KR20220070441A - An image display device comprising an optical film having a pressure-sensitive adhesive layer and an optical film having the pressure-sensitive adhesive layer - Google Patents

Abstract

The optical film provided with the adhesive layer by which adhesive bond omission was suppressed remarkably in a mold release processing part, and peeling in a high-temperature, high-humidity environment was suppressed remarkably is provided. The optical film provided with the adhesive layer of this invention has an adhesive layer in one surface of an optical film and an optical film. The optical film provided with an adhesive layer has mold release other than a rectangle, and the creep value in 85 degreeC of an adhesive layer is 500 micrometers or less.

Description

An image display device comprising an optical film having a pressure-sensitive adhesive layer and an optical film having the pressure-sensitive adhesive layer

The present invention relates to an optical film having a pressure-sensitive adhesive layer and an image display device comprising an optical film provided with the pressure-sensitive adhesive layer.

DESCRIPTION OF RELATED ART In image display apparatuses, such as a cellular phone and a notebook-type personal computer, in order to implement|achieve image display and/or to improve the said image display performance, an optical film is widely used. The optical film is typically provided with an adhesive layer, and is comprised as an optical film provided with an adhesive layer, and bonding to an image display cell is attained. In recent years, processing an optical film other than a rectangle (release processing: formation of a notch and/or a through-hole) is desired in some cases. However, in the mold release processing part of the optical film provided with an adhesive layer, there exists a problem that adhesive bond defect (the phenomenon in which the edge part of an adhesive layer is missing) is easy to generate|occur|produce. Moreover, there exists a problem of peeling in a high-temperature, high-humidity environment in an adhesive layer.

Japanese Patent Laid-Open No. 2017-090896

The present invention has been made in order to solve the above-mentioned conventional problems, and the main object thereof is an optical film provided with an adhesive layer in which adhesive glitch is remarkably suppressed in a release processing part, and peeling in a high-temperature, high-humidity environment is remarkably suppressed. is to provide

The optical film provided with the adhesive layer of this invention has an adhesive layer in one surface of an optical film and this optical film. The optical film provided with this adhesive layer has mold release other than a rectangle, and the creep value in 85 degreeC of this adhesive layer is 500 micrometers or less.

In one embodiment, the said creep value is 5 micrometers or more.

In one embodiment, the thickness of the said adhesive layer is 2 micrometers - 20 micrometers.

In one embodiment, a separator is temporarily affixed so that peeling is possible on the surface on the opposite side to the optical film of the said adhesive layer, and the peeling force of this separator is 0.04N/50mm - 0.5N/50mm.

In one embodiment, the said optical film contains a polarizer. In one embodiment, the said optical film further contains a retardation layer.

According to another aspect of the present invention, an image display apparatus is provided. This image display device contains the optical film provided with said adhesive layer.

According to an embodiment of the present invention, in an optical film provided with a pressure-sensitive adhesive layer having a release (release processing portion) other than a rectangle, by setting the creep value at 85°C of the pressure-sensitive adhesive layer into a predetermined range, the adhesive in the release processing portion An optical film provided with the adhesive layer by which omission was suppressed remarkably and peeling in a high-temperature, high-humidity environment was suppressed remarkably is realizable.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic top view explaining an example of the mold release in an optical film provided with the adhesive layer by embodiment of this invention, or a mold release processing part.
It is a schematic plan view explaining the modification of the mold release or a mold release process part in the optical film provided with the adhesive layer by embodiment of this invention.
It is a schematic plan view explaining still another modified example of the mold release or mold release processing part in the optical film provided with the adhesive layer by embodiment of this invention.
It is a schematic plan view explaining still another modified example of the mold release or mold release processing part in the optical film provided with the adhesive layer by embodiment of this invention.

EMBODIMENT OF THE INVENTION Hereinafter, although specific embodiment of this invention is described with reference to drawings, this invention is not limited to these embodiment. In addition, in order to make it easy to see, the drawing is represented schematically, and the ratio of length, width|variety, thickness, etc. in a drawing, an angle, etc. differ from reality.

A. Outline of optical film provided with an adhesive layer

The optical film provided with the adhesive layer by embodiment of this invention has an adhesive layer in one surface of an optical film and this optical film. In embodiment of this invention, the optical film provided with an adhesive layer has a mold release other than a rectangle. In this specification, "having a mold release other than a rectangle" means that the planar shape of an optical film provided with an adhesive layer has a shape other than a rectangle (a rectangle and the case where a corner is chamfered is included). A mold release is typically the mold release processing part by which the mold release process was carried out. Therefore, the "optical film provided with an adhesive layer having a release shape other than a rectangle" (hereinafter, may be referred to as a "release optical film") is the entire release optical film (that is, the outer edge defining the planar shape of the film) ) is not only a case other than a rectangle, but also the case where the mold release processing part is formed in the part spaced inward from the outer edge of a rectangular optical film is included. Adhesive glitch is easy to generate|occur|produce in such a mold release process part, According to embodiment of this invention, such adhesive glitch can be suppressed remarkably. As a mold release (a mold release part), as shown to FIG. 1 and FIG. 2, for example, a through-hole and a cutting part used as a recessed part in planar view are mentioned. Representative examples of the concave portion include a shape close to a linear shape, a V-shaped notch, and a U-shaped notch. As another example of a mold release (a mold release processing part), as shown to FIG. 3 and FIG. 4, the shape corresponding to the meter panel of an automobile is mentioned. The shape includes a portion in which the outer edge is formed in an arc shape along the rotational direction of the meter needle, and the outer edge forms a V-shape (including a curved shape) convex inward in the plane direction. Of course, the shape of the mold release (the mold part) is not limited to the illustrated example. For example, as for the shape of the through hole, any suitable shape (eg, oval, triangular, square, pentagonal, hexagonal, octagonal) may be adopted depending on the purpose other than the substantially circular shape of the illustrated example. In addition, the through hole is provided in arbitrary suitable positions according to the objective. As shown in FIG. 2, a through hole may be provided in the substantially central part of the long side direction edge part of a rectangular optical film, it may be provided in the predetermined position of a long side direction edge part, It is provided in the corner part of an optical film also be; Although not shown, it may be provided at the end of the rectangular optical film in the short side direction; As shown in FIG. 3 or FIG. 4, you may provide in the center part of a mold release optical film. In addition, you may combine the shape of an illustration suitably according to the objective. For example, you may form a through hole in arbitrary positions of the release optical film of FIG. 1; You may form a V-notch and/or a U-notch in arbitrary suitable positions of the outer edge of the release optical film of FIG. 3 or FIG. Such a release optical film may be suitably used in an image display device such as a meter panel of an automobile, a smart phone, a tablet-type PC, or a smart watch.

In embodiment of this invention, the creep value in 85 degreeC of an adhesive layer is 500 micrometers or less, Preferably they are 5 micrometers - 500 micrometers. If the creep value of the pressure-sensitive adhesive layer is within such a range, it is possible to realize an optical film provided with the pressure-sensitive adhesive layer in which adhesive glitch is remarkably suppressed in the mold release processing portion, and peeling in a high-temperature, high-humidity environment is remarkably suppressed. The structure of an adhesive layer is demonstrated concretely in C term mentioned later.

The adhesive loss amount of the adhesive layer (in particular, the adhesive layer in a mold release part) in the optical film provided with an adhesive layer becomes like this. Preferably it is 80 micrometers or less, More preferably, it is 65 micrometers or less, More preferably is 50 μm or less. The smaller the amount of missing adhesive is, the more preferable it is, and the lower limit thereof may be, for example, 5 μm. In this specification, "adhesive missing|missing amount" means the maximum value in the said direction of the adhesive layer missing in the surface direction from the optical film outer edge (the outer edge of a through-hole is also included).

In one embodiment, a separator is temporarily affixed on the surface on the opposite side to the optical film of an adhesive layer so that peeling is possible. As the separator, for example, a plastic (e.g., polyethylene terephthalate (PET), polyethylene, polypropylene) film, nonwoven fabric or paper coated with a release agent such as a silicone-based release agent, a fluorine-based release agent, or a long-chain alkyl acrylate-based release agent. and the like. Any suitable thickness can be employ|adopted for the thickness of a separator according to the objective. The thickness of the separator is, for example, 10 µm to 100 µm.

The peeling force of the separator is preferably 0.04N/50mm to 0.5N/50mm, and more preferably 0.07N/50mm to 0.45N/50mm. If the peeling force of the separator is within such a range, the amount of missing adhesive in the pressure-sensitive adhesive layer (particularly, the pressure-sensitive adhesive layer in the mold release portion) may become small. When the peeling force of the separator exceeds 0.5N/50mm, the peelability of the separator is lowered, and process problems may occur.

B. Optical Film

A film comprised from a single layer may be sufficient as an optical film, and a laminated body may be sufficient as it. As a specific example of the optical film comprised from a single layer, a window film, a polarizer, and retardation film are mentioned. Specific examples of the optical film constituted as a laminate include a polarizing plate (typically, a laminate of a polarizer and a protective film), a conductive film for a touch panel, a surface treatment film, and an optical film and/or laminate composed of a single layer thereof The laminated body (For example, the circularly-polarizing plate for reflection prevention, the polarizing plate provided with the conductive layer for touch panels) which laminated|stacked the optical film comprised as a sieve suitably according to the objective is mentioned. Hereinafter, as representative examples of the optical film, a polarizing plate and a circularly polarizing plate will be briefly described.

B-1. Polarizer

A polarizing plate typically has a polarizer and the protective layer provided in one or both sides of the said polarizer.

B-1-1. polarizer

A polarizer is typically comprised from the resin film containing a dichroic substance. As the resin film, any suitable resin film that can be used as a polarizer can be employed. A resin film is typically a polyvinyl alcohol-type resin (henceforth "PVA-type resin") film. A single-layered resin film may be sufficient as a resin film, and the laminated body of two or more layers may be sufficient as it.

As a specific example of the polarizer comprised from a single-layered resin film, the thing by which the dyeing process by iodine and the extending|stretching process (typically, uniaxial stretching) were given to the PVA system resin film is mentioned. Dyeing with the said iodine is performed by immersing a PVA type film in iodine aqueous solution, for example. The draw ratio of the said uniaxial stretching becomes like this. Preferably it is 3 to 7 times. Extending may be performed after a dyeing process, and may be performed, dyeing|staining. Moreover, after extending|stretching, you may dye|stain. A swelling process, a crosslinking process, a washing process, a drying process, etc. are given to a PVA-type resin film as needed. For example, by immersing the PVA-based resin film in water before dyeing and washing with water, it is possible not only to wash the surface of the PVA-based film and the anti-blocking agent, but also to swell the PVA-based resin film to prevent staining of dyeing. .

As a specific example of a polarizer obtained using a laminate, a laminate of a resin substrate and a PVA-based resin layer (PVA-based resin film) laminated on the resin substrate, or a resin substrate and a PVA-based resin layer coated on the resin substrate. The polarizer obtained using a laminated body is mentioned. A polarizer obtained by using a laminate of a resin substrate and a PVA-based resin layer coated on the resin substrate is applied, for example, a PVA-based resin solution is applied to the resin substrate, dried to form a PVA-based resin layer on the resin substrate to obtain a laminate of a resin substrate and a PVA-based resin layer; It can be produced by; stretching and dyeing the laminate to make the PVA-based resin layer a polarizer. In this embodiment, extending|stretching includes extending|stretching by immersing a laminated body in boric-acid aqueous solution typically. Moreover, extending|stretching may further include air-stretching the laminated body at high temperature (for example, 95 degreeC or more) before extending|stretching in boric acid aqueous solution, if necessary. The obtained laminate of resin substrate / polarizer may be used as it is (that is, the resin substrate may be used as a protective layer of polarizer), and the resin substrate is peeled from the laminate of resin substrate / polarizer, may be used by laminating an appropriate protective layer of The detail of the manufacturing method of such a polarizer is described in Unexamined-Japanese-Patent No. 2012-73580, and Unexamined-Japanese-Patent No. 6470455, for example. These publications are incorporated herein by reference in their entirety.

The thickness of the polarizer is preferably 25 µm or less, more preferably 1 µm to 12 µm, still more preferably 3 µm to 12 µm, and particularly preferably 3 µm to 8 µm. If the thickness of a polarizer is such a range, the curl at the time of a heating can be suppressed favorably, and the external appearance durability at the time of a favorable heating is acquired.

The polarizer preferably exhibits absorption dichroism at any wavelength of 380 nm to 780 nm. The single transmittance of the polarizer is preferably 43.0% to 46.0%, and more preferably 44.5% to 46.0%. The polarization degree of a polarizer becomes like this. Preferably it is 97.0 % or more, More preferably, it is 99.0 % or more, More preferably, it is 99.9 % or more.

B-1-2. protective layer

The protective layer is formed of any suitable film that can be used as a protective layer of the polarizer. Specific examples of the material used as the main component of the film include cellulose resins such as triacetyl cellulose (TAC), polyester, polyvinyl alcohol, polycarbonate, polyamide, polyimide, and polyether alcohol. Transparent resins, such as a phone type, polysulfone type, polystyrene type, polynorbornene type, polyolefin type, (meth)acrylic type, acetate type, etc. are mentioned. Moreover, thermosetting resins, such as (meth)acrylic type, urethane type, (meth)acrylic type urethane type, epoxy type, silicone type, or ultraviolet curing type resin, etc. are mentioned. In addition, for example, glassy polymers, such as a siloxane type polymer, are also mentioned. Moreover, the polymer film of Unexamined-Japanese-Patent No. 2001-343529 (WO01/37007) can also be used. As a material for this film, for example, a resin composition containing a thermoplastic resin having a substituted or unsubstituted imide group in a side chain and a thermoplastic resin having a substituted or unsubstituted phenyl group and a nitrile group in the side chain can be used, for example For example, the resin composition which has an alternating copolymer which consists of isobutene and N-methylmaleimide, and an acrylonitrile-styrene copolymer is mentioned. The polymer film may be, for example, an extrusion molding of the resin composition.

The protective layer (outer protective layer) opposite to the pressure-sensitive adhesive layer may be subjected to a surface treatment such as a hard coat treatment, an antireflection treatment, an antistick treatment, and an antiglare treatment, if necessary.

In one embodiment, it is preferable that the protective layer (inner protective layer) on the side of an adhesive layer is optically isotropic. In this specification, "optically isotropic" means that the in-plane retardation Re(550) is 0 nm to 10 nm, and the retardation Rth(550) in the thickness direction is -10 nm to +10 nm. In another embodiment, the inner protective layer may be a retardation film, a brightness improving film, a diffusion film, or the like.

As for the thickness of the protective layer, any suitable thickness may be employed. The thickness of the protective layer is preferably 5 µm to 200 µm, more preferably 15 µm to 45 µm, still more preferably 20 µm to 40 µm. In addition, when surface treatment is performed, the thickness of a protective layer is the thickness including the thickness of a surface treatment layer.

B-2. circular polarizer

The circularly polarizing plate typically includes a polarizer and a retardation layer. The polarizer can be practically included in the circularly polarizing plate as a polarizing plate provided with a protective layer on one or both sides. The retardation layer is typically arrange|positioned between a polarizing plate and an adhesive layer. About a polarizer and a polarizing plate, it is as having demonstrated in said B-1.

A single layer may be sufficient as a retardation layer, and it may have a laminated structure.

When the retardation layer is constituted as a single layer, the retardation layer can typically function as λ/4. In this case, the in-plane retardation Re(550) of the retardation layer is preferably 100 nm to 190 nm, more preferably 110 nm to 170 nm, and still more preferably 130 nm to 160 nm. The angle between the slow axis of the retardation layer and the absorption side of the polarizer is preferably 40° to 50°, more preferably 42° to 48°, and still more preferably about 45°. The retardation layer may exhibit an inverse dispersion wavelength characteristic in which the phase difference value increases with the wavelength of the measurement light, or a positive wavelength dispersion characteristic in which the phase difference value decreases with the wavelength of the measurement light, and the phase difference value is almost dependent on the wavelength of the measurement light It may exhibit flat wavelength dispersion characteristics that do not change. In one embodiment, the retardation layer exhibits reverse dispersion wavelength characteristics. In this case, Re(450)/Re(550) of retardation layer becomes like this. Preferably it is 0.8 or more and less than 1, More preferably, it is 0.8 or more and 0.95 or less.

When the retardation layer has a laminated structure, typically, it has a two-layered structure of a first retardation layer and a second retardation layer. In this case, either one of the first retardation layer or the second retardation layer may function as a λ/2 plate, and the other may function as a λ/4 plate. For example, when the first retardation layer can function as a λ/2 plate and the second retardation layer can function as a λ/4 plate, Re (550) of the first retardation layer is preferably 200 nm. to 300 nm, more preferably 230 nm to 290 nm, still more preferably 250 nm to 280 nm, and the angle between the slow axis and the absorption side of the polarizer is preferably 10° to 20°, more preferably 12° to 18°, more preferably about 15°; Re (550) of the second retardation layer 22 is preferably 100 nm to 190 nm, more preferably 110 nm to 170 nm, still more preferably 130 nm to 160 nm, and the angle between the slow axis and the absorption side of the polarizer is preferably preferably 70° to 80°, more preferably 72° to 78°, and still more preferably about 75°.

The retardation layer may be made of any suitable material as long as it can satisfy the above characteristics. For example, a resin film (typically, a stretched film) may be sufficient as retardation layer, and the orientation-solidified layer (liquid crystal orientation-solidified layer) of a liquid crystal compound may be sufficient as it. Representative examples of the resin constituting the resin film include a polycarbonate-based resin, a polyester carbonate-based resin, a polyester-based resin, a polyvinyl acetal-based resin, a polyarylate-based resin, a cyclic olefin-based resin, a cellulose-based resin, and polyvinyl alcohol-based resins, polyamide-based resins, polyimide-based resins, polyether-based resins, polystyrene-based resins, and acrylic resins. These resins may be used independently and may be used in combination (for example, blending, copolymerization). When the retardation layer is composed of a resin film exhibiting reverse dispersion wavelength characteristics, a polycarbonate-based resin or a polyester carbonate-based resin (hereinafter, simply referred to as a polycarbonate-based resin) may be suitably used. can The details of the polycarbonate-type resin which can be used suitably for retardation layer, and the formation method of retardation layer are, for example, Unexamined-Japanese-Patent No. 2014-10291, Unexamined-Japanese-Patent No. 2014-26266, Unexamined-Japanese-Patent No. It is described in Unexamined-Japanese-Patent No. 2015-212816, Unexamined-Japanese-Patent No. 2015-212817, and Unexamined-Japanese-Patent No. 2015-212818; The specific example of a liquid crystal compound, and the detail of the formation method of an orientation solidification layer are described in Unexamined-Japanese-Patent No. 2006-163343, for example. The descriptions of these publications are incorporated herein by reference.

C. Adhesive layer

C-1. Characteristics of the adhesive layer

As described above, the pressure-sensitive adhesive layer has a creep value at 85°C of 500 µm or less, preferably 5 µm to 500 µm. In one embodiment, the creep value becomes like this. Preferably they are 200 micrometers - 450 micrometers, More preferably, they are 220 micrometers - 420 micrometers. In another embodiment, the creep value is preferably 5 µm to 300 µm, more preferably 5 µm to 200 µm, still more preferably 10 µm to 100 µm, particularly preferably 15 µm to 70 µm. μm, and particularly preferably 20 μm to 50 μm. If the creep value is within such a range, it is possible to remarkably suppress the adhesive glitch of the mold release part, and remarkably suppress peeling in a high-temperature, high-humidity environment. Even when the creep value is relatively large (e.g., 200 µm or more), the composition of the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer (e.g., the type of the base polymer (polarity, Tg, flexibility), molecular weight), the crosslinked structure (e.g. For example, it is estimated that adhesive defect can be suppressed by controlling the kind of crosslinking agent, the distance between crosslinking points (molecular weight between crosslinking points), crosslinking density, and uncrosslinked component (sol fraction). Incidentally, the creep value can be measured, for example, in the following procedure: A test sample cut out from an optical film with an adhesive layer is adhered to a support plate with a bonding surface of 10 mm x 10 mm. A load of 500 gf is applied vertically downward while the support plate to which the test sample is affixed is fixed. The amount of shift from the support plate after 1 second and 3600 seconds after the load is applied is measured, and it is referred to as Cr ₁ and Cr ₃₆₀₀ , respectively. Let (DELTA)Cr calculated|required by the following formula from Cr1 and _Cr3600 as _a creep value.

ΔCr=Cr ₃₆₀₀ -Cr ₁

The pressure-sensitive adhesive layer has a storage modulus at 85°C of preferably 1.0×10 ⁴ Pa or more, preferably 2.0×10 ⁴ Pa or more, more preferably 5.0×10 ⁴ Pa or more, still more preferably 1.0×10 ⁵ Pa or more. If the storage modulus is within this range, the desired creep value can be easily realized. On the other hand, the storage elastic modulus is, for example, 3.0×10 ⁶ Pa or less. If the upper limit of a storage elastic modulus is such a range, peeling of the adhesive layer in a high-temperature, high-humidity environment can be suppressed remarkably.

The weight average molecular weights Mw (the detail is mentioned later) of the base polymer in the adhesive composition which forms an adhesive layer are 200,000-3 million, for example, Preferably it is 1 million-250,000.

The gel fraction of the pressure-sensitive adhesive layer is preferably 55% to 95%. In one embodiment, the gel fraction is preferably 60% to 93%, and more preferably 80% to 91%. In this case, the weight average molecular weight Mw (described later) of the high molecular weight component derived from the base polymer among the uncrosslinked components (sol powder) of the pressure-sensitive adhesive composition is, for example, 50,000 to 1,000,000, preferably 50,000 to 500,000, and , More preferably, it is 100,000 - 400,000. In addition, the gel fraction is obtained by (dry weight after immersion / dry weight before immersion) x 100 when the crosslinked adhesive is immersed in a predetermined solvent (eg, ethyl acetate) for 6 days and then dried. The weight average molecular weight Mw of the high molecular weight component derived from the base polymer among the uncrosslinked components (sol powder) of the base polymer and the pressure-sensitive adhesive composition is, for example, a value calculated by gel permeation chromatography (GPC) and calculated in terms of polystyrene. saved from

The degree of swelling of the pressure-sensitive adhesive layer is preferably 35 times or less, more preferably 10 to 30 times, still more preferably 11 to 28 times, particularly preferably 12 to 20 times. If the degree of swelling is within such a range, it is possible to remarkably suppress the defect of the adhesive in the mold release portion. In addition, swelling degree is made to immerse the crosslinked adhesive in a predetermined solvent (for example, ethyl acetate) for 6 days, and is calculated|required by (weight after immersion/dry weight after immersion).

The storage elastic modulus, gel fraction, and swelling degree of the pressure-sensitive adhesive layer are determined by the composition of the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer (eg, the type of the base polymer (polarity, Tg, flexibility), molecular weight), the cross-linking structure (eg, the type of the cross-linking agent). , distance between crosslinking points (molecular weight between crosslinking points), crosslinking density), and the like. More specifically, the type and combination of monomer components of the base polymer, polymerization conditions of the base polymer, the type and amount of crosslinking agent, and the like can be appropriately set.

The thickness of the pressure-sensitive adhesive layer is preferably 2 µm to 55 µm, more preferably 2 µm to 30 µm, still more preferably 2 µm to 20 µm, and particularly preferably 5 µm to 15 µm. If the thickness of the pressure-sensitive adhesive layer is within such a range, the synergistic effect with the effect of controlling the creep value can significantly suppress the adhesive defect of the mold release section.

The pressure-sensitive adhesive layer is typically formed from a pressure-sensitive adhesive composition containing a (meth)acrylic polymer, a urethane polymer, a silicone polymer, or a rubber polymer as a base polymer. When a (meth)acrylic-type polymer is used as a base polymer, an adhesive layer is formed from the adhesive composition containing the (meth)acrylic-type polymer (A), for example. The (meth)acrylic polymer (A) contains an alkyl (meth)acrylate as a main component.

C-2. (Meth)acrylic polymer (A)

The (meth)acrylic polymer (A) contains an alkyl (meth)acrylate as a main component as described above. The alkyl (meth) acrylate is preferably 50% by weight or more from the viewpoint of improving the adhesiveness of the pressure-sensitive adhesive layer in all the monomer components forming the (meth)acrylic polymer (A), and the alkyl (meth)acryl It can set arbitrarily as remainder of monomers other than a rate. In addition, (meth)acrylate means an acrylate and/or a methacrylate.

Examples of the alkyl (meth)acrylate constituting the main skeleton of the (meth)acrylic polymer (A) include a linear or branched alkyl group having 1 to 18 carbon atoms. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, an amyl group, a hexyl group, a cyclohexyl group, a heptyl group, a 2-ethylhexyl group, an isooctyl group, a nonyl group, Decyl group, isodecyl group, dodecyl group, isomyristyl group, lauryl group, tridecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, etc. are mentioned. Alkyl (meth)acrylates may be used alone or in combination. It is preferable that the average carbon number of an alkyl group is 3-10.

The (meth)acrylic polymer (A) may contain, as a monomer component, a copolymerized monomer such as a carboxyl group-containing monomer (a1) or a hydroxyl group-containing monomer (a2) other than alkyl (meth)acrylate. Copolymerization monomers can be used individually or in combination.

A carboxyl group-containing monomer (a1) is a compound which contains a carboxyl group in the structure, and also contains polymerizable unsaturated double bonds, such as a (meth)acryloyl group and a vinyl group. Examples of the carboxyl group-containing monomer include (meth)acrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, itaconic acid, maleic acid, fumaric acid, and crotonic acid. Among these, acrylic acid is preferable from a viewpoint of improving copolymerizability, price, and the adhesive characteristic of an adhesive layer.

When a carboxyl group-containing monomer (a1) is used as the monomer component, the content of the carboxyl group-containing monomer (a1) is usually 0.01% by weight or more and 10% by weight or less in all monomer components forming the (meth)acrylic polymer (A). to be.

The hydroxyl group-containing monomer (a2) is a compound including a hydroxyl group in its structure and a polymerizable unsaturated double bond such as a (meth)acryloyl group and a vinyl group. As the hydroxyl group-containing monomer, for example, 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl ( hydroxyalkyl (meth)acrylates such as meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, and 12-hydroxylauryl (meth)acrylate; (4-hydroxymethylcyclohexyl)-methyl acrylate etc. are mentioned. Among these, from a viewpoint of improving the durability of an adhesive layer, 2-hydroxyethyl (meth)acrylate and 4-hydroxybutyl (meth)acrylate are preferable, and 4-hydroxybutyl (meth)acrylate is more desirable.

In the case of using the hydroxyl group-containing monomer (a2) as the monomer component, the content of the hydroxyl group-containing monomer (a2) is usually 0.01 wt% or more in all the monomer components forming the (meth)acrylic polymer (A). It is 10 weight% or less.

The (meth)acrylic polymer (A) preferably contains, as a monomer component, a monomer having an unsaturated carbon double bond in which the glass transition temperature of the homopolymer is 0°C or higher. Examples of the monomer (a3) having an unsaturated carbon double bond having a glass transition temperature of the homopolymer of 0°C or higher include an alkyl (meth)acrylate monomer and (meth)acrylic acid. The monomer (a3) is preferably a monomer having an unsaturated carbon double bond in which the glass transition temperature of the homopolymer is 20°C or higher, and more preferably a monomer having an unsaturated carbon double bond in which the glass transition temperature of the homopolymer is 40°C or higher.

The (meth)acrylic polymer (A) WHEREIN: The ratio containing a monomer (a3) is not specifically limited. Content is 0.1 weight% - 40 weight% normally, More preferably, they are 1 weight% - 30 weight%. In addition, content is content in a total, when using two or more types of monomers (a3) together.

As the monomer (a3), for example, methyl acrylate (Tg: 8 ° C.), methyl methacrylate (Tg: 105 ° C.), ethyl methacrylate (Tg: 65 ° C.), n-propyl acrylate (Tg: 3° C.), n-propyl methacrylate (Tg: 35° C.), n-pentyl acrylate (Tg: 22° C.), n-tetradecyl acrylate (Tg: 24° C.), n-hexadecyl acrylate (Tg : 35° C.), n-hexadecyl methacrylate (Tg: 15° C.), n-stearyl acrylate (Tg: 30° C.), and n-stearyl methacrylate (Tg: 38° C.) (meth)acrylate; t-butyl acrylate (Tg: 43° C.), t-butyl methacrylate (Tg: 48° C.), i-propyl methacrylate (Tg: 81° C.), and i-butyl methacrylate (Tg: 48° C.) ) branched chain alkyl (meth) acrylates such as; Cyclohexyl acrylate (Tg: 19° C.), cyclohexyl methacrylate (Tg: 65° C.), isobornyl acrylate (Tg: 94° C.), and isobornyl methacrylate (Tg: 180° C.) cyclic alkyl (meth)acrylate; Acrylic acid (Tg: 106 degreeC) etc. are mentioned. These may be used alone or in combination.

A copolymerization monomer becomes a reaction point with a crosslinking agent, when an adhesive composition contains the crosslinking agent mentioned later. Since the carboxyl group-containing monomer and the hydroxyl group-containing monomer have good reactivity with the intermolecular crosslinking agent, they are preferably used for improving the cohesiveness and heat resistance of the obtained pressure-sensitive adhesive layer. Moreover, a carboxyl group containing monomer is preferable at the point which makes durability and rework property compatible, and a hydroxyl group containing monomer is preferable at the point which improves rework property.

As a monomer component, you may use another copolymerization monomer (a4) further. Another copolymerization monomer (a4) has a polymerizable functional group which has unsaturated double bonds, such as a (meth)acryloyl group or a vinyl group, for example. By using other copolymerized monomers (a4), the adhesiveness and heat resistance of the pressure-sensitive adhesive layer can be improved. Other copolymerization monomers (a4) can be used individually or in combination.

As another copolymerization monomer (a4), the adhesiveness of an adhesive layer can be improved by using an amino-group containing monomer and an amide group containing monomer. The amino group-containing monomer is, for example, N,N-dimethylaminoethyl (meth)acrylate or N,N-dimethylaminopropyl (meth)acrylate. The amide group-containing monomer is, for example, (meth)acrylamide, N,N-dimethyl (meth)acrylamide, N,N-diethyl (meth)acrylamide, N-isopropylacrylamide, N-methyl ( Meth) acrylamide, N-butyl (meth) acrylamide, N-hexyl (meth) acrylamide, N-methylol (meth) acrylamide, N-methylol-N-propane (meth) acrylamide, aminomethyl ( acrylamide-based monomers such as meth)acrylamide, aminoethyl (meth)acrylamide, mercaptomethyl (meth)acrylamide, and mercaptoethyl (meth)acrylamide; N-acryloyl heterocyclic monomers, such as N-(meth)acryloylmorpholine, N-(meth)acryloylpiperidine, and N-(meth)acryloylpyrrolidine; N-vinyl group-containing lactam monomers such as N-vinylpyrrolidone and N-vinyl-ε caprolactam.

A polyfunctional monomer may be sufficient as another copolymerization monomer (a4). By use of a polyfunctional monomer, adjustment of the gel fraction of an adhesive layer and control of cohesion force can be performed. The polyfunctional monomer is, for example, hexanediol di (meth) acrylate (1,6-hexanediol di (meth) acrylate), butanediol di (meth) acrylate, (poly) ethylene glycol di (meth) acrylic rate, (poly) propylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa ( Meth) acrylate, trimethylolpropane tri (meth) acrylate, tetramethylol methane tri (meth) acrylate, allyl (meth) acrylate, vinyl (meth) acrylate, epoxy acrylate, polyester acrylate, urethane polyfunctional acrylates such as acrylates; and divinylbenzene. The polyfunctional acrylate is preferably 1,6-hexanediol diacrylate or dipentaerythritol hexa(meth)acrylate.

Other copolymer monomers (a4) other than those described above, for example, (meth) acrylic acid 2-methoxyethyl, (meth) acrylic acid 2-ethoxyethyl, (meth) acrylic acid methoxytriethylene glycol, (meth) (meth)acrylic acid alkoxyalkyl esters such as acrylic acid 3-methoxypropyl, (meth)acrylic acid 3-ethoxypropyl, (meth)acrylic acid 4-methoxybutyl, and (meth)acrylic acid 4-ethoxybutyl; Cyclization polymerizable monomers, such as 2-(allyloxymethyl) methyl acrylate; Epoxy group-containing monomers, such as (meth)acrylic-acid glycidyl and (meth)acrylic-acid methylglycidyl; Sulfonic acid group-containing monomers, such as sodium vinylsulfonate; a phosphoric acid group-containing monomer; (meth)acrylic acid ester which has alicyclic hydrocarbon groups, such as (meth)acrylic-acid cyclopentyl, (meth)acrylic-acid cyclohexyl, and (meth)acrylic-acid isobornyl; (meth)acrylic acid ester which has aromatic hydrocarbon groups, such as (meth)acrylic-acid phenyl, (meth)acrylic-acid phenoxyethyl, and (meth)acrylic-acid benzyl; vinyl esters such as vinyl acetate and vinyl propionate; aromatic vinyl compounds such as styrene and vinyltoluene; olefins or dienes such as ethylene, propylene, butadiene, isoprene, and isobutylene; vinyl ethers such as vinyl alkyl ether; Vinyl chloride can be used.

Content of the other copolymerization monomer (a4) in (meth)acrylic-type polymer becomes like this. Preferably it is 20 mass % or less, More preferably, it is 10 mass % or less, More preferably, it is 8 mass % or less, Especially preferable Preferably, it is 5 mass % or less.

C-3. Method for producing (meth)acrylic polymer (A)

The (meth)acrylic polymer (A) can be manufactured by any suitable method. As a specific example of a manufacturing method, various radical polymerizations, such as radiation polymerization, such as an electron beam and UV, solution polymerization, bulk polymerization, and emulsion polymerization, are mentioned. Any of a random copolymer, a block copolymer, a graft copolymer, etc. may be sufficient as the (meth)acrylic-type polymer (A) obtained.

In solution polymerization, ethyl acetate and toluene are used as a polymerization solvent, for example. The reaction in solution polymerization adds a polymerization initiator to a monomer component under an inert gas stream, such as nitrogen, for example, and is normally performed at about 50 degreeC - 70 degreeC for about 5 hours - about 30 hours.

The polymerization initiator, chain transfer agent, emulsifier, etc. used for radical polymerization may be appropriately selected depending on the purpose. The weight average molecular weight of the (meth)acrylic polymer (A) can be controlled by the amount of polymerization initiator and chain transfer agent used and reaction conditions, and the type and amount used can be adjusted according to the desired weight average molecular weight.

Examples of the polymerization initiator include 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-amidinopropane)dihydrochloride, 2,2'-azobis[2-(5) -Methyl-2-imidazolin-2-yl)propane]dihydrochloride, 2,2'-azobis(2-methylpropionamidine)disulfate, 2,2'-azobis(N,N'- azo initiators such as dimethylene isobutylamidine) and 2,2'-azobis[N-(2-carboxyethyl)-2-methylpropionamidine]hydrate (manufactured by Wako Pure Chemical Industries, Ltd., VA-057); and Persulfates such as potassium sulfate and ammonium persulfate, di(2-ethylhexyl)peroxydicarbonate, di(4-t-butylcyclohexyl)peroxydicarbonate, and di-sec-butylperoxydicarbonate , t-butylperoxyneodecanoate, t-hexylperoxypivalate, t-butylperoxypivalate, dilauroyl peroxide, di-n-octanoyl peroxide, 1,1,3,3 -Tetramethylbutylperoxy-2-ethylhexanoate, di(4-methylbenzoyl)peroxide, dibenzoylperoxide, t-butylperoxyisobutyrate, 1,1-di(t-hexylperoxy)cyclo A redox initiator obtained by combining a peroxide and a reducing agent, such as a peroxide-based initiator such as hexane, t-butyl hydroperoxide, and hydrogen peroxide, a combination of a persulfate and sodium hydrogensulfite, or a combination of a peroxide and sodium ascorbate, and the like.

A polymerization initiator can be used individually or in combination. It is preferable that it is about 0.005 weight part - about 1 weight part with respect to 100 weight part of monomer components, and, as for the usage-amount of a polymerization initiator as a whole, it is more preferable that it is about 0.01 weight part - 0.5 weight part.

Examples of the chain transfer agent include lauryl mercaptan, glycidyl mercaptan, mercaptoacetic acid, 2-mercaptoethanol, thioglycolic acid, thioglycolic acid 2-ethylhexyl, and 2,3-dimercapto-1-propanol. and the like. A chain transfer agent may be used independently and may mix and use 2 or more types. The usage-amount of a chain transfer agent as a whole is about 0.1 weight part or less with respect to 100 weight part of monomer components.

Examples of the emulsifier used in the case of emulsion polymerization include anionic emulsifiers such as sodium lauryl sulfate, ammonium lauryl sulfate, sodium dodecylbenzenesulfonate, ammonium polyoxyethylene alkyl ether sulfate, and sodium polyoxyethylene alkylphenyl ether sulfate; Nonionic emulsifiers, such as polyoxyethylene alkyl ether, polyoxyethylene alkylphenyl ether, polyoxyethylene fatty acid ester, and a polyoxyethylene polyoxypropylene block polymer, etc. are mentioned. The emulsifiers may be used alone or in combination.

Examples of the reactive emulsifier include an emulsifier into which a radically polymerizable functional group such as a propenyl group and an allyl ether group is introduced. Specific examples include Aqualon HS-10, HS-20, KH-10, BC-05, BC-10, BC-20 (above, all manufactured by Daiichi Kogyo Seyaku Co., Ltd.), and Adeka Riasop SE10N (made by ADEKA). can be heard Since the reactive emulsifier is introduced into the polymer chain after polymerization, it is preferable because of its improved water resistance. The amount of the emulsifier to be used is preferably 0.3 parts by weight to 5 parts by weight, more preferably 0.5 parts by weight to 1 part by weight with respect to 100 parts by weight of the total amount of the monomer component. If the usage-amount of an emulsifier is this range, it is excellent in polymerization stability and the mechanical stability of the adhesive layer obtained.

When the (meth)acrylic polymer (A) is produced by radiation polymerization, it can be produced by polymerization by irradiating the monomer component with radiation such as an electron beam or UV. When the radiation polymerization is carried out by UV polymerization, the monomer component may contain a photopolymerization initiator. Thereby, polymerization time can be shortened. In the case where radiation polymerization is performed with an electron beam, it is not particularly necessary to contain a photopolymerization initiator in the monomer component.

As a photoinitiator, arbitrary appropriate photoinitiators can be used. As a specific example, the photoinitiator of a benzoin ether type, an acetophenone type, (alpha)-ketol type, a photoactive oxime type, a benzoin type, a benzyl type, a benzophenone type, a ketal type, and a thioxanthone type is mentioned. Preferably the usage-amount of a photoinitiator is 0.02 weight part - 1.5 weight part with respect to 100 weight part of whole quantity of a monomer component, More preferably, it is 0.1 weight part - 1 weight part. A photoinitiator can be used individually or in combination.

The weight average molecular weight Mw of the (meth)acrylic polymer (A) is, for example, 200,000 to 3,000,000, preferably 1,000,000 to 2.5,000,000, more preferably 1.2,000,000 to 2.5,000,000, as described above. If the weight average molecular weight Mw is in such a range, an adhesive layer excellent in durability (particularly, heat resistance) can be obtained. When the weight average molecular weight Mw exceeds 3 million, a viscosity increase and/or gelation during polymer polymerization may occur.

The polydispersity (weight average molecular weight (Mw)/number average molecular weight (Mn)) of the (meth)acrylic polymer (A) is preferably 5.0 or less, more preferably 1.05 to 5.0, still more preferably 1.05 to It is 4.0. When the polydispersity (Mw/Mn) is large (for example, exceeding 5.0), there are many low molecular weight polymers, and even if the pressure-sensitive adhesive layer is formed so that the creep values are equal, uncrosslinked polymers or oligomers (sol powder) increases, the toughness of the pressure-sensitive adhesive layer becomes low (weak), and adhesive failure during mold release processing or peeling in a high-temperature, high-humidity environment may occur. In addition, polydispersity (Mw/Mn) is measured by GPC (gel permeation chromatography) similarly to a weight average molecular weight, and is calculated|required from the value computed by polystyrene conversion.

C-4. Reactive functional group-containing silane coupling agent

The pressure-sensitive adhesive composition may contain a reactive functional group-containing silane coupling agent. In the reactive functional group-containing silane coupling agent, the reactive functional group is typically a functional group other than an acid anhydride group. Examples of functional groups other than the acid anhydride group include an epoxy group, a mercapto group, an amino group, an isocyanate group, an isocyanurate group, a vinyl group, a styryl group, an acetoacetyl group, a ureido group, a thiourea group, and a (meth)acryl group. , heterocyclic groups, and combinations thereof. The reactive functional group-containing silane coupling agent may be used alone or in combination.

Examples of the reactive functional group-containing silane coupling agent include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 2-(3, Epoxy group-containing silane coupling agents, such as 4-epoxycyclohexyl) ethyl trimethoxysilane; mercapto group-containing silane coupling agents such as 3-mercaptopropylmethyldimethoxysilane and 3-mercaptopropyltrimethoxysilane; 3-Aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-triethoxysilyl-N-(1,3-dimethylbutylidene)propylamine, N an amino group-containing silane coupling agent such as -phenyl-γ aminopropyltrimethoxysilane; isocyanate group-containing silane coupling agents such as 3-isocyanate propyltriethoxysilane; Vinyl group-containing silane coupling agents, such as vinyl trimethoxysilane and vinyl triethoxysilane; styryl group-containing silane coupling agents such as p-styryltrimethoxysilane; (meth)acryl group containing silane coupling agents, such as 3-acryloxy propyl trimethoxysilane and 3-methacryloxy propyl triethoxysilane, etc. are mentioned. Among these, an epoxy group-containing silane coupling agent and a mercapto group-containing silane coupling agent are preferable. As an epoxy-group containing silane coupling agent, "KBM-403" by a Shin-Etsu Chemical company is marketed, for example.

As a reactive functional group containing silane coupling agent, what has a some alkoxysilyl group in a molecule|numerator (oligomer type silane coupling agent) can also be used. As a specific example, Shin-Etsu Chemical Co., Ltd. epoxy group containing oligomer type silane coupling agent, brand name "X-41-1053", "X-41-1059A", "X-41-1056", "X-40-2651"; Mercapto group-containing oligomeric silane coupling agents "X-41-1818", "X-41-1810", and "X-41-1805" are mentioned. Since the oligomeric silane coupling agent is less volatilized and has a plurality of alkoxysilyl groups, it may be effective in improving durability.

When mix|blending a reactive functional group containing silane coupling agent with an adhesive composition, the compounding quantity of a reactive functional group containing silane coupling agent is 0.001 weight part or more and 5 weight part or less normally with respect to 100 weight part of (meth)acrylic-type polymer (A).

C-5. crosslinking agent

The pressure-sensitive adhesive composition may contain a crosslinking agent. As a crosslinking agent, an organic type crosslinking agent, polyfunctional metal chelate, etc. can be used. As an organic type crosslinking agent, an isocyanate type crosslinking agent, a peroxide type crosslinking agent, an epoxy type crosslinking agent, and an imine type crosslinking agent are mentioned, for example. A polyfunctional metal chelate is one in which a polyvalent metal is covalently bonded or coordinated with an organic compound. Examples of the polyvalent metal atom include Al, Cr, Zr, Co, Cu, Fe, Ni, V, Zn, In, Ca, Mg, Mn, Y, Ce, Sr, Ba, Mo, La, Sn, Ti, and the like. have. Examples of the atom in the organic compound to be covalently bonded or coordinated include an oxygen atom, and examples of the organic compound include alkylesters, alcohol compounds, carboxylic acid compounds, ether compounds, and ketone compounds. In addition, when the pressure-sensitive adhesive composition is radiation-curable, a polyfunctional monomer may be used as a crosslinking agent. Examples of the polyfunctional monomer include hexanediol di (meth) acrylate (1,6-hexanediol di (meth) acrylate), butanediol di (meth) acrylate, (poly) ethylene glycol di (meth) acrylic rate, (poly) propylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa ( Meth) acrylate, trimethylolpropane tri (meth) acrylate, tetramethylol methane tri (meth) acrylate, allyl (meth) acrylate, vinyl (meth) acrylate, epoxy acrylate, polyester acrylate, urethane polyfunctional acrylates such as acrylates; and divinylbenzene. The polyfunctional acrylate is preferably 1,6-hexanediol diacrylate or dipentaerythritol hexa(meth)acrylate. The crosslinking agent may be used alone or in combination.

When the pressure-sensitive adhesive composition is a solvent type, the crosslinking agent is preferably an isocyanate-based crosslinking agent and/or a peroxide-based crosslinking agent, particularly from the viewpoint of reducing adhesive defects during processing, more preferably an isocyanate-based crosslinking agent, from the viewpoint of suppression of peeling in a high-temperature, high-humidity environment It is more preferable to use an isocyanate type crosslinking agent and a peroxide type crosslinking agent together.

As the isocyanate-based crosslinking agent, for example, a compound having at least two isocyanate groups (including an isocyanate regenerated functional group in which the isocyanate group is temporarily protected by a blocking agent or quantification, etc.) can be used. For example, any suitable aliphatic polyisocyanate, cycloaliphatic polyisocyanate, aromatic polyisocyanate, etc. that can be used in the urethanation reaction are used.

Examples of the aliphatic polyisocyanate include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, 1,2-propylene diisocyanate, 1,3-butylene diisocyanate, and dodecamethylene diisocyanate. and 2,4,4-trimethylhexamethylene diisocyanate.

Examples of the alicyclic isocyanate include 1,3-cyclopentene diisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogen Addition xylylene diisocyanate and hydrogenated tolylene diisocyanate hydrogenated tetramethyl xylylene diisocyanate are mentioned.

Examples of the aromatic diisocyanate include phenylene diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 2,2'-diphenylmethane diisocyanate, and 4,4'-diisocyanate. phenylmethane diisocyanate, 4,4'-toluidine diisocyanate, 4,4'-diphenyl ether diisocyanate, 4,4'-diphenyl diisocyanate, 1,5-naphthalene diisocyanate, and xylylene diisocyanate. have.

As another example of the isocyanate-based crosslinking agent, a multimer (dimer, trimer, pentamer, etc.) of the diisocyanate, a urethane modified product reacted with a polyhydric alcohol such as trimethylolpropane, a urea modified product, a biuret modified product, an alpha-nate modified product body, isocyanurate modified product, and carbodiimide modified product.

As a commercial item of an isocyanate type crosslinking agent, For example, Tosoh Corporation brand name "Millionate MT", "Millionate MTL", "Millionate MR-200", "Millionate MR-400", "Coronate L", "Coronate HL", "Coronate HX", Mitsui Chemical Co., Ltd. trade names "Takenate D-110N", "Takenate D-120N", "Takenate D-140N" , "Takenate D-160N", "Takenate D-165N", "Takenate D-170HN", "Takenate D-178N", "Takenate 500", and "Takenate 600" are mentioned.

As the isocyanate-based crosslinking agent, an aromatic polyisocyanate and an aromatic polyisocyanate-based compound as a modified form thereof, and an aliphatic polyisocyanate-based compound as an aliphatic polyisocyanate and a modified form thereof are preferable. The aromatic polyisocyanate-based compound has a good balance between the crosslinking rate and the pot life, and is preferably used. As an aromatic polyisocyanate type compound, especially tolylene diisocyanate and its modified body are preferable.

As the peroxide-based crosslinking agent, any suitable peroxide-based crosslinking agent can be used as long as radical active species are generated by heating or light irradiation to advance the crosslinking of the base polymer ((meth)acrylic polymer (A)) of the pressure-sensitive adhesive composition. Preferably, it is a peroxide having a half-life temperature of 80°C to 160°C for 1 minute, and more preferably a peroxide having a half-life temperature of 90°C to 140°C for 1 minute. Such a peroxide is excellent in workability and stability.

As the above peroxides, for example, di(2-ethylhexyl)peroxydicarbonate (1 minute half-life temperature: 90.6°C), di(4-t-butylcyclohexyl)peroxydicarbonate (1 minute) Half-life temperature: 92.1°C), di-sec-butylperoxydicarbonate (1 minute half-life temperature: 92.4°C), t-butylperoxyneodecanoate (1 minute half-life temperature: 103.5°C), t-hexylpere Oxypivalate (1 minute half-life temperature: 109.1°C), t-butylperoxypivalate (1 minute half-life temperature: 110.3°C), dilauroyl peroxide (1 minute half-life temperature: 116.4°C), di-n- Octanoyl peroxide (1-minute half-life temperature: 117.4°C), 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate (1-minute half-life temperature: 124.3°C), di(4-methylbenzoyl) ) peroxide (1 minute half-life temperature: 128.2 °C), dibenzoyl peroxide (1 minute half-life temperature: 130.0 °C), t-butylperoxyisobutyrate (1 minute half-life temperature: 136.1 °C), 1,1-di( t-hexylperoxy)cyclohexane (1 minute half-life temperature: 149.2°C). Among them, di(4-t-butylcyclohexyl)peroxydicarbonate, dilauroyl peroxide and dibenzoyl peroxide are particularly preferable from the viewpoint of excellent crosslinking reaction efficiency.

In addition, the half-life of a peroxide is an index|index which shows the decomposition rate of a peroxide, and means the time until the residual amount of a peroxide becomes half. The decomposition temperature for obtaining a half-life at an arbitrary time and the half-life time at an arbitrary temperature are described in a manufacturer's catalog, etc., for example, "Organic Peroxide Catalog 9th Edition (May 2003) of Nippon Yushi Co., Ltd." month)”, etc.

When mix|blending a crosslinking agent with an adhesive composition, the compounding quantity of a crosslinking agent is 0.01 weight part or more and 15 weight part or less normally with respect to 100 weight part of (meth)acrylic-type polymer (A).

When mix|blending an isocyanate type crosslinking agent with an adhesive composition, the compounding quantity of an isocyanate type crosslinking agent is 0.01 weight part or more and 15 weight part or less normally with respect to 100 weight part of (meth)acrylic type polymers.

When mix|blending a peroxide with an adhesive composition, the compounding quantity of a peroxide is 0.01 weight part or more and 2 weight part or less normally with respect to 100 weight part of (meth)acrylic-type polymers. In such a range, adjustment of workability, crosslinking stability, etc. is easy.

C-6. other ingredients

The adhesive composition may contain the (meth)acrylic-type oligomer. The (meth)acrylic oligomer can be obtained by polymerizing alone or copolymerizing two or more of the monomer components described in Item C-2 with respect to the (meth)acrylic polymer. The kind, number, combination, and polymerization molar ratio of the monomer components can be appropriately set according to the purpose and desired properties and the like. The weight average molecular weight Mw of the (meth)acrylic oligomer is preferably 1000 to 8000, more preferably 2000 to 7000, still more preferably 3000 to 6000. When mix|blending a (meth)acrylic-type oligomer with an adhesive composition, Preferably the compounding quantity of a (meth)acrylic-type oligomer is 5-35 weight part with respect to 100 weight part of (meth)acrylic-type polymers.

The pressure-sensitive adhesive composition may contain an ionic compound. As the ionic compound, any appropriate ionic compound can be used. As an ionic compound, what is described in Unexamined-Japanese-Patent No. 2015-4861 is mentioned, for example, Among them, (perfluoroalkylsulfonyl)imilith lithium salt is preferable, and bis(trifluoro Lithium romethanesulfonylimide) is more preferable. The compounding quantity of an ionic compound can be set suitably according to the objective. For example, the blending amount of the ionic compound is preferably 10 parts by weight or less, more preferably 5 parts by weight or less, still more preferably 3 parts by weight or less, with respect to 100 parts by weight of the (meth)acrylic polymer (A), 1 part by weight or less is particularly preferred.

The pressure-sensitive adhesive composition may contain an additive. Specific examples of the additive include colorants, powders such as pigments, dyes, surfactants, plasticizers, tackifiers, surface lubricants, leveling agents, softeners, antioxidants, antioxidants, light stabilizers, ultraviolet absorbers, polymerization inhibitors, inorganic or organic of fillers, metal powders, particulates, and thin materials. In addition, within the controllable range, you may employ|adopt the redox system which added the reducing agent. The type, number, combination, content, and the like of the additives may be appropriately set according to the purpose. Preferably content of an additive is 5 weight part or less with respect to 100 weight part of (meth)acrylic-type polymer (A), More preferably, it is 3 weight part or less, More preferably, it is 1 weight part or less.

D. Image display device

The optical film provided with the pressure-sensitive adhesive layer according to the embodiment of the present invention can be suitably applied to an image display device as described above. Therefore, the image display apparatus containing the optical film provided with an adhesive layer is also included in embodiment of this invention. An image display apparatus contains an image display cell and the optical film provided with the adhesive layer bonded to the image display cell through the adhesive layer typically. As an image display apparatus, a liquid crystal display device, an organic electroluminescent (EL) display apparatus, and a quantum dot display apparatus are mentioned, for example. Preferably, it is an organic electroluminescent display. It is because the effect by the optical film provided with an adhesive layer is remarkable.

Example

Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited to these Examples. The evaluation items in the Examples are as follows. In addition, unless otherwise indicated, "part" and "%" in an Example are a weight basis.

(1) gel fraction

The pressure-sensitive adhesive used in Examples and Comparative Examples was cross-linked, immersed in ethyl acetate for 6 days, and then dried. The gel fraction (%) was calculated|required from the following formula.

Gel fraction (%) = (dry weight after immersion / dry weight before immersion) x 100

(2) degree of swelling

The pressure-sensitive adhesive used in Examples and Comparative Examples was crosslinked and immersed in ethyl acetate for 6 days. The swelling degree (%) was calculated|required from the following formula.

Swelling degree (times) = weight after immersion / dry weight after immersion

(3) Separator Peeling Force

The optical film (before the mold release process) provided with the adhesive layer used by the Example and the comparative example was cut out to the size of 50 mm x 150 mm, and it was set as the measurement sample. Using a tensile testing machine (autograph SHIMAZU AG-150N), the separator was peeled from the measurement sample at a tensile angle of 180° and a tensile rate of 300 mm/min, and the peeling force of the separator was measured.

(4) creep value

The optical film provided with the adhesive layer obtained by the Example and the comparative example was cut out to 10 mm x 30 mm size, and it was set as the test sample. 10 mm x 10 mm of the upper end of the test sample was adhered to the SUS plate through an adhesive layer, and autoclaved for 15 minutes under conditions of 50° C. and 5 atm. A precision hot plate installed so that the heating surface is in the vertical direction is heated to 85°C, and the SUS plate to which the optical film with the pressure-sensitive adhesive layer is attached is in contact with the heating surface of the hot plate. installed to do so. After heating the SUS plate at 85°C for 5 minutes, a load of 500 gf was applied vertically downward to the lower end of the polarizing film provided with the pressure-sensitive adhesive layer. The amount of shift|offset|difference of the optical film provided with the adhesive layer in 1 second and 3600 second after applying a load, and SUS board was measured, and it was set as Cr1 and _Cr3600 , _respectively . ΔCr obtained by the following formula from Cr ₁ and Cr ₃₆₀₀ was taken as the creep value.

ΔCr=Cr ₃₆₀₀ -Cr ₁

(5) Adhesive Missing Amount

Observing the state of the cross-section of the pressure-sensitive adhesive layer in the release processing portion of the optical film having the pressure-sensitive adhesive layer obtained in Examples and Comparative Examples with an optical microscope, the omission of the pressure-sensitive adhesive layer from the outer edge to the inside in the surface direction is maximized The length of the part was measured, and the said length was made into the amount of adhesive loss (micrometer).

(6) Durability

The optical film provided with the adhesive layer obtained by the Example and the comparative example was cut out to 300 mm x 220 mm size, and it was set as the test sample. At this time, it cut out so that the absorption axis of a polarizer might become a long side direction. This test sample was bonded to 350 mm x 250 mm x 0.7 mm thick alkali-free glass (the Corning company make, brand name "EG-XG") with a laminator. Then, the autoclave process was carried out for 15 minutes at 50 degreeC and 0.5 MPa, and the adhesive layer was adhered to glass. The test sample thus treated was subjected to a treatment for 500 hours under an atmosphere of 60°C/95% RH. The appearance of the test sample after treatment was visually evaluated based on the following criteria.

(circle): There is no change in appearance, such as foaming and peeling.

(triangle|delta): Although there is peeling or foaming at the edge part although slightly, there is no problem practically.

x: There is remarkable peeling at an edge part, and there exists a problem practically.

<Production Example 1: Preparation of acrylic polymer A1>

A monomer mixture containing 99 parts of butyl acrylate and 1 part of 4-hydroxybutyl acrylate was charged to a four-neck flask equipped with a stirring blade, a thermometer, a nitrogen gas introduction tube, and a cooler. Further, with respect to 100 parts of this monomer mixture, 0.1 parts of 2,2'-azobisisobutyronitrile as a polymerization initiator is added together with 100 parts of ethyl acetate, nitrogen gas is introduced with gentle stirring to replace nitrogen, and then the flask Polymerization reaction was performed for 8 hours by maintaining the liquid temperature inside 55 degreeC vicinity, and the solution of the acrylic polymer A1 of 1.8 million weight average molecular weights (Mw) and Mw/Mn =4.8 was prepared.

<Production Example 2: Preparation of acrylic polymer A2>

In the same manner as in Production Example 1, except that a monomer mixture containing 94.9 parts of butyl acrylate, 0.1 parts of 2-hydroxyethyl acrylate, and 5 parts of acrylic acid was used, a solution of acrylic polymer A2 having Mw 2.3 million and Mw/Mn = 3.9 was prepared. prepared.

<Production Example 3: Preparation of acrylic polymer (monomer partial polymer) A3>

65 parts of 2-ethylhexyl acrylate, 15 parts of N-vinylpyrrolidone, and 2-hydroxy A monomer mixture containing 20 parts of ethyl acrylate was introduced. In addition, 0.05 parts of Ominirad651 and Omnirad184 which are photoinitiators were each injected|thrown-in with respect to 100 parts of this monomer mixture. Next, while rotating the spindle, nitrogen gas is introduced to replace the inside of the flask with nitrogen, and then, photopolymerization is carried out by irradiating ultraviolet light until the viscosity of the polymerization system measured by a viscometer becomes about 15 Pa·s, and the monomer group An acrylic polymer A3 containing a partial polymer of In addition, the Toki Sangyo BH type|mold was used for the viscometer, and the rotation speed of the spindle (rotor No. 5) was 10 rpm. In addition, the liquid temperature in the flask was maintained at 30 degreeC.

<Production Example 4: Preparation of acrylic polymer A4>

Mw 2.7 million, Mw/ A solution of acrylic polymer A4 having Mn = 3.8 was prepared.

<Production Example 5: Preparation of acrylic polymer A5>

Except having set the polymerization time to 2 hours, it carried out similarly to manufacture example 1, and prepared the solution of the acrylic polymer A5 of Mw 154 only and Mw/Mn =2.8.

<Preparation Example 6: Preparation of acrylic oligomer B1>

A monomer mixture containing 95 parts of butyl acrylate, 2 parts of acrylic acid, and 3 parts of methyl acrylate was charged to a four-neck flask equipped with a stirring blade, a thermometer, a nitrogen gas introduction tube and a cooler. Further, with respect to 100 parts of this monomer mixture, 0.1 parts of 2,2'-azobisisobutyronitrile and 140 parts of toluene as polymerization initiators are added, nitrogen gas is introduced while gently stirring, nitrogen gas is sufficiently substituted, A polymerization reaction was performed for 8 hours while maintaining the liquid temperature at around 70°C to prepare a solution of acryl oligomer B1. The Mw of the oligomer was 4500.

<Production Example 7: Preparation of acrylic oligomer B2>

A monomer mixture containing 60 parts of dicyclofentanyl methacrylate and 40 parts of methyl methacrylate, 3.5 parts of α-thioglycerol as a chain transfer agent, and 100 parts of toluene as a polymerization solvent were mixed, and stirred at 70° C. under a nitrogen atmosphere for 1 hour. . Next, 0.2 part of AIBN was thrown in as a thermal polymerization initiator, and after making it react at 70 degreeC for 2 hours, it heated up to 80 degreeC and made it react for 2 hours. Then, the reaction liquid was heated to 130 degreeC, toluene, a chain transfer agent, and unreacted monomer were dried off, and (meth)acrylic-type oligomer B2 was obtained.

<Preparation Example 8: Preparation of a polarizing plate>

(Production of TAC film with HC)

In a resin solution (manufactured by DIC Corporation, trade name: Unidic 17-806, solid content concentration: 80%) in which an ultraviolet curable resin monomer or oligomer containing urethane acrylate as a main component is dissolved in butyl acetate, per 100 parts of solid content in the solution , 5 parts of a photoinitiator (manufactured by BASF Corporation, trade name: IRGACURE907) and 0.1 part of a leveling agent (manufactured by DIC Corporation, trade name: GRANDIC PC4100) were added. Cyclopentanone and propylene glycol monomethyl ether were added to the solution in a ratio of 45:55 so that the solid content concentration in the solution was 36% to prepare a material for forming a hard coat layer. This hard-coat layer forming material was apply|coated on the TAC film (made by Fuji Film, product name: TJ40UL, thickness: 40 micrometers) so that the thickness of the hard-coat layer after hardening might be set to 7 micrometers, and the coating film was formed. The coating film was dried at 90° C. for 1 minute, and ultraviolet rays of 300 mJ/cm ² of accumulated light were irradiated with a high-pressure mercury lamp to cure the coating film to form a hard coat layer, thereby producing a TAC film having HC. The saponification process was performed to the TAC film which has obtained HC.

(Production of polarizing plate)

The 45-micrometer-thick polyvinyl alcohol film was extended|stretched up to 3 times between rolls with different speed ratios, dyeing|staining for 1 minute in 30 degreeC and 0.3% density|concentration iodine solution. Then, the total draw ratio was extended|stretched to 6 times, immersing in the aqueous solution containing 60 degreeC, 4% concentration of boric acid, and 10% concentration of potassium iodide for 0.5 minute. Then, after washing|cleaning by making it immerse for 10 second in 30 degreeC and the aqueous solution containing 1.5% of density|concentration potassium iodide, it dried at 50 degreeC for 4 minutes and obtained the 18-micrometer-thick polarizer. A TAC film (KC4CT, Konica Minolta Co., Ltd.) having a thickness of 40 μm obtained by saponification treatment on one side of the polarizer and the TAC film having HC obtained above on the other side is bonded with a polyvinyl alcohol-based adhesive to each polarizing plate was produced.

<Example 1>

(Preparation of adhesive composition)

With respect to 100 parts of solution solid content of the acrylic polymer A1 obtained in Production Example 1, 30 parts of the acrylic oligomer B1 (solid content) obtained in Production Example 4, an isocyanate crosslinking agent (manufactured by Tosoh Corporation, trade name "Takenate D110N", trimethylolpropane/xylylenedi Isocyanate adduct) 0.02 parts, peroxide crosslinking agent (manufactured by Nippon Yushi, trade name "Niper BMT") 1 part, silane coupling agent (manufactured by Shin-Etsu Chemical Co., Ltd., trade name "KBM-403") 0.2 parts was prepared.

(Preparation of a polarizing plate provided with an adhesive layer)

The solution of the acrylic pressure-sensitive adhesive composition obtained above was placed on one side of a polyethylene terephthalate film (manufactured by Mitsubishi Chemical Polyester Film, trade name “MRF38”, separator film) treated with a silicone release agent, and the pressure-sensitive adhesive layer after drying had a thickness of 50 μm. It apply|coated so that it may become possible, and it dried at 155 degreeC for 1 minute, and formed the adhesive layer on the surface of a separator film. Next, the adhesive layer formed on the separator film was bonded to the TAC film (KC4CT) side of the polarizing plate produced in manufacture example 8, and the optical film (polarizing plate provided with an adhesive layer) provided with an adhesive layer was produced. The optical film provided with the obtained adhesive layer was mold-release-processed. In that case, mold release processing was carried out using the laminated body which laminated|stacked the surface protection film (made by Nitto Denko, brand name "PPF-100T") on the TAC film side which has HC of the obtained optical film with an adhesive layer as a to-be-processed object. More specifically, the stack is fixed with a clamp so that the stacking height is 10 mm, and a through hole is drilled from the surface protection film side using an end mill with a blade diameter of 2.0 mm, and the diameter of the hole part is 2.5 mm. (processed into a shape corresponding to the center of the lower end of FIG. 2). The number of revolutions of the blade at the time of cutting was 2500 rpm, and the feed rate was 50 mm/min. The pressure-sensitive adhesive layer used for the production of the optical film having the pressure-sensitive adhesive layer is provided for evaluation of (1) and (2), and the optical film provided with the pressure-sensitive adhesive layer before release processing is provided for the evaluation of (3) above, and the release process is performed. The polarizing plate provided with the processed adhesive layer was used for evaluation of 4 to 6 above. A result is shown in Table 1.

<Examples 2 to 6 and Examples 9 to 13>

Except having changed the composition of the adhesive composition which forms an adhesive layer, and the thickness of an adhesive layer as shown in Table 1, it carried out similarly to Example 1, and produced the optical film provided with the adhesive layer by which the mold release process was carried out. The polarizing plate provided with the adhesive layer used for preparation of the adhesive layer used for preparation of the optical film provided with an adhesive layer, the adhesive layer which has a separator, and the adhesive layer by which the release process was carried out was used for evaluation similar to Example 1. A result is shown in Table 1.

<Example 7>

Except having replaced the separator once before the mold release process, it carried out similarly to Example 6, and produced the optical film provided with the adhesive layer by which the mold release process was carried out. The polarizing plate provided with the adhesive layer used for preparation of the adhesive layer used for preparation of the optical film provided with an adhesive layer, the adhesive layer which has a separator, and the adhesive layer by which the release process was carried out was used for evaluation similar to Example 1. A result is shown in Table 1.

<Example 8>

Except having replaced the separator twice, it carried out similarly to Example 6, and produced the optical film provided with the adhesive layer by which the mold release process was carried out. The polarizing plate provided with the adhesive layer used for preparation of the adhesive layer used for preparation of the optical film provided with an adhesive layer, the adhesive layer which has a separator, and the adhesive layer by which the release process was carried out was used for evaluation similar to Example 1. A result is shown in Table 1.

<Examples 14 and 15>

(Preparation of adhesive composition)

With respect to 100 parts of the acrylic polymer (monomer partial polymer) A3 obtained in Production Example 3, 10 parts of (meth)acrylic oligomer B2 obtained in Production Example 7 was added as a crosslinking agent, and a polyfunctional monomer (manufactured by Shin-Nakamura Chemical Co., Ltd., trade name "A-"HD-N", 0.1 part of 1,6- hexanediol diacrylate), 0.2 part of silane coupling agent (the Shin-Etsu Chemical Co., Ltd. make, brand name "KBM-403") was mix|blended, and the mixture was prepared. Next, after applying the mixture to the surface of a PET film (thickness 38 μm), which is a base film (separator), another PET film is placed on the coating film of the mixture, and a coating film is formed between a pair of PET films. fitting was supported. Next, the coating film was cured by irradiating ultraviolet rays under irradiation conditions of an illuminance of 4 mW/cm ² and a light amount of 1200 mJ/cm ² to form pressure-sensitive adhesive layers (25 μm and 50 μm) having the thicknesses shown in Table 1. After the formation of the pressure-sensitive adhesive layer, another PET film was peeled off to expose the pressure-sensitive adhesive layer, and an optical film provided with a release-processed pressure-sensitive adhesive layer was prepared in the same manner as in Example 1. The polarizing plate provided with the adhesive layer used for preparation of the adhesive layer used for preparation of the optical film provided with the adhesive layer, the adhesive layer which has a separator, and the adhesive layer by which the release process was carried out was used for evaluation similar to Example 1. A result is shown in Table 1.

<Examples 16 to 19 and Comparative Example 1>

Except having changed the composition of the adhesive composition which forms an adhesive layer, and the thickness of an adhesive layer as shown in Table 1, it carried out similarly to Example 1, and produced the optical film provided with the adhesive layer by which the mold release process was carried out. The polarizing plate provided with the adhesive layer used for preparation of the adhesive layer used for preparation of the optical film provided with an adhesive layer, the adhesive layer which has a separator, and the adhesive layer by which the release process was carried out was used for evaluation similar to Example 1. A result is shown in Table 1.

<Example 20>

Except having replaced the separator once, it carried out similarly to Example 19, and produced the optical film provided with the adhesive layer by which the mold release process was carried out. The polarizing plate provided with the adhesive layer used for preparation of the adhesive layer used for preparation of the optical film provided with an adhesive layer, the adhesive layer which has a separator, and the adhesive layer by which the release process was carried out was used for evaluation similar to Example 1. A result is shown in Table 1.

<Example 21>

(Production of polarizing plate)

A long roll of 30 µm thick polyvinyl alcohol film (Kurare product name "PE3000") was uniaxially stretched in the longitudinal direction to 5.9 times in the longitudinal direction by a roll stretching machine, while swelling, dyeing, crosslinking, and washing treatment were performed at the same time. , and finally, a polarizer having a thickness of 12 μm was produced by performing a drying treatment.

Specifically, the swelling treatment was stretched 2.2 times while processing with 20°C pure water. Subsequently, in the dyeing treatment, the polarizing film to be produced was stretched 1.4 times while being treated in an aqueous solution at 30° C. in which the weight ratio of iodine to potassium iodide was 1:7 in which the iodine concentration was adjusted so that the transmittance of the polarizing film was 45.0%. In the crosslinking treatment, two steps of crosslinking treatment were employed, and the crosslinking treatment of the first step was elongated by 1.2 times while being treated in an aqueous solution in which boric acid and potassium iodide were dissolved at 40°C. The boric acid content of the aqueous solution of the crosslinking process of the 1st stage was 5.0 weight%, and potassium iodide content was 3.0 weight%. The crosslinking treatment in the second step was stretched 1.6 times while being treated in an aqueous solution in which boric acid and potassium iodide were dissolved at 65°C. The boric acid content of the aqueous solution of the crosslinking process of the 2nd stage was 4.3 weight%, and potassium iodide content was 5.0 weight%. In addition, the washing process was processed with the potassium iodide aqueous solution at 20 degreeC. Potassium iodide content of the aqueous solution of a washing process was 2.6 weight%. Finally, the drying process dried at 70 degreeC for 5 minutes, and obtained the polarizer.

On both surfaces of the obtained polarizer, a TAC film (product name: KC2UA thickness: 25 µm) manufactured by Konica Minolta Corporation through a polyvinyl alcohol-based adhesive, respectively, and an HC-TAC film having an HC layer on one side of the TAC film (thickness: 32 micrometers) was bonded and the polarizing plate 1 by which the protective film was bonded on both surfaces of the polarizer was obtained.

(Production of retardation layer A)

10 g of a polymerizable liquid crystal exhibiting a nematic liquid crystal phase (manufactured by BASF, product name “PaliocolorLC242”, expressed by the following formula), and a photopolymerization initiator for the polymerizable liquid crystal compound (manufactured by Chiba Specialty Chemicals, product name “Irgacure 907”) 3 g was dissolved in 40 g of toluene to prepare a liquid crystal composition (coating solution).

The surface of a polyethylene terephthalate (PET) film (38 micrometers in thickness) was rubbed using the rubbing cloth, and orientation treatment was performed. As for the conditions of orientation treatment, the number of times of rubbing (the number of rubbing rolls) was 1, the radius of the rubbing roll r was 76.89 mm, the number of rotations of the rubbing roll nr was 1500 rpm, and the film conveying speed v was 83 mm/sec.

The direction of orientation treatment was made so that it might become -75 degree direction as seen from the visual recognition side with respect to the direction of the absorption axis of a polarizer when sticking with a polarizing plate. The liquid crystal compound was orientated by applying the said coating liquid to this orientation-treated surface with a bar coater, and heating and drying at 90 degreeC for 2 minute(s). The liquid crystal layer thus formed was irradiated with light of 1 mJ/cm ² using a metal halide lamp to cure the liquid crystal layer, thereby forming a retardation layer A on the PET film. The thickness of the retardation layer A was 2 µm, and the in-plane retardation Re was 270 nm. Moreover, the retardation layer A had refractive index distribution of nx>ny=nz.

(Production of retardation layer B)

The surface of a polyethylene terephthalate (PET) film (thickness 38 micrometers) was rubbed using the rubbing cloth, and orientation treatment was performed. The direction of orientation treatment was made so that it might become a -15 degree direction as seen from the visual recognition side with respect to the direction of the absorption axis of a polarizer when sticking with a polarizing plate. The liquid crystal coating liquid similar to the above was coated on this orientation-processed surface, the liquid crystal was orientated and hardened similarly to the above, and the retardation layer B was formed on the PET film. The thickness of the retardation layer B was 1.2 μm, and the in-plane retardation Re was 140 nm. Moreover, the retardation layer B had the refractive index distribution of nx>ny=nz.

(Production of polarizing plate with retardation layer)

The TAC film surface of the polarizing plate and the retardation layer A were bonded to each other through an ultraviolet curable adhesive so that the angle between the absorption axis of the polarizing plate and the slow axis of the retardation layer A was 75°. Next, by bonding the retardation layer A and the retardation layer B through the same adhesive (thickness 5 μm) as in Example 16 so that the angle between the absorption axis of the polarizing plate and the slow axis of the retardation layer B is 15°, the retardation layer is provided A polarizing plate was obtained. Moreover, the adhesive layer similar to Examples 1-20 and Comparative Example 1 was formed on the outer side of the retardation layer B, respectively. The polarizing plate provided with the obtained retardation layer was carried out similarly to Example 1, the mold release process was carried out, and it used for evaluation similar to Example 1. As a result, even in a polarizing plate having a retardation layer, those using the adhesive layer corresponding to Examples 1 to 20 had good adhesive defects and durability, and those using the adhesive layer corresponding to Comparative Example 1 had large adhesive defects. Confirmed.

The abbreviations in Table 1 are as follows. In addition, the compounding quantity of each component in Table 1 is the number with respect to 100 parts of polymers.

BA: butyl acrylate

MMA: methyl methacrylate

MA: methyl acrylate

AA: acrylic acid

HBA: 4-hydroxybutyl acrylate

HEA: 2-hydroxyethyl acrylate

2EHA: 2-ethylhexyl acrylate

NVP: N-vinylpyrrolidone

DCPM: dicyclofentanyl methacrylate

ACMO: N-acryloylmorpholine

D110N: trimethylolpropane/xylylene diisocyanate adduct (manufactured by Tosoh Corporation, trade name “Takenate D110N”)

C/L: Trimethylolpropane/tolylene diisocyanate adduct (manufactured by Tosoh Corporation, trade name “Coronate L”)

Peroxide: Peroxide crosslinking agent (manufactured by Nippon Yushi, trade name "Nyper BMT")

A-HD-N: 1,6-hexaindiol diacrylate (manufactured by Shin-Nakamura Chemical, trade name "A-HD-N")

Si-cup agent: Epoxy group-containing silane coupling agent (manufactured by Shin-Etsu Chemical Co., Ltd., trade name "KBM-403")

Antioxidant: pentaerythritol tetrakis(3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate) (manufactured by BASF, trade name "Irganox1010")

<Evaluation>

As is clear from Table 1, according to the Example of the present invention, an optical film provided with an adhesive layer in which adhesive glitch was remarkably suppressed in a mold release part and peeling in a high-temperature, high-humidity environment was suppressed was actually obtained. In Comparative Example 1 with a large creep value of the pressure-sensitive adhesive layer, the amount of missing adhesive was large. Moreover, in the optical film provided with the adhesive layer which has a separator, when the peeling force of a separator was small, the amount of adhesive loss was large (for example, comparison of Examples 6 and 8, and a comparison of Examples 19 and 20).

The optical film having the pressure-sensitive adhesive layer of the present invention is suitably used for an image display device, and in particular, it is suitably used for an image display device having a mold release processing unit typified by an instrument panel of an automobile, a smartphone, a tablet-type PC or a smart watch. can

Claims (7)

It is an optical film provided with the adhesive layer which has an adhesive layer on one side of an optical film and the said optical film,
The optical film provided with this adhesive layer has a mold release other than a rectangle,
The creep value at 85 ° C. of the pressure-sensitive adhesive layer is 500 μm or less,
An optical film provided with an adhesive layer. According to claim 1,
The said creep value is 5 micrometers or more, The optical film provided with the adhesive layer. 3. The method of claim 1 or 2,
The thickness of the pressure-sensitive adhesive layer is 2㎛ to 20㎛, the optical film provided with the pressure-sensitive adhesive layer. 4. The method according to any one of claims 1 to 3,
A separator is temporarily attached to the side opposite to the optical film of the pressure-sensitive adhesive layer so as to be peelable;
The optical film provided with the adhesive layer whose peeling force of this separator is 0.04N/50mm - 0.5N/50mm. 5. The method according to any one of claims 1 to 4,
An optical film having a pressure-sensitive adhesive layer, wherein the optical film includes a polarizer. 6. The method of claim 5,
The optical film having a pressure-sensitive adhesive layer further comprising a retardation layer. The image display device containing the optical film provided with the adhesive layer in any one of Claims 1-6.

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