flow. In addition, since the surface of the cured liquid curable resin has no adhesive force after sealing, it is necessary to laminate the covering member using an adhesive or the like, and there is a problem that more man-hours and members are required.

The present invention is conceived on the basis of the above situation, and the purpose of the present invention is to reduce the production process of self-luminous display devices such as Mini/Micro LED display devices with improved anti-reflection function and/or anti-glare function and contrast. The number of processes and necessary components.

solutions to problems

As a result of earnest studies by the present inventors to achieve the aforementioned object, it has been found that an optical laminate obtained by laminating a base material subjected to antireflection treatment and/or antiglare treatment on one side and an adhesive layer containing a colorant The body is used to manufacture a self-luminous display device, which can reduce the number of steps and necessary components, and can efficiently manufacture a self-luminous display device with improved anti-reflection function and/or anti-glare function and contrast. The present invention has been accomplished based on these findings.

That is, the first aspect of the present invention provides an optical laminate comprising a base material and an adhesive layer containing a colorant, wherein one side of the base material is subjected to antireflection treatment and/or antiglare treatment. treatment, the adhesive layer is laminated on the surface of the substrate that is not subjected to the anti-reflection treatment and/or anti-glare treatment. By using the optical laminate according to the first aspect of the present invention for the production of a self-luminous display device, the adhesive layer becomes an encapsulating material for encapsulating light-emitting elements arranged on the display panel, and the base material constitutes the outermost covering member. Therefore, it is not necessary to separately laminate the covering member after packaging, the number of steps and necessary members can be reduced, and the manufacturing efficiency can be improved.

In addition, the solution that the aforementioned adhesive layer contains a colorant is suitable for the following reason: when the aforementioned adhesive layer is used to encapsulate the light-emitting element in the manufacture of a self-luminous display device, the aforementioned problem caused by the difference in thickness is unlikely to occur. Black level unevenness caused by uniformity, filling unevenness, uneven pigment dispersion, etc. can prevent reflection of metal wiring, etc., prevent RGB color mixing, and improve contrast.

Furthermore, antireflection treatment and/or antiglare treatment on one side of the base material is preferable in order to prevent deterioration of visibility due to reflection of external light, image reflection, etc., and to adjust aesthetics such as glossiness.

In the optical laminate according to the first aspect of the present invention, the pressure-sensitive adhesive layer is preferably formed of a photocurable pressure-sensitive adhesive composition containing a polymer, a photopolymerizable compound, a photopolymerization initiator, and a colorant. adhesive layer. It is preferable that the maximum value of the transmittance of the wavelength 330-400nm of the said coloring agent is larger than the maximum value of the transmittance of the wavelength 400-700nm. It is preferable that the said photoinitiator has at least one maximum absorption in the wavelength range of 330-400 nm. Preferably, the optical layered body has a maximum value of transmittance at 350 nm to 450 nm. Preferably, the total light transmittance of the pressure-sensitive adhesive layer is 80% or less. Preferably, the adhesive layer has a thickness of 10 to 500 μm. These aspects are preferable in that photocurability by ultraviolet irradiation can be imparted to the pressure-sensitive adhesive layer while having sufficient light-shielding properties in the visible light region.

In the optical laminated body of the first aspect of the present invention, it is preferable that the aforementioned polymer is an acrylic polymer. Preferably, the aforementioned polymer has a glass transition temperature of 0°C or lower. Preferably, the shear storage modulus of the aforementioned adhesive layer at a temperature of 85° C. is 3 to 300 kPa. These aspects are preferable in that when the optical laminate of the first aspect of the present invention is used to manufacture a self-luminous display device, the aforementioned adhesive layer fills gaps between the light-emitting elements arranged on the display panel. Excellent height difference absorbency.

In the optical laminate of the first aspect of the present invention, it is preferable that the aforementioned photocurable adhesive composition further contains a crosslinking agent capable of crosslinking with the aforementioned polymer. Preferably, the shear storage modulus of the aforementioned adhesive layer at a temperature of 25° C. is 10 to 1000 kPa. These aspects are preferable in that the processability and bonding reliability of the aforementioned pressure-sensitive adhesive layer can be improved.

In the optical laminate according to the first aspect of the present invention, it is preferable that the antireflection treatment and/or the antiglare treatment is an antiglare layer provided on one surface of the substrate. Preferably, the aforementioned anti-glare layer is formed using an anti-glare layer forming material comprising a resin, particles, and a thixotropy-imparting agent, and the aforementioned anti-glare layer is aggregated by the aforementioned particles and the aforementioned thixotropy-imparting agent, so that The surface has aggregates forming convex portions. Preferably, the convex portion on the surface of the anti-glare layer has an average inclination angle θa (°) in the range of 0.1 to 5.0. These aspects are preferable in that an antireflection function and/or an antiglare function are imparted to the surface of the optical layered body of the first aspect of the present invention, and that a decrease in visibility due to reflection of external light, image reflection, etc. is prevented, or adjustment is made. Aesthetics such as gloss.

In the optical laminate according to the first aspect of the present invention, a surface protection film may be further laminated on the surface of the base material that has been subjected to antireflection treatment and/or antiglare treatment. This aspect is suitable in order to prevent damage and dirt adhesion at the time of manufacture, transportation, and shipment of the said optical laminated body and the optical product containing it.

In addition, the second aspect of the present invention provides a self-luminous display device, the self-luminous display device includes: a display panel in which a plurality of light-emitting elements are arranged on a single surface of a substrate, and the optical display device of the first aspect of the present invention. In the laminated body, the surface of the display panel on which the light-emitting elements are arranged is laminated on the adhesive layer of the optical laminated body. In the self-luminous display device according to the second aspect of the present invention, the display panel may be an LED panel in which a plurality of LED chips are arranged on one side of a substrate. This solution is preferable in the following aspects: the self-luminous display device of the second aspect of the present invention can prevent reflection of metal wiring on the substrate, prevent RGB color mixing, improve contrast, and prevent reflection by external light, image reflection, etc. The resulting reduction in visibility, or the adjustment of gloss and other aesthetics.

The effect of the invention

By using the optical laminate of the present invention to produce a self-luminous display device, the number of steps and necessary components can be reduced, and a self-luminous display device with improved antireflection function, anti-glare function and contrast can be efficiently produced.

Description of drawings

FIG. 1 is a schematic view (sectional view) showing one embodiment of the optical laminate of the present invention.

FIG. 2 is a schematic view (sectional view) showing another embodiment of the optical laminate of the present invention.

3 is a schematic diagram (sectional view) showing an embodiment of a self-luminous display device (Mini/Micro LED display device) of the present invention.

4 is a schematic diagram (sectional view) showing another embodiment of the self-luminous display device (Mini/Micro LED display device) of the present invention.

Detailed ways

The optical laminated body according to the first aspect of the present invention is an optical laminated body including a substrate and an adhesive layer containing a colorant, wherein one side of the substrate is subjected to antireflection treatment and/or antiglare treatment, and The aforementioned adhesive layer is laminated on the side of the material that is not subjected to the aforementioned anti-reflection treatment and/or anti-glare treatment.

"Optics" in the optical layered body of the first aspect of the present invention means use for optical applications, more specifically means use for manufacture of products (optical products) using optical members, and the like. As an optical product, for example, input devices such as image display devices and touch screens, etc., are preferably self-luminous display devices such as Mini/Micro LED display devices and organic EL (electroluminescence) display devices, and can be suitably used in particular. Manufacture of Mini/Micro LED display devices.

Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited thereto and is merely an illustration.

FIG. 1 is a schematic view (sectional view) showing one embodiment of an optical laminate according to the first aspect of the present invention.

In this embodiment, an optical laminate 10 includes a substrate 1 and an adhesive layer 2 containing a colorant. One side 1a of the substrate 1 is subjected to antireflection treatment and/or antiglare treatment 3 . An adhesive layer 2 is laminated on the surface 1 b of the substrate 1 that is not subjected to antireflection treatment and/or antiglare treatment.

<Substrate>

In this embodiment, the substrate 1 is not particularly limited, and examples thereof include glass, transparent plastic film substrates, and the like. The aforementioned transparent plastic film substrate is not particularly limited, preferably a substrate with excellent visible light transmittance (preferably more than 90% transmittance) and excellent transparency (preferably a substrate with a haze value of 5% or less), for example, The transparent plastic film base material described in Unexamined-Japanese-Patent No. 2008-90263 is mentioned. As the above-mentioned transparent plastic film substrate, a substrate with little optical birefringence can be suitably used. In this embodiment, the substrate 1 can also be used, for example, as a covering member of a self-luminous display device. In this case, as the aforementioned transparent plastic film substrate, it is preferably made of triacetyl cellulose (TAC), polycarbonate, acrylic acid, etc. Films formed from polymers, polyolefins with cyclic or norbornene structures, etc. In addition, the base material 1 may be the aforementioned covering member itself in the present embodiment. According to such a configuration, the process of separately laminating the covering member can be eliminated in the manufacture of the self-luminous display device, so that the number of steps and necessary members can be reduced, and the production efficiency can be improved. In addition, according to such a configuration, the aforementioned covering member can be further thinned. It should be noted that, when the base material 1 is a covering member, the surface 1a that has been subjected to anti-reflection treatment and/or anti-glare treatment constitutes the outermost surface of the self-illuminating display device, and plays the following role: preventing the reflection caused by external light. Reduce visibility due to reflection, image reflection, etc., and adjust gloss and other aesthetics.

In the present embodiment, the thickness of the base material 1 is not particularly limited, but is preferably in the range of 10 to 500 μm, and more preferably in the range of 20 to 300 μm, in consideration of, for example, workability such as strength and handleability, and thin layer properties. , the optimum range is 30-200 μm. The refractive index of the substrate 1 is not particularly limited, and is, for example, in the range of 1.30 to 1.80, preferably in the range of 1.40 to 1.70. The visible light transmittance of the substrate 1 is not particularly limited, and is, for example, 85 to 100%, and may be 88% or more, 90% or more, or 92% or more.

In the present embodiment, as the antireflection treatment performed on the single surface 1 a of the substrate 1 , known antireflection treatments can be used without particular limitation, and examples include antireflection (AR) treatment.

As the aforementioned anti-reflection (AR) treatment, known AR treatment can be applied without particular limitation. Specifically, two or more layers of optical elements whose thickness and refractive index are strictly controlled can be formed on one side 1a of the substrate 1. film or an anti-reflection layer (AR layer) obtained by laminating the aforementioned optical films. The aforementioned AR layer exhibits an anti-reflection function by making use of the interference effect of light to cancel out phase reversals of incident light and reflected light. The wavelength region of visible light exhibiting antireflection function is, for example, 380-780nm, especially the wavelength region with high visual sensitivity is in the range of 450-650nm. It is preferable to design the AR layer so that the reflectance of its central wavelength of 550nm is minimized.

As the aforementioned AR layer, generally, a multilayer antireflection layer having a structure of laminating two to five optically thin layers (thin films with strictly controlled thickness and refractive index) can be mentioned. Forming multiple layers in thickness improves the freedom of optical design of the AR layer, further improves the anti-reflection effect, and makes the spectroscopic reflection characteristics uniform (flat) in the visible light region. In the aforementioned optical thin film, since high thickness accuracy is required, the formation of each layer is generally carried out by vacuum evaporation, sputtering, CVD, etc. which are dry methods.

As the aforementioned anti-glare (AG) treatment, known AG treatment can be applied without particular limitation, and can be performed, for example, by forming an anti-glare layer on one side 1 a of the substrate 1 . Fig. 2 is a schematic view (sectional view) showing another embodiment of the optical laminate according to the first aspect of the present invention. In the optical laminate 11 of the present embodiment, the antiglare layer 3 a is formed on one surface 1 a of the substrate 1 . As the anti-glare layer 3a, a known anti-glare layer can be used without limitation, and it is generally formed as a layer in which inorganic or organic particles as an anti-glare agent are dispersed in a resin.

In this embodiment, the anti-glare layer 3a is formed using an anti-glare layer forming material including resin, particles, and a thixotropy-imparting agent. When the particles and the thixotropy-imparting agent are aggregated, the anti-glare layer 3a is formed on the surface of the anti-glare layer 3a. A convex portion is formed. According to this aspect, the anti-glare layer 3a has excellent display characteristics in which both anti-glare and white blur are prevented, and although the anti-glare layer is formed by the aggregation of particles, it is possible to prevent protrusions on the surface of the anti-glare layer that become defects in appearance. The generation of solids improves the yield of products.

Examples of the aforementioned resin include thermosetting resins and ionizing radiation curable resins that are cured by ultraviolet rays or light. As the aforementioned resin, commercially available thermosetting resins, ultraviolet curable resins, and the like can also be used.

As the above-mentioned thermosetting resin and ultraviolet curable resin, for example, a curable resin having at least one of an acrylate group and a methacrylate group that is cured by heat, light (ultraviolet rays, etc.) or electron beams, can be used. Compounds include, for example, silicone resins, polyester resins, polyether resins, epoxy resins, urethane resins, alkyd resins, spiroacetal resins, polybutadiene resins, polythiol polyene resins Oligomers or prepolymers of polyfunctional compounds such as acrylates and methacrylates, polyols, etc. These may be used individually by 1 type, and may use 2 or more types together.

A reactive diluent having at least one of an acrylate group and a methacrylate group, for example, may also be used in the aforementioned resin. The aforementioned reactive diluent, for example, can use the reactive diluent described in Japanese Patent Application Laid-Open No. 2008-88309, including, for example, monofunctional acrylate, monofunctional methacrylate, polyfunctional acrylate, polyfunctional methacrylate, etc. . As the reactive diluent, trifunctional or higher acrylates and trifunctional or higher methacrylates are preferable. This is because the hardness of the anti-glare layer 3a can be made excellent. Examples of the reactive diluent include butylene glycol glyceryl ether diacrylate, acrylate of isocyanuric acid, methacrylate of isocyanuric acid, and the like. These may be used individually by 1 type, and may use 2 or more types together.

The particles used to form the anti-glare layer 3 a have the main functions of imparting anti-glare properties and controlling the haze value of the anti-glare layer 3 a by making the surface of the formed anti-glare layer 3 a concavo-convex. The haze value of the anti-glare layer 3a can be designed by controlling the refractive index difference between the aforementioned particles and the aforementioned resin. As the aforementioned particles, there are, for example, inorganic particles and organic particles. The aforementioned inorganic particles are not particularly limited, and examples include: silicon oxide particles, titanium oxide particles, aluminum oxide particles, zinc oxide particles, tin oxide particles, calcium carbonate particles, barium sulfate particles, talc particles, kaolin particles, calcium sulfate particles Wait. In addition, the aforementioned organic particles are not particularly limited, for example, polymethyl methacrylate resin powder (PMMA microparticles), silicone resin powder, polystyrene resin powder, polycarbonate resin powder, acrylic styrene resin ( acrylicstyrene resin) powder, benzoguanamine resin powder, melamine resin powder, polyolefin resin powder, polyester resin powder, polyamide resin powder, polyimide resin powder, polyvinyl fluoride resin powder, etc. These inorganic particles and organic particles may be used alone or in combination of two or more.

It is preferable that the weight average particle diameter (D) of the said particle exists in the range of 2.5-10 micrometers. By making the weight average particle diameter of the said particle|grains into the said range, for example, anti-glare property can be made more excellent, and white blurring can be prevented. It is more preferable that the weight average particle diameter of the said particle exists in the range of 3-7 micrometers. In addition, the weight average particle diameter of the said particle|grains can be measured by the Coulter counter method, for example. For example, by using a particle size distribution measuring device (trade name: Coulter particle size analyzer, manufactured by Beckman Coulter, Inc.) utilizing the pore resistance method, the resistance of the electrolyte solution corresponding to the volume of the particles when the particles pass through the aforementioned pores is measured. , thereby measuring the number and volume of the aforementioned particles, and calculating the weight average particle diameter.

The shape of the aforementioned particles is not particularly limited, for example, it can be bead-like approximately spherical, or amorphous particles such as powder, preferably approximately spherical particles, more preferably approximately spherical particles with an aspect ratio of 1.5 or less, Spherical particles are most preferred.

The proportion of the particles in the anti-glare layer 3a is preferably in the range of 0.2 to 12 parts by weight, more preferably in the range of 0.5 to 12 parts by weight, and still more preferably in the range of 1 to 7 parts by weight, based on 100 parts by weight of the resin. scope. By setting it as the said range, for example, anti-glare property becomes more excellent, and white blurring can be prevented.

As a thixotropy imparting agent for forming the anti-glare layer 3a, organoclay, oxidized polyolefin, modified urea, etc. are mentioned, for example.

In order to improve the affinity with the aforementioned resin, the aforementioned organoclay is preferably organically treated clay. Examples of organoclays include layered organoclays. The aforementioned organoclay can be prepared by itself, or a commercially available one can be used. Examples of commercially available products include: LUCENTITE SAN, LUCENTITE STN, LUCENTITE SEN, LUCENTITE SPN, SOMASIF ME-100, SOMASIF MAE, SOMASIF MTE, SOMASIF MEE, SOMASIF MPE (both are Co-op Chemical Co. .,Ltd.); S-BEN, S-BEN C, S-BEN E, S-BEN W, S-BENP, S-BEN WX, S-BEN N-400, S-BEN NX, S-BEN NX80, S-BEN NO12S, S-BEN NEZ, S-BEN NO12, S-BEN NE, S-BEN NZ, S-BEN NZ70, ORGANITE, ORGANITE D, ORGANITE T (trade names, all are HOJUN Co.,Ltd. manufactured); KUNIPIA F, KUNIPIA G, KUNIPIA G4 (trade names, all manufactured by KUNIMINE INDUSTRIESCO., LTD.); TIXOGEL VZ, CLAYTONE HT, CLAYTONE40 (trade names, all manufactured by Rockwood Additives Ltd.), etc.

The aforementioned oxidized polyolefin can be produced by itself, or a commercially available product can be used. As said commercial item, DISPARLON 4200-20 (brand name, the product made by Kusumoto Chemical Co., Ltd.), FLOWNON SA300 (brand name, the Kyoeisha Chemical Co., Ltd. make), etc. are mentioned, for example.

The aforementioned modified urea is a reactant of isocyanate monomer or its adduct and organic amine. The aforementioned modified urea can be prepared by itself, or a commercially available product can be used. As said commercial item, BYK410 (made by BYK Chemicals), etc. are mentioned, for example.

The said thixotropy imparting agent may be used individually by 1 type, and may use 2 or more types together.

In the optical layered body 11 of the present embodiment, it is preferable that the height of the convex portion from the average roughness line of the anti-glare layer 3a is less than 0.4 times the thickness of the anti-glare layer 3a. More preferably, it is in the range of 0.01 times or more and less than 0.4 times, and it is still more preferably in the range of 0.01 times or more and less than 0.3 times. If it is this range, it can prevent suitably the protrusion which becomes an appearance defect from being formed in the said convex-shaped part. The anti-glare layer 3 a of the present embodiment can make appearance defects less likely to occur by having such a high convex portion. Here, the height from the mean line can be measured, for example, by the method described in JP-A-2017-138620.

The ratio of the thixotropy-imparting agent in the anti-glare layer 3a is preferably in the range of 0.1 to 5 parts by weight, more preferably in the range of 0.2 to 4 parts by weight, based on 100 parts by weight of the resin.

The thickness (d) of the anti-glare layer 3 a is not particularly limited, but is preferably within a range of 3 to 12 μm. By making the thickness (d) of the anti-glare layer 3a into the said range, for example, curling of the optical laminated body 11 can be prevented, and the problem of productivity fall, such as conveyance failure, can be avoided. Moreover, when the said thickness (d) is the said range, it is preferable that the weight average particle diameter (D) of the said particle exists in the range of 2.5-10 micrometers as mentioned above. By making the thickness (d) of the antiglare layer 3a and the weight average particle diameter (D) of the aforementioned particles into the aforementioned combination, it is possible to make the antiglare property more excellent. The thickness (d) of the anti-glare layer 3a is more preferably within a range of 3 to 8 μm.

The relationship between the thickness (d) of the anti-glare layer 3a and the weight average particle diameter (D) of the particles is preferably within the range of 0.3≦D/d≦0.9. By having such a relationship, the anti-glare property can be further improved, white blurring can be prevented, and an anti-glare layer free from appearance defects can be formed.

In the optical layered body 11 of the present embodiment, as described above, the anti-glare layer 3a is aggregated by the particles and the thixotropy-imparting agent to form convex portions on the surface of the anti-glare layer 3a. At the aggregated portion forming the convex portion, the aforementioned particles exist in a state of being aggregated in a plurality in the plane direction of the anti-glare layer 3a. Thereby, the said convex-shaped part forms a smooth shape. The anti-glare layer 3 a of the present embodiment can prevent white blurring while maintaining the anti-glare property by having the convex portion in such a shape, and furthermore, appearance defects can be made less likely to occur.

The surface shape of the antiglare layer 3a can be arbitrarily designed by controlling the aggregation state of the particles contained in the antiglare layer forming material. The aggregation state of the aforementioned particles can be controlled, for example, by the material of the aforementioned particles (such as the state of chemical modification of the particle surface, affinity to solvents and resins, etc.), the type and combination of resin (binder) or solvent, and the like. Here, in this embodiment, the aggregation state of the particles can be controlled by the thixotropy-imparting agent contained in the anti-glare layer forming material. As a result, in the present embodiment, the aggregation state of the particles can be made as described above, and the convex portion can be formed into a smooth shape.

In the optical layered body 11 of this embodiment, when the base material 1 is formed of resin etc., it is preferable to have a permeable layer in the interface of the base material 1 and the antiglare layer 3a. The permeable layer is formed by permeating the base material 1 with the resin component contained in the forming material of the anti-glare layer 3 a. If the permeable layer is formed, the adhesion between the base material 1 and the anti-glare layer 3a can be improved, which is preferable. The thickness of the permeable layer is preferably in the range of 0.2 to 3 μm, more preferably in the range of 0.5 to 2 μm. For example, when the substrate 1 is triacetyl cellulose and the resin contained in the anti-glare layer 3a is an acrylic resin, the permeable layer can be formed. The permeable layer can be confirmed, for example, by observing the cross section of the optical layered body 11 with a transmission electron microscope (TEM), and its thickness can be measured.

Even when the present embodiment is applied to the optical layered body 11 having such a permeable layer, it is possible to easily form a desired smooth surface irregularity shape that achieves both anti-glare and white blur prevention. Among the aforementioned permeable layers, the less the base material 1 has less adhesiveness with the anti-glare layer 3a, the more preferably it is formed thicker in order to improve the adhesiveness.

In the present embodiment, the number of appearance defects having a maximum diameter of 200 μm or more in the anti-glare layer 3 a is preferably one or less on average per 1 m ² of the anti-glare layer 3 a. It is more preferably free from the aforementioned appearance defects.

In this embodiment, the substrate 1 on which the anti-glare layer 3 a is formed preferably has a haze value within a range of 0 to 10%. The aforementioned haze value refers to a haze value (haze) according to JIS K 7136 (2000 edition). The aforementioned haze value is more preferably in the range of 0 to 5%, and still more preferably in the range of 0 to 3%. In order to make the haze value into the said range, it is preferable to select the said particle|grains and the said resin so that the refractive index difference of the said particle|grains and the said resin may be in the range of 0.001-0.02. By making the haze value into the above-mentioned range, a clear image can be obtained, and the contrast in a dark place can also be improved.

In this embodiment, it is preferable that the average inclination angle θa (°) is in the range of 0.1 to 5.0, more preferably in the range of 0.3 to 4.5, and still more preferably in the range of 1.0 to 4.0 at the concave-convex shape of the surface of the anti-glare layer 3a, especially Preferably it is 1.6-4.0. Here, the aforementioned average inclination angle θa is a value defined by the following formula (1). The aforementioned average inclination angle θa is, for example, a value measured by the method described in JP 2017-138620.

Average inclination θa=tan-1Δa(1)

In the above-mentioned formula (1), Δa is expressed by the following formula (2), and is the reference length L of the roughness curve specified in JIS B 0601 (1994 edition), using the apex and valley of the adjacent mountain The value obtained by dividing the sum (h1+h2+h3...+hn) of the difference (height h) of the lowest point of the above by the aforementioned reference length L. The aforementioned roughness curve is a curve obtained by removing surface waviness components longer than a predetermined wavelength from the cross-sectional curve by using a phase difference compensation type high-pass filter. In addition, the above-mentioned cross-sectional curve refers to a contour that appears at the incision when the target surface is cut with a plane perpendicular to the target surface.

Δa=(h1+h2+h3...+hn)/L (2)

When θa is in the above-mentioned range, the anti-glare property is more excellent, and white blurring can be prevented.

When forming the antiglare layer 3a, the prepared antiglare layer forming material (coating solution) preferably exhibits thixotropy, and the Ti value specified below is preferably in the range of 1.3 to 3.5, more preferably in the range of 1.3 to 2.8.

Ti value = β1/β2

Here, β1 is the viscosity measured at a shear rate of 20 (1/s) using RheoStress 6000 manufactured by HAAKE, and β2 is the viscosity measured at a shear rate of 200 (1/s) using RheoStress 6000 manufactured by HAAKE. Viscosity measured under the conditions.

If the Ti value is less than 1.3, defects in appearance are likely to occur, and the anti-glare properties and the properties related to white blur are deteriorated. In addition, if the Ti value exceeds 3.5, the aforementioned particles are less likely to aggregate and become more likely to form a dispersed state.

The method for producing the anti-glare layer 3a of the present embodiment is not particularly limited, and any method may be used. For example, an anti-glare layer forming material (coating solution) comprising the aforementioned resin, the aforementioned particles, the aforementioned thixotropy-imparting agent, and a solvent may be prepared, The anti-glare layer forming material (coating liquid) is coated on one side 1a of the substrate 1 to form a coating film, and the coating film is cured to form the anti-glare layer 3a, thereby manufacturing. In this embodiment, a method of imparting concavo-convex shapes by an appropriate method such as a transfer method using a mold, sand blasting, and an embossing roll may also be used together.

The above-mentioned solvent is not particularly limited, and various solvents may be used, and one kind may be used alone, or two or more kinds may be used in combination. There are optimal solvent types and solvent ratios depending on the composition of the resin, the types and contents of the particles and the thixotropy-imparting agent, and the like. The solvent is not particularly limited, and examples thereof include alcohols such as methanol, ethanol, isopropanol, butanol, and 2-methoxyethanol; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclopentanone. ; methyl acetate, ethyl acetate, butyl acetate and other esters; diisopropyl ether, propylene glycol monomethyl ether and other ethers; ethylene glycol, propylene glycol and other glycols; ethyl cellosolve, butyl cellosolve and other solvents Cellulose agents; Aliphatic hydrocarbons such as hexane, heptane, octane; Aromatic hydrocarbons such as benzene, toluene, xylene, etc.

As the substrate 1, for example, when triacetyl cellulose (TAC) is used to form the permeation layer, a good solvent for TAC can be suitably used. As this solvent, ethyl acetate, methyl ethyl ketone, cyclopentanone etc. are mentioned, for example.

In addition, by appropriately selecting the solvent, the thixotropy to the anti-glare layer forming material (coating liquid) due to the thixotropy-imparting agent can be expressed favorably. For example, in the case of using organoclay, toluene and xylene can be suitably used alone or in combination. For example, in the case of using oxidized polyolefin, methyl ethyl ketone, ethyl acetate, and propylene glycol monomethyl ether can be suitably used alone or in combination, such as When using modified urea, butyl acetate and methyl isobutyl ketone can be used singly or in combination as appropriate.

Various leveling agents can be added to the aforementioned anti-glare layer forming material. As the above-mentioned leveling agent, for the purpose of preventing coating unevenness (homogenization of the coated surface), for example, a fluorine-based or silicone-based leveling agent can be used. In this embodiment, depending on the case where antifouling properties are required for the surface of the antiglare layer 3a, or the case where an antireflection layer (low refractive index layer) or a layer containing an interlayer filler is to be formed on the antiglare layer 3a, etc. And properly select the leveling agent. In this embodiment, for example, by including the aforementioned thixotropy-imparting agent, it is possible to make the coating liquid express thixotropy, and thus coating unevenness is less likely to occur. Therefore, this embodiment has, for example, the advantage that the options of the aforementioned leveling agent can be expanded.

The compounding quantity of the said leveling agent is 5 weight part or less with respect to 100 weight part of said resins, for example, Preferably it is the range of 0.01-5 weight part.

Pigments, fillers, dispersants, plasticizers, ultraviolet absorbers, surfactants, antifouling agents, antioxidants, etc. may be added to the aforementioned antiglare layer forming materials as needed within a range that does not impair performance. These additives may be used alone or in combination of two or more.

As the anti-glare layer forming material, for example, conventionally known photopolymerization initiators as described in JP-A-2008-88309 can be used.

As a method of coating the aforementioned anti-glare layer forming material on one side 1a of the substrate 1, for example, a spray coating method, a die coating method, a spin coating method, a spray coating method, and a gravure coating method can be used. , roll coating method, rod coating method and other coating methods.

The aforementioned anti-glare layer forming material is applied to form a coating film on the substrate 1, and the aforementioned coating film is cured. It is preferable to dry the aforementioned coating film before the aforementioned curing. The aforementioned drying may be, for example, natural drying, blown air drying, heat drying, or a method combining them.

There is no particular limitation on the curing method of the coating film of the aforementioned anti-glare layer forming material, but ultraviolet curing is preferred. The irradiation dose of the energy ray source is preferably 50-500 mJ/cm ² in terms of cumulative exposure dose at an ultraviolet wavelength of 365 nm. When the irradiation amount is 50 mJ/cm ² or more, curing is more sufficient, and the hardness of the formed anti-glare layer is also more sufficient. In addition, if it is 500 mJ/cm ² or less, the formed anti-glare layer can be prevented from being colored.

As described above, the anti-glare layer 3 a can be formed on the single surface 1 a of the substrate 1 . It should be noted that the anti-glare layer 3a may be formed by a production method other than the aforementioned method. Regarding the hardness of the anti-glare layer 3 a of the present embodiment, it is preferable to have a hardness of 2H or more in pencil hardness, although it is affected by the thickness of the layer.

In this embodiment, the anti-glare layer 3 a may have a multilayer structure in which two or more layers are laminated.

In this embodiment, the aforementioned AR layer (low refractive index layer) may be disposed on the anti-glare layer 3a. For example, when the optical layered body 22 of this embodiment is mounted on a self-luminous display device, reflection of light at the interface between air and the anti-glare layer can be cited as one of factors that reduce image visibility. The AR layer will reduce this surface reflection. It should be noted that the anti-glare layer 3 a and the AR layer may each have a multilayer structure in which two or more layers are stacked.

In addition, in order to prevent the adhesion of pollutants and improve the ease of removal of the adhering pollutants, it is preferable to laminate an anti-pollution layer formed of a fluorine-containing silane compound or a fluorine-containing organic compound on the anti-glare layer 3a.

In this embodiment, at least one of the substrate 1 and the anti-glare layer 3 a is preferably surface-treated. When the surface of the base material 1 is surface-treated, the adhesiveness with the anti-glare layer 3a will be further improved. Moreover, when the surface of the anti-glare layer 3a is surface-treated, the adhesiveness with the said AR layer will improve further.

In order to prevent the substrate 1 from curling, the other side of the anti-glare layer 3a may be treated with a solvent. In addition, in order to prevent curling, a transparent resin layer may be formed on the other surface of the anti-glare layer 3a.

<Adhesive layer>

In this embodiment, it is preferable that the adhesive layer 2 is an adhesive formed of an adhesive composition selected from a photocurable adhesive composition and a solvent-based adhesive composition containing a colorant. Floor.

<Photocurable Adhesive Composition>

The aforementioned photocurable adhesive composition contains, in addition to the colorant, a polymer, a photopolymerizable compound, and a photopolymerization initiator. That is, the photocurable adhesive composition for forming the adhesive layer 2 of this embodiment contains a polymer, a photopolymerizable compound, a photopolymerization initiator, and a coloring agent. The pressure-sensitive adhesive layer 2 of the present embodiment is a pressure-sensitive adhesive layer that absorbs visible light.

The adhesive layer formed using the photocurable adhesive composition is roughly divided into: a type of adhesive layer that undergoes photocuring (the first form); A type of adhesive layer that is photocured after bonding (second mode).

[first way]

The pressure-sensitive adhesive layer of the first aspect can be formed by applying a photocurable pressure-sensitive adhesive composition containing a polymer, a photopolymerizable compound, a photopolymerization initiator, and a colorant on a release film, and then photocuring it.

<Photocurable Adhesive Composition>

(polymer)

Examples of the polymer contained in the aforementioned photocurable adhesive composition include: acrylic polymers, silicone polymers, polyesters, polyurethanes, polyamides, polyvinyl ethers, vinyl acetate/vinyl chloride Polymers such as copolymers, modified polyolefins, epoxy, fluorine, natural rubber, synthetic rubber and other rubbers. In particular, an acrylic polymer can be suitably used from the viewpoint of exhibiting moderate wettability, agglomeration, adhesive properties, and other adhesive properties, as well as being excellent in weather resistance, heat resistance, and the like.

The aforementioned acrylic polymer contains an alkyl (meth)acrylate as a main constituent monomer component. In addition, in this specification, "(meth)acryl" means acryl and/or methacryl. The amount of the alkyl (meth)acrylate is preferably 50% by weight or more, more preferably 55% by weight or more, and still more preferably 60% by weight or more, based on the total amount of monomer components constituting the acrylic polymer.

As the alkyl (meth)acrylate, an alkyl (meth)acrylate having 1 to 20 carbon atoms in the alkyl group can be suitably used. The alkyl group of the alkyl (meth)acrylate may have a branch or may have a cyclic alkyl group.

Specific examples of alkyl (meth)acrylates having a chain alkyl group include methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, (meth)acrylate, ) isobutyl acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, pentyl (meth)acrylate, isopentyl (meth)acrylate, neopentyl (meth)acrylate, Hexyl (meth)acrylate, Heptyl (meth)acrylate, 2-Ethylhexyl (meth)acrylate, Octyl (meth)acrylate, Isooctyl (meth)acrylate, Acrylic acid (meth) Nonyl, isononyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate , Isotridecyl (meth)acrylate, Myristyl (meth)acrylate, Isotetradecyl (meth)acrylate, Pentadecyl (meth)acrylate, Cetyl (meth)acrylate, Heptadecyl (meth)acrylate, Octadecyl (meth)acrylate, Isostearyl (meth)acrylate, Nadecyl (meth)acrylate Alkyl esters, etc. Preferred alkyl (meth)acrylates having a chain alkyl group used in the first aspect include butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, (meth)acrylic acid Octadecyl ester, lauryl (meth)acrylate. The amount of the alkyl (meth)acrylate having a chain alkyl group relative to the total amount of monomer components constituting the acrylic polymer is, for example, about 40 to 90% by weight, and may be 45 to 80% by weight or 50 to 50% by weight. 70% by weight.

Specific examples of alkyl (meth)acrylates having an alicyclic alkyl group include cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate, and cycloheptyl (meth)acrylate. Cycloalkyl (meth)acrylates such as cyclooctyl (meth)acrylate; (meth)acrylates with bicyclic aliphatic hydrocarbon rings such as isobornyl (meth)acrylate; (meth) Dicyclopentyl acrylate, Dicyclopentyloxyethyl (meth)acrylate, Tricyclopentyl (meth)acrylate, 1-adamantyl (meth)acrylate, 2-methyl (meth)acrylate - A (meth)acrylate having an aliphatic hydrocarbon ring having three or more rings, such as 2-adamantyl ester and 2-ethyl-2-adamantyl (meth)acrylate. As a preferable alkyl (meth)acrylate which has an alicyclic alkyl group used for a 1st aspect, there exist cyclohexyl (meth)acrylate and isobornyl (meth)acrylate. The amount of the alkyl (meth)acrylate having an alicyclic alkyl group relative to the total amount of monomer components constituting the acrylic polymer is, for example, about 3 to 50% by weight, and may be 5 to 40% by weight or 10% by weight. ~30% by weight.

The acrylic polymer may contain polar group-containing monomers such as hydroxyl-containing monomers, carboxyl-containing monomers, and nitrogen-containing monomers as constituent monomer components. When the acrylic polymer contains a polar group-containing monomer as a constituent monomer component, the cohesive force of the adhesive tends to be improved and the adhesive force tends to be improved. Preferred polar group-containing monomers used in the first aspect are hydroxyl-containing monomers and nitrogen-containing monomers. The amount of the polar group-containing monomer (the sum of the hydroxyl group-containing monomer, carboxyl group-containing monomer, and nitrogen-containing monomer) relative to the total amount of monomer components constituting the acrylic polymer is, for example, about 3 to 50% by weight. , may be 5 to 40% by weight or 10 to 30% by weight.

Examples of hydroxyl-containing monomers include: 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxybutyl (meth)acrylate, Hydroxyhexyl, 8-Hydroxyoctyl (meth)acrylate, 10-Hydroxydecyl (meth)acrylate, 12-Hydroxylauryl (meth)acrylate, (4-Hydroxymethylcyclohexyl (meth)acrylate) )-methyl ester and other (meth)acrylates. When a crosslinked structure is introduced into a polymer using an isocyanate crosslinking agent, the hydroxyl group can constitute a reaction site (crosslinking point) with an isocyanate group. Preferred hydroxyl-containing monomers used in the first aspect include 2-hydroxyethyl (meth)acrylate and 4-hydroxybutyl (meth)acrylate. The amount of the hydroxyl group-containing monomer relative to the total amount of monomer components constituting the acrylic polymer is, for example, about 3 to 50% by weight, and may be 5 to 40% by weight or 10 to 30% by weight.

Examples of carboxyl group-containing monomers include acrylic monomers such as (meth)acrylic acid, carboxyethyl (meth)acrylate, and carboxypentyl (meth)acrylate, itaconic acid, maleic acid, and fumaric acid. , crotonic acid, etc. When introducing a crosslinked structure into a polymer using an epoxy-based crosslinking agent, the carboxyl group can constitute a reaction site (crosslinking point) with an epoxy group. As a preferable carboxyl group-containing monomer used in the first aspect, there is (meth)acrylic acid. The amount of the carboxyl group-containing monomer relative to the total amount of monomer components constituting the acrylic polymer is, for example, about 3 to 50% by weight, and may be 5 to 40% by weight or 10 to 30% by weight.

Examples of nitrogen-containing monomers include N-vinylpyrrolidone, methylvinylpyrrolidone, vinylpyridine, vinylpiperidone, vinylpyrimidine, vinylpiperazine, vinylpyrazine, vinylpyrrole, Vinylimidazole, vinyl oxazole, vinyl morpholine, (meth)acryloyl morpholine, N-vinyl carboxylic acid amides, N-vinyl caprolactam, acrylamide and other vinyl monomers, acrylonitrile, Cyanide-containing monomers such as methacrylonitrile. As a preferable nitrogen-containing monomer used in the first mode, there is N-vinylpyrrolidone. The amount of nitrogen-containing monomers relative to the total amount of monomer components constituting the acrylic polymer is, for example, about 3 to 50% by weight, and may be 5 to 40% by weight or 10 to 30% by weight.

Acrylic polymers may include, as monomer components other than the above (sometimes referred to as “other monomers”): monomers containing anhydride groups, caprolactone adducts of (meth)acrylic acid, sulfonic acid group-containing Monomers, phosphoric acid group-containing monomers, vinyl acetate, vinyl propionate, styrene, α-methylstyrene and other vinyl monomers; (meth)glycidyl acrylate and other epoxy group-containing monomers; Polyethylene glycol (meth)acrylate, polypropylene glycol (meth)acrylate, methoxyethylene glycol (meth)acrylate, methoxypolypropylene glycol (meth)acrylate and other glycol-based acrylates Monomer: tetrahydrofurfuryl (meth)acrylate, fluoro(meth)acrylate, silicone (meth)acrylate, 2-methoxyethyl (meth)acrylate and other acrylate monomers, etc. .

The glass transition temperature (Tg) of the polymer contained in the photocurable adhesive composition is preferably 0° C. or lower. The glass transition temperature of the polymer may be below -5°C, below -10°C or below -15°C. The glass transition temperature of a polymer is the peak top temperature of the loss tangent (tan δ) based on dynamic viscoelasticity measurements. When a crosslinked structure is introduced into the polymer, the glass transition temperature may be calculated based on the theoretical Tg according to the composition of the polymer. Theoretical Tg was calculated using the Fox formula mentioned later.

A polymer can be obtained by polymerizing the above monomer components by various known methods. There is no particular limitation on the polymerization method, but it is preferable to prepare the polymer by photopolymerization. Since photopolymerization can produce a polymer without using a solvent, it is not necessary to dry and remove a solvent when forming an adhesive layer, and can uniformly form a thick adhesive layer.

In the preparation of the pressure-sensitive adhesive layer of the first aspect, it is preferable to prepare it as a polymer (prepolymer) with a low degree of polymerization in which a part of the monomer components remain unreacted. The composition for preparing a prepolymer (prepolymer-forming composition) preferably further contains a photopolymerization initiator in addition to a monomer. What is necessary is just to select a photoinitiator suitably according to the kind of monomer. For example, polymerization of acrylic polymers can use photoradical polymerization initiators. Examples of photopolymerization initiators include: benzoin ether photopolymerization initiators, acetophenone photopolymerization initiators, α-keto alcohol photopolymerization initiators, aromatic sulfonyl chloride photopolymerization initiators, Active oxime photopolymerization initiator, benzoin photopolymerization initiator, benzil photopolymerization initiator, benzophenone photopolymerization initiator, ketal photopolymerization initiator, thioxanthone photopolymerization Initiators, acylphosphine oxide-based photopolymerization initiators, etc.

During polymerization, a chain transfer agent, a polymerization inhibitor (polymerization retarder), and the like can be used for the purpose of molecular weight adjustment and the like. Examples of the chain transfer agent include α-thioglycerol, lauryl mercaptan, glycidyl mercaptan, thioglycolic acid, 2-mercaptoethanol, thioglycolic acid, 2-ethylhexyl thioglycolate, 2,3- Thiols such as dimercapto-1-propanol, α-methylstyrene dimer, etc.

The polymerization rate of the prepolymer is not particularly limited, but is preferably 3 to 50% by weight, more preferably 5 to 40% by weight, from the viewpoint of forming a viscosity suitable for coating on a substrate. The polymerization rate of the prepolymer can be adjusted to a desired range by adjusting the type and amount of the photopolymerization initiator, the irradiation intensity/irradiation time of active light such as UV light, and the like. The polymerization rate of the prepolymer is a non-volatile matter when heated at 130° C. for 3 hours, and is calculated by the following formula. The polymerization ratio (non-volatile matter) of the adhesive layer was also measured by the same method.

Polymerization rate (%) = weight after heating / weight before heating × 100

As mentioned above, the photocurable adhesive composition for forming an adhesive layer contains a polymer, a photopolymerizable compound, a photopolymerization initiator, and a coloring agent. For example, a photocurable adhesive composition can be obtained by adding a photopolymerizable compound, a photopolymerization initiator, and a colorant to a prepolymer. It is also possible to use a low-molecular-weight polymer (oligomer) instead of a prepolymer, and to mix a photopolymerizable compound, a photopolymerization initiator, and a colorant into the low-molecular-weight polymer to prepare a photocurable adhesive set thing.

(photopolymerizable compound)

The photopolymerizable compound contained in the said photocurable adhesive composition has 1 or more photopolymerizable functional groups in 1 molecule. The photopolymerizable functional group may be any of radical polymerizability, cation polymerizability, and anion polymerizability, and is preferably a radical having an unsaturated double bond (ethylenically unsaturated group) from the viewpoint of excellent reactivity. polymerizable functional groups.

The prepolymer contains monomers that have not reacted with the polymer, and the unreacted monomers maintain photopolymerization. Therefore, it is not necessarily necessary to add a photopolymerizable compound in the preparation of the photocurable adhesive composition. When adding a photopolymerizable compound to a prepolymer, the photopolymerizable compound to be added may be the same as or different from the monomer used to prepare the prepolymer.

When the polymer is an acrylic polymer, the compound added as a photopolymerizable compound is preferably a monomer having a (meth)acryloyl group as a photopolymerizable functional group from the viewpoint of high compatibility with the polymer. or oligomers. The photopolymerizable compound may be a polyfunctional compound having two or more photopolymerizable functional groups in one molecule. As a photopolymerizable polyfunctional compound, polyfunctional (meth)acrylate is mentioned. Examples of polyfunctional (meth)acrylates include polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, and polytetramethylene glycol di(meth)acrylate. , Bisphenol A ethylene oxide modified di(meth)acrylate, bisphenol A propylene oxide modified di(meth)acrylate, alkanediol di(meth)acrylate, tricyclodecane Dimethanol Di(meth)acrylate, Pentaerythritol Di(meth)acrylate, Neopentyl Glycol Di(meth)acrylate, Glycerin Di(meth)acrylate, Urethane Di(meth)acrylate Bifunctional (meth)acrylates such as esters; pentaerythritol tri(meth)acrylate, trimethylolpropane tri(meth)acrylate and ethoxylated isocyanurate tri(meth)acrylate, etc. Functional (meth)acrylates; 4 functional (meth)acrylates such as di(trimethylolpropane)tetra(meth)acrylate, ethoxylated pentaerythritol tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate base) acrylates; pentaerythritol penta(meth)acrylates, dipentaerythritol hexa(meth)acrylates, etc., and pentafunctional or more (meth)acrylates.

When a polyfunctional compound is used as the photopolymerizable compound, the amount of the polyfunctional compound is preferably 10 parts by weight or less, more preferably 0.001 to 1 part by weight, based on 100 parts by weight of the polymer (including the prepolymer). , and more preferably 0.005 to 0.5 parts by weight. When the usage-amount of a polyfunctional monomer is too large, the viscosity of the adhesive layer after photocuring may become low and adhesive force may be inferior. The usage amount of the multifunctional compound is less than 10 parts by weight, may be less than 5 parts by weight, less than 3 parts by weight or less than 1 part by weight. The amount of the multifunctional monomer used may be 0, 0.001 parts by weight or more, 0.01 parts by weight or more, or 0.1 parts by weight or more.

When using a prepolymer-forming monomer as the photopolymerizable compound, a hydroxyl group-containing monomer is preferable, and 2-hydroxyethyl (meth)acrylate and 4-hydroxybutyl (meth)acrylate are more preferable. When a hydroxyl-containing monomer is used as a photopolymerizable compound, the amount of the hydroxyl-containing monomer is preferably 40 parts by weight or less, more preferably 1 to 30 parts by weight, based on 100 parts by weight of the polymer (including the prepolymer). The weight part is more preferably 5 to 20 weight parts. The amount of the hydroxyl group-containing monomer is less than 40 parts by weight, may be less than 30 parts by weight, or less than 20 parts by weight. The usage amount of the hydroxyl group-containing monomer may be 0, 1 part by weight or more, 5 parts by weight or more, or 10 parts by weight or more.

(photopolymerization initiator)

The photocurable adhesive composition contains a photopolymerization initiator. The photopolymerization initiator generates radicals, acids, bases and the like upon irradiation with active rays such as ultraviolet rays, and can be appropriately selected according to the type of photopolymerizable compound and the like. When the photopolymerizable compound is a compound having a (meth)acryloyl group (for example, a monofunctional or polyfunctional (meth)acrylate), a photoradical polymerization initiator is preferably used as the photopolymerization initiator. A photoinitiator may be used individually or in mixture of 2 or more types.

When the photopolymerization initiator used in the preparation (polymerization) of the aforementioned polymer (including the prepolymer) remains without deactivation, addition of the photopolymerization initiator can be omitted. When adding a photopolymerization initiator to a polymer, the photopolymerization initiator to be added may be the same as or different from the photopolymerization initiator used to prepare the polymer.

The photopolymerization initiator contained in the photocurable adhesive composition preferably has a maximum absorption in a wavelength region where light absorption by a colorant described later is small. Specifically, the photopolymerization initiator preferably has a maximum absorption in a wavelength region of 330 to 400 nm. Since the photopolymerization initiator has the maximum absorption in a region where the light absorption by the colorant is small, the inhibition of curing by the colorant can be suppressed, and thus the polymerization rate can be sufficiently increased by photocuring. Examples of photoradical polymerization initiators having a maximum absorption in the wavelength region of 330 to 400 nm include hydroxy ketones, benzil dimethyl ketals, amino ketones, acyl phosphine oxides, and benzophenones. Classes, trichloromethyl-containing triazine derivatives, etc.

Regarding the content of the photopolymerization initiator in the photocurable adhesive composition, it is About 0.01 to 10 parts by weight, preferably about 0.05 to 5 parts by weight.

(Colorant)

The photocurable adhesive composition used for forming an adhesive layer contains a coloring agent. The coloring agent may be a dye or a pigment as long as it can be dissolved or dispersed in the photocurable adhesive composition. A dye is preferable from the viewpoint that low haze can be achieved by adding a small amount, and that it is easy to distribute uniformly without sedimentation like a pigment. In addition, pigments are also preferable from the viewpoint of obtaining high color rendering properties by adding a small amount. When a pigment is used as a colorant, a pigment having low or no conductivity is preferable. Moreover, when using a dye, it is preferable to use together with the antioxidant etc. mentioned later.

As the colorant, a colorant that absorbs visible light and has ultraviolet transmittance can be used. The colorant preferably has a maximum value of transmittance at a wavelength of 330 to 400 nm greater than a maximum value of transmittance at a wavelength of 400 to 700 nm. In addition, the colorant preferably has an average transmittance at a wavelength of 330 to 400 nm greater than that at a wavelength of 400 to 700 nm. Regarding the transmittance of the colorant, use an appropriate solvent such as tetrahydrofuran (THF) or a dispersion medium (an organic solvent with small absorption in the range of wavelength 330 to 700 nm) so that the transmittance at a wavelength of 400 nm is about 50 to 60%. ) for the diluted solution or dispersion.

As an ultraviolet-transmissive black pigment whose absorption of ultraviolet rays is smaller than the absorption of visible light, "9050BLACK" by Tokushiki Co., Ltd., "UVBK-0001", etc. are mentioned. "SOC-L-0123" manufactured by ORIENT CHEMICAL INDUSTRIES CO., LTD. etc. are mentioned as an ultraviolet-ray transparent black dye.

Carbon black and titanium black, which are generally used as black colorants, absorb more ultraviolet light than visible light (ultraviolet light transmittance is smaller than visible light transmittance). Therefore, if a colorant such as carbon black is added to a photocurable adhesive composition sensitive to ultraviolet rays, most of the ultraviolet rays irradiated for photocuring will be absorbed by the colorant, and the amount of light absorbed by the photopolymerization initiator will be small. , Photocuring will take time (the cumulative amount of light exposure will increase). In addition, when the thickness of the pressure-sensitive adhesive layer is large, since there are few ultraviolet rays reaching the surface opposite to the light-irradiated surface, photocuring tends to be insufficient even when light is irradiated for a long time. On the other hand, by using a colorant having a higher transmittance of ultraviolet rays than visible light, inhibition of curing by the colorant can be suppressed.

The content of the colorant in the photocurable adhesive composition is, for example, about 0.01 to 20 parts by weight with respect to 100 parts by weight of the total amount of monomers. It is enough to set the rate appropriately. The colorant may be added to the composition in the form of a solution or dispersion dissolved or dispersed in an appropriate solvent.

(A silane coupling agent)

In the photocurable adhesive composition, the silane coupling agent can be contained in the range which does not impair the effect of this invention. When the photocurable adhesive composition contains a silane coupling agent, the adhesion reliability to glass (particularly, the adhesion reliability to glass under a high-temperature and high-humidity environment) is improved, which is preferable.

The aforementioned silane coupling agent is not particularly limited, but preferred examples include: γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-aminopropyl Trimethoxysilane, N-phenyl-aminopropyltrimethoxysilane, 3-acryloyloxypropyltrimethoxysilane, and the like. Among them, γ-glycidoxypropyltrimethoxysilane is preferable. Moreover, as a commercial item, a brand name "KBM-403" (made by Shin-Etsu Chemical Co., Ltd.) is mentioned, for example. In addition, a silane coupling agent can be used individually or in combination of 2 or more types.

The content of the silane coupling agent in the photocurable adhesive composition is not particularly limited, but is preferably 0.01 to 1 part by weight, more preferably 0.03 to 0.5 parts by weight, based on 100 parts by weight of the polymer.

(other ingredients)

In the first aspect, the photocurable adhesive composition may contain components other than a polymer, a photopolymerizable compound, a photopolymerization initiator, and a colorant. For example, a chain transfer agent may be contained for the purpose of adjusting the photocuring rate or the like. In addition, an oligomer and a tackifier may be contained for the purpose of adjusting the viscosity of the photocurable adhesive composition, adjusting the adhesive force of the adhesive layer, and the like. As an oligomer, the oligomer whose weight average molecular weight is about 1000-30000 can be used, for example. As the oligomer, an acrylic oligomer is preferable from the viewpoint of excellent compatibility with an acrylic polymer. The aforementioned photocurable adhesive composition may contain additives such as plasticizers, softeners, anti-deterioration agents, fillers, antioxidants, surfactants, and antistatic agents.

[Second way]

The adhesive layer of the second aspect is a type that does not undergo photocuring, and is an adhesive layer formed by forming a photocurable adhesive composition into a sheet shape. Since the adhesive layer of the second aspect contains a photopolymerizable compound in an unreacted state, the adhesive layer has photocurability.

<Photocurable Adhesive Composition>

The photocurable adhesive composition for forming the adhesive layer of the second aspect contains a polymer, a photopolymerizable compound, a photopolymerization initiator, and a colorant.

(polymer)

As the polymer contained in the photocurable adhesive composition, various polymers can be applied in the same manner as in the first embodiment, and an acrylic polymer can be suitably used. The monomer components constituting the acrylic polymer are the same as those of the first embodiment.

In order to introduce a crosslinked structure by a crosslinking agent described later, it is preferable to include a hydroxyl group-containing monomer and/or a carboxyl group-containing monomer in the monomer components constituting the polymer. For example, when an isocyanate-based crosslinking agent is used, it is preferable to contain a hydroxyl group-containing monomer as a monomer component. When using an epoxy-type crosslinking agent, it is preferable to contain a carboxyl group-containing monomer as a monomer.

In the second mode, since photocuring is not performed on the base material, in order to form a solid (fixed shape) adhesive layer, a polymer with a relatively high molecular weight can be used as the polymer contained in the photocurable adhesive composition. . The weight-average molecular weight of the polymer is, for example, about 100,000 to 2 million.

Since a high-molecular-weight polymer is a solid, the photocurable adhesive composition is preferably a solution in which a polymer is dissolved in an organic solvent. For example, a polymer solution can be obtained by solution-polymerizing monomer components. A polymer solution can be prepared by dissolving a solid polymer in an organic solvent.

As a solvent for solution polymerization, ethyl acetate, toluene, and the like are generally used. The solution concentration is usually about 20 to 80% by weight. As the polymerization initiator, it is preferable to use an azo initiator, a peroxide initiator, a redox initiator obtained by combining a peroxide and a reducing agent (for example, a combination of persulfate and sodium bisulfite, a persulfate oxide and sodium ascorbate) and other thermal polymerization initiators. The amount of the polymerization initiator used is not particularly limited. For example, it is preferably about 0.005 to 5 parts by weight, more preferably about 0.02 to 3 parts by weight, based on 100 parts by weight of the total monomer components forming the polymer.

(photopolymerizable compound)

The photopolymerizable compound contained in the photocurable adhesive composition in a 2nd aspect is the same as what was demonstrated about the 1st aspect above, and the compound which has 1 or 2 or more photopolymerizable functional groups can be used.

(photopolymerization initiator)

The photopolymerization initiator contained in the photocurable adhesive composition in the second aspect is the same as that described above for the first aspect, and is preferably a photopolymerization initiator having a maximum absorption in a wavelength range of 330 to 400 nm. The quantity of a photoinitiator is about 0.01-10 weight part with respect to 100 weight part of polymers, Preferably it is about 0.05-5 weight part.

(Colorant)

In the second aspect, the colorant contained in the photocurable adhesive composition is the same as that described above for the first aspect, and the maximum value of the transmittance at a wavelength of 330 to 400 nm is preferably greater than that at a wavelength of 400 to 700 nm. the maximum value. In addition, the colorant preferably has an average transmittance at a wavelength of 330 to 400 nm greater than that at a wavelength of 400 to 700 nm.

(crosslinking agent)

It is preferable that the photocurable adhesive composition of a 2nd aspect contains the crosslinking agent which can crosslink with the said polymer. Specific examples of crosslinking agents for introducing a crosslinked structure into polymers include isocyanate crosslinking agents, epoxy crosslinking agents, oxazoline crosslinking agents, and aziridine crosslinking agents. agent, carbodiimide crosslinking agent, metal chelate crosslinking agent, etc. Among them, isocyanate-based crosslinking agents and epoxy-based crosslinking agents are preferable from the viewpoint of high reactivity with the hydroxyl group and carboxyl group of the polymer and ease of introduction of a crosslinked structure. These crosslinking agents react with functional groups such as hydroxyl groups and carboxyl groups introduced into the polymer to form a crosslinked structure.

As an isocyanate crosslinking agent, the polyisocyanate which has 2 or more isocyanate groups in 1 molecule can be used. Examples of isocyanate-based crosslinking agents include lower aliphatic polyisocyanates such as butylene diisocyanate and hexamethylene diisocyanate; cyclopentylene diisocyanate, cyclohexylene diisocyanate, and isophorone diisocyanate; Cycloaliphatic isocyanates such as 2,4-toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, xylylene diisocyanate and other aromatic isocyanates; trimerization of trimethylolpropane/toluene diisocyanate Trimeric adducts (such as "CORONATE L" manufactured by Tosoh Corporation), trimethylolpropane/hexamethylene diisocyanate trimer adducts (such as "CORONATE HL" manufactured by Tosoh Corporation), benzene Trimethylolpropane adduct of methyl diisocyanate (such as "TAKENATE D110N" manufactured by Mitsui Chemicals, Inc., isocyanurate body of hexamethylene diisocyanate (such as "CORONATE HX" manufactured by Tosoh Corporation) and other isocyanate adducts, etc.

As an epoxy crosslinking agent, the polyfunctional epoxy compound which has 2 or more epoxy groups in 1 molecule can be used. The epoxy group of the epoxy crosslinking agent may be a glycidyl group. Examples of epoxy-based crosslinking agents include N,N,N',N'-tetraglycidyl-m-xylylenediamine, diglycidylaniline, 1,3-bis(N,N-di Glycidylaminomethyl) 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, glycerin polyglycidyl ether, pentaerythritol polyglycidyl ether, polyglycerol polyglycidyl ether, sorbitan polyglycidyl ether, trimethylol Propane polyglycidyl ether, diglycidyl adipate, diglycidyl phthalate, triglycidyl-tris(2-hydroxyethyl) isocyanurate, resorcinol diglycidyl ether , Bisphenol-S-diglycidyl ether, etc. Commercial items such as "DENACOL" manufactured by Nagase ChemteX Corporation and "TETRAD X" and "TETRAD C" manufactured by Mitsubishi Gas Chemical Co., Ltd. can be used as the epoxy-based crosslinking agent.

The amount of the crosslinking agent is about 0.01 to 5 parts by weight relative to 100 parts by weight of the polymer, may be 0.05 parts by weight or more, 0.1 parts by weight or more, or 0.2 parts by weight or more, may be 3 parts by weight or less, 2 parts by weight or less, or 1 part by weight. parts by weight or less.

(other ingredients)

The photocurable adhesive composition of the second aspect may contain an oligomer, a tackifier, a silane coupling agent, a chain transfer agent, a plasticizer, a softener, an anti-deterioration agent, and a filler in addition to the above-mentioned components. , antioxidants, surfactants, antistatic agents, etc.

<Solvent-based adhesive composition>

In this embodiment, the adhesive layer 2 may be an adhesive layer formed of a solvent-based adhesive composition containing a colorant (third aspect). The aforementioned solvent-based adhesive composition further contains at least a polymer and a solvent in addition to a colorant, and may contain a crosslinking agent. That is, the solvent-based adhesive composition for forming the adhesive layer 2 of this embodiment contains a polymer, a solvent, and a colorant, and may contain a crosslinking agent as necessary. The pressure-sensitive adhesive layer 2 of the present embodiment is a pressure-sensitive adhesive layer that absorbs visible light.

[Third way]

The pressure-sensitive adhesive layer of the third aspect can be formed by applying a solvent-based pressure-sensitive adhesive composition containing a polymer, a solvent, a colorant, and a crosslinking agent if necessary, on a release film, and drying and removing the solvent.

The solvent-based adhesive composition for forming the adhesive layer of the third aspect contains a polymer, a solvent, a colorant, and if necessary, a crosslinking agent.

(polymer)

As the polymer contained in the solvent-based adhesive composition, as in the first embodiment, various polymers can be applied, and an acrylic polymer can be suitably used. The monomer components constituting the acrylic polymer are the same as those of the first embodiment.

In the third aspect, in order to form a solid (fixed shape) pressure-sensitive adhesive layer on the substrate, a polymer having a relatively high molecular weight can be used as the polymer contained in the solvent-based pressure-sensitive adhesive composition. The weight-average molecular weight of the polymer is, for example, about 100,000 to 2 million.

The aforementioned acrylic polymer contained in the solvent-based adhesive composition of the third aspect may be a (meth)acrylic block copolymer. When the pressure-sensitive adhesive layer 2 is formed of a solvent-based pressure-sensitive adhesive composition containing a (meth)acrylic block copolymer, since it is excellent in height difference absorbability and processability, it can be formed without leaving air bubbles. The gaps between LED chips arranged on the substrate 5 of the display panel are packaged with gaps in height, and the processability is excellent, so it is difficult for the adhesive layer to ooze out from the end during storage.

In this embodiment, it is preferable that the aforementioned (meth)acrylic block copolymer includes: a high Tg segment having a glass transition temperature of 0°C to 100°C; The low Tg segment with a glass transition temperature of 0°C has peaks of tan δ in regions above 0°C and in regions below 0°C, respectively.

In this specification, "a high Tg segment having a glass transition temperature of not less than 0°C and not more than 100°C" is sometimes simply referred to as a "high Tg segment", and "a glass segment having a glass transition temperature of not less than -100°C and not more than 0°C" The low Tg segment of transition temperature" is referred to as "low Tg segment", the peak of tanδ in the region above 0°C is referred to as "high temperature region tanδ peak", and the peak of tanδ in the region below 0°C is referred to as "Low temperature region tanδ peak", the (meth)acrylic block copolymer having the aforementioned high Tg segment, the aforementioned low Tg segment, the aforementioned high temperature region tanδ peak, and low temperature region tanδ peak is called "(meth)acrylic block copolymer block copolymer A", and the solvent-based adhesive composition containing the aforementioned (meth)acrylic block copolymer A is referred to as "solvent-based adhesive composition A".

The "segment" in the high Tg segment and the low Tg segment refers to the partial structure of each block unit constituting the (meth)acrylic block copolymer A.

The structure of the aforementioned (meth)acrylic block copolymer A may be a linear block copolymer, a branched (star) block copolymer, or a mixture thereof. The structure of such a block copolymer may be appropriately selected according to the desired physical properties of the block copolymer, but a linear block copolymer is preferable from the viewpoint of cost and ease of production. In addition, the linear block copolymer may have any structure (arrangement), and from the viewpoint of the physical properties of the linear block copolymer or the physical properties of the solvent-based adhesive composition A, it is preferable to have a structure selected from (AB) _n A block copolymer of at least one structure in the group consisting of type, (AB) _n -A type (n is an integer of 1 or more, for example, an integer of 1 to 3). In these structures, A and B represent segments composed of different monomer compositions. In this specification, the segment represented by A constituting the linear block copolymer may be referred to as "A segment", and the segment represented by B may be referred to as "B segment".

Among these, from the viewpoints of ease of manufacture, physical properties of the solvent-based adhesive composition A, etc., an AB type diblock copolymer represented by A-B and an ABA type triblock copolymer represented by A-B-A are preferable, More preferred is an ABA type triblock copolymer. It is considered that the pseudo-crosslinking between the A chain segments at both ends of the ABA type triblock copolymer makes the crosslinking structure between the block copolymers become a more highly crosslinking structure, and the cohesive force of the block copolymer is improved, which can Exhibits higher adhesion (adhesion). It should be noted that, in the ABA type triblock copolymer, the two A segments located at both ends may be the same as or different from each other.

When the (meth)acrylic block copolymer A is an ABA type triblock copolymer, at least one of the two A segments and one B segment (3 in total) is a high Tg chain Segment, at least one other is a low Tg segment. From the viewpoints of ease of manufacture, physical properties of the solvent-based adhesive composition A, etc., an ABA-type triblock copolymer in which the A segment is the aforementioned high Tg segment and the B segment is the aforementioned low Tg segment is preferred. . In this case, it is preferred that at least one of the two A segments is a high Tg segment and the B segment is a low Tg segment, and it is more preferred that both A segments are high Tg chains. Segment and B segment are ABA type triblock copolymers with low Tg segment.

The glass transition temperature (Tg) of the high Tg segment which comprises (meth)acryl-type block copolymer A is 0 degreeC or more and 100 degreeC or less as mentioned above. When the Tg of the high Tg segment is within this range, there is a tendency that the storage modulus of the solvent-based adhesive composition A at room temperature (25° C.) is easily controlled to be high, hard and excellent in workability, Furthermore, the storage modulus significantly decreases in the region exceeding 50° C., resulting in a highly fluid adhesive composition. From the viewpoint of improving the processability of the solvent-based adhesive composition A at room temperature (25°C), the Tg of the high Tg segment is preferably 4°C or higher, more preferably 6°C or higher, even more preferably 8°C above, more preferably 10°C or higher, particularly preferably 12°C or higher. On the other hand, the Tg of the high Tg segment is preferably 90°C or lower, more preferably 85°C or lower, even more preferably 60°C or lower, still more preferably 50°C or lower, particularly preferably 35°C or lower.

Tg of the low Tg segment constituting the (meth)acrylic block copolymer A is -100°C or higher and lower than 0°C as described above. When the glass Tg of the low Tg segment is within this range, there is a tendency that only the low Tg segment becomes fluidized at room temperature (25°C), and moderate adhesive force can be imparted to the solvent while ensuring processability type adhesive composition A. The Tg of the low Tg segment is preferably -95°C or higher, more preferably - 90°C or higher, more preferably -80°C or higher. On the other hand, the Tg of the low Tg segment is preferably -5°C or less, more Preferably it is -10°C or lower, more preferably -20°C or lower, still more preferably -30°C or lower, particularly preferably -40°C or lower.

The difference between the Tg of the high Tg segment and the low Tg segment constituting the (meth)acrylic block copolymer A (Tg of the high Tg segment - Tg of the low Tg segment) is not particularly limited. The storage modulus of adhesive composition A at room temperature (25°C) is controlled to be high, hard and excellent in processability, and the storage modulus is significantly reduced in the region exceeding 50°C, resulting in a highly fluid adhesive. From the viewpoint of the mixture composition, it is preferably 30°C or higher, more preferably 35°C or higher, more preferably 40°C or higher, more preferably 45°C or higher, still more preferably 50°C or higher, particularly preferably 55°C or higher, It is preferably 120°C or lower, more preferably 115°C or lower, more preferably 110°C or lower, more preferably 105°C or lower, further preferably 100°C or lower, particularly preferably 95°C or lower.

The glass transition temperature (Tg) of the high Tg segment and the low Tg segment which comprise (meth)acryl-type block copolymer A is the calculated glass transition temperature calculated by the following Fox formula. The calculated glass transition temperature is calculated based on the type and amount of each monomer component constituting the high Tg segment or the low Tg segment of the (meth)acrylic block copolymer A. Therefore, by selecting each segment The type and amount of the monomer components are adjusted.

The calculated glass transition temperature (calculated Tg) can be calculated according to the following Fox formula [1].

1/ Calculate Tg=W1/Tg(1)+W2/Tg(2)+...+Wn/Tg(n)[1]

Here, W1, W2, ... Wn represent the respective weight fractions (% by weight) of monomer components (1), monomer components (2), ... monomer components (n) constituting the copolymer with respect to the total monomer components, Tg (1), Tg (2), ... Tg (n) represents the glass transition temperature of the homopolymer of monomer component (1), monomer component (2), ... monomer component (n) (unit is absolute temperature: K).

In addition, the glass transition temperature of a homopolymer is well-known in various literature, a catalog, etc., For example, it describes in J.Brandup, E.H.Immergut, E.A.Grulke: Polymer Handbook: JOHNWILEY & SONS, INC. For monomers for which there are no numerical descriptions in various literatures, values measured by conventional thermal analysis, such as differential thermal analysis, dynamic viscoelasticity measurement, and the like can be used.

The temperature range in which the high-temperature range tanδ peak of the (meth)acrylic block copolymer A appears is 0° C. or higher (for example, 0° C. or higher and 100° C. or lower) as described above. By setting the tan δ peak in the high temperature region in this temperature range, there is a tendency that the storage modulus of the solvent-based adhesive composition A at room temperature (25° C.) can be easily controlled to be high, hard and excellent in workability, and In the region exceeding 50° C., the storage modulus is significantly lowered, and it becomes a highly fluid adhesive composition. From the viewpoint of improving the workability of the solvent-based adhesive composition A at room temperature (25° C.), the temperature at which the tan δ peak appears in the high-temperature region is preferably 3° C. or higher, more preferably 6° C. or higher, and even more preferably 9°C or higher, more preferably 12°C or higher, particularly preferably 15°C or higher. On the other hand, from the point of view that the storage modulus (G') of the solvent-based adhesive composition A significantly decreases in the region exceeding 50°C and high fluidity is easily obtained, the temperature at which the tanδ peak appears in the high-temperature region Preferably it is 90°C or lower, more preferably 80°C or lower, even more preferably 70°C or lower, even more preferably 65°C or lower, particularly preferably 60°C or lower.

The temperature range in which the low-temperature range tanδ peak of the (meth)acrylic block copolymer A appears is lower than 0° C. (for example, -100° C. or higher and lower than 0° C.) as described above. By setting the tanδ peak in the low temperature region in this temperature range, there is a tendency that only the low Tg segment becomes fluidized at room temperature (25°C), and moderate adhesive force can be imparted to solvent-based adhesives while ensuring processability. Mixture composition A. The temperature at which the tanδ peak appears in the low temperature range is preferably -95°C or higher, more preferably It is -90°C or higher, more preferably -80°C or higher, even more preferably -70°C or higher. On the other hand, the temperature at which the tan δ peak in the low temperature region appears is preferably -5°C or lower from the viewpoint of being able to improve the moderate adhesive force and processability of the solvent-based adhesive composition A at room temperature (25°C). , more preferably -10°C or lower, even more preferably -20°C or lower, even more preferably -30°C or lower, particularly preferably -40°C or lower.

The maximum value of the tanδ peak in the high temperature region is not particularly limited, but is preferably 0.5 to 3.0. By making the maximum value of the tan δ peak in the high temperature region within this range, it is preferable in that the excellent processability and shape stability of the (meth)acrylic block copolymer A can be achieved. The maximum value of the tanδ peak in the high-temperature region is preferably 0.6 or more, more preferably 0.7 or more, from the viewpoint of achieving excellent workability. In addition, the maximum value of the tan δ peak in the high-temperature region is preferably 2.5 or less, more preferably 2.2 or less, from the viewpoint that indentation is less likely to occur.

The maximum value of the tanδ peak in the low temperature region is not particularly limited, but is preferably 0.1 to 2.0. By making the maximum value of the tan δ peak in the low temperature region within this range, it is preferable in that the excellent processability and shape stability of the (meth)acrylic block copolymer A can be achieved. The maximum value of the tanδ peak in the high-temperature region is preferably 0.2 or more, more preferably 0.3 or more, from the viewpoint of achieving excellent workability. In addition, the maximum value of the tanδ peak in the low temperature region is preferably 1.5 or less, and more preferably 1 or less, from the viewpoint that indentation is less likely to occur.

It should be noted that the tanδ peak in the high-temperature region and the tanδ peak in the low-temperature region, the temperature at which they appear, and the maximum value are measured by dynamic viscoelasticity measurement.

The (meth)acrylic block copolymer A is composed of a plurality of segments (including high Tg segments and low Tg segments) obtained by polymerizing monomer components. ) acryloyl monomer (acrylic monomer).

The (meth)acrylic block copolymer A or each segment thereof is contained preferably at least 70% by weight, more preferably at least 80% by weight, particularly preferably at least 90% by weight, based on the total amount of monomer components (100% by weight). The above acrylic monomers.

As the acrylic monomer constituting the (meth)acrylic block copolymer A or each segment (including a high Tg segment and a low Tg segment), an acrylic acid having a linear or branched alkyl group is included. An alkyl ester and/or a monomer component derived from an alkyl methacrylate having a linear or branched alkyl group is the main monomer unit having the largest proportion by weight.

Examples of the alkyl (meth)acrylate having a linear or branched alkyl group for forming the segment of the (meth)acrylic block copolymer A include the above-mentioned Specific examples of alkyl (meth)acrylates. As the alkyl (meth)acrylate used for the aforementioned segment, one kind of alkyl (meth)acrylate may be used, or two or more kinds of alkyl (meth)acrylate may be used. As the alkyl (meth)acrylate used for the aforementioned segment, preferably used are selected from the group consisting of methyl acrylate, n-butyl acrylate and 2-ethylhexyl acrylate, tert-butyl acrylate, hexyl acrylate, and heptyl acrylate. , At least one of the group consisting of octyl acrylate and isononyl acrylate.

The segment of the (meth)acrylic block copolymer A may contain a monomer unit derived from an alicyclic monomer. As an alicyclic monomer used for forming the monomer unit of the said segment, the specific example of the alkyl (meth)acrylate which has the said alicyclic alkyl group is mentioned. The aforementioned alicyclic alkyl group may have a substituent. Examples of such substituents include halogen atoms (such as fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms), straight-chain or branched alkyl groups having 1 to 6 carbon atoms (such as methyl, ethyl, n-propyl, and base, isopropyl, etc.) and so on. The number of the aforementioned substituents is not particularly limited, and can be appropriately selected from 1 to 6. When there are two or more substituents, the two or more substituents may be the same or different. As the alicyclic monomer used for the aforementioned segment, one type of alicyclic monomer may be used, or two or more alicyclic monomers may be used. As the alicyclic monomer used for the aforementioned segment, it is preferably a cycloalkyl group having 4 to 10 carbons optionally having a substituent (for example, a linear or branched alkyl group having 1 to 6 carbons). As cycloalkyl (meth)acrylate, it is more preferable to use at least one selected from the group consisting of cyclohexyl acrylate and 3,3,5-trimethylcyclohexyl (meth)acrylate.

The segment of the (meth)acrylic block copolymer A may contain a monomer unit derived from a hydroxyl group-containing monomer. A hydroxyl group-containing monomer is a monomer having at least one hydroxyl group within the monomer unit. When the segment in the (meth)acrylic block copolymer A contains a hydroxyl group-containing monomer unit, it is easy to obtain adhesiveness and moderate cohesion in the solvent-type adhesive composition A.

Specific examples of the above-mentioned hydroxyl-containing monomers can be mentioned as the hydroxyl-containing monomer used to form the monomer unit of the aforementioned segment. As the hydroxyl group-containing monomer used for the aforementioned segment, one type of hydroxyl group-containing monomer may be used, or two or more types of hydroxyl group-containing monomers may be used. As the hydroxyl group-containing monomer used for the aforementioned chain segment, preferably a hydroxyl group-containing (meth)acrylate, more preferably used selected from the group consisting of 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, and 2-hydroxypropyl acrylate. At least one of the group consisting of ester, 2-hydroxypropyl methacrylate, 4-hydroxybutyl acrylate and 4-hydroxybutyl methacrylate.

The segment of the (meth)acrylic block copolymer A may contain a monomer unit derived from a nitrogen atom-containing monomer. A nitrogen atom-containing monomer is a monomer having at least one nitrogen atom within the monomer unit. When the segment of the (meth)acrylic block copolymer A contains a nitrogen atom-containing monomer unit, in the solvent-based adhesive composition A, hardness and good adhesion reliability can be easily obtained.

As the nitrogen atom-containing monomer used to form the aforementioned segment, specific examples of the nitrogen atom-containing monomer described above can be mentioned. As the nitrogen-atom-containing monomer used in the acrylic polymer, one kind of nitrogen-atom-containing monomer may be used, or two or more kinds of nitrogen-atom-containing monomers may be used. As the nitrogen atom-containing monomer used for the aforementioned segment, N-vinyl-2-pyrrolidone is preferably used.

The segment of the (meth)acrylic block copolymer A may contain a monomer unit derived from a carboxyl group-containing monomer. A carboxyl group-containing monomer is a monomer having at least one carboxyl group in a monomer unit. In the case where the segment of the (meth)acrylic block copolymer A contains a carboxyl group-containing monomer unit, in the solvent-type adhesive composition A, good adhesion reliability may be obtained in some cases.

Specific examples of the above-mentioned carboxyl group-containing monomers can be mentioned as the carboxyl group-containing monomer used to form the monomer unit of the aforementioned segment. As the carboxyl group-containing monomer used for the aforementioned segment, one kind of carboxyl group-containing monomer may be used, or two or more kinds of carboxyl group-containing monomers may be used. As the carboxyl group-containing monomer used for the aforementioned segment, acrylic acid is preferably used.

Furthermore, as a monomer unit for forming the said segment, the said other monomer is mentioned. The content of other monomers in the monomer units constituting the segment of the (meth)acrylic block copolymer A is not particularly limited as long as it is 30% by weight or less based on the total amount of the monomer components (100% by weight). The limitation can be appropriately selected within the range that does not impair the effect of the present invention.

As a monomer component constituting the high Tg segment of the (meth)acrylic block copolymer A, it is easy to control the Tg of the high Tg segment within a predetermined range, and it is possible to give the (meth)acrylic block copolymer From the viewpoint of desired physical properties, Alkyl (meth)acrylate (hereinafter sometimes referred to as "(meth)acrylic acid C _{1 -3} linear alkyl esters"), alkyl (meth)acrylates having branched alkyl groups with 3 or 4 carbon atoms (hereinafter sometimes referred to as "(meth)acrylic acid C _3-4 branched At least one of the group consisting of "chain alkyl ester") and alicyclic monomers. Homopolymers of these monomers have relatively high Tg. Therefore, by containing monomers selected from them as monomer components constituting the high Tg segment, it is easy to control the Tg of the high Tg segment within the range specified in the present invention.

As the aforementioned alicyclic monomer, (meth)acrylic acid having a cycloalkyl group having 4 to 10 carbons optionally having a substituent (such as a linear or branched alkyl group having 1 to 6 carbons) is preferable. A cycloalkyl ester, more preferably a cycloalkyl acrylate having a cycloalkyl group with a carbon number of 4 to 10 optionally having a substituent (such as a linear or branched alkyl group with a carbon number of 1 to 6), especially Preferred are cyclohexyl acrylate (Tg of homopolymer: 15°C) and 3,3,5-trimethylcyclohexyl (meth)acrylate (Tg of homopolymer: 52°C).

In the case where an alicyclic monomer is contained as a monomer component constituting the high Tg segment, the content of the alicyclic monomer relative to the total amount (100% by weight) of the monomer component can easily control the Tg of the high Tg segment. In the predetermined range, it is preferably 10% by weight or more (for example, 10 to 100% by weight), and more preferably 20% by weight or more from the viewpoint of being able to impart desired physical properties to the (meth)acrylic block copolymer A , more preferably 30% by weight or more, more preferably 30% by weight or more, more preferably 40% by weight or more, more preferably 50% by weight or more, more preferably 60% by weight or more, more preferably 70% by weight or more, more preferably It is preferably 80% by weight or more, more preferably 80% by weight or more, still more preferably 90% by weight or more, particularly preferably 95% by weight or more.

The C _1-3 linear alkyl (meth)acrylate is preferably a C _1-3 linear alkyl acrylate, particularly methyl acrylate (Tg of the homopolymer: 8° C.).

As the aforementioned C _3-4 branched alkyl (meth)acrylate, a C _3-4 branched alkyl acrylate is preferable, and tert-butyl acrylate is particularly preferable (Tg of a homopolymer: 35° C.).

In the case of containing a C _1-3 linear alkyl (meth)acrylate and/or a C _3-4 branched alkyl (meth)acrylate as a monomer component constituting a high Tg segment, regarding The content of C _1-3 linear alkyl (meth)acrylate and/or C _3-4 branched alkyl (meth)acrylate relative to the total amount of monomer components (100% by weight) can be easily adjusted from From the viewpoint of controlling the Tg of the high Tg segment within a predetermined range and imparting desired physical properties to the (meth)acrylic block copolymer A, it is preferably 10% by weight or more (for example, 10 to 100% by weight), More preferably 20% by weight or more, more preferably 30% by weight or more, more preferably 30% by weight or more, more preferably 40% by weight or more, more preferably 50% by weight or more, more preferably 60% by weight or more, more preferably It is 70% by weight or more, more preferably 80% by weight or more, more preferably 80% by weight or more, still more preferably 90% by weight or more, particularly preferably 95% by weight or more.

As a monomer component constituting the low Tg segment of the (meth)acrylic block copolymer A, it is easy to control the Tg of the low Tg segment within a predetermined range, and it is possible to give the (meth)acrylic block copolymer From the viewpoint of desired physical properties, it is preferable to contain an alkyl (meth)acrylate (hereinafter sometimes referred to as "(methyl) At least one of the group consisting of C _4-18 alkyl acrylate") and hydroxyl-containing monomers. That is, the homopolymer of C _4-18 alkyl (meth)acrylate has a relatively low Tg, so by containing it as a monomer component constituting the low Tg segment, it is easy to control the Tg of the low Tg segment to this value. scope of the invention. On the other hand, the hydroxyl group-containing monomer also has a low Tg, and furthermore, in the (meth)acrylic block copolymer A, it is easy to obtain adhesiveness and moderate cohesive force. Therefore, as monomer components constituting the low Tg segment of the (meth)acrylic block copolymer A, it is more preferable to contain both a C _4-18 alkyl (meth)acrylate and a hydroxyl group-containing monomer.

As the aforementioned C _4-18 alkyl (meth)acrylate, C _4-18 alkyl acrylate is preferred, especially butyl acrylate (Tg of homopolymer: -55°C), 2-ethylhexyl acrylate ( Homopolymer Tg: -70°C), n-hexyl acrylate (homopolymer Tg: -57°C), n-octyl acrylate (homopolymer Tg: -65°C), isononyl acrylate (homopolymer Tg: -58°C).

In the case of containing a C _4-18 alkyl (meth)acrylate as a monomer component constituting a low Tg segment, the ratio of the C _4-18 alkyl (meth)acrylate to the total amount of monomer components (100 % by weight) is preferably at least 10% by weight ( For example, 10 to 100% by weight), more preferably 20% by weight or more, more preferably 30% by weight or more, more preferably 30% by weight or more, more preferably 40% by weight or more, more preferably 50% by weight or more, and more preferably It is preferably 60% by weight or more, more preferably 70% by weight or more, more preferably 80% by weight or more, more preferably 80% by weight or more, still more preferably 90% by weight or more, particularly preferably 95% by weight or more.

As the aforementioned hydroxyl group-containing monomers, hydroxyl group-containing alkyl (meth)acrylates are preferred, especially 4-hydroxybutyl acrylate (Tg of homopolymer: -65°C), 2-hydroxyethyl acrylate (Tg of homopolymer) Tg: -15°C).

When a hydroxyl group-containing monomer is contained as a monomer component constituting the low Tg segment, it is easy to control the Tg of the low Tg segment with respect to the content of the hydroxyl group-containing monomer relative to the total amount (100% by weight) of the monomer components. In the predetermined range, from the viewpoint of being able to impart desired physical properties to the (meth)acrylic block copolymer A, it is preferably 1% by weight or more, more preferably 1.5% by weight or more, and more preferably 2% by weight or more. More preferably, it is 2.5 weight% or more, Especially preferably, it is 3 weight% or more. On the other hand, the content of the hydroxyl group-containing monomer is preferably 50% by weight or less, more preferably 40% by weight or less, more preferably 30% by weight or less, and more preferably 20% by weight relative to the total amount of monomer components (100% by weight). % or less, more preferably 10% by weight or less, particularly preferably 5% by weight or less.

In the case where both the _C4-18 alkyl (meth)acrylate and the hydroxyl-containing monomer are contained as monomer components constituting the low Tg segment of the (meth)acrylic block copolymer A, the hydroxyl-containing The ratio of the monomer to the C _4-18 alkyl (meth)acrylate (hydroxyl-containing monomer/C _4-18 alkyl (meth)acrylate) is not particularly limited, and the lower limit is preferably 1/99, more preferably Preferably 1.5/98.5, more preferably 2/98, further preferably 2.5/97.5, particularly preferably 3/97, on the other hand, the upper limit is preferably 50/50, more preferably 40/60, more preferably 30/70, more preferably 20/80.

The (meth)acrylic block copolymer A can be produced by the living radical polymerization method of the above-mentioned monomer components. The living radical polymerization method is preferable in the following aspects: while maintaining the simplicity and versatility of the existing radical polymerization method, termination reaction and chain transfer are not easy to occur, and the growth terminal does not grow inactivated, so It is easy to precisely control the molecular weight distribution and produce polymers with uniform composition.

In the living radical polymerization method, the high Tg segment can be produced first, and then the monomer of the low Tg segment can be polymerized with the high Tg segment; Polymerization of Tg segments.

In the case where the (meth)acrylic block copolymer A is an ABA type triblock copolymer, from the viewpoint of ease of manufacture, it is preferable to first manufacture the A segment and then combine the monomers of the B segment with the A chain segment aggregation.

The above-mentioned living radical polymerization method can use known methods without particular limitation, and depending on the method of stabilizing the end of the polymerization growth, there are: a method using a transition metal catalyst (ATRP method); a reversible addition-fragmentation method using sulfur A method (RAFT method) using a chain transfer agent (RAFT agent); a method using an organotellurium compound (TERP method); and the like. Among these methods, the RAFT method is preferably used from the viewpoint of diversity of monomers that can be used, ease of molecular weight control, and absence of metal residues in the solvent-based adhesive composition.

The above-mentioned RAFT method can use a known method without particular limitation, for example, it has the following steps: Step 1, for example, using a RAFT agent to polymerize the monomer component to prepare the first segment (first RAFT polymerization); and Step 2, for the step The first segment obtained in step 1 is further added/polymerized with a monomer component different from the monomer composition in step 1, and the second segment is added to the first segment (second RAFT polymerization). After the second RAFT polymerization, the 3rd, 4th... RAFT polymerizations are further performed in the same manner as the 2nd RAFT polymerization, and the 3rd, 4th... segments can be further added.

The aforementioned steps 1 and 2 can be carried out by known and commonly used methods, for example, a solution polymerization method, an emulsion polymerization method, a bulk polymerization method, a polymerization method based on heat or active energy ray irradiation (thermal polymerization method, active energy ray irradiation, etc.) aggregation method), etc. Among them, the solution polymerization method is preferable in terms of transparency, water resistance, cost, and the like. It should be noted that, from the viewpoint of suppressing polymerization inhibition by oxygen, the polymerization is preferably performed while avoiding contact with oxygen. For example, polymerization is preferably performed under a nitrogen atmosphere.

When the (meth)acrylic block copolymer A is an ABA type triblock copolymer, it is preferable to prepare the A segment in the aforementioned step 1, and to add the B segment to the obtained A segment in the aforementioned step 2. to prepare. In this case, it is preferable to use the high Tg segment as the A segment and the low Tg segment as the B segment.

As the aforementioned RAFT agent, known substances can be used without particular limitation, for example, compounds represented by the following formula (1), formula (2) or formula (3) (trithiocarbonate, dithioester, dithiocarbonate).

In formula (1), formula (2), or formula (3) [formulas (1) to (3)], R ^1a and R ^1b are the same or different, and represent a hydrogen atom, a hydrocarbon group or a cyano group. R ^1c represents a hydrocarbon group optionally having a cyano group. The hydrocarbon groups as the above-mentioned R ^1a , R ^1b and R ^1c include, for example, hydrocarbon groups having 1 to 20 carbon atoms (straight-chain, branched-chain or cyclic saturated or unsaturated hydrocarbon groups, etc.), among which carbon number 1 is preferred. ~12 hydrocarbon groups. Specific examples of the hydrocarbon group include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, cyclohexyl, dodecyl, octadecyl Straight-chain, branched or cyclic alkyl groups with 1 to 12 carbons such as radicals; aryl groups with 6 to 12 carbons such as phenyl; arylalkyl groups with 7 to 10 carbons in total such as benzyl and phenethyl Wait. Examples of the hydrocarbon group having a cyano group as R ^1c include groups in which 1 to 3 hydrogen atoms of the hydrocarbon group are substituted with cyano groups.

In the formulas (1) to (3), R ² represents a hydrocarbon group or a group obtained by substituting a part of the hydrogen atoms of the hydrocarbon group with carboxyl groups (for example, carboxyalkyl). Examples of the hydrocarbon group include hydrocarbon groups having 1 to 20 carbons (straight chain, branched or cyclic saturated or unsaturated hydrocarbon groups, etc.), among which hydrocarbon groups having 1 to 12 carbons are preferred. Specific examples of the hydrocarbon group include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, cyclohexyl, dodecyl, octadecyl Linear, branched or cyclic alkyl groups with 1 to 12 carbons; arylalkyls with 7 to 10 total carbons such as benzyl and phenethyl, etc.

In the RAFT method, a raw material monomer is polymerized by reacting so that a sulfur atom in the RAFT agent represented by formulas (1) to (3) is inserted into a methylene group adjacent to the sulfur atom.

Most of the aforementioned RAFT agents are commercially available. Those that are not commercially available can be easily synthesized by known and customary methods. In the present invention, RAFT agents may be used alone or in combination of two or more.

Examples of the RAFT agent include trithiocarbonates such as dibenzyl trithiocarbonate and S-cyanomethyl-S-dodecyl trithiocarbonate; cyanoethyl dithiopropionate; dithioesters, benzyl dithiopropionate, benzyl dithiobenzoate, acetoxyethyl dithiobenzoate and other dithioesters; dithiocarbonic acid O-ethyl-S-(1-benzene Ethyl) ester, O-ethyl-S-(2-propoxyethyl) dithiocarbonate, O-ethyl-S-(1-cyano-1-methylethyl) dithiocarbonate Dithiocarbonate esters such as base) esters, etc., among them, preferred trithiocarbonate esters, more preferably trithiocarbonate esters having a left-right symmetrical structure in formula (1), particularly preferably dibenzyl trithiocarbonate ester, bis{4-[ethyl-(2-acetoxyethyl)carbamoyl]benzyl} trithiocarbonate.

The aforementioned step 1 can be performed by polymerizing monomer components in the presence of a RAFT agent. The amount of the RAFT agent used in step 1 is usually 0.05 to 20 parts by weight, preferably 0.05 to 10 parts by weight, based on 100 parts by weight of the total amount of monomer components. When it is used in such an amount, it is easy to control the reaction, and it is also easy to control the weight average molecular weight of the obtained segment.

The aforementioned step 2 can be carried out by adding monomer components to the polymerization reaction mixture obtained in the aforementioned step 1 and further polymerizing.

The RAFT method is preferably performed in the presence of a polymerization initiator. As a polymerization initiator, a common organic type polymerization initiator is mentioned, for example, A peroxide and an azo compound are specifically mentioned, Among these, an azo compound is preferable. A polymerization initiator can be used individually by 1 type or in combination of 2 or more types.

Examples of the peroxide-based polymerization initiator include benzoyl peroxide and tert-butyl permaleate.

Examples of the azo compound include 2,2'-azobisisobutyronitrile, 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), 2, 2'-Azobis(2-cyclopropylpropionitrile), 2,2'-Azobis(2,4-Dimethylvaleronitrile), 2,2'-Azobis(2-methylbutadiene nitrile), 1,1'-azobis(cyclohexane-1-carbonitrile), 2-(carbamoylazo)isobutyronitrile, 2-phenylazo-4-methoxy-2,4 - Dimethylvaleronitrile, 2,2'-azobis(2-amidinopropane) dihydrochloride, 2,2'-azobis(N,N'-dimethylisobutylamidine) , 2,2'-Azobis(isobutylamide) dihydrate, 4,4'-Azobis(4-cyanopentanoic acid), 2,2'-Azobis(2-cyano propanol), dimethyl-2,2'-azobis(2-methylpropionate), 2,2'-azobis[2-methyl-N-(2-hydroxyethyl)propane amides].

The usage-amount of a polymerization initiator is 0.001-2 weight part normally with respect to 100 weight part of total monomer components, Preferably it is 0.002-1 weight part. When used in such an amount, it is easy to control the weight average molecular weight of the resulting segment.

The RAFT method may be bulk polymerization without using a polymerization solvent, but preferably uses a polymerization solvent. Examples of polymerization solvents include: aromatic hydrocarbons such as benzene, toluene, and xylene; aliphatic hydrocarbons such as n-pentane, n-hexane, n-heptane, and n-octane; cyclopentane, cyclohexane, and cycloheptane , cyclooctane and other alicyclic hydrocarbons; chloroform, carbon tetrachloride, 1,2-dichloroethane, chlorobenzene and other halogenated hydrocarbons; diethyl ether, diisopropyl ether, 1,2-dimethoxyethane Alkane, dibutyl ether, tetrahydrofuran, dioxane, anisole, phenetole, diphenyl ether and other ethers; ethyl acetate, propyl acetate, butyl acetate, methyl propionate and other esters; acetone, methyl ethyl ketone, diethyl ketone , methyl isobutyl ketone, cyclohexanone and other ketones; N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone and other amides; acetonitrile, benzonitrile and other nitriles; Sulfoxides such as methyl sulfoxide and sulfolane. The polymerization solvent may be used alone or in combination of two or more.

The amount of the polymerization solvent used is not particularly limited. For example, it is preferably 0.01 mL or more, more preferably 0.05 mL or more, still more preferably 0.1 mL or more, preferably 50 mL or less, more preferably 10 mL or less, with respect to 1 g of the monomer component. Preferably it is 1 mL or less.

The reaction temperature in the RAFT method is usually 60 to 120°C, preferably 70 to 110°C, and is usually performed under an inert gas atmosphere such as nitrogen. This reaction can be performed under any conditions of normal pressure, increased pressure and reduced pressure, and is usually performed under normal pressure. In addition, the reaction time is usually 1 to 20 hours, preferably 2 to 14 hours.

The above-mentioned polymerization reaction conditions of the RAFT method can be applied to step 1 and step 2, respectively.

After the completion of the polymerization reaction, the target (meth)acrylic block copolymer A can be isolated from the obtained reaction mixture by using a common separation and purification means to remove the solvent used, residual monomers, and the like.

In the case of preparing the high Tg segment or the low Tg segment of the (meth)acrylic block copolymer A in the aforementioned step 1, there is no difference in the weight average molecular weight (Mw) of the high Tg segment or the low Tg segment. Particularly limited, it is preferably 10,000 to 1,000,000, more preferably 50,000 to 500,000, and still more preferably 100,000 to 300,000. It is suitable for the Mw of the high Tg segment or the low Tg segment to be within this range for the effect of the present invention described above.

When two or more high Tg segments or low Tg segments exist in (meth)acrylic block copolymer A, said Mw is Mw of these sum.

The weight average molecular weight (Mw) of the (meth)acrylic block copolymer A is not particularly limited, but is preferably 200,000 (200,000) or more, more preferably 300,000 to 5,000,000, and still more preferably 400,000 to 2,500,000. It is suitable for the Mw of the (meth)acrylic block copolymer A to be within this range for the effect of the present invention described above.

The molecular weight distribution (Mw/Mn) of the (meth)acrylic block copolymer A is not particularly limited, but is preferably greater than 1, more preferably 1.5 or more, still more preferably 2 or more, particularly preferably 2.5 or more, preferably 5 or less , more preferably 4.5 or less, still more preferably 4 or less, particularly preferably 3.5 or less.

In addition, the said weight average molecular weight (Mw) and molecular weight distribution (Mw/Mn) are measured by the GPC method.

The content of the high Tg segment in the (meth)acrylic block copolymer A is preferably 10% by weight or more, more preferably 20% by weight or more, more preferably 25% by weight or more, particularly preferably 30% by weight or more, preferably 95% by weight or less, more preferably 90% by weight or less, even more preferably 85% by weight or less.

The content of the low Tg segment in the (meth)acrylic block copolymer A is preferably 5% by weight or more, more preferably 10% by weight or more, more preferably 15% by weight or more, preferably 60% by weight or less, more preferably 50% by weight or less, further preferably 40% by weight or less, particularly preferably 30% by weight or less.

The content of each of the aforementioned segments and their ratios can be calculated from the weight average molecular weight (Mw) of each segment or (meth)acrylic block copolymer A obtained in each step of the aforementioned RAFT method. The dosage ratio of the monomers in the chain segment and the polymerization rate of each monomer are controlled.

The content of the (meth)acrylic block copolymer A in the solvent-based adhesive composition A is not particularly limited, and excellent processability at room temperature (25°C) and excellent performance in a region exceeding 50°C are obtained. From the viewpoint of height difference absorbability, it is preferably 50% by weight or more (for example, 50 to 100% by weight) with respect to the total amount of the solvent-based adhesive composition A (total weight, 100% by weight), more preferably 60% by weight or more, more preferably 80% by weight or more, particularly preferably 90% by weight or more.

(solvent)

Since the polymer in the third aspect is solid, the solvent-based adhesive composition is a solution in which a polymer is dissolved in an organic solvent. For example, a polymer solution can be obtained by solution-polymerizing monomer components. A polymer solution can be prepared by dissolving a solid polymer in an organic solvent.

As a solvent, ethyl acetate, toluene, or the like is generally used. The solution concentration is usually about 20 to 80% by weight.

As a polymerization initiator for solution polymerization of monomer components, it is preferable to use an azo initiator, a peroxide initiator, a redox initiator obtained by combining a peroxide and a reducing agent (for example, a persulfate salt). combination with sodium bisulfite, combination of peroxide and sodium ascorbate) and other thermal polymerization initiators. The amount of the polymerization initiator used is not particularly limited. For example, it is preferably about 0.005 to 5 parts by weight, more preferably about 0.02 to 3 parts by weight, based on 100 parts by weight of the total monomer components forming the polymer.

(Colorant)

The solvent-based adhesive composition used to form the adhesive layer of the third aspect contains a colorant. The coloring agent may be a dye or a pigment as long as it is soluble or dispersible in the solvent-based adhesive composition. A dye is preferable from the viewpoint that low haze can be achieved by adding a small amount, and that it is easy to distribute uniformly without sedimentation like a pigment. In addition, pigments are also preferable from the viewpoint of obtaining high color rendering properties by adding a small amount. When a pigment is used as a colorant, a pigment having low or no conductivity is preferable. Moreover, when using a dye, it is preferable to use together with the antioxidant etc. mentioned later.

In the third aspect, as the colorant contained in the solvent-based adhesive composition, in addition to the ultraviolet-transmitting colorant described above for the first aspect, an ultraviolet-absorbing colorant is also included.

"9050BLACK" and "UVBK-0001" manufactured by TOKUSHIKI CO., Ltd. etc. are mentioned as an ultraviolet-ray transparent black pigment. Examples of the ultraviolet absorbing black dye include "VALIFAST BLACK 3810" and "NUBIAN BLACK PA-2802" manufactured by ORIENT CHEMICAL INDUSTRIES CO., LTD. Carbon black, titanium black, etc. are mentioned as an ultraviolet absorbing black pigment.

The content of the colorant in the solvent-based adhesive composition is, for example, about 0.01 to 20 parts by weight with respect to 100 parts by weight of the total amount of monomers. rate, etc., can be set appropriately. The colorant may be added to the composition as a solution or dispersion dissolved or dispersed in a suitable solvent.

(crosslinking agent)

The solvent-based adhesive composition of the third aspect may contain a crosslinking agent capable of crosslinking with the above polymer. In addition, when the solvent-type adhesive composition contains a (meth)acrylic block copolymer, since the adhesive layer of the 3rd aspect has sufficient shape stability, it does not need to contain a crosslinking agent .

In the third aspect, when the solvent-based adhesive composition contains a crosslinking agent, the crosslinking agent is preferably an isocyanate-based crosslinking agent and an epoxy-based crosslinking agent as described above for the second aspect. agent.

In the third aspect, when the solvent-based adhesive composition contains a crosslinking agent, its content is about 0.01 to 5 parts by weight with respect to 100 parts by weight of the polymer, and may be 0.05 parts by weight or more, 0.1 parts by weight or more Or 0.2 parts by weight or more, may be 3 parts by weight or less, 2 parts by weight or less, or 1 part by weight or less.

(other ingredients)

The solvent-based adhesive composition of the third aspect may contain oligomers, tackifiers, silane coupling agents, chain transfer agents, plasticizers, softeners, anti-deterioration agents, fillers, Antioxidants, surfactants, antistatic agents, etc.

<Optical laminate>

In this embodiment, the optical layered body 10 or 11 can be produced by laminating the adhesive layer 2 on the surface 1 b of the substrate 1 that is not subjected to antireflection treatment and/or antiglare treatment.

[first way]

The method of laminating the adhesive layer of the first embodiment on the surface 1b is not particularly limited. For example, the photocurable adhesive composition of the first embodiment can be coated on a release film and shaped into a sheet to perform photocuring. A sheet-shaped pressure-sensitive adhesive layer is prepared, and then bonded to the surface 1b of the base material 1 .

Photocuring is carried out by applying the photocurable adhesive composition of the first embodiment in a sheet form (layer form) on the release film, and irradiating the coating film of the photocurable adhesive composition on the release film with ultraviolet rays. , so that the adhesive of the first form can be obtained. When performing photocuring, it is preferable to further attach a release film to the surface of the coating film, and to irradiate the photocurable adhesive composition with ultraviolet light in a state sandwiched between two release films to prevent polymerization inhibition by oxygen. Before photocuring, the sheet-shaped coating film may be heated for the purpose of removing the solvent of the colorant, the dispersion medium, and the like. When performing removal of a solvent etc. by heating, it is preferable to carry out before attaching a peeling film.

As the film substrate of the release film, films made of various resin materials can be used. Examples of the resin material include polyester resins such as polyethylene terephthalate and polyethylene naphthalate, acetate resins, polyethersulfone resins, polycarbonate resins, poly Amide resins, polyimide resins, polyolefin resins, (meth)acrylic resins, polyvinyl chloride resins, polyvinylidene chloride resins, polystyrene resins, polyvinyl alcohol resins, Polyarylate resin, polyphenylene sulfide resin, etc. Among these, polyester-based resins such as polyethylene terephthalate are particularly preferable. The thickness of the film substrate is preferably 10 to 200 μm, more preferably 25 to 150 μm. Examples of the material for the release layer include silicone-based release agents, fluorine-based release agents, long-chain alkyl-based release agents, fatty acid amide-based release agents, and the like. The thickness of the release layer is generally about 10 to 2000 nm.

As a method for coating the photocurable adhesive composition on the release film, roll coating, lick coating, gravure coating, reverse coating, roll brush, spray coating, dip roll coating, bar coating, etc. can be used. Various methods such as coating, blade coating, air knife coating, curtain coating, lip coating, die coater, etc.

The thickness of the adhesive layer containing the coloring agent is not particularly limited, and it is appropriately set so as to sufficiently package the light-emitting elements arranged on the display panel described later, and to reach the height of the light-emitting elements or more. Can. For example, the thickness of the adhesive layer containing the coloring agent is 1.0 to 4.0 times the height of the light-emitting element, preferably 1.1 to 3.0 times, more preferably 1.2 to 2.5 times, and even more preferably 1.3 to 2.0 times. . Specifically, the thickness of the pressure-sensitive adhesive layer containing a colorant is, for example, about 10 to 500 μm, and may be 20 μm or more, 30 μm or more, 40 μm or more, or 50 μm or more. As described above, since the colorant has ultraviolet transmittance, even when the thickness of the pressure-sensitive adhesive layer is large, the photocurable pressure-sensitive adhesive composition can be uniformly photocured in the thickness direction. The thickness of the colorant-containing adhesive layer may be 400 μm or less, 300 μm or less, 250 μm or less, or 200 μm or less.

By irradiating ultraviolet light to the photocurable adhesive composition coated in a layer on the release film, active species are generated from the photopolymerization initiator, and the photopolymerizable compound is polymerized, accompanied by an increase in the polymerization rate (unreacted monomer reduction), the liquid photocurable adhesive composition forms a solid (definite shape) adhesive layer. The light source for ultraviolet irradiation is not particularly limited as long as it can irradiate light in the wavelength range to which the photopolymerization initiator contained in the adhesive composition is sensitive, and LED light sources, high-pressure mercury lamps, ultra-high-pressure mercury lamps, and lamps, metal halide lamps, xenon lamps, etc.

The accumulated light amount of the irradiation light is, for example, about 100 to 5000 mJ/cm ² . The polymerization ratio (non-volatile content) of the adhesive layer formed from the photocured product of the photocurable adhesive composition is preferably 80% or more, more preferably 85% or more, and still more preferably 90% or more. The polymerization rate may be 93% or more or 95% or more. In order to reduce non-volatile components, the pressure-sensitive adhesive layer may be heated to remove volatile components such as residual monomers, unreacted polymerization initiators, and solvents.

When the release film is provided on both surfaces of the pressure-sensitive adhesive layer, the thickness of the release film on one side may be the same as or different from the thickness of the release film on the other side. The peeling force when peeling the release film temporarily bonded on one side from the adhesive layer and the peeling force when peeling the release film temporarily bonded on the other side from the adhesive layer may be the same or different. When the peeling forces of the two are different, by first peeling the peeling film (light peeling film) with relatively small peeling force from the adhesive layer and sticking the adhesive layer on the surface 1b of the substrate 1, it is possible to An optical laminate having the pressure-sensitive adhesive layer of the first embodiment was produced.

In addition, the above-mentioned photocurable adhesive composition is coated on the surface 1b of the substrate 1, and after forming into a sheet shape, a peeling film is attached to the surface of the coating film, and ultraviolet rays are irradiated. An optical laminate having the pressure-sensitive adhesive layer of the first embodiment was produced.

The adhesive layer containing the colorant has light absorption for visible light. The total light transmittance of the optical laminated body of the first aspect is, for example, 80% or less, may be 70% or less, 60% or less, 50% or less, 40% or less, 30% or less, 20% or less, 10% or less, or 5% the following.

In the first aspect, as described above, a colorant whose absorption of ultraviolet light is smaller than that of visible light can be used as the colorant. Therefore, the average transmittance T _UV of wavelength 330-400nm of an adhesive layer is larger than the average transmittance T _VIS of wavelength 400-700nm. The average transmittance T _VIS of the adhesive layer at a wavelength of 400 to 700 nm is, for example, 80% or less, may be 70% or less, 60% or less, 50% or less, 40% or less, 30% or less, 20% or less, or 10% the following. The average transmittance T _UV of the adhesive layer at a wavelength of 330 to 400 nm is preferably 5% or more, and may be 10% or more, 15% or more, 20% or more, or 25% or more. The difference T _UV -T _VIS between T _UV and T _VIS may be 3% or more, 5% or more, 8% or more, or 10% or more.

In the first aspect, the shear storage modulus G'25°C of the adhesive layer at a temperature of 25°C is, for example, about 10 to 1000 kPa, may be 30 kPa or more, 50 kPa or more, 70 kPa or more, or 100 kPa or more, may be 700 kPa Below, below 500kPa, below 300kPa or below 200kPa. The shear storage modulus G'85°C of the adhesive layer at a temperature of 85°C is, for example, about 3 to 300 kPa, may be 5 kPa or more, 7 kPa or more, or 10 kPa or more, and may be 200 kPa or less, 150 kPa or less, or 100 kPa or less. When the shear storage modulus of the pressure-sensitive adhesive layer is within the above-mentioned range, moderate flexibility and adhesiveness can be made compatible. The shear storage modulus is a measured value based on a dynamic viscoelasticity measurement at a frequency of 1 Hz.

[Second way]

The optical laminate having the adhesive layer of the second embodiment can be laminated on the surface 1b of the substrate 1 by coating the curable adhesive composition of the second embodiment on a release film, drying and removing the solvent as necessary, thus prepared. In addition, the optical laminate having the adhesive layer of the second embodiment can also be prepared by coating the curable adhesive composition of the second embodiment on the surface 1b of the substrate 1, and drying and removing the solvent if necessary. .

When the photocurable adhesive composition contains a solvent, it is preferable to dry the solvent after coating the adhesive composition. As a drying method, an appropriate method can be appropriately adopted according to the purpose. The heat drying temperature is preferably 40°C to 200°C, more preferably 50°C to 180°C, particularly preferably 70°C to 170°C. An appropriate time can be appropriately adopted as the drying time. The drying time is preferably 5 seconds to 20 minutes, more preferably 5 seconds to 15 minutes, particularly preferably 10 seconds to 10 minutes.

After applying the photocurable adhesive composition, heating is performed as necessary to introduce a crosslinked structure into the polymer. The heating temperature and the heating time may be appropriately set depending on the type of crosslinking agent used, and are usually in the range of 20°C to 160°C, about 1 minute to 7 days. The heating for drying the solvent can double as the heating for crosslinking. The introduction of the crosslinked structure does not necessarily need to be accompanied by heating.

The adhesive layer of the second aspect preferably has the same thickness, light transmittance, and shear storage modulus as those of the adhesive layer of the first aspect. Since the pressure-sensitive adhesive layer of the second aspect does not undergo photocuring, the photopolymerizable compound is contained in an unreacted state. That is, the pressure-sensitive adhesive layer of the second aspect is a photocurable pressure-sensitive adhesive layer containing a polymer, a photopolymerizable compound, a photopolymerization initiator, and a colorant.

The optical laminate having the photocurable pressure-sensitive adhesive layer of the second aspect can be photocured by irradiating ultraviolet rays after being bonded to a display panel described later. Photocuring can change the adhesive force between the optical laminate and the display panel. For example, the adhesive layer before photocuring has high flexibility, so it can fill the concave-convex shape and height difference formed by the light-emitting elements arranged on the display panel. After photocuring, the adhesive force to the display panel can be improved and the bonding is reliable. sex.

Ultraviolet rays can be used as the active rays for photocuring the adhesive layer of the second aspect. Like the pressure-sensitive adhesive layer of the first aspect, since the colorant has a higher transmittance of ultraviolet rays than visible light, even when the thickness of the pressure-sensitive adhesive layer is large, inhibition of curing during photocuring can be suppressed.

[Third way]

The optical laminate having the pressure-sensitive adhesive layer of the third embodiment can be produced by coating the aforementioned solvent-based pressure-sensitive adhesive composition on a release film, drying and removing the solvent, and laminating on the surface 1b of the substrate 1 . Moreover, the optical laminated body which has the adhesive layer of the 3rd aspect can also be prepared by coating the said solvent-type adhesive composition on the surface 1b of the base material 1, and drying and removing a solvent.

After coating the solvent-based adhesive composition, drying of the solvent is performed. As a drying method, an appropriate method can be appropriately adopted according to the purpose. The heat drying temperature is preferably 40°C to 200°C, more preferably 50°C to 180°C, particularly preferably 70°C to 170°C. An appropriate time can be appropriately adopted as the drying time. The drying time is preferably 5 seconds to 20 minutes, more preferably 5 seconds to 15 minutes, particularly preferably 10 seconds to 10 minutes.

After applying the photocurable adhesive composition, heating may be performed as necessary. The heating temperature and the heating time may be appropriately set depending on the type of crosslinking agent used, and are usually in the range of 20°C to 160°C, about 1 minute to 7 days.

The pressure-sensitive adhesive layer of the third aspect preferably has the same thickness, light transmittance, and shear storage modulus as those of the pressure-sensitive adhesive layer of the first aspect.

In addition, the storage modulus (G'25) of the adhesive layer at 25°C when the solvent-based adhesive composition contains the (meth)acrylic block copolymer A is not particularly limited. In terms of processability, it is preferably 1MPa or more, more preferably 1.5MPa or more, more preferably 2MPa or more, more preferably 2.5MPa or more, more preferably 3MPa or more, from the perspective of improving the adhesion reliability at room temperature From the point of view, it is preferably 50 MPa or less, more preferably 45 MPa or less, more preferably 40 MPa or less, more preferably 35 MPa or less, more preferably 30 MPa or less.

The storage modulus (G'50) of the adhesive layer at 50°C when the solvent-based adhesive composition contains the (meth)acrylic block copolymer A is not particularly limited. From the viewpoint of the level difference absorbability of the region, it is preferably 0.5 MPa or less, more preferably 0.45 MPa or less, more preferably 0.4 MPa or less, more preferably 0.35 MPa or less, and more preferably 0.3 MPa or less. From the viewpoint of operability of the region, it is preferably 0.0001 MPa or more, more preferably 0.0005 MPa or more, more preferably 0.001 MPa or more, more preferably 0.005 MPa or more, and more preferably 0.01 MPa or more.

The ratio of the storage modulus at 25°C to the storage modulus at 50°C of the adhesive layer when the solvent-based adhesive composition contains the (meth)acrylic block copolymer A (G'25 /G'50) is not particularly limited, and is preferably 3 or more, more preferably 5 or more, and more preferably 10 or more, from the viewpoint of improving the workability at room temperature and improving the level difference absorbability in a region exceeding 50°C, More preferably 15 or more, particularly preferably 20 or more, from the viewpoints of bonding reliability, operability, etc., preferably 100 or less, more preferably 95 or less, more preferably 90 or less, still more preferably 85 or less, especially Preferably it is 80 or less.

It should be noted that the storage modulus (G'25) at 25°C and the storage modulus (G'25) at 50°C and their ratio (G'25/G'50) were determined by dynamic viscosity Measured by elasticity assay.

An optical laminate having an adhesive layer containing a colorant has light absorption for visible light. The optical layered body of the present embodiment preferably has a maximum value of the transmittance at 350 nm to 450 nm.

The total light transmittance of the optical laminate of this embodiment is, for example, 80% or less, and may be 70% or less, 60% or less, 50% or less, 40% or less, 30% or less, 20% or less, 10% or less, or 5%. the following.

The optical laminate of the present embodiment may be provided with a release film on the pressure-sensitive adhesive layer until use. In addition, in the optical laminated body of this embodiment, the surface protection film may be laminated|stacked on the surface 1a which performed the antireflection process and/or the antiglare process of the base material 1. The surface protection film is suitable for preventing damage and adhesion of dirt at the time of manufacture, transportation, and shipment of the aforementioned optical layered body or an optical product containing the same.

In addition to the substrate 1, the pressure-sensitive adhesive layer 2, the release film, and the surface protection film, the optical laminate of the present embodiment may have other layers on the surface or between arbitrary layers within the range that does not impair the effects of the present invention. For example, substrates other than substrate 1, adhesive layers other than adhesive layer 2, intermediate layers, primer layers, and the like.

<Self-luminous display device>

In the self-luminous display device according to the second aspect of the present invention, by arranging tiny and numerous light-emitting elements on a wiring substrate, and using a light-emitting control means connected thereto to make each light-emitting element selectively emit light, it is possible to utilize each light-emitting element. A display device that directly displays visual information such as text, images, and images on the display screen when the components turn on and off. Examples of self-luminous display devices include Mini/Micro LED display devices and organic EL (electroluminescence) display devices. The optical laminate of the third aspect of the present invention is particularly suitable for manufacturing Mini/Micro LED display devices.

3 is a schematic diagram (sectional view) showing an embodiment of a self-luminous display device (Mini/Micro LED display device) according to the second aspect of the present invention. The Mini/Micro LED display device 20 of this embodiment includes a display panel in which a plurality of LED chips 6 are arranged on one side of a substrate 4, and the optical laminate 10 according to the first aspect of the present invention. The surface on which the LED chips 6 are arranged on the display panel is laminated with the adhesive layer 2 of the optical laminate 10 .

In the present embodiment, a metal wiring layer 5 for transmitting a light emission control signal to each LED chip 6 is laminated on the substrate 4 of the display panel. The LED chips 6 that emit light of various colors of red (R), green (G), and blue (B) are alternately arranged on the substrate 4 of the display panel via the metal wiring layer 5 . The metal wiring layer 5 is formed of metal such as copper, which reflects the light emitted by each LED chip 6 and reduces image visibility. In addition, the lights emitted by the LED chips 6 of the RGB colors are mixed, and the contrast ratio is lowered.

In the Mini/Micro LED display device of this embodiment, the LED chips 6 arranged on the display panel are packaged without gaps by the adhesive layer 2 . Since the pressure-sensitive adhesive layer 2 contains a colorant, it has sufficient light-shielding properties in the visible light region. Since each LED chip 6 is encapsulated by the adhesive layer 2 with high light-shielding property, reflection by the metal wiring layer 5 can be prevented. In addition, since the adhesive layer 2 also encapsulates the LED chips 6 without gaps, color mixing between the LED chips 6 can be prevented and contrast can be improved.

As described above, since the adhesive layer of the optical laminate according to the present embodiment contains a colorant, reflection and gloss on the metal surface can be prevented even when a metal adherend is laminated on the adhesive layer. When the metal adherend is laminated on the pressure-sensitive adhesive layer of the optical laminate of this embodiment, the reflectance in the visible light region of the 5° regular reflection of the substrate surface 1 a is preferably 50% or less, more preferably 30% or less, It is more preferably 15% or less, particularly preferably 10% or less. The glossiness (based on JIS Z8741-1997) of the substrate surface 1a when the metal adherend is laminated on the pressure-sensitive adhesive layer of the optical laminate of this embodiment is preferably 100% or less, more preferably 80% or less, and further Preferably it is 60% or less, especially preferably 50% or less.

In addition, copper, aluminum, stainless steel, etc. can be used as said metal to-be-adhered body.

In addition, in the Mini/Micro LED display device of this embodiment, the surface 1a of the substrate 1 is subjected to anti-reflection treatment and/or anti-glare treatment 3, which prevents the reflection of external light and image reflection on the surface 1a of the substrate 1a. As a result, the visibility is reduced, or aesthetic properties such as glossiness are adjusted. 4 is a schematic diagram (sectional view) showing another embodiment of a self-luminous display device (Mini/Micro LED display device) according to the second aspect of the present invention. The Mini/Micro LED display device 21 of this embodiment is the same as that of FIG. 3 except that the anti-glare layer 3 a is formed on the surface 1 a of the substrate 1 . The average inclination angle θa (°) of the anti-glare layer 3a of the Mini/Micro LED display device 21 of this embodiment is the same as above.

The self-luminous display device of the present embodiment may include optical members other than the display panel and the optical laminate. It does not specifically limit as said optical member, A polarizing plate, a retardation film, an antireflection film, a viewing angle adjustment film, an optical compensation film etc. are mentioned. It should be noted that optical members also include members (decorative films, decorative films, surface protection plates, etc.) that play a role of decoration and protection while maintaining the visibility of display devices and input devices.

The Mini/Micro LED display device of this embodiment can be manufactured by laminating a display panel in which a plurality of LED chips are arranged on one side of a substrate and the adhesive layer of the optical laminate according to the first aspect of the present invention.

Specifically, the bonding of the optical laminate having the display panel and the pressure-sensitive adhesive layer of the first embodiment can be carried out by laminating under heating and/or pressure. When bonding the optical laminated body which has a display panel and the adhesive layer of a 2nd aspect, it can carry out by performing photocuring after laminating|stacking under heating and/or pressure. Photocuring can be performed in the same manner as photocuring to form the pressure-sensitive adhesive layer of the first embodiment described above.

When the pressure-sensitive adhesive layer is formed of a solvent-based pressure-sensitive adhesive composition containing the (meth)acrylic block copolymer A, the bonding is preferably carried out under heat and pressure at 50° C. or higher. By heating and pressing at 50° C. or higher, the pressure-sensitive adhesive layer becomes highly fluid, and can sufficiently follow the height difference of the LED chips arranged on the substrate, and can be closely bonded without gaps. The heating is performed at 50°C or higher, preferably at 60°C or higher, more preferably at 70°C or higher. The pressurization is not particularly limited, but it is performed at, for example, 1.5 atm or more, preferably 2 atm or more, more preferably 3 atm or more. Heating and pressurization can be performed using an autoclave etc., for example. After the Mini/Micro LED display device thus manufactured is returned to room temperature (25° C.), the storage modulus of the adhesive layer increases, and the processability and bonding reliability are improved.

Example

Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples. In addition, various characteristics in the following manufacture examples were evaluated or measured by the following method.

(Surface shape measurement)

A glass plate (thickness 1.3 mm) manufactured by Satsunami Glass Industry Co., Ltd. was attached to the surface of the anti-glare film on which the anti-glare layer was not formed with an adhesive, and a high-precision micro-shape measuring instrument (trade name; Surfcorder ET4000, Co., Ltd. (manufactured by Kosaka Laboratories) measured the surface shape of the anti-glare layer under the condition of a cutoff value of 0.8 mm to obtain the average inclination angle θa. It should be noted that the above-mentioned high-precision micro-shape measuring instrument automatically calculates the above-mentioned average inclination angle θa. The aforementioned average inclination angle θa is based on JIS B 0601 (1994 edition).

(haze)

According to the method specified in JIS K 7136, the haze meter (manufactured by Murakami Color Technology Laboratory Co., Ltd., trade name "HN-150") is set so that light is incident on the anti-glare layer of the anti-glare film, and the haze is measured. value.

Manufacturing example 1

(Preparation of anti-glare film)

100 parts by weight of ultraviolet curable urethane acrylate resin (manufactured by DIC Corporation, brand name "UNIDIC 17-806", solid content 80%) was prepared as resin contained in the anti-glare layer. With respect to 100 parts by weight of the resin solid content of the aforementioned resin, styrene crosslinked particles (manufactured by Soken Chemical Co., Ltd., trade name "MX-350H", weight average particle diameter: 3.5 μm, refractive index 1.59) 14 parts by weight, 2.5 parts by weight of synthetic montmorillonite (manufactured by KUNIMINE INDUSTRIES CO., LTD., trade name "SUMECTON SAN") belonging to organoclay as a thixotropy-imparting agent, photopolymerization initiator (manufactured by BASF Corporation, 5 parts by weight of a brand name "OMNIRAD907", and 0.5 parts by weight of a leveling agent (manufactured by DIC Corporation, brand name "MEGAFAC F-556", solid content 100%). This mixture was diluted with a toluene/ethyl acetate mixed solvent (weight ratio 90/10) to a solid content concentration of 30% by weight to prepare a light diffusion element forming material (coating solution).

On one side of a triacetyl cellulose (TAC) film (manufactured by Fujifilm Co., Ltd., product name "TG60UL", thickness: 60 μm) that can function as a protective layer, an anti-glare layer forming material ( coating solution) to form a coating film. Then, the transparent TAC film base material on which this coating film was formed is sent to a drying process. In a drying process, the said coating film was dried by heating at 110 degreeC for 1 minute. Then, the above-mentioned coating film was cured by irradiating ultraviolet rays with a cumulative light intensity of 300 mJ/cm ² with a high-pressure mercury lamp, and a light diffusion element with a thickness of 5.0 μm was formed on one side of the TAC film to obtain an anti-glare film 1 . The haze value of the anti-glare film 1 was 42%. The θa (°) of the antiglare layer of the antiglare film 1 was 1.22.

Manufacturing example 2

(Preparation of anti-glare film)

As light-diffusing fine particles, 14 parts by weight of amorphous silica (manufactured by Fuji Silysia Chemical Ltd., trade name "SYLOPHOBIC 100", weight average particle diameter: 2.6 μm) was added to make the thickness after curing treatment 7.0 μm, except In addition, the light-diffusion element was formed in the single surface of a TAC film by the method similar to manufacture example 1, and the anti-glare film 2 was obtained. The haze value of the anti-glare film 2 was 11%. The θa (°) of the antiglare layer of the antiglare film 2 was 1.43.

Manufacturing example 3

(Preparation of anti-glare film)

As resin contained in the anti-glare layer forming material, 100 parts by weight of ultraviolet curable urethane acrylate resin (manufactured by DIC Corporation, brand name "UNIDIC 17-806", solid content 80%) was prepared. With respect to 100 parts by weight of the resin solid content of the aforementioned resin, 7 parts by weight of amorphous silica (manufactured by FujiSilysia chemical Ltd., trade name "SYLOPHOBIC 702"), amorphous silica (FujiSilysia Chemical Ltd., product name "SYLOPHOBIC 100") 6.5 parts by weight, photopolymerization initiator (manufactured by BASF Corporation, product name "OMNIRAD184") 5 parts by weight, leveling agent (manufactured by DIC Corporation, product name "MEGAFAC F- 556") 0.5 parts by weight. This mixture was diluted with toluene to a solid content concentration of 30%, to prepare an anti-glare layer forming material (coating liquid).

As a translucent base material, a transparent plastic film base material (TAC film, manufactured by Fuji Film Co., Ltd., trade name "TD80UL", thickness: 80 μm) was prepared. The aforementioned anti-glare layer forming material (coating solution) was formed into a coating film on one side of the aforementioned transparent plastic film substrate using a bar coater. Then, the transparent plastic film base material on which this coating film was formed is sent to a drying process. In a drying process, the said coating film was dried by heating at 110 degreeC for 1 minute. Then, ultraviolet rays with a cumulative light intensity of 300 mJ/cm ² were irradiated with a high-pressure mercury lamp to cure the coating film to form an anti-glare layer with a thickness of 5.0 μm, thereby obtaining an anti-glare film 3 . The θa (°) of the antiglare layer of the antiglare film 3 was 3.5.

Manufacturing Example 4

(Preparation of anti-glare film)

As anti-glare layer forming particles, 6.5 parts by weight of amorphous silica (manufactured by Fuji Silysia chemical Ltd., trade name "SYLOPHOBIC 702"), amorphous silica (manufactured by Fuji Silysia chemical Ltd., trade name "SYLOPHOBIC 200") were added. ") 6.5 parts by weight, tackifier (manufactured by Co-op Chemical Co., Ltd., trade name "LUCENTITE SAN") 2.5 parts by weight, so that the thickness after curing treatment is 8.0 μm, except that as in the production example 3 The anti-glare film 4 was obtained by the same method. The θa (°) of the antiglare layer of the antiglare film 4 was 2.3.

Manufacturing Example 5

(prepolymer preparation)

67 parts by weight of butyl acrylate (BA), cyclohexyl acrylate (CHA, manufactured by Osaka Organic Chemical Industry Co., Ltd., trade name "Viscoat #155") 14 parts by weight, 4-hydroxybutyl acrylate (4-HBA) 19 parts by weight, photopolymerization initiator (manufactured by BASF Corporation, trade name "IRGACURE 184") 0.09 parts by weight, and photopolymerization initiator (BASF Corporation Manufactured, trade name "IRGACURE 651") 0.09 parts by weight, nitrogen gas was blown in, and nitrogen replacement was performed for about 1 hour while stirring. Then, UVA was irradiated at 5 mW/cm ² to carry out polymerization, and the reaction rate was adjusted to 5 to 15%, to obtain an acrylic prepolymer solution.

Manufacturing example 6

(Preparation of black adhesive composition)

Add 2-hydroxyethyl acrylate (HEA) 9 weight parts, 4-hydroxybutyl acrylate (4-HBA ) 8 parts by weight, 0.02 parts by weight of dipentaerythritol hexaacrylate (manufactured by Shin-Nakamura Chemical Industry Co., Ltd., trade name "KAYARAD DPHA") as a polyfunctional monomer, 3-glycidoxypropane as a silane coupling agent A photopolymerizable adhesive composition solution was prepared using 0.35 parts by weight of trimethoxysilane and 0.3 parts by weight of a photopolymerization initiator (manufactured by BASF Corporation, trade name "IRGACURE 651").

To 100 parts by weight of the photopolymerizable adhesive composition solution obtained above, 0.2 parts by weight of a photopolymerization initiator (manufactured by BASF Corporation, trade name "IRGACURE 651") and a black pigment dispersion (TOKUSHIKICO., Ltd. Manufactured, trade name "TOKUSHIKI 9050 Black") 4 parts by weight to prepare a photopolymerizable black adhesive composition solution.

Manufacturing example 7

(Preparation of Adhesive Composition)

Add 2-hydroxyethyl acrylate (HEA) 9 weight parts, 4-hydroxybutyl acrylate (4-HBA ) 8 parts by weight, 0.12 parts by weight of dipentaerythritol hexaacrylate (manufactured by Shin-Nakamura Chemical Industry Co., Ltd., trade name "KAYARAD DPHA") as a polyfunctional monomer, and 3-glycidoxypropane as a silane coupling agent 0.35 parts by weight of trimethoxysilane to prepare a photopolymerizable adhesive composition solution.

Manufacturing example 8

(Preparation of Adhesive Sheet)

Production example 6 was coated on the release surface of a release film R1 (manufactured by Mitsubishi Plastics Corporation, trade name "MRF#38") with a thickness of 38 μm (manufactured by Mitsubishi Plastics Corporation, trade name "MRF#38"), one side of which was the release surface, so that the thickness after curing was 100 μm. The black adhesive composition solution prepared in , was covered with release film R2 (manufactured by Mitsubishi Plastics Corporation, MRE#38) with one side of the polyester film as the release surface to block air. Ultraviolet rays were irradiated from one side of the laminated body using a black light lamp (manufactured by Toshiba Corporation, trade name "FL15BL") under conditions of an illuminance of 5 mW/cm ² and a cumulative light intensity of 1300 mJ/cm ² . Thus, a 100-μm-thick PSA sheet 1 in which the photocrosslinkable adhesive, which is a cured product of the black PSA composition, was sandwiched between the release films R1 and R2 was obtained in the form of a substrate-less PSA sheet.

In addition, the value of the illuminance of the said black light lamp is the measured value based on the industrial UV detector (manufactured by TOPCON CORPORATION, trade name: UVR-T1, light-receiving part model UD-T36) with a peak sensitivity wavelength of about 350 nm.

Manufacturing example 9

(Preparation of Adhesive Sheet)

Coating was carried out in such a manner that the thickness after curing was 50 μm, and in the same manner as in Production Example 8, a photocrosslinkable adhesive that was a cured product of a black adhesive composition was obtained in the form of a substrate-free adhesive sheet. PSA sheet 2 having a thickness of 50 μm sandwiched between release films R1 and R2.

Manufacturing example 10

(Preparation of Adhesive Sheet)

Except using the adhesive composition solution prepared in Production Example 7, proceed in the same manner as in Production Example 8 to obtain a cured product of the adhesive composition as a photocrosslinkable adhesive sheet in the form of a substrate-less adhesive sheet. An adhesive sheet 3 having a thickness of 50 μm sandwiched between release films R1 and R2.

Embodiment 1-4

(Preparation of Optical Laminate)

The adhesive surface exposed by peeling off the release film on one side from the adhesive sheet 1 obtained in Production Example 8 was bonded to the surfaces of the antiglare films 1 to 4 obtained in Production Examples 1 to 4 on which the antiglare layer was not formed. , and optical laminates composed of antiglare films 1 to 4/adhesive sheet 1/release film were respectively obtained.

Embodiment 5-8

(Preparation of Optical Laminate)

Except using the pressure-sensitive adhesive sheet 2 obtained in manufacture example 9, it carried out similarly to Examples 1-4, and obtained the optical laminated body which consists of anti-glare film 1-4/pressure-sensitive adhesive sheet 2/release film, respectively.

Comparative example 1-4

(Preparation of Optical Laminate)

Except using the pressure-sensitive adhesive sheet 3 obtained in manufacture example 10, it carried out similarly to Examples 1-4, and obtained the optical laminated body which consists of anti-glare film 1-4 / pressure-sensitive adhesive sheet 3 / release film, respectively.

Comparative Example 5

(Preparation of Optical Laminate)

Instead of the anti-glare film, a TAC film (manufactured by Konica Minolta, trade name "KC4UY") was used, except that it was carried out in the same manner as in Examples 1 to 4, to obtain a TAC film/adhesive sheet 1/peeling film constituted optical laminates.

Comparative example 6

(Preparation of Optical Laminate)

Instead of the anti-glare film, a TAC film (manufactured by Konica Minolta, trade name "KC4UY") was used, except that it was carried out in the same manner as in Examples 5 to 8, to obtain TAC film/adhesive sheet 2/peeling film constituted optical laminates.

Comparative Example 7

(Preparation of Optical Laminate)

Instead of the anti-glare film, a TAC film (manufactured by Konica Minolta, trade name "KC4UY") was used, except that it was carried out in the same manner as in Comparative Examples 1 to 4, to obtain TAC film/adhesive sheet 3/peeling film constituted optical laminates.

(Evaluation)

The transmittance, reflectance, and glossiness were measured using the optical laminates obtained in the above Examples and Comparative Examples. The measurement method is shown below. The results of the measurement are shown in Table 1.

(1) Transmittance

The release film of the optical laminate obtained in the above-mentioned Examples and Comparative Examples was peeled off, and the light was set in a spectrophotometer U4100 (manufactured by Hitachi High-Technologies Corporation) so that light was incident from the anti-glare film/TAC film side, and the optical density in the visible light region was measured. Transmittance (%). The transmittance is a Y value measured with a 2-degree field of view (C light source) in accordance with JIS Z 8701 and corrected for visual sensitivity.

(2) Reflectance/Gloss

A board made of laminated aluminum foil on a black acrylic board. The exposed adhesive surface was laminated on the aluminum foil side of the above-mentioned plate to prepare a sample by peeling off the release film of the optical laminate obtained in the above-mentioned Examples and Comparative Examples. The obtained sample was set in a spectrophotometer U4100 (manufactured by Hitachi High-Technologies Corporation) so that the anti-glare film/TAC film was positioned on the light source side, and the reflectance (%) in the visible region of 5° regular reflection was measured. In addition, the obtained sample was set in a gloss meter (manufactured by Murakami Color Science Research Institute Co., Ltd., trade name "GM-26PRO") with the anti-glare film/TAC film on the light source side by the method specified in JIS Z 8741-1997. ”) to measure the gloss (%).

[Table 1]

(Table 1)

Various modifications of the present invention are appended below.

[Appendix 1] An optical laminate comprising a substrate and an adhesive layer containing a colorant,

Anti-reflection treatment and/or anti-glare treatment are carried out on one side of the aforementioned substrate,

The pressure-sensitive adhesive layer is laminated on the surface of the base material that is not subjected to the anti-reflection treatment and/or anti-glare treatment.

[Appendix 2] The optical laminate according to Appendix 1, wherein the adhesive layer is composed of a photocurable adhesive composition containing a polymer, a photopolymerizable compound, a photopolymerization initiator, and a colorant. formed adhesive layer.

[Additional note 3] The optical layered body according to additional note 2, wherein the colorant has a maximum value of transmittance at a wavelength of 330 to 400 nm larger than a maximum value of transmittance at a wavelength of 400 to 700 nm.

[Supplementary Note 4] The optical laminate according to Supplementary Note 2 or 3, wherein the photopolymerization initiator has at least one maximum absorption in a wavelength range of 330 to 400 nm.

[Supplementary Note 5] The optical laminate according to any one of Supplementary Notes 2 to 4, wherein the polymer is an acrylic polymer.

[Supplementary Note 6] The optical laminate according to any one of Supplementary Notes 2 to 5, wherein the polymer has a glass transition temperature of 0° C. or lower.

[Appendix 7] The optical laminate according to any one of Appendices 2 to 6, wherein the photocurable adhesive composition further contains a crosslinking agent capable of crosslinking the polymer.

[Supplementary Note 8] The optical laminated body according to any one of Supplementary Notes 1 to 7, wherein the optical laminated body has a maximum value of transmittance at 350 nm to 450 nm.

[Additional Note 9] The optical laminate according to any one of Additional Notes 1 to 8, wherein the pressure-sensitive adhesive layer has a total light transmittance of 80% or less.

[Additional Note 10] The optical laminate according to any one of Additional Notes 1 to 9, wherein the pressure-sensitive adhesive layer has a thickness of 10 to 500 μm.

[Supplementary Note 11] The optical laminate according to any one of Supplementary Notes 1 to 10, wherein the shear storage modulus of the pressure-sensitive adhesive layer at a temperature of 25° C. is 10 to 1000 kPa.

[Supplementary Note 12] The optical laminate according to any one of Supplementary Notes 1 to 11, wherein the shear storage modulus of the pressure-sensitive adhesive layer at a temperature of 85° C. is 3 to 300 kPa.

[Supplementary Note 13] The optical laminate according to any one of Supplementary Notes 1 to 12, wherein the anti-glare treatment is an anti-glare layer provided on one surface of the substrate.

[Additional Note 14] The optical laminate according to Additional Note 13, wherein the antiglare layer is formed using an antiglare layer forming material containing a resin, particles, and a thixotropic imparting agent,

The anti-glare layer is aggregated by the particles and the thixotropy-imparting agent, and has an aggregated portion forming a convex portion on the surface of the anti-glare layer.

[Supplementary Note 15] The optical laminate according to Supplementary Note 14, wherein the convex portion on the surface of the anti-glare layer has an average inclination angle θa (°) in the range of 0.1 to 5.0.

[Supplementary Note 16] The optical laminate according to any one of Supplementary Notes 1 to 15, wherein a surface protection film is further laminated on the surface of the base material subjected to antireflection treatment and/or antiglare treatment.

[Appendix 17] A self-illuminating display device, the self-illuminating display device comprising:

a display panel in which a plurality of light emitting elements are arranged on one side of a substrate; and

The optical laminate according to any one of Supplements 1 to 16,

The surface of the display panel on which the light-emitting elements are arranged is laminated with the pressure-sensitive adhesive layer of the optical laminate.

[Supplementary note 18] The self-luminous display device according to supplementary note 17, wherein the display panel is an LED panel in which a plurality of LED chips are arranged on one side of a substrate.

Industrial availability

The optical adhesive composition and optical laminate of the present invention are suitable for encapsulation of light-emitting elements of self-luminous display devices such as Mini/Micro LEDs.

Explanation of reference signs

10, 11 Optical laminates

1 substrate

2 adhesive layers

3 Anti-reflection and/or anti-glare treatment

3a Anti-glare layer

20, 21 Self-luminous display device (Mini/Micro LED display device)

4 Substrate

5 metal wiring layers

6 Light-emitting elements (LED chips)

Claims (18)

1. An optical laminate comprising a substrate and an adhesive layer comprising a colorant,

one side of the substrate is subjected to anti-reflection treatment and/or anti-glare treatment,

the adhesive layer is laminated on the surface of the substrate on the side not subjected to the antireflection treatment and/or the antiglare treatment.

2. The optical laminate according to claim 1, wherein the adhesive layer is an adhesive layer formed from a photocurable adhesive composition containing a polymer, a photopolymerizable compound, a photopolymerization initiator, and a colorant.

3. The optical laminate according to claim 2, wherein the maximum value of the transmittance at a wavelength of 330 to 400nm of said colorant is greater than the maximum value of the transmittance at a wavelength of 400 to 700 nm.

4. The optical laminate according to claim 2 or 3, wherein the photopolymerization initiator has at least 1 absorption maximum in a wavelength range of 330 to 400 nm.

5. The optical stack according to any one of claims 2 to 4, wherein the polymer is an acrylic polymer.

6. The optical laminate according to any one of claims 2 to 5, wherein the glass transition temperature of the polymer is 0 ℃ or lower.

7. The optical laminate according to any one of claims 2 to 6, wherein said photocurable adhesive composition further comprises a crosslinking agent capable of crosslinking with said polymer.

8. The optical stack of any of claims 1-7, wherein the optical stack has a maximum in transmittance between 350nm and 450 nm.

9. The optical stack according to any one of claims 1 to 8, wherein the adhesive layer has a total light transmittance of 80% or less.

10. The optical stack according to any one of claims 1 to 9, wherein the adhesive layer has a thickness of 10 to 500 μm.

11. The optical laminate of any one of claims 1-10, wherein the adhesive layer has a shear storage modulus of 10 to 1000kPa at a temperature of 25 ℃.

12. The optical laminate of any one of claims 1-11, wherein the adhesive layer has a shear storage modulus at a temperature of 85 ℃ of 3 to 300kPa.

13. The optical stack according to any one of claims 1 to 12, wherein the anti-glare treatment is an anti-glare layer provided on one side of the substrate.

14. The optical laminate according to claim 13, wherein the antiglare layer is formed using an antiglare layer-forming material comprising a resin, particles, and a thixotropy-imparting agent,

the antiglare layer has an aggregate portion on the surface thereof, which forms a convex portion, by aggregating the particles and the thixotropic agent.

15. The optical laminate according to claim 14, wherein the average inclination angle θ a (°) at the convex portion of the surface of the antiglare layer is in the range of 0.1 to 5.0.

16. The optical laminate according to any one of claims 1 to 15, further comprising a surface protective film laminated on the antireflection-treated and/or antiglare-treated surface of the substrate.

17. A self-luminous display device includes;

display panel having a plurality of light-emitting elements arranged on one surface of substrate, and

the optical stack of any one of claims 1-16,

the surface of the display panel on which the light-emitting elements are arranged is laminated with the adhesive layer of the optical laminate.

18. The self-luminous display device according to claim 17, wherein the display panel is an LED panel in which a plurality of LED chips are arranged on one surface of a substrate.

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