JP2018084836A - Polarization film, manufacturing method thereof, optical film, and image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polarization film capable of preventing occurrence of a heat shock crack, excellent in durability to separation at a drop test, and excellent in water proofness.SOLUTION: A polarization film includes transparent protective films (3a) and (3b) on both sides of a polarizer (1) via adhesive layers (2a) and (2b). The adhesive layer (2a) has glass-transition temperature of -60°C or more and less than 30°C, and includes a radical polymerizable compound as a curable component. If an entire amount of the radical polymerizable compound is 100 wt.%, ratio of a polyfunctional radical polymerizable compound (A) is over 5 wt.% and 50 wt.% or less. The adhesive layer (2b) on the other side has glass-transition temperature of 30°C or more.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a polarizing film in which a polarizer and a transparent protective film are formed of an active energy ray-curable adhesive composition and laminated via an adhesive layer, and a method for producing the same. The polarizing film can form an image display device such as a liquid crystal display device (LCD), an organic EL display device, a CRT, or a PDP alone or as an optical film obtained by laminating the polarizing film.

  Liquid crystal display devices are rapidly expanding in watches, mobile phones, PDAs, notebook computers, personal computer monitors, DVD players, TVs, and the like. The liquid crystal display device visualizes the polarization state by switching of the liquid crystal, and a polarizer is used from the display principle. In particular, in applications such as TV, higher brightness, higher contrast, and wider viewing angle are required, and polarizing films are also required to have higher transmittance, higher degree of polarization, and higher color reproducibility.

  As the polarizer, since it has a high transmittance and a high degree of polarization, for example, an iodine-based polarizer having a stretched structure by adsorbing iodine to polyvinyl alcohol (hereinafter also simply referred to as “PVA”) is most widely used. It is used. In general, a polarizing film is used in which a transparent protective film is bonded to both sides of a polarizer with a so-called aqueous adhesive in which a polyvinyl alcohol-based material is dissolved in water. As the transparent protective film, triacetyl cellulose having a high moisture permeability is used.

  When manufacturing a polarizing film, when a water-based adhesive such as a polyvinyl alcohol-based adhesive is used (so-called wet lamination), a drying step is required after the polarizer and the transparent protective film are bonded together. . In recent years, in order to improve productivity, a polarizing film using an active energy ray-curable adhesive that does not require a drying step instead of an aqueous adhesive has been proposed (Patent Documents 1 to 4).

  In Patent Documents 1 to 3, a polarizing film using an adhesive layer designed so that Tg (glass transition temperature) is 60 ° C. or more is proposed, and the polarizing film using the adhesive layer is heated. This is effective for preventing cracks in the polarizer during the freeze cycle test (heat shock cycle test). On the other hand, Patent Document 4 proposes a polarizing film using an adhesive layer having a Tg of −80 ° C. to 0 ° C., and the polarizing film has an adhesive force between a polarizer and a specific protective film. It is described that the punching workability is good.

JP 2008-287207 A JP 2012-068593 A JP 2012-144690 A JP 2010-282161 A

  However, in the polarizing films described in Patent Documents 1 to 3, since the adhesive layer has a high Tg, peeling occurs in a drop test in which an impact is applied, so that the durability is not sufficient. In addition, the active energy ray-curable adhesive forming the adhesive layer uses a hydrophilic monomer such as hydroxyethyl acrylamide or acryloyl morpholine for most of the adhesive composition in order to ensure adhesion to the polarizer. In many cases, the water resistance was not sufficient. In Patent Document 4, since the adhesive layer has a low Tg, when the low Tg adhesive layer is used for a polarizer and a transparent protective film on both sides, a heating and freezing cycle test (heat shock cycle test). ) There was a problem that the crack of the polarizer occurred.

  An object of this invention is to provide the polarizing film which can prevent generation | occurrence | production of a heat shock crack, has the durability with respect to peeling in a drop test, and has favorable water resistance, and its manufacturing method.

  Furthermore, an object of the present invention is to provide an optical film using the polarizing film, and further an image display device using the polarizing film or the optical film.

  The present inventors have intensively studied to solve the above problems and found that the above problems can be solved by the following polarizing film, etc., and have completed the present invention.

That is, the present invention relates to the adhesive layer (2a) and (2b) formed by a cured layer formed by irradiating the active energy ray-curable adhesive composition with active energy rays on both sides of the polarizer (1). In the polarizing film provided with transparent protective films (3a) and (3b) on the respective surfaces,
The single-sided adhesive layer (2a) has a glass transition temperature of −60 ° C. to less than 30 ° C.,
And the active energy ray-curable adhesive composition forming the adhesive layer (2a) contains a radical polymerizable compound as a curable component, and when the total amount of the radical polymerizable compound is 100% by weight, The ratio of the polyfunctional radically polymerizable compound (A) is more than 5% by weight and 50% by weight or less,
The adhesive layer (2b) on the other side relates to a polarizing film having a glass transition temperature of 30 ° C. or higher.

  In the polarizing film, the radical polymerizable compound preferably contains an alkyl (meth) acrylate (B) having an alkyl group having 2 to 18 carbon atoms.

  In the polarizing film, the radical polymerizable compound preferably contains (meth) acrylate (C) having a hydroxyl group.

  In the polarizing film, the active energy ray-curable adhesive composition forming the adhesive layer (2a) preferably contains a silane coupling agent (D). The silane coupling agent (D) is preferably a silane coupling agent that does not have a radical polymerizable functional group.

  In the polarizing film, the active energy ray-curable adhesive composition forming the adhesive layer (2a) preferably contains an acrylic oligomer (E) formed by polymerizing a (meth) acrylic monomer.

  In the polarizing film, the active energy ray-curable adhesive composition forming the adhesive layer (2a) comprises a radical polymerizable compound (F) having an active methylene group and a radical polymerization initiator ( G) is preferably contained.

  The active methylene group of the radical polymerizable compound (F) is preferably an acetoacetyl group. The radically polymerizable compound (F) having an active methylene group is preferably acetoacetoxyalkyl (meth) acrylate. The radical polymerization initiator (G) is preferably a thioxanthone radical polymerization initiator.

  The radical polymerizable compound (F) having the active methylene group when the total amount of the radical polymerizable compound in the active energy ray-curable adhesive composition forming the adhesive layer (2a) is 100% by weight. 1 to 50 wt%, and 0.1 to 10 parts by weight of the radical polymerization initiator (G) with respect to 100 parts by weight of the total amount of the radical polymerizable compound in the active energy ray-curable adhesive composition. It is preferable.

In the polarizing film, the active energy ray-curable adhesive composition that forms the adhesive layer (2a) preferably contains a photoacid generator (H). The photoacid generator (H) preferably contains a photoacid generator having at least one selected from the group consisting of PF ₆ ⁻ , SbF ₆ ^— and AsF ₆ ^— as a counter anion.

  In the polarizing film, the active energy ray-curable adhesive composition forming the adhesive layer (2a) comprises the compound (I) containing any one of the photoacid generator (H), an alkoxy group, and an epoxy group. It is preferable to use together.

  In the polarizing film, the adhesive layers (2a) and (2b) preferably both have a thickness of 5 μm or less.

In the polarizing film, it is preferable moisture permeability of the transparent protective film (3a) and (3b) are both less 150g ^/ m 2 ^/ 24h.

  In the polarizing film, the transparent protective film (3a) is preferably a cyclic polyolefin resin film or a fluorinated polystyrene film. Moreover, it is preferable that the said transparent protective film (3b) is an acrylic resin film, a cyclic polyolefin resin film, or a polyester resin film.

  In the polarizing film, it is preferable that at least one of the transparent protective films (3a) and (3b) has a light transmittance of less than 5% at a wavelength of 365 nm.

Further, the present invention is a method for producing the polarizing film described above,
A coating step of coating the active energy ray-curable adhesive composition on at least one surface of the polarizer (1) and the transparent protective film (3a);
A coating step of coating the active energy ray-curable adhesive composition on at least one surface of the polarizer (1) and the transparent protective film (3b);
A bonding step of bonding the polarizer (1) and the transparent protective films (3a) and (3b);
Through the adhesive layers (2a) and (2b) obtained by irradiating the active energy rays and curing the active energy ray-curable adhesive composition, the polarizer (1) and the transparent The manufacturing method of a polarizing film characterized by including the adhesion process which adheres protective films (3a) and (3b).

  In the manufacturing method of the polarizing film, before the coating step, a corona is applied to at least one surface of the polarizer (1) and the transparent protective films (3a) and (3b) on the surface to be bonded. It is preferable to perform treatment, plasma treatment, excimer treatment or flame treatment.

  In the manufacturing method of the polarizing film, first, an active energy ray is irradiated from the side of one transparent protective film (3a) or (3b), and then activated from the side of the other transparent protective film (3b) or (3a). Through the adhesive layers (2a) and (2b) obtained by irradiating energy rays and curing the active energy ray-curable adhesive composition, the polarizer (1) and the transparent protective film It is preferable to include an adhesion step of adhering (3a) and (3b).

In the method for producing the polarizing film, the transparent protective films (3a) and (3b) both have a light transmittance of a wavelength of 365 nm of less than 5%,
The active energy ray preferably includes visible light having a wavelength range of 380 to 450 nm.

  In the manufacturing method of the polarizing film, the active energy ray preferably has a ratio of an integrated illuminance in a wavelength range of 380 to 440 nm and an integrated illuminance in a wavelength range of 250 to 370 nm of 100: 0 to 100: 50.

  In the manufacturing method of the said polarizing film, it is preferable that the moisture content of the said polarizer at the time of the said bonding process is less than 15%.

The present invention provides the polarizing film described above,
Curing formed by irradiating an active energy ray-curable adhesive composition with an active energy ray on either one of the transparent protective film (3a) and the transparent protective film (3b). Laminated through an adhesive layer (2a ′) formed by a physical layer,
The adhesive layer (2a ′) has a glass transition temperature of −60 ° C. to less than 30 ° C.,
And the active energy ray hardening-type adhesive composition which forms the said adhesive bond layer (2a ') contains the radically polymerizable compound as a sclerosing | hardenable component, and when the whole quantity of a radically polymerizable compound is 100 weight%. , The ratio of the polyfunctional radically polymerizable compound (A) can be used as a polarizing film having more than 5% by weight and 50% by weight or less.

The present invention provides the polarizing film described above,
The transparent protective film (3a) provided on one side of the polarizer (1) via the adhesive layer (2a),
It can be used as a polarizing film laminated on a transparent protective film (3c) provided on one side of the polarizer (1) via an adhesive layer (2b) having a glass transition temperature of 30 ° C. or higher. .

  The present invention also relates to an optical film, wherein at least one polarizing film is laminated.

  Moreover, this invention relates to the image display apparatus characterized by using the polarizing film of the said description, or the said optical film.

Moreover, this invention is an active energy ray hardening-type adhesive composition used for formation of the hardened | cured material layer which concerns on the adhesive bond layer (2a) of the said polarizing film,
The active energy ray-curable adhesive composition has a glass transition temperature of −60 ° C. to less than 30 ° C. when the adhesive layer (2a) is formed,
And the said active energy ray hardening-type adhesive composition contains the radically polymerizable compound as a sclerosing | hardenable component, and when the total amount of a radically polymerizable compound is 100 weight%, a polyfunctional radically polymerizable compound (A) The active energy ray-curable adhesive composition is characterized in that the ratio is more than 5% by weight and 50% by weight or less.

  In the polarizing film of the present invention, a transparent protective film is provided on both sides of the polarizer (1) via an adhesive layer formed from an active energy ray-curable adhesive composition. A low Tg adhesive layer (2a) having a glass transition temperature (hereinafter also referred to as Tg) of −60 ° C. to less than 30 ° C. by the active energy ray-curable adhesive composition containing the polyfunctional radical polymerizable compound (A). The transparent protective film (3b) is provided through the adhesive layer (2b) with a high Tg having a glass transition temperature of 60 ° C. or higher on the other side. Is provided. The high Tg adhesive layer (2b) can prevent the occurrence of heat shock cracks between the polarizer (1) and the transparent protective films (3a) and (3b), and the low Tg adhesive layer (2a). ), The durability and water resistance against peeling in the drop test are good, the above is good, and the water resistance is good. Thus, in the polarizing film of this invention, generation | occurrence | production of a heat shock crack can be prevented by providing the adhesive bond layers (2a) and (2b) of different glass transition temperatures on both sides of a polarizer (1). And a polarizing film having good durability against peeling in the drop test and good water resistance.

It is sectional drawing which shows one Embodiment of the polarizing film of this invention. It is sectional drawing which shows one Embodiment of the polarizing film of this invention. It is sectional drawing which shows one Embodiment of the polarizing film of this invention. It is sectional drawing which shows one Embodiment of the polarizing film of this invention.

  Embodiments of the polarizing film of the present invention will be described below with reference to the drawings.

  1 to 4 are sectional views showing an embodiment of the polarizing film of the present invention. The polarizing film shown in FIG. 1 is provided with a transparent protective film (3a) on one side of a polarizer (1) via an adhesive layer (2a), and an adhesive on the other side of the polarizer (1). The transparent protective film (3b) is provided through the layer (2b). The adhesive layers (2a) and (2b) are both formed by a cured product layer formed by irradiating an active energy ray-curable adhesive composition with active energy rays.

  The adhesive layer (2a) has a glass transition temperature of −60 ° C. to less than 30 ° C., and the active energy ray-curable adhesive composition forming the adhesive layer (2a) is a curable component. As a radically polymerizable compound. The adhesive layer (2a) has good durability against peeling in the drop test and good water resistance. The glass transition temperature of the adhesive layer (2a) is preferably -40 ° C to 0 ° C, more preferably -30 ° C to -5 ° C, particularly preferably -30 ° C to -10 ° C. The durability against peeling in the drop test is good and the water resistance is good.

  The adhesive layer (2b) has a glass transition temperature of 30 ° C. or higher, and the polarizer (1) and the transparent protective film (3b) are firmly bonded via the adhesive layer (2b). Durability is good and the occurrence of heat shock cracks can be prevented. “Heat shock crack” means, for example, a phenomenon in which when the polarizer contracts, it tears in the stretching direction. To prevent this, the polarizer expands in the heat shock temperature range (−40 ° C. to 60 ° C.). -It is important to suppress shrinkage. The adhesive layer (2b) suppresses a sudden change in elastic modulus of the adhesive layer in the heat shock temperature range, and can reduce the expansion / contraction force acting on the polarizer. Can be prevented. The adhesive layer (2b) is selected so that the glass transition temperature is 30 ° C. or higher, preferably 60 ° C. or higher, more preferably 70 ° C. or higher, and more preferably 80 ° C. or higher. preferable. On the other hand, if the glass transition temperature of the adhesive layer (2b) becomes too high, the flexibility of the polarizing plate is lowered. Therefore, the glass transition temperature of the adhesive layer (2b) is 300 ° C. or lower, further 240 ° C. or lower, Is preferably 180 ° C. or lower. Moreover, the glass transition temperature of the said adhesive bond layer (2a) and the glass transition temperature of the said adhesive bond layer (2b) are the point of the effect of this invention so that the difference of these glass transition temperatures may be 60 degreeC or more. preferable.

  In the polarizing film of the present invention, a transparent protective film (3a) is provided on one side of the polarizer (1) via an adhesive layer (2a), and an adhesive layer is provided on the other side of the polarizer (1). If the transparent protective film (3b) is provided via (2b), the transparent protective film (3a) and the transparent protective film (3b) may be further transparently protected via an adhesive layer on either side. A film (3c) may be provided. In FIG. 2, a transparent protective film (3c) is further provided on the transparent protective film (3a) side of the polarizing film of FIG. 1, and in FIG. 3, the transparent protective film (3b) of the polarizing film of FIG. A transparent protective film (3c) is further provided on the side. As an adhesive layer used for lamination of the transparent protective film (3c), an adhesive layer (2a ′) formed by a cured product layer formed by irradiating an active energy ray-curable adhesive composition with active energy rays. Is preferred. The adhesive layer (2a ') can be the same as the adhesive layer (2a). As the transparent protective film (3c), a film similar to the transparent protective film (3a) or the transparent protective film (3b) can be used. In FIG. 2 and FIG. 3, one transparent protective film (3c) is provided via the adhesive layer (2a ′), but the transparent protective film (3a) and the transparent protective film of the polarizing film of the present invention are provided. On one side of the film (3b), for example, two or more transparent protective films (3c) can be laminated by combining the adhesive layer (2a ′) and the transparent protective film (3c).

FIG. 4 shows the polarizing film of FIG. 1, in which a transparent protective film (3c) is provided on one side of the polarizer (1) via an adhesive layer (2b). ) Is provided with a transparent protective film (3a) through an adhesive layer (2a). That is, in the polarizing film of the present invention, the transparent protective film (3a) is provided on one side of the polarizer (1) via the adhesive layer (2a), and is bonded to the other side of the polarizer (1). If the transparent protective film (3b) is provided via the agent layer (2b), the transparent protective film (3b) may not be provided directly to the polarizer (1) via the adhesive layer (2a). Good. FIG. 4 illustrates the case where the transparent protective film (3c) is provided on the polarizer via the adhesive layer (2b), but another adhesive is used instead of the adhesive layer (2b). A transparent protective film (3c) can also be provided using a layer.

<Adhesive layer (2a)>
The adhesive layer (2a) is a cured product layer formed by irradiating an active energy ray-curable adhesive composition containing a radical polymerizable compound as a curable component with active energy rays. The active energy ray-curable adhesive composition contains the polyfunctional radical polymerizable compound (A) in a proportion of more than 5 wt% and not more than 50 wt% when the total amount of the radical polymerizable compound is 100 wt%. To do. The said active energy ray hardening-type adhesive composition can contain another radically polymerizable compound in the range in which an adhesive bond layer (2a) becomes -60 degreeC-less than 30 degreeC in glass transition temperature.

<Polyfunctional radically polymerizable compound (A)>
The polyfunctional radically polymerizable compound (A) is a compound having at least two radically polymerizable functional groups having an unsaturated double bond such as a (meth) acryloyl group or a vinyl group. Examples of the polyfunctional radical polymerizable compound (A) include tetraethylene glycol diacrylate (Tg of homopolymer: 50 ° C., hereinafter referred to as only Tg), polyethylene glycol diacrylate, neopentyl glycol diacrylate (Tg). : 117 ° C), 3-methyl-1,5-pentanediol diacrylate (Tg: 105 ° C), 1,6-hexanediol diacrylate (Tg: 63 ° C), 1,9-nonanediol diacrylate (Tg: 68 ° C), 2-methyl-1,8-octanediol diacrylate and 1,9-nonanediol diacrylate mixture (Tg: 88 ° C), dimethylol-tricyclodecane diacrylate (Tg: 75 ° C), bisphenol A EO adduct diacrylate (Tg: 75 ° C), bisphenol EO-modified (n = 2) diacrylate (Tg: 75 ° C.), bisphenol A EO-modified (n = 2) diacrylate (Tg: 75 ° C.), isocyanuric acid EO-modified diacrylate (Tg: 166 ° C.), polypropylene glycol di Acrylate (n = 3, Tg 69 ° C.), (n = 7, Tg: −8 ° C.), (n = 12, Tg: −32 ° C.), trimethylolpropane triacrylate (Tg: 250 ° C. or higher), trimethylolpropane PO-modified triacrylate (n = 1, Tg: 120 ° C.), (n = 2, Tg: 50 ° C.), trimethylolpropane EO-modified triacrylate (n = 1, Tg unmeasured), (n = 2, Tg: 53 ° C.), isocyanuric acid EO-modified di- and triacrylate (di: 30-40%, Tg: 250 ° C. or higher), (di: 3-13%, Tg: 250) ° C or higher), pentaerythritol tri- and tetraacrylate (tri: 65-70%, Tg: 250 ° C or higher), (tri: 55-63%, Tg: 250 ° C or higher), (tri: 40-60%, Tg: 250 ° C. or higher), (tri: 25-40%, Tg: 250 ° C. or higher), (tri: less than 10%, Tg: 250 ° C. or higher), ditrimethylolpropane tetraacrylate (Tg: 250 ° C. or higher), dipentaerythritol Penta and hexaacrylate (penta: 50-60%, Tg: 250 ° C. or higher), (penta: 40-50%, Tg: 250 ° C. or higher), (penta: 30-40%, Tg: 250 ° C. or higher), ( Penta: 25-35%, Tg: 250 ° C. or higher), (Penta: 10-20%, Tg: 250 ° C. or higher), other urethane acrylates and polyester resins Relate and the like. In addition, as a radically polymerizable compound (A), a commercial item can also be used suitably, for example, light acrylate 4EG-A, light acrylate NP-A, light acrylate MPD-A, light acrylate 1.6HX-A, acrylate 1 .9ND-A, light acrylate MOD-A, light acrylate DCP-A, light acrylate BP-4EAL or more (manufactured by Kyoeisha Chemical Co., Ltd.), Aronix M-208, M-211B, M-215, M-220, M-225 , M-270, M-240, M-309, M-310, M-321, M-350, M-360, M-313, M-315, M-306, M-305, M-303, M -452, M-450, M-408, M-403, M-400, M-402, M-404, M-406, M-405 -1100, M-1200, M-6100, M-6200, M-6250, M-6500, M-7100, M-7300, M-8030, M-8060, M-8100, M-8530, M-8560 , M-9050 (manufactured by Toagosei Co., Ltd.), SR-531 (manufactured by SARTOMER), CD-536 (manufactured by SARTOMER), and the like. The polyfunctional radically polymerizable compound (A) preferably has a homopolymer Tg satisfying −40 to 100 ° C.

  The ratio of the polyfunctional radically polymerizable compound (A) is more than 5% by weight and 50% by weight or less when the total amount of the radically polymerizable compound in the active energy ray-curable adhesive composition is 100% by weight. When the ratio is 5% by weight or less, even if the adhesive layer (2a) satisfies the glass transition temperature of −60 ° C. to 30 ° C., the adhesive layer (2a) satisfies the durability against peeling and the water resistance in the drop test. The ratio is preferably 10 to 50% by weight, more preferably 20 to 40% by weight.

<Alkyl (meth) acrylate (B) having an alkyl group having 2 to 18 carbon atoms>
The active energy ray-curable adhesive composition used for forming the adhesive layer (2a) contains an alkyl (meth) acrylate (B) having an alkyl group having 2 to 18 carbon atoms as a radical polymerizable compound. Can do. Examples of the alkyl (meth) acrylate (B) include linear or branched alkyl groups having 1 to 18 carbon atoms. For example, as the alkyl group, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, amyl group, hexyl group, cyclohexyl group, heptyl group, 2-ethylhexyl group, isooctyl group, nonyl group Decyl group, isodecyl group, dodecyl group, isomyristyl group, lauryl group, tridecyl group, pentadecyl group, hexadecyl group, heptadecyl group, stearyl group, isostearyl group and the like. These can be used alone or in combination. The alkyl (meth) acrylate (B) preferably has 3 to 18 carbon atoms in the alkyl group. The alkyl (meth) acrylate (B) preferably has a Tg of homopolymer satisfying −80 to 60 ° C. from the viewpoint of durability against peeling in a drop test and water resistance. For example, methyl acrylate (Tg: 8 ° C), ethyl acrylate (Tg: -20 ° C), n-propyl acrylate (Tg: 8 ° C), n-butyl acrylate (Tg: -45 ° C), isobutyl acrylate (Tg:- 26 ° C.), t-butyl acrylate (Tg: 14 ° C.), isoamyl acrylate (Tg: −45 ° C.), cyclohexyl acrylate (Tg: 8 ° C.), 2-ethylhexyl acrylate (Tg: −55 ° C.), n-octyl acrylate (Tg: -65 ° C), isooctyl acrylate (Tg: -58 ° C), isononyl acrylate (Tg: -58 ° C), lauryl acrylate (Tg: 15 ° C), stearyl acrylate (Tg: 30 ° C), isostearyl Use alkyl acrylate such as acrylate (Tg: -18 ° C). It is preferred.

  The ratio of the alkyl (meth) acrylate (B) is a viewpoint of durability and water resistance in the drop test when the total amount of the radical polymerizable compound in the active energy ray-curable adhesive composition is 100% by weight. To 60% by weight or less. The ratio is preferably 10 to 50% by weight, more preferably 20 to 40% by weight.

<(Meth) acrylate having hydroxyl group (C)>
The active energy ray-curable adhesive composition used for forming the adhesive layer (2a) can contain (meth) acrylate (C) having a hydroxyl group as a radical polymerizable compound. As the (meth) acrylate (C) having a hydroxyl group, those having a (meth) acryloyl group and a hydroxyl group can be used. Specific examples of the (meth) acrylate (C) having a hydroxyl group include, 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, 12-hydroxylauryl (meth) acrylate, and (4-hydroxymethylcyclohexyl) -methyl acrylate Etc. The (meth) acrylate (C) having a hydroxyl group preferably has a homopolymer Tg satisfying −80 to 40 ° C. from the viewpoint of durability against peeling in a drop test. For example, it is preferable to use hydroxyethyl acrylate (Tg: −15 ° C.), hydroxypropyl acrylate (Tg: −7 ° C.), hydroxybutyl acrylate (Tg: −32 ° C.), or the like.

  The proportion of the hydroxyl group-containing (meth) acrylate (C) is defined as the durability against water cracking and water resistance in a drop test when the total amount of radically polymerizable compounds in the active energy ray-curable adhesive composition is 100% by weight. In view of the above, it is preferably used at a ratio of 60% by weight or less. The ratio is preferably 10 to 50% by weight, more preferably 20 to 40% by weight.

<Other radical polymerizable compounds>
The active energy ray-curable adhesive composition used for forming the adhesive layer (2a) can contain other radical polymerizable compounds other than the above as the radical polymerizable compound. As other radically polymerizable compounds, those having a polar group are preferable from the viewpoint of improving the adhesiveness, durability and water resistance of the adhesive layer in a more balanced manner. Examples of other radical polymerizable compounds include hydroxyethyl acrylamide, N-methylol acrylamide, acryloyl morpholine, N-methoxymethyl acrylamide, N-ethoxymethyl acrylamide, N-vinyl caprolactam, and the like. Other radically polymerizable compounds are preferably those in which the Tg of the homopolymer satisfies −40 to 150 ° C. from the viewpoint of durability.

  The ratio of the other radical polymerizable compound is from the viewpoint of adhesiveness, durability and water resistance of the adhesive layer when the total amount of the radical polymerizable compound in the active energy ray-curable adhesive composition is 100% by weight. It is preferably used at a ratio of 30% by weight or less. The proportion is preferably 2 to 25% by weight, more preferably 5 to 20% by weight.

<Silane coupling agent (D) having no polymerization group>
The active energy ray-curable adhesive composition used for forming the adhesive layer (2a) can contain a silane coupling agent (D) in addition to the radical polymerizable compound. As the silane coupling agent (D), a silane coupling agent having no radical polymerizable functional group is preferable (the silane coupling agent having no radical polymerizable functional group acts on the polarizer surface, and further Water resistance can be imparted.

  Specific examples of the silane coupling agent having no radical polymerizable functional group include a silane coupling agent having an amino group. Specific examples of the silane coupling agent having an amino group include γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropyltriisopropoxysilane, γ-aminopropylmethyldimethoxysilane, and γ-amino. Propylmethyldiethoxysilane, γ- (2-aminoethyl) aminopropyltrimethoxysilane, γ- (2-aminoethyl) aminopropylmethyldimethoxysilane, γ- (2-aminoethyl) aminopropyltriethoxysilane, γ- (2-aminoethyl) aminopropylmethyldiethoxysilane, γ- (2-aminoethyl) aminopropyltriisopropoxysilane, γ- (2- (2-aminoethyl) aminoethyl) aminopropyltrimethoxysilane, γ- (6-Aminohexyl) aminop Pyrtrimethoxysilane, 3- (N-ethylamino) -2-methylpropyltrimethoxysilane, γ-ureidopropyltrimethoxysilane, γ-ureidopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, N-benzyl-γ-aminopropyltrimethoxysilane, N-vinylbenzyl-γ-aminopropyltriethoxysilane, N-cyclohexylaminomethyltriethoxysilane, N-cyclohexylaminomethyldiethoxymethylsilane, N-phenylaminomethyltri Amino group-containing silanes such as methoxysilane, (2-aminoethyl) aminomethyltrimethoxysilane, N, N′-bis [3- (trimethoxysilyl) propyl] ethylenediamine; N- (1,3-dimethylbutylidene ) -3- (G Can be exemplified triethoxysilyl) -1-propane ketimines type silanes such as amines.

  Examples of the silane coupling agent having an amino group include γ-aminopropyltrimethoxysilane, γ- (2-aminoethyl) aminopropyltrimethoxysilane, γ- (2-aminoethyl) aminopropylmethyldimethoxysilane, γ- ( 2-aminoethyl) aminopropyltriethoxysilane, γ- (2-aminoethyl) aminopropylmethyldiethoxysilane, N- (1,3-dimethylbutylidene) -3- (triethoxysilyl) -1-propanamine Is preferred.

  Specific examples of the silane coupling agent having no radical polymerizable functional group other than the silane coupling agent having an amino group include 3-chloropropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, and 3-mercaptopropyl. Examples include trimethoxysilane, bis (triethoxysilylpropyl) tetrasulfide, 3-isocyanatopropyltriethoxysilane, and imidazolesilane.

  As the silane coupling agent (D), active energy ray curable compounds such as vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, 2- (3,4 epoxycyclohexyl) ethyltrimethoxysilane, 3- Glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyl Examples include trimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, and 3-acryloxypropyltrimethoxysilane.

  A silane coupling agent (D) may use only 1 type and may use it in combination of multiple types. The compounding amount of the silane coupling agent (D) having no radical polymerizable functional group is usually 20 parts by weight with respect to 100 parts by weight of the total amount of the radical polymerizable compound in the active energy ray-curable adhesive composition. The range is 0.01 to 20 parts by weight, preferably 0.05 to 15 parts by weight, and more preferably 0.1 to 10 parts by weight. In the case of a blending amount exceeding 20 parts by weight, the storage stability of the adhesive may be deteriorated.

<Acrylic oligomer (E) formed by polymerizing (meth) acrylic monomer>
The active energy ray-curable adhesive composition used for forming the adhesive layer (2a) contains, in addition to the radical polymerizable compound, an acrylic oligomer (E) obtained by polymerizing a (meth) acrylic monomer. Can do. By containing the acrylic oligomer (E) in the active energy ray-curable adhesive composition, curing shrinkage when the active energy ray is irradiated and cured on the composition is reduced, and an adhesive, a polarizer, Interfacial stress with an adherend such as a transparent protective film can be reduced. As a result, it is possible to suppress a decrease in adhesiveness between the adhesive layer and the adherend.

The active energy ray-curable adhesive composition preferably has a low viscosity in consideration of workability and uniformity during coating. Therefore, an acrylic oligomer (E) obtained by polymerizing a (meth) acrylic monomer. It is also preferable that the viscosity is low. The acrylic oligomer having a low viscosity and capable of preventing curing shrinkage of the adhesive layer preferably has a weight average molecular weight (Mw) of 15000 or less, more preferably 10,000 or less, and particularly preferably 5000 or less. preferable. On the other hand, in order to sufficiently suppress the curing shrinkage of the cured product layer (adhesive layer), the weight average molecular weight (Mw) of the acrylic oligomer (E) is preferably 500 or more, and more preferably 1000 or more. More preferably, it is particularly preferably 1500 or more. Specific examples of the (meth) acrylic monomer constituting the acrylic oligomer (E) include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, and 2 -Methyl-2
-Nitropropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, S-butyl (meth) acrylate, t-butyl (meth) acrylate, n-pentyl (meth) acrylate, t-pentyl ( (Meth) acrylate, 3-pentyl (meth) acrylate, 2,2-dimethylbutyl (meth) acrylate, n-hexyl (meth) acrylate, cetyl (meth) acrylate, n-octyl (meth) acrylate, 2-ethylhexyl (meth) ) Acrylate, 4-methyl-2-propylpentyl (meth) acrylate, N-octadecyl (meth) acrylate and other (meth) acrylic acid (1-20 carbon atoms) alkyl esters, and for example, cycloalkyl (meth) Acrylates (eg cyclo Xyl (meth) acrylate, cyclopentyl (meth) acrylate, etc.), aralkyl (meth) acrylate (eg, benzyl (meth) acrylate, etc.), polycyclic (meth) acrylate (eg, 2-isobornyl (meth) acrylate, 2- Norbornylmethyl (meth) acrylate, 5-norbornen-2-yl-methyl (meth) acrylate, 3-methyl-2-norbornylmethyl (meth) acrylate, etc.), hydroxyl group-containing (meth) acrylic esters (For example, hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2,3-dihydroxypropylmethyl-butyl (meth) methacrylate, etc.), alkoxy group or phenoxy group-containing (meth) acrylic acid esters (2 -Met Siethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 2-methoxymethoxyethyl (meth) acrylate, 3-methoxybutyl (meth) acrylate, ethyl carbitol (meth) acrylate, phenoxyethyl (meth) acrylate, etc.) , Epoxy group-containing (meth) acrylic acid esters (for example, glycidyl (meth) acrylate), halogen-containing (meth) acrylic acid esters (for example, 2,2,2-trifluoroethyl (meth) acrylate, 2, 2,2-trifluoroethylethyl (meth) acrylate, tetrafluoropropyl (meth) acrylate, hexafluoropropyl (meth) acrylate, octafluoropentyl (meth) acrylate, heptadecafluorodecyl (meth) acrylate And alkylaminoalkyl (meth) acrylate (for example, dimethylaminoethyl (meth) acrylate) and the like. These (meth) acrylates can be used alone or in combination of two or more. Specific examples of the acrylic oligomer (E) include “ARUFON” manufactured by Toagosei Co., Ltd., “Act Flow” manufactured by Soken Chemical Co., Ltd., “JONCRYL” manufactured by BASF Japan.

  The blending amount of the acrylic oligomer (E) is usually 20 parts by weight or less with respect to 100 parts by weight of the total amount of the radical polymerizable compound in the active energy ray-curable adhesive composition, and the acrylic system in the composition When there is too much content of an oligomer (E), the fall of the reaction rate at the time of irradiating this composition with an active energy ray is severe, and it may become a hardening defect. The content of the acrylic oligomer (E) in the composition is more preferably 15 parts by weight or less. On the other hand, in order to sufficiently suppress the curing shrinkage of the cured product layer (adhesive layer 2a), the composition preferably contains 3 parts by weight or more of the acrylic oligomer (E) and contains 5 parts by weight or more. It is more preferable.

<Radically polymerizable compound (F) having an active methylene group and radical polymerization initiator (G) having a hydrogen abstracting action>
The active energy ray-curable adhesive composition used for forming the adhesive layer (2a) further includes a radical polymerizable compound (F) having an active methylene group in addition to the radical polymerizable compound, and a hydrogen abstraction function. A certain radical polymerization initiator (G) can be contained. According to such a configuration, the adhesiveness of the adhesive layer of the polarizing film is remarkably improved even in a high humidity environment or immediately after being taken out from water (non-dried state). The reason for this is not clear, but the following causes are considered. That is, the radical polymerizable compound (F) having an active methylene group is polymerized together with other radical polymerizable compounds constituting the adhesive layer (2a), while the main chain and / or the side of the base polymer in the adhesive layer. It is taken into the chain and forms the adhesive layer (2a). In such a polymerization process, when a radical polymerization initiator (G) having a hydrogen abstracting action is present, the base polymer constituting the adhesive layer (2a) is formed, and the radical polymerizable compound (F) having an active methylene group is formed. Hydrogen is extracted and a radical is generated in the methylene group. And the methylene group which the radical generate | occur | produced, and the hydroxyl group of polarizers, such as PVA, react, and a covalent bond is formed between an adhesive bond layer (2a) and a polarizer (1). As a result, it is speculated that the adhesiveness of the adhesive layer of the polarizing film is remarkably improved even in a non-dry state.

  The radically polymerizable compound (F) having an active methylene group is a compound having an active double bond group such as a (meth) acryl group at the terminal or in the molecule and having an active methylene group. Examples of the active methylene group include an acetoacetyl group, an alkoxymalonyl group, and a cyanoacetyl group. Specific examples of the radically polymerizable compound (F) having an active methylene group include 2-acetoacetoxyethyl (meth) acrylate, 2-acetoacetoxypropyl (meth) acrylate, 2-acetoacetoxy-1-methylethyl (meta) ) Acetoacetoxyalkyl (meth) acrylates such as acrylate; 2-ethoxymalonyloxyethyl (meth) acrylate, 2-cyanoacetoxyethyl (meth) acrylate, N- (2-cyanoacetoxyethyl) acrylamide, N- (2-propionyl) Acetoxybutyl) acrylamide, N- (4-acetoacetoxymethylbenzyl) acrylamide, N- (2-acetoacetylaminoethyl) acrylamide and the like.

（式中、Ｒ^１およびＲ^２は−Ｈ、−ＣＨ_２ｂＨ_３、−ｉＰｒまたはＣｌを示し、Ｒ^１およびＲ^２は同一または異なっても良い）が挙げられる。 Examples of the radical polymerization initiator (G) having a hydrogen abstracting action include thioxanthone radical polymerization initiators and benzophenone radical polymerization initiators. As a thioxanthone radical polymerization initiator, a compound represented by the following general formula (1);

Wherein R ¹ and R ² represent —H, —CH _2b H ₃ , —iPr or Cl, and R ¹ and R ² may be the same or different.

  Since the photopolymerization initiator of the general formula (1) can initiate polymerization by light having a long wavelength that passes through a transparent protective film having UV absorption ability, the adhesive can be cured even through a UV absorbing film. Specifically, for example, even when laminating a transparent protective film having UV absorbing ability on both sides like triacetylcellulose-polarizer-triacetylcellulose, when containing the photopolymerization initiator of the general formula (1), Curing of the adhesive composition is possible.

Specific examples of the compound represented by the general formula (1) include thioxanthone, dimethylthioxanthone, diethylthioxanthone, isopropylthioxanthone, and chlorothioxanthone. Among the compounds represented by the general formula (1), diethylthioxanthone in which R ¹ and R ² are —CH _2b H ₃ is particularly preferable.

（式中、Ｒ^３、Ｒ^４およびＲ^５は−Ｈ、−ＣＨ_３ｂＨ_２ｂＨ_３、−ｉＰｒまたはＣｌを示し、Ｒ^３、Ｒ^４およびＲ^５は同一または異なっても良い）を含有することが好ましい。上記一般式（１）および一般式（２）の光重合開始剤を併用することで、これらの光増感反応により反応が高効率化し、接着剤層の接着性が特に向上する。 Moreover, in the said active energy ray hardening-type adhesive composition, in addition to the photoinitiator of General formula (1) as a photoinitiator, the compound represented by following General formula (2);

In which R ³ , R ⁴ and R ⁵ represent —H, —CH _3b H _2b H ₃ , —iPr or Cl, and R ³ , R ⁴ and R ⁵ may be the same or different. It is preferable. By using together the photoinitiator of the said General formula (1) and General formula (2), reaction becomes highly efficient by these photosensitization reaction, and the adhesiveness of an adhesive bond layer improves especially.

  As described above, in the present invention, a radical is generated in the methylene group of the radical polymerizable compound (F) having an active methylene group in the presence of the radical polymerization initiator (G) having a hydrogen abstracting action, and the methylene group And a hydroxyl group of a polarizer such as PVA react to form a covalent bond. Therefore, the radically polymerizable compound (F) having an active methylene group generates radicals in the methylene group of the radically polymerizable compound (F) having an active methylene group, and the active energy is sufficient to form such a covalent bond. When the total amount of the radical polymerizable compound in the linear curable adhesive composition is 100%, it is preferably contained in an amount of 1 to 50% by weight, more preferably 3 to 30% by weight. When the radically polymerizable compound (F) having an active methylene group is less than 1% by weight, the effect of improving adhesiveness in a non-dry state is low, and the water resistance may not be sufficiently improved, and exceeds 50% by weight. In some cases, poor curing of the adhesive layer may occur. Further, the radical polymerization initiator (G) having a hydrogen abstracting action is contained in an amount of 0.1 to 10 parts by weight with respect to 100 parts by weight of the total amount of the radical polymerizable compound in the active energy ray-curable adhesive composition. It is more preferable to contain 0.3 to 9 parts by weight. If the radical polymerization initiator (G) having a hydrogen abstraction action is less than 0.1 part by weight, the hydrogen abstraction reaction may not sufficiently proceed. If it exceeds 10 parts by weight, it is not completely dissolved in the composition. There is a case.

<Photoacid generator (H)>
The active energy ray-curable adhesive composition used for forming the adhesive layer (2a) can further contain a photoacid generator (H) in addition to the radical polymerizable compound. When the active energy ray-curable resin composition contains a photoacid generator, the water resistance and durability of the adhesive layer can be dramatically improved as compared with the case where no photoacid generator is contained. . The photoacid generator (H) can be represented by the following general formula (3).

（ただし、Ｌ^＋は、任意のオニウムカチオンを表す。また、Ｘ⁻は、ＰＦ_６ ⁻、ＳｂＦ_６ ⁻、ＡｓＦ_６ ⁻、ＳｂＣｌ_６ ⁻、ＢｉＣｌ_５ ⁻、ＳｎＣｌ_６ ⁻、ＣｌＯ_４ ⁻、ジチオカルバメートアニオン、ＳＣＮ⁻よりからなる群より選択されるカウンターアニオンを表す。） General formula (3)

(However, L ⁺ represents an arbitrary onium cation. X ⁻ represents PF ₆ ⁻ , SbF ₆ ⁻ , AsF ₆ ⁻ , SbCl ₆ ⁻ , BiCl ₅ ⁻ , SnCl ₆ ⁻ , ClO ₄ ⁻ , dithiocarbamate. anion, SCN ^- represents a counter anion selected from the group more consisting).

Preferred examples of the onium cation structure as the onium cation L ⁺ constituting the general formula (3) include onium cations selected from the following general formulas (4) to (12).

General formula (4)

General formula (5)

General formula (6)

General formula (7)

General formula (8)

General formula (9)

General formula (10)

Formula (11)

（上記一般式（４）−（１２）中、ただし、Ｒ^１、Ｒ^２およびＲ^３は、それぞれ独立に、水素原子、置換もしくは未置換のアルキル基、置換もしくは未置換のアルケニル基、置換もしくは未置換のアリール基、置換もしくは未置換の複素環基、置換もしくは未置換のアルコキシル基、置換もしくは未置換のアリールオキシ基、置換もしくは未置換の複素環オキシ基、置換もしくは未置換のアシル基、置換もしくは未置換のカルボニルオキシ基、置換もしくは未置換のオキシカルボニル基、またはハロゲン原子より選ばれる基を表す。Ｒ^４は、Ｒ^１、Ｒ^２およびＲ^３に記載した基と同様の基を表す。Ｒ^５は、置換もしくは未置換のアルキル基、置換もしくは未置換のアルキルチオ基を表す。Ｒ^６およびＲ^７は、それぞれ独立に、置換もしくは未置換のアルキル基、置換もしくは未置換のアルコキシル基を表す。Ｒは、ハロゲン原子、水酸基、カルボキシル基、メルカプト基、シアノ基、ニトロ基、置換もしくは未置換のカルバモイル基、置換もしくは未置換のアルキル基、置換もしくは未置換のアルケニル基、置換もしくは未置換のアリール基、置換もしくは未置換の複素環基、置換もしくは未置換のアルコキシル基、置換もしくは未置換のアリールオキシ基、置換もしくは未置換の複素環オキシ基、置換もしくは未置換のアルキルチオ基、置換もしくは未置換のアリールチオ基、置換もしくは未置換の複素環チオ基、置換もしくは未置換のアシル基、置換もしくは未置換のカルボニルオキシ基、置換もしくは未置換のオキシカルボニル基のいずれかを表す。Ａｒ^４、Ａｒ^５は、置換もしくは未置換のアリール基、置換もしくは未置換の複素環基のいずれかを表す。Ｘは、酸素もしくは硫黄原子を表す。ｉは０〜５の整数を表す。ｊは０〜４の整数を表す。ｋは０〜３の整数を表す。また、隣接したＲ同士、Ａｒ^４とＡｒ^５、Ｒ^２とＲ^３、Ｒ^２とＲ^４、Ｒ^３とＲ^４、Ｒ^１とＲ^２、Ｒ^１とＲ^３、Ｒ^１とＲ^４、Ｒ^１とＲ、もしくはＲ^１とＲ^５は、相互に結合した環状構造であってもよい。） Formula (12)

(In the general formulas (4) to (12), R ¹ , R ² and R ³ are each independently a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, substituted or An unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted alkoxyl group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted heterocyclic oxy group, a substituted or unsubstituted acyl group, R ⁴ represents a group selected from a substituted or unsubstituted carbonyloxy group, a substituted or unsubstituted oxycarbonyl group, or a halogen atom, and R ⁴ represents a group similar to the groups described in R ¹ , R ² and R ^3. .R ⁵ is a substituted or unsubstituted alkyl group, is .R ⁶ and R ⁷ represents a substituted or unsubstituted alkylthio group, independently, be substituted Represents an unsubstituted alkyl group, a substituted or unsubstituted alkoxyl group, and R represents a halogen atom, a hydroxyl group, a carboxyl group, a mercapto group, a cyano group, a nitro group, a substituted or unsubstituted carbamoyl group, a substituted or unsubstituted group. Alkyl group, substituted or unsubstituted alkenyl group, substituted or unsubstituted aryl group, substituted or unsubstituted heterocyclic group, substituted or unsubstituted alkoxyl group, substituted or unsubstituted aryloxy group, substituted or unsubstituted Heterocyclic oxy group, substituted or unsubstituted alkylthio group, substituted or unsubstituted arylthio group, substituted or unsubstituted heterocyclic thio group, substituted or unsubstituted acyl group, substituted or unsubstituted carbonyloxy group, substituted or ^.Ar 4 represent either a non-substituted oxycarbonyl group, Ar Represents a substituted or unsubstituted aryl group, .X represent either a substituted or unsubstituted heterocyclic group, an oxygen or sulfur atom .i is .j is 0-4 represents an integer of 0 to 5 K represents an integer of 0 to ^3. Adjacent Rs, Ar ⁴ and Ar ⁵ , R ² and R ³ , R ² and R ⁴ , R ³ and R ⁴ , R ¹ and R ² , R ¹ and R ³ , R ¹ and R ⁴ , R ¹ and R, or R ¹ and R ⁵ may be a cyclic structure bonded to each other.)

  Onium cation (sulfonium cation) corresponding to the general formula (4): dimethylphenylsulfonium, dimethyl (o-fluorophenyl) sulfonium, dimethyl (m-chlorophenyl) sulfonium, dimethyl (p-bromophenyl) sulfonium, dimethyl (p-cyano) Phenyl) sulfonium, dimethyl (m-nitrophenyl) sulfonium, dimethyl (2,4,6-tribromophenyl) sulfonium, dimethyl (pentafluorophenyl) sulfonium, dimethyl (p- (trifluoromethyl) phenyl) sulfonium, dimethyl ( p-hydroxyphenyl) sulfonium, dimethyl (p-mercaptophenyl) sulfonium, dimethyl (p-methylsulfinylphenyl) sulfonium, dimethyl (p-methylsulfonylphenyl) Lu) sulfonium, dimethyl (o-acetylphenyl) sulfonium, dimethyl (o-benzoylphenyl) sulfonium, dimethyl (p-methylphenyl) sulfonium, dimethyl (p-isopropylphenyl) sulfonium, dimethyl (p-octadecylphenyl) sulfonium, dimethyl (P-cyclohexylphenyl) sulfonium, dimethyl (p-methoxyphenyl) sulfonium, dimethyl (o-methoxycarbonylphenyl) sulfonium, dimethyl (p-phenylsulfanylphenyl) sulfonium, (7-methoxy-2-oxo-2H-chromene- 4-yl) dimethylsulfonium, (4-methoxynaphthalen-1-yl) dimethylsulfonium, dimethyl (p-isopropoxycarbonylphenyl) sulfonium, Methyl (2-naphthyl) sulfonium, dimethyl (9-anthryl) sulfonium, diethylphenylsulfonium, methylethylphenylsulfonium, methyldiphenylsulfonium, triphenylsulfonium, diisopropylphenylsulfonium, diphenyl (4-phenylsulfanyl-phenyl) -sulfonium, 4 , 4′-bis (diphenylsulfonium) diphenyl sulfide, 4,4′-bis [di [(4- (2-hydroxy-ethoxy) -phenyl)] sulfonium]] diphenyl sulfide, 4,4′-bis (diphenylsulfonium) ) Biphenylene, diphenyl (o-fluorophenyl) sulfonium, diphenyl (m-chlorophenyl) sulfonium, diphenyl (p-bromophenyl) sulfonium, dipheny Ru (p-cyanophenyl) sulfonium, diphenyl (m-nitrophenyl) sulfonium, diphenyl (2,4,6-tribromophenyl) sulfonium, diphenyl (pentafluorophenyl) sulfonium, diphenyl (p- (trifluoromethyl) phenyl ) Sulfonium, diphenyl (p-hydroxyphenyl) sulfonium, diphenyl (p-mercaptophenyl) sulfonium, diphenyl (p-methylsulfinylphenyl) sulfonium, diphenyl (p-methylsulfonylphenyl) sulfonium, diphenyl (o-acetylphenyl) sulfonium, Diphenyl (o-benzoylphenyl) sulfonium, diphenyl (p-methylphenyl) sulfonium, diphenyl (p-isopropylphenyl) sulfonium, di Phenyl (p-octadecylphenyl) sulfonium, diphenyl (p-cyclohexylphenyl) sulfonium, diphenyl (p-methoxyphenyl) sulfonium, diphenyl (o-methoxycarbonylphenyl) sulfonium, diphenyl (p-phenylsulfanylphenyl) sulfonium, (7- Methoxy-2-oxo-2H-chromen-4-yl) diphenylsulfonium, (4-methoxynaphthalen-1-yl) diphenylsulfonium, diphenyl (p-isopropoxycarbonylphenyl) sulfonium, diphenyl (2-naphthyl) sulfonium, diphenyl (9-anthryl) sulfonium, ethyldiphenylsulfonium, methylethyl (o-tolyl) sulfonium, methyldi (p-tolyl) sulfonium, tri ( -Tolyl) sulfonium, diisopropyl (4-phenylsulfanylphenyl) sulfonium, diphenyl (2-thienyl) sulfonium, diphenyl (2-furyl) sulfonium, diphenyl (9-ethyl-9Hcarbazol-3-yl) sulfonium, and the like. However, it is not limited to these.

  Onium cation (sulfoxonium cation) corresponding to general formula (5): dimethylphenylsulfoxonium, dimethyl (o-fluorophenyl) sulfoxonium, dimethyl (m-chlorophenyl) sulfoxonium, dimethyl (p-bromophenyl) ) Sulfoxonium, dimethyl (p-cyanophenyl) sulfoxonium, dimethyl (m-nitrophenyl) sulfoxonium, dimethyl (2,4,6-tribromophenyl) sulfoxonium, dimethyl (pentafluorophenyl) sulfo Xonium, dimethyl (p- (trifluoromethyl) phenyl) sulfoxonium, dimethyl (p-hydroxyphenyl) sulfoxonium, dimethyl (p-mercaptophenyl) sulfoxonium, dimethyl (p-methylsulfinylphenyl) Rufoxonium, dimethyl (p-methylsulfonylphenyl) sulfoxonium, dimethyl (o-acetylphenyl) sulfoxonium, dimethyl (o-benzoylphenyl) sulfoxonium, dimethyl (p-methylphenyl) sulfoxonium, dimethyl (p -Isopropylphenyl) sulfoxonium, dimethyl (p-octadecylphenyl) sulfoxonium, dimethyl (p-cyclohexylphenyl) sulfoxonium, dimethyl (p-methoxyphenyl) sulfoxonium, dimethyl (o-methoxycarbonylphenyl) sulfo Xonium, dimethyl (p-phenylsulfanylphenyl) sulfoxonium, (7-methoxy-2-oxo-2H-chromen-4-yl) dimethylsulfoxonium, (4-methoxynaphthalene) 1-yl) dimethylsulfoxonium, dimethyl (p-isopropoxycarbonylphenyl) sulfoxonium, dimethyl (2-naphthyl) sulfoxonium, dimethyl (9-anthryl) sulfoxonium, diethylphenylsulfoxonium, methylethyl Phenylsulfoxonium, methyldiphenylsulfoxonium, triphenylsulfoxonium, diisopropylphenylsulfoxonium, diphenyl (4-phenylsulfanyl-phenyl) -sulfoxonium, 4,4'-bis (diphenylsulfoxonium) diphenyl Sulfide, 4,4′-bis [di [(4- (2-hydroxy-ethoxy) -phenyl)] sulfoxonium] diphenyl sulfide, 4,4′-bis (diphenylsulfoxonium) biphenylene, Phenyl (o-fluorophenyl) sulfoxonium, diphenyl (m-chlorophenyl) sulfoxonium, diphenyl (p-bromophenyl) sulfoxonium, diphenyl (p-cyanophenyl) sulfoxonium, diphenyl (m-nitrophenyl) Sulfoxonium, diphenyl (2,4,6-tribromophenyl) sulfoxonium, diphenyl (pentafluorophenyl) sulfoxonium, diphenyl (p- (trifluoromethyl) phenyl) sulfoxonium, diphenyl (p-hydroxy) Phenyl) sulfoxonium, diphenyl (p-mercaptophenyl) sulfoxonium, diphenyl (p-methylsulfinylphenyl) sulfoxonium, diphenyl (p-methylsulfonylphenyl) sulfoxonium, di Phenyl (o-acetylphenyl) sulfoxonium, diphenyl (o-benzoylphenyl) sulfoxonium, diphenyl (p-methylphenyl) sulfoxonium, diphenyl (p-isopropylphenyl) sulfoxonium, diphenyl (p-octadecylphenyl) ) Sulfoxonium, diphenyl (p-cyclohexylphenyl) sulfoxonium, diphenyl (p-methoxyphenyl) sulfoxonium, diphenyl (o-methoxycarbonylphenyl) sulfoxonium, diphenyl (p-phenylsulfanylphenyl) sulfoxonium , (7-methoxy-2-oxo-2H-chromen-4-yl) diphenylsulfoxonium, (4-methoxynaphthalen-1-yl) diphenylsulfoxonium, diphenyl (p-iso Propoxycarbonylphenyl) sulfoxonium, diphenyl (2-naphthyl) sulfoxonium, diphenyl (9-anthryl) sulfoxonium, ethyldiphenylsulfoxonium, methylethyl (o-tolyl) sulfoxonium, methyldi (p-tolyl) Sulfoxonium, tri (p-tolyl) Sulfoxonium, diisopropyl (4-phenylsulfanylphenyl) Sulfoxonium, diphenyl (2-thienyl) Sulfoxonium, diphenyl (2-furyl) Sulfoxonium, diphenyl (9) -Ethyl-9H carbazol-3-yl) Although sulfoxonium etc. can be mentioned, it is not limited to these.

  Onium cation (phosphonium cation) corresponding to general formula (6): Examples of phosphonium cation: trimethylphenylphosphonium, triethylphenylphosphonium, tetraphenylphosphonium, triphenyl (p-fluorophenyl) phosphonium, triphenyl (o-chlorophenyl) phosphonium , Triphenyl (m-bromophenyl) phosphonium, triphenyl (p-cyanophenyl) phosphonium, triphenyl (m-nitrophenyl) phosphonium, triphenyl (p-phenylsulfanylphenyl) phosphonium, (7-methoxy-2-oxo -2H-chromen-4-yl) triphenylphosphonium, triphenyl (o-hydroxyphenyl) phosphonium, triphenyl (o-acetylphenyl) phosphonium Triphenyl (m-benzoylphenyl) phosphonium, triphenyl (p-methylphenyl) phosphonium, triphenyl (p-isopropoxyphenyl) phosphonium, triphenyl (o-methoxycarbonylphenyl) phosphonium, triphenyl (1-naphthyl) phosphonium , Triphenyl (9-anthryl) phosphonium, triphenyl (2-thienyl) phosphonium, triphenyl (2-furyl) phosphonium, triphenyl (9-ethyl-9Hcarbazol-3-yl) phosphonium, and the like. However, it is not limited to these.

  Onium cation (pyridinium cation) corresponding to general formula (7): Examples of pyridinium cation: N-phenylpyridinium, N- (o-chlorophenyl) pyridinium, N- (m-chlorophenyl) pyridinium, N- (p-cyanophenyl) ) Pyridinium, N- (o-nitrophenyl) pyridinium, N- (p-acetylphenyl) pyridinium, N- (p-isopropylphenyl) pyridinium, N- (p-octadecyloxyphenyl) pyridinium, N- (p-methoxy) Carbonylphenyl) pyridinium, N- (9-anthryl) pyridinium, 2-chloro-1-phenylpyridinium, 2-cyano-1-phenylpyridinium, 2-methyl-1-phenylpyridinium, 2-vinyl-1-phenylpyridinium, 2-Feni -1-phenylpyridinium, 1,2-diphenylpyridinium, 2-methoxy-1-phenylpyridinium, 2-phenoxy-1-phenylpyridinium, 2-acetyl-1- (p-tolyl) pyridinium, 2-methoxycarbonyl-1 -(P-Tolyl) pyridinium, 3-fluoro-1-naphthylpyridinium, 4-methyl-1- (2-furyl) pyridinium, N-methylpyridinium, N-ethylpyridinium and the like can be mentioned, but are not limited thereto. Is not to be done.

  Onium cation (quinolinium cation) corresponding to general formula (8): Examples of quinolinium cation: N-methylquinolinium, N-ethylquinolinium, N-phenylquinolinium, N-naphthylquinoli Ni, N- (o-chlorophenyl) quinolinium, N- (m-chlorophenyl) quinolinium, N- (p-cyanophenyl) quinolinium, N- (o-nitrophenyl) quinolinium, N- (p-acetylphenyl) quinolinium, N- (p-isopropylphenyl) quinolinium, N- (p-octadecyloxyphenyl) quinolinium, N- (p-methoxycarbonylphenyl) quinolinium, N- (9-anthryl) quinolinium, 2-chloro-1-phenylquinolin Ni, 2-cyano-1-phenylquinolinium, 2-methyl- -Phenylquinolinium, 2-vinyl-1-phenylquinolinium, 2-phenyl-1-phenylquinolinium, 1,2-diphenylquinolinium, 2-methoxy-1-phenylquinolinium, 2- Phenoxy-1-phenylquinolinium, 2-acetyl-1-phenylquinolinium, 2-methoxycarbonyl-1-phenylquinolinium, 3-fluoro-1-phenylquinolinium, 4-methyl-1-phenyl Quinolinium, 2-methoxy-1- (p-tolyl) quinolinium, 2-phenoxy-1- (2-furyl) quinolinium, 2-acetyl-1- (2-thienyl) quinolinium, 2-methoxycarbonyl-1- Mention methylquinolinium, 3-fluoro-1-ethylquinolinium, 4-methyl-1-isopropylquinolinium, etc. Although it is not intended to be limited thereto.

  Onium cation (isoquinolinium cation) corresponding to general formula (9): Examples of isoquinolinium cation: N-phenylisoquinolinium, N-methylisoquinolinium, N-ethylisoquinolinium, N- (o-chlorophenyl) isoquinolinium, N- (m-chlorophenyl) isoquinolinium, N- (p-cyanophenyl) isoquinolinium, N- (o-nitrophenyl) isoquinolinium, N- (p-acetylphenyl) isoquinolinium, N- (P-isopropylphenyl) isoquinolinium, N- (p-octadecyloxyphenyl) isoquinolinium, N- (p-methoxycarbonylphenyl) isoquinolinium, N- (9-anthryl) isoquinolinium, 1,2-diphenylisoquinolinium, N -(2-furyl) iso Noriniumu, N- (2-thienyl) isoquinolinium, there may be mentioned N- naphthyl isoquinolinium, etc., but is not limited thereto.

  Onium cations corresponding to general formula (10) (benzoxazolium cation, benzothiazolium cation): Examples of benzoxazolium cation: N-methylbenzoxazolium, N-ethylbenzoxazolium, N- Naphthylbenzoxazolium, N-phenylbenzoxazolium, N- (p-fluorophenyl) benzoxazolium, N- (p-chlorophenyl) benzoxazolium, N- (p-cyanophenyl) benzoxazo L, N- (o-methoxycarbonylphenyl) benzoxazolium, N- (2-furyl) benzoxazolium, N- (o-fluorophenyl) benzoxazolium, N- (p-cyanophenyl) benzo Oxazolium, N- (m-nitrophenyl) benzoxazolium, N- ( -Isopropoxycarbonylphenyl) benzoxazolium, N- (2-thienyl) benzoxazolium, N- (m-carboxyphenyl) benzoxazolium, 2-mercapto-3-phenylbenzoxazolium, 2- Methyl-3-phenylbenzoxazolium, 2-methylthio-3- (4-phenylsulfanylphenyl) benzoxazolium, 6-hydroxy-3- (p-tolyl) benzoxazolium, 7-mercapto-3- Examples thereof include phenylbenzoxazolium and 4,5-difluoro-3-ethylbenzoxazolium, but are not limited thereto.

  Examples of benzothiazolium cations: N-methylbenzothiazolium, N-ethylbenzothiazolium, N-phenylbenzothiazolium, N- (1-naphthyl) benzothiazolium, N- (p-fluoro Phenyl) benzothiazolium, N- (p-chlorophenyl) benzothiazolium, N- (p-cyanophenyl) benzothiazolium, N- (o-methoxycarbonylphenyl) benzothiazolium, N- (p -Tolyl) benzothiazolium, N- (o-fluorophenyl) benzothiazolium, N- (m-nitrophenyl) benzothiazolium, N- (p-isopropoxycarbonylphenyl) benzothiazolium, N -(2-furyl) benzothiazolium, N- (4-methylthiophenyl) benzothiazolium, N- (4-phenyls Fanylphenyl) benzothiazolium, N- (2-naphthyl) benzothiazolium, N- (m-carboxyphenyl) benzothiazolium, 2-mercapto-3-phenylbenzothiazolium, 2-methyl-3 -Phenylbenzothiazolium, 2-methylthio-3-phenylbenzothiazolium, 6-hydroxy-3-phenylbenzothiazolium, 7-mercapto-3-phenylbenzothiazolium, 4,5-difluoro-3 -Phenylbenzothiazolium etc. can be mentioned, but it is not limited to these.

  Onium cation (furyl or thienyliodonium cation) corresponding to the general formula (11): difuryliodonium, dithienyliodonium, bis (4,5-dimethyl-2-furyl) iodonium, bis (5-chloro-2-thienyl) Iodonium, bis (5-cyano-2-furyl) iodonium, bis (5-nitro-2-thienyl) iodonium, bis (5-acetyl-2-furyl) iodonium, bis (5-carboxy-2-thienyl) iodonium, Bis (5-methoxycarbonyl-2-furyl) iodonium, bis (5-phenyl-2-furyl) iodonium, bis (5- (p-methoxyphenyl) -2-thienyl) iodonium, bis (5-vinyl-2- Furyl) iodonium, bis (5-ethynyl-2-thienyl) iodo Bis (5-cyclohexyl-2-furyl) iodonium, bis (5-hydroxy-2-thienyl) iodonium, bis (5-phenoxy-2-furyl) iodonium, bis (5-mercapto-2-thienyl) iodonium, Examples thereof include, but are not limited to, bis (5-butylthio-2-thienyl) iodonium, bis (5-phenylthio-2-thienyl) iodonium, and the like.

  Onium cation (diaryliodonium cation) corresponding to general formula (12): diphenyliodonium, bis (p-tolyl) iodonium, bis (p-octylphenyl) iodonium, bis (p-octadecylphenyl) iodonium, bis (p-octyl) Oxyphenyl) iodonium, bis (p-octadecyloxyphenyl) iodonium, phenyl (p-octadecyloxyphenyl) iodonium, 4-isopropyl-4′-methyldiphenyliodonium, (4-isobutylphenyl) -p-tolyliodonium, bis ( 1-naphthyl) iodonium, bis (4-phenylsulfanylphenyl) iodonium, phenyl (6-benzoyl-9-ethyl-9H-carbazol-3-yl) iodonium, (7-methoxy) 2-oxo -2H- chromen-3-yl) -4' can be exemplified isopropylphenyl iodonium, etc., but is not limited thereto.

Next, the counter anion X ⁻ in the general formula (3) will be described.

The counter anion X ⁻ in the general formula (3) is not particularly limited in principle, but a non-nucleophilic anion is preferable. When the counter anion X ⁻ is a non-nucleophilic anion, the nucleophilic reaction in the cations coexisting in the molecule and various materials used in combination is unlikely to occur. As a result, the photoacid generator itself represented by the general formula (2) It is possible to improve the aging stability of a composition using the same. The non-nucleophilic anion here refers to an anion having a low ability to cause a nucleophilic reaction. Examples of such anions include PF ₆ ⁻ , SbF ₆ ⁻ , AsF ₆ ⁻ , SbCl ₆ ⁻ , BiCl ₅ ⁻ , SnCl ₆ ⁻ , ClO ₄ ⁻ , dithiocarbamate anion, SCN ^{− and the} like.

Among the exemplified anions described above, PF ₆ ⁻ , SbF ₆ ⁻ , and AsF ₆ ⁻ are particularly preferable as the counter anion X ⁻ in the general formula (3), and PF ₆ ⁻ , SbF ₆ ^- is mentioned.

Therefore, as a specific example of a preferable onium salt constituting the photoacid generator (H) of the present invention, a specific example of the structure of the onium cation represented by the above general formulas (3) to (12) An onium salt composed of an anion selected from PF ₆ ⁻ , SbF ₆ ⁻ , AsF ₆ ⁻ , SbCl ₆ ⁻ , BiCl ₅ ⁻ , SnCl ₆ ⁻ , ClO ₄ ⁻ , dithiocarbamate anion, and SCN ⁻ .

  Specifically, “Syracure UVI-6922”, “Syracure UVI-6974” (above, manufactured by Dow Chemical Japan Co., Ltd.), “Adekaoptomer SP150”, “Adekaoptomer SP152”, “Adekaoptomer” “SP170”, “Adekaoptomer SP172” (manufactured by ADEKA Corporation), “IRGACURE250” (manufactured by Ciba Specialty Chemicals), “CI-5102”, “CI-2855” (manufactured by Nippon Soda Co., Ltd.), “Sun-Aid SI-60L”, “Sun-Aid SI-80L”, “Sun-Aid SI-100L”, “Sun-Aid SI-110L”, “Sun-Aid SI-180L” (above, manufactured by Sanshin Chemical Co., Ltd.), “CPI-100P”, “CPI-100A” (San Apro Co., Ltd.), “WPI-069 , “WPI-113”, “WPI-116”, “WPI-041”, “WPI-044”, “WPI-054”, “WPI-055”, “WPAG-281”, “WPAG-567”, “ “WPAG-596” (manufactured by Wako Pure Chemical Industries, Ltd.) is a preferred specific example of the photoacid generator (H) of the present invention.

  The content of the photoacid generator (H) is preferably 0.01 to 10 parts by weight relative to 100 parts by weight of the total amount of radical polymerizable compounds in the active energy ray-curable adhesive composition. The amount is more preferably 0.05 to 5 parts by weight, and particularly preferably 0.1 to 3 parts by weight.

  In the active energy ray-curable adhesive composition, the active energy ray-curable adhesive composition is preferably used in combination with a photoacid generator (H) and a compound (I) containing either an alkoxy group or an epoxy group. .

(Compounds and polymers having an epoxy group) (I)
When using a compound having one or more epoxy groups in the molecule or a polymer (epoxy resin) having two or more epoxy groups in the molecule, two functional groups having reactivity with the epoxy group are contained in the molecule. Two or more compounds may be used in combination. Here, examples of the functional group having reactivity with an epoxy group include a carboxyl group, a phenolic hydroxyl group, a mercapto group, a primary or secondary aromatic amino group, and the like. It is particularly preferable to have two or more of these functional groups in one molecule in consideration of three-dimensional curability.

Examples of the polymer having one or more epoxy groups in the molecule include epoxy resins, bisphenol A type epoxy resins derived from bisphenol A and epichlorohydrin, bisphenol F type epoxy derived from bisphenol F and epichlorohydrin. Resin, bisphenol S type epoxy resin, phenol novolak type epoxy resin, cresol novolak type epoxy resin, bisphenol A novolak type epoxy resin, bisphenol F novolak type epoxy resin, alicyclic epoxy resin, diphenyl ether type epoxy resin, hydroquinone type epoxy resin, Polyfunctional epoxy resins such as naphthalene type epoxy resin, biphenyl type epoxy resin, fluorene type epoxy resin, trifunctional type epoxy resin and tetrafunctional type epoxy resin, There are lysidyl ester type epoxy resins, glycidyl amine type epoxy resins, hydantoin type epoxy resins, isocyanurate type epoxy resins, aliphatic chain epoxy resins, etc. These epoxy resins may be halogenated and hydrogenated. It may be. As commercially available epoxy resin products, for example, JER Coat 828, 1001, 801N, 806, 807, 152, 604, 630, 871, YX8000, YX8034, YX4000 manufactured by Japan Epoxy Resin Co., Ltd., Epicron manufactured by DIC Corporation 830, EXA835LV, HP4032D, HP820, EP4100 series, EP4000 series, EPU series, manufactured by ADEKA Co., Ltd., Celoxide series (2021, 2021P, 2083, 2085, 3000, etc.) manufactured by Daicel Chemical Industries, Ltd., Eporide series, EHPE Series, YD series, YDF series, YDCN series, YDB series, phenoxy resin (polyethylene synthesized from bisphenols and epichlorohydrin) B carboxymethyl having an epoxy group at both ends with polyether; YP series, etc.), Nagase ChemteX Corporation of Denacol series manufactured by Kyoeisha but Chemical Co. Epo light series, and the like are not limited thereto. Two or more of these epoxy resins may be used in combination. In calculating the glass transition temperature Tg of the adhesive layer, the compound having an epoxy group and the polymer (H) are not included in the calculation.

(Compounds and polymers having an alkoxyl group) (I)
The compound having an alkoxyl group in the molecule is not particularly limited as long as it has one or more alkoxyl groups in the molecule, and known compounds can be used. Representative examples of such compounds include melamine compounds and amino resins.

  The compounding amount of the compound (I) containing either an alkoxy group or an epoxy group is usually 30 parts by weight or less with respect to 100 parts by weight of the total amount of radically polymerizable compounds in the active energy ray-curable adhesive composition. If the content of the compound (I) in the composition is too large, the adhesiveness may be lowered, and the impact resistance against a drop test may be deteriorated. The content of compound (I) in the composition is more preferably 20 parts by weight or less. On the other hand, from the viewpoint of water resistance of the cured product layer (adhesive layer 2a), the composition preferably contains 2 parts by weight or more of compound (I), more preferably 5 parts by weight or more.

<Adhesive layer (2b)>
The adhesive layer (2b) is a cured product layer formed by irradiating the active energy ray-curable adhesive composition with active energy rays. The said active energy ray hardening-type adhesive composition is adjusted so that the glass transition temperature of an adhesive bond layer (2b) may be 30 degreeC or more.

  As the active energy ray curable adhesive composition for forming the adhesive layer (2b), an electron beam curable adhesive or an ultraviolet curable adhesive can be used. The ultraviolet curable adhesive can be roughly classified into a radical polymerization curable adhesive and a cationic polymerization adhesive.

  Examples of the curable component of the radical polymerization curable adhesive include a compound having a (meth) acryloyl group and a radical polymerizable compound having a vinyl group. These curable components may be monofunctional or bifunctional or higher. Moreover, these curable components can be used individually by 1 type or in combination of 2 or more types. As these curable components, for example, compounds having a (meth) acryloyl group are suitable.

  The active energy ray-curable adhesive composition (radical polymerizable compound) for forming the adhesive layer (2b) is disclosed in Patent Document 1 (Japanese Patent Laid-Open No. 2008-287207) and Patent Document 2 (Japanese Patent Laid-Open No. 2012-068593). And those described in Japanese Patent Application Laid-Open No. 2012-144690. In addition, the components (D) to (I) used in the active energy ray-curable adhesive composition for forming the adhesive layer (2a) can be appropriately combined and blended.

  Examples of the curable component of the cationic polymerization curable adhesive include compounds having an epoxy group or an oxetanyl group. The compound having an epoxy group is not particularly limited as long as it has at least two epoxy groups in the molecule, and various generally known curable epoxy compounds can be used. Preferred epoxy compounds include compounds having at least two epoxy groups and at least one aromatic ring in the molecule (hereinafter referred to as “aromatic epoxy compounds”), and having at least two epoxy groups in the molecule. Examples of such a compound include at least one compound formed between two adjacent carbon atoms constituting an alicyclic ring.

  When the active energy ray curable adhesive composition according to the adhesive layers (2a) and (2b) of the present invention is used in an electron beam curable type, it is not particularly necessary to include a photopolymerization initiator in the composition. However, when used in an ultraviolet curing type, it is preferable to use a photopolymerization initiator, and it is particularly preferable to use a photopolymerization initiator that is highly sensitive to light of 380 nm or more. A photopolymerization initiator that is highly sensitive to light of 380 nm or more will be described later.

（式中、Ｒ^１およびＲ^２は−Ｈ、−ＣＨ_２ｂＨ_３、−ｉＰｒまたはＣｌを示し、Ｒ^１およびＲ^２は同一または異なっても良い）を単独で使用するか、あるいは一般式（１）で表される化合物と後述する３８０ｎｍ以上の光に対して高感度な光重合開始剤とを併用することが好ましい。一般式（１）で表される化合物を使用した場合、３８０ｎｍ以上の光に対して高感度な光重合開始剤を単独で使用した場合に比べて接着性に優れる。一般式（１）で表される化合物の中でも、Ｒ^１およびＲ^２が−ＣＨ_２ｂＨ_３であるジエチルチオキサントンが特に好ましい。組成物中の一般式（１）で表される化合物の組成比率は、活性エネルギー線硬化型接着剤組成物中のラジカル重合性化合物の全量１００重量部に対して、０．１〜５．０重量部であることが好ましく、０．５〜４．０重量部であることがより好ましく、０．９〜３．０重量部であることがさらに好ましい。 In the active energy ray-curable adhesive composition according to the adhesive layers (2a) and (2b) of the present invention, a compound represented by the above general formula (1) as a photopolymerization initiator;

(Wherein R ¹ and R ² represent —H, —CH _2b H ₃ , —iPr or Cl, and R ¹ and R ² may be the same or different), respectively, or a general formula ( It is preferable to use together the compound represented by 1) and a photopolymerization initiator that is highly sensitive to light of 380 nm or more, which will be described later. When the compound represented by the general formula (1) is used, the adhesiveness is excellent as compared with a case where a photopolymerization initiator having high sensitivity to light of 380 nm or more is used alone. Among the compounds represented by the general formula (1), diethylthioxanthone in which R ¹ and R ² are —CH _2b H ₃ is particularly preferable. The composition ratio of the compound represented by the general formula (1) in the composition is 0.1 to 5.0 with respect to 100 parts by weight of the total amount of the radical polymerizable compound in the active energy ray-curable adhesive composition. The amount is preferably parts by weight, more preferably 0.5 to 4.0 parts by weight, and even more preferably 0.9 to 3.0 parts by weight.

  Moreover, it is preferable to add a polymerization initiation assistant as required. Examples of polymerization initiators include triethylamine, diethylamine, N-methyldiethanolamine, ethanolamine, 4-dimethylaminobenzoic acid, methyl 4-dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate, isoamyl 4-dimethylaminobenzoate, and the like. Among them, ethyl 4-dimethylaminobenzoate is particularly preferable. When using a polymerization initiation assistant, the amount added is usually 0 to 5 parts by weight, preferably 0 to 4 parts per 100 parts by weight of the total amount of radical polymerizable compounds in the active energy ray-curable adhesive composition. Parts by weight, most preferably 0 to 3 parts by weight.

  Moreover, a well-known photoinitiator can be used together as needed. Since the transparent protective film having UV absorbing ability does not transmit light of 380 nm or less, it is preferable to use a photopolymerization initiator that is highly sensitive to light of 380 nm or more as the photopolymerization initiator. Specifically, 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1 2- (Dimethylamino) -2-[(4-methylphenyl) methyl] -1- [4- (4-morpholinyl) phenyl] -1-butanone, 2,4,6-trimethylbenzoyl-diphenyl-phosphine Oxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, bis (Η5-2,4-cyclopentadien-1-yl) -bis (2,6-difluoro-3- (1H-pyrrole) 1-yl) -phenyl) titanium and the like.

（式中、Ｒ^３、Ｒ^４およびＲ^５は−Ｈ、−ＣＨ_３ｂＨ_２ｂＨ_３、−ｉＰｒまたはＣｌを示し、Ｒ^３、Ｒ^４およびＲ^５は同一または異なっても良い）を使用することが好ましい。一般式（２）で表される化合物としては、市販品でもある２−メチル−１−（４−メチルチオフェニル）−２−モルフォリノプロパン−１−オン（商品名：ＩＲＧＡＣＵＲＥ９０７ メーカー：ＢＡＳＦ）が好適に使用可能である。その他、２−ベンジル−２−ジメチルアミノ−１−（４−モルフォリノフェニル）−ブタノン−１（商品名：ＩＲＧＡＣＵＲＥ３６９ メーカー：ＢＡＳＦ）、２−（ジメチルアミノ）−２−［（４−メチルフェニル）メチル］−１−［４−（４−モルホリニル）フェニル］−１−ブタノン（商品名：ＩＲＧＡＣＵＲＥ３７９ メーカー：ＢＡＳＦ）が感度が高いため好ましい。 In particular, as a photopolymerization initiator, in addition to the photopolymerization initiator of the general formula (1), a compound represented by the following general formula (2);

(Wherein R ³ , R ⁴ and R ⁵ represent —H, —CH _3b H _2b H ₃ , —iPr or Cl, and R ³ , R ⁴ and R ⁵ may be the same or different). It is preferable. As the compound represented by the general formula (2), 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one (trade name: IRGACURE907 manufacturer: BASF) which is also a commercially available product is suitable. Can be used. In addition, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1 (trade name: IRGACURE369 manufacturer: BASF), 2- (dimethylamino) -2-[(4-methylphenyl) Methyl] -1- [4- (4-morpholinyl) phenyl] -1-butanone (trade name: IRGACURE379 manufacturer: BASF) is preferable because of its high sensitivity.

  In addition, the active energy ray-curable adhesive composition according to the adhesive layers (2a) and (2b) of the present invention includes various additives as other optional components as long as the objects and effects of the present invention are not impaired. Can be blended. Such additives include epoxy resin, polyamide, polyamideimide, polyurethane, polybutadiene, polychloroprene, polyether, polyester, styrene-butadiene block copolymer, petroleum resin, xylene resin, ketone resin, cellulose resin, fluorine-based oligomer, Polymers or oligomers such as silicone oligomers and polysulfide oligomers; polymerization inhibitors such as phenothiazine and 2,6-di-T-butyl-4-methylphenol; polymerization initiators; leveling agents; wettability improvers; Plasticizers; UV absorbers; inorganic fillers; pigments; dyes and the like.

  The active energy ray-curable adhesive composition according to the present invention is cured by irradiating active energy rays to form adhesive layers (2a) and (2b).

  As the active energy ray, an electron beam, one containing visible light having a wavelength range of 380 nm to 450 nm can be used. The long wavelength limit of visible light is about 780 nm, but visible light exceeding 450 nm does not contribute to the absorption of the polymerization initiator, but may cause heat generation of the transparent protective film and the polarizer. For this reason, in the present invention, it is preferable to block visible light on the long wavelength side exceeding 450 nm using a band-pass filter.

  As long as the irradiation conditions of an electron beam are conditions which can harden the said active energy ray hardening-type adhesive composition, arbitrary appropriate conditions are employable. For example, in the electron beam irradiation, the acceleration voltage is preferably 5 kV to 300 kV, and more preferably 10 kV to 250 kV. If the acceleration voltage is less than 5 kV, the electron beam may not reach the adhesive and may be insufficiently cured. If the acceleration voltage exceeds 300 kV, the penetration force through the sample is too strong and damages the transparent protective film and the polarizer. There is a risk of giving. The irradiation dose is 5 to 100 kGy, more preferably 10 to 75 kGy. When the irradiation dose is less than 5 kGy, the adhesive becomes insufficiently cured, and when it exceeds 100 kGy, the transparent protective film and the polarizer are damaged, resulting in a decrease in mechanical strength and yellowing, thereby obtaining predetermined optical characteristics. I can't.

  Electron beam irradiation is usually performed in an inert gas, but if necessary, it may be performed in the atmosphere or under a condition in which a small amount of oxygen is introduced. Depending on the material of the transparent protective film, by appropriately introducing oxygen, the transparent protective film surface where the electron beam first hits can be obstructed to prevent oxygen damage and prevent damage to the transparent protective film. An electron beam can be irradiated efficiently.

  However, in the method for producing a polarizing film according to the present invention, while improving the adhesive performance of the adhesive layers (2a) and (2b) between the polarizer (1) and the transparent protective films (3a) and (3b), In order to prevent curling of the polarizing film, use active energy rays containing visible light having a wavelength range of 380 nm to 450 nm, particularly active energy rays having the largest irradiation amount of visible light having a wavelength range of 380 nm to 450 nm. Is preferred. When using a transparent protective film (ultraviolet non-transparent transparent protective film) imparted with ultraviolet absorbing ability, light having a wavelength shorter than 380 nm is absorbed, so that light having a wavelength shorter than 380 nm is an active energy ray-curable adhesive composition. Since it does not reach the product, it does not contribute to the polymerization reaction. Furthermore, light having a wavelength shorter than 380 nm absorbed by the transparent protective film is converted into heat, and the transparent protective film itself generates heat, which causes defects such as curling and wrinkling of the polarizing film. Therefore, in the present invention, it is preferable to use a device that does not emit light having a wavelength shorter than 380 nm as the active energy ray generator, and more specifically, the integrated illuminance in the wavelength range of 380 to 440 nm and the wavelength range of 250 to 370 nm. Is preferably 100: 0 to 100: 50, and more preferably 100: 0 to 100: 40. As the active energy ray satisfying such a relationship of integrated illuminance, a gallium-filled metal halide lamp and an LED light source that emits light in the wavelength range of 380 to 440 nm are preferable. Alternatively, low pressure mercury lamp, medium pressure mercury lamp, high pressure mercury lamp, ultra high pressure mercury lamp, incandescent lamp, xenon lamp, halogen lamp, carbon arc lamp, metal halide lamp, fluorescent lamp, tungsten lamp, gallium lamp, excimer laser or sunlight as the light source, It is also possible to use a light having a wavelength shorter than 380 nm by using a band pass filter. In order to prevent the curling of the polarizing film while improving the adhesive performance of the adhesive layer between the polarizer and the transparent protective film, it is obtained by using a bandpass filter capable of blocking light having a wavelength shorter than 400 nm. It is preferable to use an active energy ray having a wavelength of 405 nm obtained by using an active energy ray or an LED light source.

  In the visible light curable type, it is preferable to warm the active energy ray-curable adhesive composition before irradiation with visible light (pre-irradiation warming), in which case it is preferable to heat to 40 ° C. or higher. It is more preferable to heat to more than ° C. It is also preferable to warm the active energy ray-curable adhesive composition after irradiation with visible light (heating after irradiation), in which case it is preferable to warm to 40 ° C. or higher, and warm to 50 ° C. or higher. It is more preferable.

  The active energy ray-curable adhesive composition according to the present invention can be suitably used particularly when forming an adhesive layer that bonds a polarizer and a transparent protective film having a light transmittance of less than 5% at a wavelength of 365 nm. It is. Here, the active energy ray-curable adhesive composition according to the adhesive layers (2a) and (2b) contains the above-described photopolymerization initiator of the general formula (1), thereby having a UV absorbing ability. The adhesive layers (2a) and (2b) can be cured by irradiation with ultraviolet rays through the protective films (3a) and (3b). Accordingly, the adhesive layers (2a) and (2b) can be cured also in the polarizing film in which the transparent protective films (3a) and (3b) having UV absorbing ability are laminated on both surfaces of the polarizer (1). However, as a matter of course, the adhesive layers (2a) and (2b) can be cured also in a polarizing film in which the transparent protective films (3a) and (3b) having no UV absorbing ability are laminated. In addition, the transparent protective films (3a) and (3b) having UV absorbing ability mean transparent protective films having a transmittance of less than 10% for light of 380 nm.

  As a method for imparting UV absorbing ability to the transparent protective films (3a) and (3b), a method of containing an ultraviolet absorber in the transparent protective film or a surface treatment layer containing an ultraviolet absorber on the surface of the transparent protective film The method of laminating is mentioned.

  Specific examples of the ultraviolet absorber include conventionally known oxybenzophenone compounds, benzotriazole compounds, salicylic acid ester compounds, benzophenone compounds, cyanoacrylate compounds, nickel complex compounds, triazine compounds, and the like. .

  The adhesive layers (2a) and (2b) formed by the active energy ray-curable adhesive composition have higher durability than the aqueous adhesive layer. Moreover, it is preferable to control so that the thickness of an adhesive bond layer may be set to 0.01-5 micrometers. The thickness of the adhesive layer is more preferably 0.01 to 2 μm, and still more preferably 0.01 to 1 μm. When the thickness of the adhesive layer is smaller than 0.01 μm, the cohesive force of the adhesive force itself cannot be obtained, and the adhesive strength may not be obtained.

The method for producing a polarizing film according to the present invention includes a coating step of coating an active energy ray-curable adhesive composition on at least one surface of the photon (1) and the transparent protective film (3a),
A coating step of coating the active energy ray-curable adhesive composition on at least one surface of the polarizer (1) and the transparent protective film (3b);
A bonding step of bonding the polarizer (1) and the transparent protective films (3a) and (3b);
Through the adhesive layers (2a) and (2b) obtained by irradiating the active energy rays and curing the active energy ray-curable adhesive composition, the polarizer (1) and the transparent A bonding step of bonding the protective films (3a) and (3b). When the moisture content of the said polarizer at the time of the said bonding process is less than 15%, since the drying load of the polarizing film obtained after a bonding process (lamination) can be reduced, it is preferable. Examples of such a low moisture content polarizer include a thin polarizer that can easily reduce the moisture content during drying by heating. The thin polarizer will be described later.

  The polarizer (1) and the transparent protective films (3a) and (3b) may be subjected to a surface modification treatment before applying the active energy ray-curable adhesive composition. Specific examples of the treatment include corona treatment, plasma treatment, saponification treatment, excimer treatment, or flame treatment.

  The coating method of the active energy ray-curable adhesive composition is appropriately selected depending on the viscosity of the composition and the target thickness. Examples of coating methods include reverse coaters, gravure coaters (direct, reverse and offset), bar reverse coaters, roll coaters, die coaters, bar coaters, rod coaters and the like. In addition, for coating, a method such as a dapping method can be appropriately used.

  The polarizer (1) and the transparent protective films (3a) and (3b) are bonded to each other through the adhesive applied as described above. Bonding of the polarizer and the transparent protective film can be performed with a roll laminator or the like.

After laminating the polarizer (1) and the transparent protective films (3a) and (3b), the active energy ray-curable adhesive composition is cured by irradiating active energy rays (such as electron beams, ultraviolet rays and visible rays). To form an adhesive layer. Irradiation directions of active energy rays (such as electron beams, ultraviolet rays, and visible rays) can be applied from any appropriate direction. Preferably, it irradiates from the transparent protective film side. When irradiated from the polarizer side, the polarizer may be deteriorated by active energy rays (electron beams, ultraviolet rays, visible rays, etc.).

  In addition, transparent protective films (3a) and (3b) having a light transmittance of less than 5% at a wavelength of 365 nm are provided on both surfaces of the polarizer (1) via the adhesive layers (2a) and (2b). When manufacturing a polarizing film, the active energy ray is first irradiated from the side of one transparent protective film (3a) or (3b), and then from the side of the other transparent protective film (3b) or (3a). Through the adhesive layers (2a) and (2b) obtained by irradiating active energy rays to cure the active energy ray-curable adhesive composition, the polarizer (1) and the transparent protective film ( An adhesion step of adhering 3a) and (3b) may be included.

  First, active energy rays are irradiated from the side of one transparent protective film (3a) or (3b), and then active energy rays are irradiated from the side of the other transparent protective film (3b) or (3a) (2 Stepped irradiation) prevents curling of the transparent protective film (3a) or (3b) compared to one-step irradiation of irradiating active energy rays only from one transparent protective film (3a) or (3b) side. Meanwhile, the reaction rate of the adhesive layers (2a) and (2b) can be increased, and the adhesion between the polarizer (1) and the transparent protective films (3a) and (3b) can be increased.

  When the polarizing film according to the present invention is produced in a continuous line, the line speed depends on the curing time of the adhesive, but is preferably 1 to 500 m / min, more preferably 5 to 300 m / min, and still more preferably 10 to 100 m / min. min. If the line speed is too low, the productivity is poor, or the damage to the transparent protective films (3a) and (3b) is too great, and a polarizing film that can withstand a durability test cannot be produced. When the line speed is too high, the adhesive is not sufficiently cured, and the target adhesiveness may not be obtained.

  The polarizing film of the present invention comprises an adhesive layer (2a) in which the polarizer (1) and the transparent protective films (3a) and (3b) are formed by a cured layer of the active energy ray-curable adhesive composition. ) And (2b), an easy-adhesion layer can be provided between the transparent protective films (3a) and (3b) and the adhesive layers (2a) and (2b). The easy adhesion layer can be formed of, for example, various resins having a polyester skeleton, a polyether skeleton, a polycarbonate skeleton, a polyurethane skeleton, a silicone-based, a polyamide skeleton, a polyimide skeleton, a polyvinyl alcohol skeleton, and the like. These polymer resins can be used alone or in combination of two or more. Moreover, you may add another additive for formation of an easily bonding layer. Specifically, a stabilizer such as a tackifier, an ultraviolet absorber, an antioxidant, and a heat resistance stabilizer may be used.

  The easy adhesion layer is usually provided in advance on a transparent protective film, and the easy adhesion layer side of the transparent protective film and the polarizer are bonded together with an adhesive layer. The easy-adhesion layer is formed by coating and drying the material for forming the easy-adhesion layer on the transparent protective film by a known technique. The material for forming the easy-adhesion layer is usually adjusted as a solution diluted to an appropriate concentration in consideration of the thickness after drying and the smoothness of coating. The thickness of the easy adhesion layer after drying is preferably 0.01 to 5 μm, more preferably 0.02 to 2 μm, and still more preferably 0.05 to 1 μm. Note that a plurality of easy-adhesion layers can be provided, but also in this case, the total thickness of the easy-adhesion layers is preferably in the above range.

  The polarizer (1) is not particularly limited, and various types can be used. Examples of the polarizer include hydrophilic polymer films such as polyvinyl alcohol film, partially formalized polyvinyl alcohol film, and ethylene / vinyl acetate copolymer partially saponified film, and two colors such as iodine and dichroic dye. And polyene-based oriented films such as those obtained by adsorbing a functional material and uniaxially stretched, polyvinyl alcohol dehydrated products and polyvinyl chloride dehydrochlorinated products. Among these, a polarizer composed of a polyvinyl alcohol film and a dichroic material such as iodine is preferable. The thickness of these polarizers is not particularly limited, but is generally about 80 μm or less.

  A polarizer obtained by dyeing a polyvinyl alcohol film with iodine and uniaxially stretching it can be produced, for example, by dyeing polyvinyl alcohol in an aqueous solution of iodine and stretching it 3 to 7 times the original length. If necessary, it can be immersed in an aqueous solution of boric acid or potassium iodide. Further, if necessary, the polyvinyl alcohol film may be immersed in water and washed before dyeing. In addition to washing the polyvinyl alcohol film surface with dirt and anti-blocking agents by washing the polyvinyl alcohol film with water, it also has the effect of preventing unevenness such as uneven coloring by swelling the polyvinyl alcohol film. is there. Stretching may be performed after dyeing with iodine, may be performed while dyeing, or may be dyed with iodine after stretching. The film can be stretched in an aqueous solution of boric acid or potassium iodide or in a water bath.

  As the polarizer, a thin polarizer having a thickness of 10 μm or less can be used. From the viewpoint of thinning, the thickness is preferably 1 to 7 μm. Such a thin polarizer is preferable in that the thickness unevenness is small, the visibility is excellent, the dimensional change is small, the durability is excellent, and the thickness of the polarizing film can be reduced. Further, since the thin polarizer can easily reduce the moisture content during heat drying, it can be suitably used as a polarizer having a moisture content of 15% or less.

  As the thin polarizer, representatively, JP-A-51-069644, JP-A-2000-338329, WO2010 / 100917 pamphlet, PCT / JP2010 / 001460 specification, or Japanese Patent Application 2010- The thin polarizing film described in 269002 specification and Japanese Patent Application No. 2010-263692 specification can be mentioned. These thin polarizing films can be obtained by a production method including a step of stretching a polyvinyl alcohol-based resin (hereinafter also referred to as PVA-based resin) layer and a stretching resin base material in a laminated state and a step of dyeing. With this manufacturing method, even if the PVA-based resin layer is thin, it can be stretched without problems such as breakage due to stretching by being supported by the stretching resin substrate.

  As the thin polarizing film, among the production methods including the step of stretching in the state of a laminate and the step of dyeing, WO2010 / 100917 pamphlet, PCT / PCT / PCT / JP 2010/001460 specification, or Japanese Patent Application No. 2010-269002 and Japanese Patent Application No. 2010-263692 as described in the manufacturing method including a step of stretching in a boric acid aqueous solution is preferable. What is obtained by the manufacturing method including the process of extending | stretching in the air auxiliary | assistant before extending | stretching in the boric acid aqueous solution as described in Japanese Patent Application No. 2010-269002 and Japanese Patent Application No. 2010-263692 is preferable.

  The thin high-performance polarizing film described in the specification of PCT / JP2010 / 001460 is a thin film having a thickness of 7 μm or less made of a PVA-based resin oriented with a dichroic material, which is integrally formed on a resin base material. It is a high-functional polarizing film, and has optical properties such as a single transmittance of 42.0% or more and a degree of polarization of 99.95% or more.

  The thin high-performance polarizing film generates a PVA-based resin layer by applying and drying a PVA-based resin on a resin substrate having a thickness of at least 20 μm, and the generated PVA-based resin layer is used as a dichroic dyeing solution. So that the dichroic substance is adsorbed on the PVA resin layer, and the PVA resin layer on which the dichroic substance is adsorbed is integrated with the resin base material in the boric acid aqueous solution so that the total draw ratio is the original length. It can manufacture by extending | stretching so that it may become 5 times or more.

  Moreover, it is a method for producing a laminate film including a thin high-performance polarizing film in which a dichroic substance is oriented, and includes a resin base material having a thickness of at least 20 μm and a PVA resin on one side of the resin base material. The said laminated body containing the process of producing | generating the laminated body film containing the PVA-type resin layer formed by apply | coating and drying aqueous solution, and the PVA-type resin layer formed in the single side | surface of the resin base material A step of adsorbing the dichroic substance to the PVA resin layer contained in the laminate film by immersing the film in a dye solution containing the dichroic substance, and a PVA resin adsorbing the dichroic substance A step of stretching the laminate film including a layer in a boric acid aqueous solution so that the total stretching ratio is 5 times or more of the original length, and a PVA resin layer on which a dichroic substance is adsorbed Stretched together with As a result, a thickness of 7 μm or less, a single transmittance of 42.0% or more, and a degree of polarization of 99.95% or more are formed of a PVA resin layer in which a dichroic material is oriented on one side of a resin base The thin high-performance polarizing film can be manufactured by including a step of manufacturing a laminate film on which a thin high-performance polarizing film having the above optical characteristics is formed.

  The above-mentioned Japanese Patent Application Nos. 2010-269002 and 2010-263692 are thin polarizing films, which are polarizing films of a continuous web made of a PVA-based resin in which a dichroic material is oriented, and are amorphous esters. A laminate including a PVA-based resin layer formed on a thermoplastic resin base material is stretched in a two-stage stretching process consisting of air-assisted stretching and boric acid-water stretching to a thickness of 10 μm or less. It is. Such a thin polarizing film has P> − (100.929T-42.4-1) × 100 (where T <42.3) and P ≧ 99, where T is the single transmittance and P is the polarization degree. .9 (where T ≧ 42.3) is preferable.

  Specifically, the thin polarizing film is a stretch intermediate formed of an oriented PVA resin layer by high-temperature stretching in the air with respect to the PVA resin layer formed on the amorphous ester thermoplastic resin substrate of the continuous web. A colored intermediate product comprising a PVA-based resin layer in which a dichroic material (preferably iodine or a mixture of iodine and an organic dye) is oriented by adsorption of the dichroic material to the stretched intermediate product and a step of generating the product. A thin polarizing film comprising a step of forming a product, and a step of generating a polarizing film having a thickness of 10 μm or less comprising a PVA-based resin layer in which a dichroic material is oriented by stretching in a boric acid solution with respect to a colored intermediate product It can be manufactured by a manufacturing method.

In this production method, the total draw ratio of the PVA resin layer formed on the amorphous ester thermoplastic resin base material by high-temperature drawing in air and drawing in boric acid solution should be 5 times or more. desirable. The liquid temperature of the boric acid aqueous solution for boric-acid water extending | stretching can be 60 degreeC or more. Before stretching the colored intermediate product in the aqueous boric acid solution, it is desirable to insolubilize the colored intermediate product. In this case, the colored intermediate product is added to the aqueous boric acid solution whose liquid temperature does not exceed 40 ° C. It is desirable to do so by dipping. The amorphous ester-based thermoplastic resin base material is amorphous polyethylene containing copolymerized polyethylene terephthalate copolymerized with isophthalic acid, copolymerized polyethylene terephthalate copolymerized with cyclohexanedimethanol, or other copolymerized polyethylene terephthalate. It can be terephthalate and is preferably made of a transparent resin, and the thickness thereof can be 7 times or more the thickness of the PVA resin layer to be formed. Moreover, the draw ratio of the high temperature stretching in the air is preferably 3.5 times or less, and the stretching temperature of the high temperature stretching in the air is preferably not less than the glass transition temperature of the PVA resin, specifically in the range of 95 ° C to 150 ° C. When performing high temperature stretching in the air by free end uniaxial stretching, the total stretching ratio of the PVA resin layer formed on the amorphous ester thermoplastic resin base material is preferably 5 to 7.5 times . In addition, when performing high-temperature stretching in the air by uniaxial stretching at the fixed end, the total stretching ratio of the PVA-based resin layer formed on the amorphous ester-based thermoplastic resin base material is 5 times or more and 8.5 times or less. Is preferred.
More specifically, a thin polarizing film can be produced by the following method.

  A base material of a continuous web of isophthalic acid copolymerized polyethylene terephthalate (amorphous PET) in which 6 mol% of isophthalic acid is copolymerized is prepared. The glass transition temperature of amorphous PET is 75 ° C. A laminate comprising a continuous web of amorphous PET substrate and a polyvinyl alcohol (PVA) layer is prepared as follows. Incidentally, the glass transition temperature of PVA is 80 ° C.

  A 200 μm-thick amorphous PET base material and a 4-5% concentration PVA aqueous solution in which PVA powder having a polymerization degree of 1000 or more and a saponification degree of 99% or more are dissolved in water are prepared. Next, a PVA aqueous solution is applied to a 200 μm thick amorphous PET substrate and dried at a temperature of 50 to 60 ° C. to obtain a laminate in which a 7 μm thick PVA layer is formed on the amorphous PET substrate. .

  A laminated body including a PVA layer having a thickness of 7 μm is subjected to the following steps including a two-step stretching process of air-assisted stretching and boric acid water stretching to produce a thin high-functional polarizing film having a thickness of 3 μm. In the first-stage aerial auxiliary stretching step, the laminate including the 7 μm-thick PVA layer is integrally stretched with the amorphous PET substrate to produce a stretched laminate including the 5 μm-thick PVA layer. Specifically, in this stretched laminate, a laminate including a 7 μm-thick PVA layer is subjected to a stretching apparatus disposed in an oven set to a stretching temperature environment of 130 ° C. so that the stretching ratio is 1.8 times. Are stretched uniaxially at the free end. By this stretching treatment, the PVA layer contained in the stretched laminate is changed to a 5 μm thick PVA layer in which PVA molecules are oriented.

  Next, a colored laminate in which iodine is adsorbed on a PVA layer having a thickness of 5 μm in which PVA molecules are oriented is generated by a dyeing process. Specifically, this colored laminate has a single layer transmittance of the PVA layer constituting the high-functional polarizing film that is finally produced by using the stretched laminate in a staining solution containing iodine and potassium iodide at a liquid temperature of 30 ° C. Iodine is adsorbed to the PVA layer contained in the stretched laminate by dipping for an arbitrary period of time so as to be 40 to 44%. In this step, the staining solution uses water as a solvent and an iodine concentration in the range of 0.12 to 0.30% by weight and a potassium iodide concentration in the range of 0.7 to 2.1% by weight. The concentration ratio of iodine and potassium iodide is 1 to 7. Incidentally, potassium iodide is required to dissolve iodine in water. More specifically, by immersing the stretched laminate in a dyeing solution having an iodine concentration of 0.30% by weight and a potassium iodide concentration of 2.1% by weight for 60 seconds, iodine is applied to a 5 μm-thick PVA layer in which PVA molecules are oriented. A colored laminate is adsorbed on the substrate.

  Further, the colored laminated body is further stretched integrally with the amorphous PET base material by the second stage boric acid underwater stretching step to produce an optical film laminate including a PVA layer constituting a highly functional polarizing film having a thickness of 3 μm. To do. Specifically, this optical film laminate is stretched by applying a colored laminate to a stretching apparatus provided in a treatment apparatus set to a boric acid aqueous solution having a liquid temperature range of 60 to 85 ° C. containing boric acid and potassium iodide. It is stretched uniaxially at the free end so that the magnification is 3.3 times. More specifically, the liquid temperature of the boric acid aqueous solution is 65 ° C. It also has a boric acid content of 4 parts by weight with respect to 100 parts by weight of water and a potassium iodide content of 5 parts by weight with respect to 100 parts by weight of water. In this step, the colored laminate with adjusted iodine adsorption amount is first immersed in a boric acid aqueous solution for 5 to 10 seconds. After that, the colored laminate is passed as it is between a plurality of sets of rolls having different peripheral speeds, which is a stretching apparatus provided in the processing apparatus, and the stretching ratio is freely increased to 3.3 times over 30 to 90 seconds. Stretch uniaxially. By this stretching treatment, the PVA layer contained in the colored laminate is changed into a PVA layer having a thickness of 3 μm in which the adsorbed iodine is oriented higher in one direction as a polyiodine ion complex. This PVA layer constitutes a highly functional polarizing film of the optical film laminate.

  Although not an indispensable step for the production of an optical film laminate, the optical film laminate was removed from the boric acid aqueous solution and adhered to the surface of the 3 μm-thick PVA layer formed on the amorphous PET substrate by the washing step. It is preferable to wash boric acid with an aqueous potassium iodide solution. Thereafter, the washed optical film laminate is dried by a drying process using hot air at 60 ° C. The cleaning process is a process for eliminating appearance defects such as boric acid precipitation.

  Similarly, it is not an indispensable process for producing an optical film laminate, but an adhesive is applied to the surface of a 3 μm-thick PVA layer formed on an amorphous PET substrate by a bonding and / or transfer process. However, after bonding the 80 μm thick triacetyl cellulose film, the amorphous PET substrate can be peeled off, and the 3 μm thick PVA layer can be transferred to the 80 μm thick triacetyl cellulose film.

[Other processes]
The manufacturing method of said thin-shaped polarizing film may include another process other than the said process. Examples of other steps include an insolubilization step, a crosslinking step, and a drying (adjustment of moisture content) step. The other steps can be performed at any appropriate timing.
The insolubilization step is typically performed by immersing the PVA resin layer in a boric acid aqueous solution. By performing the insolubilization treatment, water resistance can be imparted to the PVA resin layer. The concentration of the boric acid aqueous solution is preferably 1 to 4 parts by weight with respect to 100 parts by weight of water. The liquid temperature of the insolubilizing bath (boric acid aqueous solution) is preferably 20 ° C to 50 ° C. Preferably, the insolubilization step is performed after the laminate is manufactured and before the dyeing step and the underwater stretching step.
The crosslinking step is typically performed by immersing the PVA resin layer in an aqueous boric acid solution. By performing the crosslinking treatment, water resistance can be imparted to the PVA resin layer. The concentration of the boric acid aqueous solution is preferably 1 to 4 parts by weight with respect to 100 parts by weight of water. Moreover, when performing a bridge | crosslinking process after the said dyeing | staining process, it is preferable to mix | blend iodide further. By blending iodide, elution of iodine adsorbed on the PVA resin layer can be suppressed. The blending amount of iodide is preferably 1 part by weight to 5 parts by weight with respect to 100 parts by weight of water. Specific examples of the iodide are as described above. The liquid temperature of the crosslinking bath (boric acid aqueous solution) is preferably 20 ° C to 50 ° C. Preferably, the crosslinking step is performed before the second boric acid aqueous drawing step. In a preferred embodiment, the dyeing step, the crosslinking step, and the second boric acid aqueous drawing step are performed in this order.

The material for forming the transparent protective films (3a) and (3b) provided on both surfaces of the polarizer (1) is excellent in transparency, mechanical strength, thermal stability, moisture barrier property, isotropy, etc. are preferred, more preferably those particular moisture permeability is not more than 150g ^/ m 2 ^/ 24h, being particularly preferred less 140g ^/ m 2 ^/ 24h, further the following are preferred 120g ^/ m 2 ^/ 24h. The moisture permeability is determined by the method described in the examples.

In the polarizing film, when the moisture permeability less is used in the transparent protective film 150g / m 2 / ^24h is hardly contains the moisture in the air in the polarizing film, to suppress the moisture content change of the polarizing film itself it can. As a result, the curling and dimensional change of the polarizing film caused by the storage environment can be suppressed.

  The thickness of the transparent protective films (3a) and (3b) can be appropriately determined, but is generally about 1 to 500 μm from the viewpoint of workability such as strength and handleability, and thin layer properties, and 1 to 300 μm is Preferably, 5-200 micrometers is more preferable. Furthermore, 10-200 micrometers is preferable and 20-80 micrometers is preferable.

  Examples of the material for forming the transparent protective film satisfying the low moisture permeability include polyester resins such as polyethylene terephthalate and polyethylene naphthalate; polycarbonate resins; arylate resins; amide resins such as nylon and aromatic polyamide; polyethylene and polypropylene Polyolefin polymers such as ethylene / propylene copolymers, cyclic olefin resins having a cyclo or norbornene structure, (meth) acrylic resins, fluorinated polystyrene, or a mixture thereof can be used. Among the resins, polycarbonate resins, cyclic polyolefin resins, and (meth) acrylic resins are preferable, and cyclic polyolefin resins, (meth) acrylic resins, and fluorinated polystyrene are particularly preferable.

  A specific example of the cyclic polyolefin resin is preferably a norbornene resin. The cyclic olefin-based resin is a general term for resins that are polymerized using a cyclic olefin as a polymerization unit. Resin. Specific examples include ring-opening (co) polymers of cyclic olefins, addition polymers of cyclic olefins, cyclic olefins and soot-olefins such as ethylene and propylene (typically random copolymers), And graft polymers obtained by modifying them with an unsaturated carboxylic acid or a derivative thereof, and hydrides thereof. Specific examples of the cyclic olefin include norbornene monomers.

  Various products are commercially available as the cyclic polyolefin resin. As specific examples, trade names “ZEONEX” and “ZEONOR” manufactured by ZEON CORPORATION, product names “ARTON” manufactured by JSR Corporation, “TOPAS” manufactured by TICONA, and product names manufactured by Mitsui Chemicals, Inc. “APEL”.

  The (meth) acrylic resin preferably has a Tg (glass transition temperature) of 115 ° C. or higher, more preferably 120 ° C. or higher, still more preferably 125 ° C. or higher, and particularly preferably 130 ° C. or higher. When Tg is 115 ° C. or higher, the polarizing plate can be excellent in durability. Although the upper limit of Tg of the (meth) acrylic resin is not particularly limited, it is preferably 170 ° C. or lower from the viewpoint of moldability and the like. From (meth) acrylic resin, a film having in-plane retardation (RE) and thickness direction retardation (RTH) of almost zero can be obtained.

  As the (meth) acrylic resin, any appropriate (meth) acrylic resin can be adopted as long as the effects of the present invention are not impaired. For example, poly (meth) acrylic acid ester such as polymethyl methacrylate, methyl methacrylate- (meth) acrylic acid copolymer, methyl methacrylate- (meth) acrylic acid ester copolymer, methyl methacrylate-acrylic acid ester- (Meth) acrylic acid copolymer, (meth) methyl acrylate-styrene copolymer (MS resin, etc.), polymer having an alicyclic hydrocarbon group (for example, methyl methacrylate-cyclohexyl methacrylate copolymer, Methyl methacrylate- (meth) acrylate norbornyl copolymer, etc.). Preferably, poly (meth) acrylate C1-6 alkyl such as poly (meth) acrylate methyl is used. More preferred is a methyl methacrylate resin containing methyl methacrylate as a main component (50 to 100% by weight, preferably 70 to 100% by weight).

  Specific examples of (meth) acrylic resins include (meth) acrylic resins having a ring structure in the molecule described in, for example, Acrypet VH and Acrypet VRL20A manufactured by Mitsubishi Rayon Co., Ltd., and JP-A-2004-70296. And high Tg (meth) acrylic resins obtained by intramolecular crosslinking or intramolecular cyclization reaction.

  As the (meth) acrylic resin, a (meth) acrylic resin having a lactone ring structure can also be used. It is because it has high mechanical strength by high heat resistance, high transparency, and biaxial stretching.

  Examples of the (meth) acrylic resin having a lactone ring structure include JP 2000-230016, JP 2001-151814, JP 2002-120326, JP 2002-254544, and JP 2005. Examples thereof include (meth) acrylic resins having a lactone ring structure described in Japanese Patent No. 146084.

  The transparent protective films (3a) and (3b) having low moisture permeability provided on both sides of the polarizer (1) may use transparent protective films made of the same polymer material on the front and back sides, and different polymer materials. You may use the transparent protective film which consists of etc.

  As the transparent protective film (3a), a cyclic polyolefin resin film or a fluorinated polystyrene film is preferably used from the viewpoint of retardation design and film strength. As the transparent protective film (3b), it is preferable to use an acrylic resin film, a cyclic polyolefin resin film, or a polyester resin film from the viewpoint of cost and versatility.

  As the transparent protective film (3a) and / or (3b), a retardation plate having a retardation with a front phase difference of 40 nm or more and / or a thickness direction retardation of 80 nm or more can be used. The front phase difference is usually controlled in the range of 40 to 200 nm, and the thickness direction phase difference is usually controlled in the range of 80 to 300 nm. When a retardation film is used as the transparent protective film, the retardation film functions also as a transparent protective film, so that the thickness can be reduced.

  Examples of the retardation plate include a birefringent film obtained by uniaxially or biaxially stretching a polymer material, a liquid crystal polymer alignment film, and a liquid crystal polymer alignment layer supported by a film. The thickness of the retardation plate is not particularly limited, but is generally about 20 to 150 μm.

  In addition, the film which has the said phase difference can be separately bonded to the transparent protective film which does not have a phase difference, and the said function can be provided.

  A functional layer such as a hard coat layer, an antireflection layer, an anti-sticking layer, a diffusion layer or an antiglare layer is provided on the surface of the transparent protective film (3a) and / or (3b) where the polarizer (1) is not adhered. Can do. The functional layers such as the hard coat layer, the antireflection layer, the antisticking layer, the diffusion layer and the antiglare layer can be provided on the transparent protective film (3a) and / or (3b) itself. The film (3a) and / or (3b) may be provided separately.

  Moreover, as the transparent protective film (3c) shown in FIGS. 2 to 4, the same material as the transparent protective film (3a) and / or (3b) can be used. The transparent protective film (3c) of the embodiment shown in FIGS. 2 to 4 is preferably a cyclic polyolefin resin film from the viewpoint of retardation design and film strength.

  The polarizing film of the present invention can be used as an optical film laminated with another optical layer in practical use. The optical layer is not particularly limited. For example, for forming a liquid crystal display device such as a reflection plate, a semi-transmission plate, a retardation plate (including wavelength plates such as 1/2 and 1/4), and a viewing angle compensation film. One or more optical layers that may be used can be used. In particular, a reflective polarizing film or semi-transmissive polarizing film in which a polarizing plate or a semi-transmissive reflecting plate is further laminated on the polarizing film of the present invention, an elliptical polarizing film or circularly polarizing film in which a retardation film is further laminated on a polarizing film. A wide viewing angle polarizing film obtained by further laminating a viewing angle compensation film on a film or a polarizing film, or a polarizing film obtained by further laminating a brightness enhancement film on the polarizing film is preferred.

  An optical film obtained by laminating the above optical layer on a polarizing film can be formed by a method of sequentially laminating separately in the manufacturing process of a liquid crystal display device or the like. It is excellent in stability and assembly work, and has the advantage of improving the manufacturing process of a liquid crystal display device and the like. Appropriate bonding means such as an adhesive layer can be used for lamination. When adhering the above polarizing film and other optical films, their optical axes can be set at an appropriate arrangement angle in accordance with the target retardation characteristics.

  An adhesive layer for adhering to other members such as a liquid crystal cell can be provided on the polarizing film described above or an optical film in which at least one polarizing film is laminated. The pressure-sensitive adhesive forming the pressure-sensitive adhesive layer is not particularly limited. For example, an acrylic polymer, silicone-based polymer, polyester, polyurethane, polyamide, polyether, fluorine-based or rubber-based polymer is appropriately selected. Can be used. In particular, those having excellent optical transparency such as an acrylic pressure-sensitive adhesive, exhibiting appropriate wettability, cohesiveness, and adhesive pressure-sensitive adhesive properties, and being excellent in weather resistance, heat resistance and the like can be preferably used.

  The pressure-sensitive adhesive layer can be provided on one side or both sides of a polarizing film or an optical film as an overlapping layer of different compositions or types. Moreover, when providing in both surfaces, it can also be set as adhesive layers, such as a different composition, a kind, and thickness, in the front and back of a polarizing film or an optical film. The thickness of the pressure-sensitive adhesive layer can be appropriately determined according to the purpose of use and adhesive force, and is generally 1 to 500 μm, preferably 1 to 200 μm, and particularly preferably 1 to 100 μm.

  The exposed surface of the adhesive layer is temporarily covered with a separator for the purpose of preventing contamination until it is put into practical use. Thereby, it can prevent contacting an adhesion layer in the usual handling state. As the separator, except for the above thickness conditions, for example, an appropriate thin leaf body such as a plastic film, rubber sheet, paper, cloth, non-woven fabric, net, foamed sheet, metal foil, or a laminate thereof, or a silicone-based or long sheet as necessary. Appropriate ones according to the prior art, such as those coated with an appropriate release agent such as a chain alkyl type, fluorine type or molybdenum sulfide, can be used.

  The polarizing film or the optical film of the present invention can be preferably used for forming various devices such as a liquid crystal display device. The liquid crystal display device can be formed according to the conventional method. That is, a liquid crystal display device is generally formed by appropriately assembling components such as a liquid crystal cell, a polarizing film or an optical film, and an illumination system as necessary, and incorporating a drive circuit. There is no limitation in particular except the point which uses the polarizing film or optical film by invention, and it can apply according to the former. As the liquid crystal cell, any type such as a TN type, an STN type, or a π type can be used.

  An appropriate liquid crystal display device such as a liquid crystal display device in which a polarizing film or an optical film is disposed on one side or both sides of a liquid crystal cell, or a backlight or a reflecting plate that is used in an illumination system can be formed. In that case, the polarizing film or optical film by this invention can be installed in the one side or both sides of a liquid crystal cell. When providing a polarizing film or an optical film on both sides, they may be the same or different. Further, when forming the liquid crystal display device, for example, a single layer or a suitable layer such as a diffusing plate, an antiglare layer, an antireflection film, a protective plate, a prism array, a lens array sheet, a light diffusing plate, a backlight, etc. Two or more layers can be arranged.

  Examples of the present invention will be described below, but the embodiments of the present invention are not limited thereto.

<Tg: Glass transition temperature>
Tg was measured under the following measurement conditions using a TA Instruments dynamic viscoelasticity measuring device RSAIII.
Sample size: width 10mm, length 30mm,
Clamp distance 20mm,
Measurement mode: Tensile, Frequency: 1 Hz, Temperature rising rate: 5 ° C./min Dynamic viscoelasticity was measured and adopted as the temperature Tg of tan δ peak top.

<Water vapor permeability of transparent protective film>
The moisture permeability was measured according to a moisture permeability test (cup method) of JIS Z0208. A sample cut to a diameter of 60 mm was set in a moisture permeable cup containing about 15 g of calcium chloride, and the temperature was 40 ° C. and the humidity was 90% R.D. H. The placed in a constant temperature machine, to determine the moisture permeability by measuring the weight increase of calcium chloride before and after allowing to stand for 24 hours ^{(g / m 2 / 24h)} .

<Transparent protective film>
Transparent protective film (3a): A cyclic polyolefin film having a thickness of 18 μm (manufactured by ZEON Corporation: ZEONOR) was subjected to corona treatment and used.
Transparent protective film (3b): it was used after the corona treatment having a lactone ring structure having a thickness of 50 [mu] m (meth) acrylic resin (moisture permeability ^96g / m 2 / 24h).
Transparent protective film (3c): A fluorinated polystyrene film (manufactured by Eastman Chemical Co.) having a thickness of 5 μm was subjected to corona treatment.

<Active energy rays>
As an active energy ray, ultraviolet rays (gallium filled metal halide lamp) Irradiation device: Fusion UV Systems, Inc. Light HAMMER10 bulb: V bulb Peak illuminance: 1600 mW / cm ² , integrated irradiation amount 1000 / mJ / cm ² (wavelength 380 to 440 nm) )It was used. In addition, the illumination intensity of the ultraviolet-ray was measured using the Sola-Check system by Solatell.

<Production of polarizer>
A polyvinyl alcohol film having an average polymerization degree of 2400, a saponification degree of 99.9 mol%, and a thickness of 75 μm was immersed in warm water at 30 ° C. for 60 seconds to swell. Subsequently, the film was stretched to 3.5 times while dyeing in an iodine solution of 0.3 wt% (weight ratio: iodine / potassium iodide = 0.5 / 8) at 30 ° C. for 1 minute. Thereafter, the total draw ratio was stretched to 6 times while being immersed in a 4% by weight boric acid aqueous solution at 65 ° C. for 0.5 minutes. After stretching, drying was performed in an oven at 70 ° C. for 3 minutes to obtain a polarizer having a thickness of 26 μm. The moisture content of the polarizer was 13.5% by weight.

Examples 1-12 and Comparative Examples 1-10
(Adjustment of active energy ray-curable adhesive composition according to adhesive layer (2a))
According to the recipe shown in Table 1, the components were mixed and stirred at 50 ° C. for 1 hour to obtain an active energy ray-curable adhesive composition. The numerical value of the active energy ray-curable adhesive composition in the table indicates parts by weight.

(Adjustment of active energy ray-curable adhesive composition according to adhesive layer (2b))
40.0 parts by weight of N-hydroxyethylacrylamide (manufactured by Kojinsha),
20.0 parts by weight of tripropylene glycol diacrylate (trade name: Aronix M-220, manufactured by Toagosei Co., Ltd.)
40.0 parts by weight of acryloylmorpholine (manufactured by Kojin Co., Ltd.) and 1.5 parts by weight of a photopolymerization initiator (trade name: KAYACURE DETX-S, diethylthioxanthone, Nippon Kayaku Co., Ltd.) were mixed at 50 ° C. The mixture was stirred for 1 hour to obtain an active energy ray-curable adhesive.

(Production method of polarizing film 1)
An active energy ray-curable adhesive composition relating to the adhesive layer (2a) shown in Table 1 is applied to the corona surface of the transparent protective film (3a) by an MCD coater (manufactured by Fuji Machine Co., Ltd.) (cell shape: honeycomb, gravure roll). (Number of lines: 1000 / INCH, rotation speed 140% / vs. Line speed) was applied to a thickness of 0.5 μm.
Further, an active energy ray-curable adhesive composition related to the adhesive layer (2b) is coated on the corona surface of the transparent protective film (3b) with an MCD coater (manufactured by Fuji Machine Co., Ltd.) (cell shape: honeycomb, number of gravure roll wires). : 1000 pieces / INCH, rotational speed 140% / vs. Line speed), and applied so as to have a thickness of 0.5 μm.
The adhesive-coated surfaces of the transparent protective films (3a) and (3b) were bonded to both sides of the polarizer. Thereafter, from the bonded transparent protective film side (both sides), it is heated to 50 ° C. using an IR heater, and the ultraviolet rays are irradiated on both sides, and the active energy rays according to the adhesive layers (2a) and (2b) After the curable adhesive composition was cured, it was dried with hot air at 70 ° C. for 3 minutes to obtain a polarizing film 1. The line speed of the bonding was 15 m / min.

The following evaluation was performed about the polarizing film obtained in each case. The results are shown in Table 1.
The Tg of the adhesive layer (2b) was 118.9 ° C.

(Production method of polarizing film 2)
An active energy ray-curable adhesive composition relating to the adhesive layer (2a) shown in Table 1 is applied to the corona surface of the transparent protective film (3a) by an MCD coater (manufactured by Fuji Machine Co., Ltd.) (cell shape: honeycomb, gravure roll). (Number of lines: 1000 / INCH, rotation speed 140% / vs. Line speed) was applied to a thickness of 0.5 μm.
Further, an active energy ray-curable adhesive composition related to the adhesive layer (2b) is coated on the corona surface of the transparent protective film (3b) with an MCD coater (manufactured by Fuji Machine Co., Ltd.) (cell shape: honeycomb, number of gravure roll wires). : 1000 pieces / INCH, rotational speed 140% / vs. Line speed), and applied so as to have a thickness of 0.5 μm.
The adhesive-coated surfaces of the transparent protective films (3a) and (3b) were bonded to both sides of the polarizer. Thereafter, from the bonded transparent protective film side (both sides), it is heated to 50 ° C. using an IR heater, and the ultraviolet rays are irradiated on both sides, and the active energy rays according to the adhesive layers (2a) and (2b) After the curable adhesive composition is cured to obtain the polarizing film 1, the active energy ray-curable adhesive according to the adhesive layer (2a) shown in Table 1 is further applied to the corona surface of the transparent protective film (3c). The composition was applied to a thickness of 0.5 μm using an MCD coater (manufactured by Fuji Machinery Co., Ltd.) (cell shape: honeycomb, number of gravure roll wires: 1000 / INCH, rotational speed 140% / vs line speed). The adhesive coating surface of the transparent protective film (3c) was bonded to the (3a) side of the polarizing film 1. Then, after irradiating one side of the ultraviolet rays from the bonded transparent protective film side (3c), the film was dried with hot air at 70 ° C. for 3 minutes to obtain a polarizing film 2. The line speed of the bonding was 15 m / min.

The following evaluation was performed about the polarizing films 1 and 2 obtained by each example. The results are shown in Table 1.
The Tg of the adhesive layer (2b) was 118.9 ° C.

<Adhesive strength>
The polarizing films 1 and 2 are cut into a size of 200 mm parallel to the stretching direction of the polarizer and 20 mm in the orthogonal direction. For the polarizing film 1, between the transparent protective film (3a) and the polarizer, A cut was made with a cutter knife between the transparent protective film (3c) and the transparent protective film (3a), and the polarizing film was bonded to the glass plate. Tensilon peels off the transparent protective film (3a) and the polarizer for the polarizer film 1 in the 90 degree direction, and the transparent protective film (3a) and the transparent protective film (3c) for the polarizer film 2 at a peeling speed of 500 mm / Peeling was performed at min, and the peel strength was measured. Moreover, the infrared absorption spectrum of the peeling surface after peeling was measured by ATR method, and the peeling interface was evaluated based on the following reference | standard.
A: Cohesive failure of the protective film.
B: Interfacial peeling between the protective film / adhesive layer.
C: Interfacial peeling between adhesive layer / polarizer or transparent protective film.
D: Polarization cohesive failure.
In the above criteria, A and D mean that the adhesive force is very excellent because the adhesive force is not less than the cohesive force of the film. On the other hand, B and C mean that the adhesive force at the transparent protective film / adhesive layer (adhesive layer / polarizer) interface is insufficient (adhesive strength is poor). Taking these into consideration, the adhesive strength in the case of A or D is ○, A · B ("cohesive failure of transparent protective film" and "interfacial peeling between transparent protective film / adhesive layer" occur simultaneously) or A -Adhesive strength in the case of C ("cohesive failure of transparent protective film" and "interfacial peeling between adhesive layer / polarizer" occur simultaneously) Δ, adhesive strength in the case of B or C as x To do.

<Drop test>
For the polarizing film 1, an adhesive layer is laminated on the transparent protective film (3a: cyclic polyolefin film) surface, and for the polarizing film 2 on the transparent protective film (3c: fluorinated polystyrene film) surface, and 50 mm in the stretching direction of the polarizer. Cut into a 100 mm rectangle in the vertical direction. A sample was prepared by laminating the polarizing film on a glass plate having a thickness of 0.5 mm, a length of 120 mm, and a width of 60 mm. In addition, the cellophane tape was stuck on the whole surface in order to prevent destruction on the back surface of the glass plate.
The prepared sample was naturally dropped from a height of 1 m. After the dropping was repeated 100 times, the peeled state of the end portion was visually observed.
○: No peeling is confirmed.
(Triangle | delta): Peeling from an edge part is less than 1 mm.
X: Peeling from the end is 1 mm or more.

<Water resistance (warm water immersion test)>
The polarizing films 1 and 2 were cut into a rectangle of 50 mm in the stretching direction of the polarizer and 25 mm in the vertical direction. Immediately after the polarizing films 1 and 2 were immersed in warm water at 60 ° C. for 6 hours, evaluation was performed based on the following criteria. As for the polarizing film 1, peeling between the polarizer / transparent protective films (3a) and (3b) was visually observed. For the polarizing film 2, peeling between the polarizer / transparent protective films (3a) and (3b) and between the transparent protective films (3a) and (3c) was visually observed.
○: No peeling was observed between the two.
(Triangle | delta): Although peeling has arisen from the edge part between one, peeling of a center part is not confirmed.
X: Peeling occurred on the entire surface between either.

<Damp heat durability>
For the polarizing film 1, a pressure-sensitive adhesive layer is laminated on the transparent protective film (3a: cyclic polyolefin film) surface, and for the polarizing film 2, a pressure-sensitive adhesive layer is laminated on the transparent protective film (3c: fluorinated polystyrene film) surface. The end of the polarizing film was subjected to a full-back end face treatment. This polarizing film with a pressure-sensitive adhesive layer was laminated on a non-alkali glass plate, and a temperature of 60 ° C. and 95% R.C. H. The polarizing film after 1000 hours of treatment under the environment was visually observed and evaluated based on the following criteria.
○: No peeling.
(Triangle | delta): The peeling of less than 1 mm generate | occur | produces from the polarizing film edge part.
X: The peeling of 1 mm or more occurs from the end of the polarizing film.

<Durability (heat shock test)>
For the polarizing film 1, a pressure-sensitive adhesive layer is laminated on the transparent protective film (3a: cyclic polyolefin film) surface, and for the polarizing film 2, a pressure-sensitive adhesive layer is laminated on the transparent protective film (3c: fluorinated polystyrene film) surface. A rectangle of 200 mm and 400 mm in the vertical direction was cut. The polarizing film was laminated on the glass plate through the pressure-sensitive adhesive layer, a heat cycle test at −40 ° C. to 85 ° C. was performed, the polarizing film after 50 cycles was visually observed, and evaluated based on the following criteria.
○: No cracks are observed.
(Triangle | delta): The crack which does not penetrate in the extending | stretching direction of a polarizer generate | occur | produced (crack length 200 mm or less).
X: A crack penetrating in the stretching direction of the polarizer was generated (crack length 200 mm).

<Adhesive strength after immersion in warm water (water resistance evaluation)>
Polarizing films 1 and 2 were cut into a size of 200 mm parallel to the direction of stretching of the polarizer and 15 mm in the orthogonal direction. The polarizing film 1 was cut with a cutter knife between the transparent protective film (3a) and the polarizer, and the polarizing film 2 was cut between the transparent protective film (3c) and the transparent protective film (3a). Then, the polarizing films 1 and 2 were bonded together to the glass plate. After immersing the polarizing films 1 and 2 in warm water at 40 ° C. for 2 hours, the protective film and the polarizer were peeled off at a rate of 300 mm / min in a 90-degree direction by Tensilon within 30 minutes (in a non-dry state). And peel strength (N / 15 mm) was measured. Evaluation was based on the following criteria.
○: Peel strength is 0.5 N / 15 mm or more.
Δ: Peel strength is 0.3 N / 15 mm to less than 0.5 N / 15 mm.
X: Peel strength is less than 0.3 N / 15 mm.

(A): Polyfunctional radically polymerizable compound Aronix M-220 represents tripropylene glycol diacrylate (manufactured by Toagosei Co., Ltd.).
(B): an alkyl (meth) acrylate having an alkyl group having 2 to 12 carbon atoms, BA is n-butyl acrylate;
: 2EHA is 2-ethylhexyl acrylate;
: EA represents ethyl acrylate.
(C): (meth) acrylate having a hydroxyl group 2HEA is 2-hydroxyethyl acrylate;
: 4HBA represents 4-hydroxybutyl acrylate.
(Others): Radical polymerizable compound other than the above HEAA is hydroxyethylacrylamide (manufactured by Kojin Co., Ltd.);
: ACMO indicates acryloylmorpholine (manufactured by Kojin Co., Ltd.).
(D): Silane coupling agent (D)
KBM403 is 3-glycidoxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd.);
: KBM602 indicates γ- (2-aminoethyl) aminopropylmethyldimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd.).
(E): Acrylic oligomer UP-1190 obtained by polymerizing a (meth) acrylic monomer represents an acrylic oligomer (ARUFUON UP-1190, manufactured by Toagosei Co., Ltd.) obtained by polymerizing a (meth) acrylic monomer.
(F): Radical polymerizable compound having an active methylene group AAEM represents 2-acetoacetoxyethyl methacrylate (manufactured by Nippon Synthetic Chemical Co., Ltd.).
(G): Radical polymerization initiator having a hydrogen abstraction action KAYACURE DETX-S indicates a radical polymerization initiator having a hydrogen abstraction action (diethylthioxanthone, KAYACURE DETX-S, manufactured by Nippon Kayaku Co., Ltd.).
(H): Photoacid generator CPI-100P represents a photoacid generator (a propylene carbonate solution containing 50% active ingredient mainly composed of triarylsulfonium hexafluorophosphate, manufactured by San Apro).
(I): Compound containing either an alkoxy group or an epoxy group Denacol EX-611 is sorbitol polyglycidyl ether (Denacol EX-611, manufactured by Nagase ChemteX Corporation);
NICARESIN S-260 indicates methylolated melamine (manufactured by Nippon Carbide Industries Co., Ltd.).
(Photopolymerization initiator: other) (compound represented by formula (2))
IRGACURE907 indicates 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one (IRGACURE907, manufactured by BASF).

DESCRIPTION OF SYMBOLS 1 Polarizer 2a, 2b Adhesive layer 3a, 3b, 3c Transparent protective film 3a 'Optical film

Claims (27)

On both sides of the polarizer (1), an adhesive layer (2a) and (2b) formed by a cured product layer formed by irradiating an active energy ray-curable adhesive composition with active energy rays on each side. In the polarizing film provided with the transparent protective films (3a) and (3b),
The single-sided adhesive layer (2a) has a glass transition temperature of −60 ° C. to less than 30 ° C.,
And the active energy ray-curable adhesive composition forming the adhesive layer (2a) contains a radical polymerizable compound as a curable component, and when the total amount of the radical polymerizable compound is 100% by weight, The ratio of the polyfunctional radically polymerizable compound (A) is more than 5% by weight and 50% by weight or less,
The other one-sided adhesive layer (2b) has a glass transition temperature of 30 ° C. or higher,
Curing formed by irradiating an active energy ray-curable adhesive composition with an active energy ray on either one of the transparent protective film (3a) and the transparent protective film (3b). Laminated through an adhesive layer (2a ′) formed by a physical layer,
The adhesive layer (2a ′) has a glass transition temperature of −60 ° C. to less than 30 ° C.,
And the active energy ray hardening-type adhesive composition which forms the said adhesive bond layer (2a ') contains the radically polymerizable compound as a sclerosing | hardenable component, and when the whole quantity of a radically polymerizable compound is 100 weight%. A polarizing film, wherein the ratio of the polyfunctional radically polymerizable compound (A) is more than 5% by weight and 50% by weight or less.   The polarizing film according to claim 1, wherein the radical polymerizable compound contains an alkyl (meth) acrylate (B) having an alkyl group having 2 to 18 carbon atoms.   The polarizing film according to claim 1, wherein the radical polymerizable compound contains (meth) acrylate (C) having a hydroxyl group.   The polarizing film according to claim 1, wherein the active energy ray-curable adhesive composition forming the adhesive layer (2 a) contains a silane coupling agent (D).   The polarizing film according to claim 4, wherein the silane coupling agent (D) is a silane coupling agent having no radical polymerizable functional group.   The active energy ray-curable adhesive composition forming the adhesive layer (2a) contains an acrylic oligomer (E) obtained by polymerizing a (meth) acrylic monomer. The polarizing film in any one of.   The active energy ray-curable adhesive composition forming the adhesive layer (2a) contains a radical polymerizable compound (F) having an active methylene group and a radical polymerization initiator (G) having a hydrogen abstracting action. The polarizing film according to any one of claims 1 to 6, wherein:   The polarizing film according to claim 7, wherein the active methylene group is an acetoacetyl group.   The polarizing film according to claim 7 or 8, wherein the radical polymerizable compound (F) having an active methylene group is acetoacetoxyalkyl (meth) acrylate.   The polarizing film according to claim 7, wherein the radical polymerization initiator (G) is a thioxanthone radical polymerization initiator.   When the total amount of the radical polymerizable compound in the active energy ray-curable adhesive composition forming the adhesive layer (2a) is 100% by weight, the radical polymerizable compound (F) having the active methylene group is 1 The radical polymerization initiator (G) is contained in an amount of 0.1 to 10 parts by weight with respect to 100 parts by weight of the radically polymerizable compound in the active energy ray-curable adhesive composition. The polarizing film according to claim 7, wherein the polarizing film is a film. The polarizing film according to claim 1, wherein the active energy ray-curable adhesive composition forming the adhesive layer (2 a) contains a photoacid generator (H). The polarizing film according to claim 12, wherein the photoacid generator (H) contains a photoacid generator having, as a counter anion, at least one selected from the group consisting of PF ₆ ⁻ , SbF ₆ ^— and AsF ₆ ^—. .   The active energy ray-curable adhesive composition for forming the adhesive layer (2a) uses the photoacid generator (H) and the compound (I) containing either an alkoxy group or an epoxy group in combination. The polarizing film according to claim 12 or 13.   The thickness of the said adhesive bond layers (2a) and (2b) are all 5 micrometers or less, The polarizing film in any one of Claims 1-14 characterized by the above-mentioned. Polarizing film according to any one of the transparent protective film (3a) and (3b) according to claim 15 moisture permeability is less than both 150g ^/ m 2 ^/ 24h of.   The polarizing film according to any one of claims 1 to 16, wherein the transparent protective film (3a) is a cyclic polyolefin resin film or a fluorinated polystyrene film.   The polarizing film according to claim 1, wherein the transparent protective film (3 b) is an acrylic resin film, a cyclic polyolefin resin film, or a polyester resin film.   The polarizing film according to any one of claims 1 to 18, wherein at least one of the transparent protective films (3a) and (3b) has a light transmittance of a wavelength of 365 nm of less than 5%. It is a manufacturing method of the polarizing film in any one of Claims 1-19,
A coating step of coating the active energy ray-curable adhesive composition on at least one surface of the polarizer (1) and the transparent protective film (3a);
A coating step of coating the active energy ray-curable adhesive composition on at least one surface of the polarizer (1) and the transparent protective film (3b);
A bonding step of bonding the polarizer (1) and the transparent protective films (3a) and (3b);
Through the adhesive layers (2a) and (2b) obtained by irradiating the active energy rays and curing the active energy ray-curable adhesive composition, the polarizer (1) and the transparent The manufacturing method of a polarizing film characterized by including the adhesion process which adheres protective films (3a) and (3b).   Before the coating step, at least one surface of the polarizer (1) and the transparent protective films (3a) and (3b), the surface to be bonded is subjected to corona treatment, plasma treatment, excimer treatment or The method for producing a polarizing film according to claim 20, wherein a frame treatment is performed.   First, the active energy ray is irradiated from the side of one transparent protective film (3a) or (3b), and then the active energy ray is irradiated from the side of the other transparent protective film (3b) or (3a), The polarizer (1) and the transparent protective films (3a) and (3b) are bonded via the adhesive layers (2a) and (2b) obtained by curing the active energy ray-curable adhesive composition. The manufacturing method of the polarizing film of Claim 20 or 21 including the adhesion | attachment process made to adhere | attach. The transparent protective films (3a) and (3b) both have a light transmittance of a wavelength of 365 nm of less than 5%,
The method for producing a polarizing film according to any one of claims 20 to 22, wherein the active energy ray includes visible light having a wavelength range of 380 to 450 nm.   The ratio of the integrated illuminance in the wavelength range of 380 to 440 nm and the integrated illuminance in the wavelength range of 250 to 370 nm of the active energy ray is 100: 0 to 100: 50. Production method.   The method for producing a polarizing film according to any one of claims 20 to 24, wherein a moisture content of the polarizer in the bonding step is less than 15%.   An optical film, wherein at least one polarizing film according to claim 1 is laminated.   The image display apparatus characterized by using the polarizing film in any one of Claims 1-19, or the optical film of Claim 26.

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