JP2016186618A - Optical film with adhesive layer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical film with an adhesive layer which has the excellent durability and which does not make a display panel warp easily and does not cause thermal unevenness easily, even if the optical film has the reduced thickness.SOLUTION: An optical film 10A with an adhesive layer includes an optical film and an adhesive layer 1 stacked on at least one surface of the optical film. A surface of the optical film in contact with the adhesive layer 1 is formed of acrylic resin. The adhesive layer 1 is formed of an adhesive including: a (meth)acrylic acid ester copolymer (A) containing a monomer (a1) including an alicyclic structure and a monomer (a2) including an aromatic ring as the monomer unit of the polymer; a crosslinking agent (B); and an adhesive composition containing a low-molecular-weight compound by 5 mass% or less.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an optical film with an adhesive layer, and more particularly to an optical film with an adhesive layer used for bonding an optical film such as a polarizing plate or a composite polarizing plate to a liquid crystal cell or the like.

  In recent years, as a display panel of various electronic devices, a touch panel that serves as both a display device and an input unit is often used. The types of touch panels are mainly resistive film type, capacitance type, optical type and ultrasonic type. Resistance film type includes analog resistance film type and matrix resistance film type. There are types and projection types.

  As a touch panel in a mobile electronic device such as a smartphone or a tablet terminal that has been attracting attention recently, a projected capacitive type is often used. As a projected capacitive touch panel in such mobile electronic devices, for example, in order from the bottom, a liquid crystal display (LCD), an adhesive layer, a transparent conductive film (tin-doped indium oxide: ITO), a glass substrate, a transparent conductive film ( ITO) and a laminate of protective plates such as tempered glass have been proposed.

  A liquid crystal cell is generally used as an optical component constituting the liquid crystal display device. In general, the liquid crystal cell is arranged such that the alignment layers of the two transparent electrode substrates on which the alignment layers are formed are placed inside, with a predetermined interval by a spacer, and the periphery thereof is sealed to form the two transparent electrode substrates. A liquid crystal material is sandwiched between them. Usually, a polarizing plate or a composite polarizing plate having a retardation plate is bonded to the outside of the two transparent electrode substrates in the liquid crystal cell via an adhesive.

  As an optical pressure-sensitive adhesive, for example, the one shown in Patent Document 1 is known. This pressure-sensitive adhesive contains 0.2 to 20 parts by weight of a carboxyl group-containing monomer as a copolymer component with respect to 100 parts by weight of an alkyl (meth) acrylate having an alkyl group having 4 to 14 carbon atoms as a monomer unit. 0.02 to 2 parts by mass of a peroxide and 0.005 to 5 parts by mass of an epoxy crosslinking agent as a crosslinking agent with respect to 100 parts by mass of the (meth) acrylic polymer and (meth) acrylic polymer to be formed Containing.

JP 2009-242786 A

  Here, with the recent demand for thinner mobile electronic devices, it is also required to reduce the thickness of optical films such as polarizing plates. However, the thin film polarizing plate has a high shrinkage rate due to heat or the like, and the conventional adhesive such as Patent Document 1 causes warping of the display panel, and floating or peeling under high temperature conditions or wet heat conditions. End up. Furthermore, there has been pointed out a problem that light leakage (so-called heat unevenness) occurs due to a shift of the optical axis of the optical film due to the stress at the time of thermal shrinkage of the optical film.

  In addition, when priority is given to thinning the optical film, the adhesiveness with the adhesive deteriorates, and the conventional adhesive such as Patent Document 1 has insufficient adhesiveness at the interface between the optical film and the adhesive. The durability tends to be further deteriorated.

  The present invention has been made in view of such a situation, and even when a thin optical film is used, the adhesive is excellent in durability, the display panel is hardly warped, and heat unevenness is unlikely to occur. It aims at providing the optical film with an agent layer.

  In order to achieve the above object, first, the present invention is an optical film with an adhesive layer comprising an optical film and an adhesive layer laminated on at least one surface of the optical film, wherein the optical film includes: The surface in contact with the pressure-sensitive adhesive layer is composed of an acrylic resin, and the pressure-sensitive adhesive layer contains the alicyclic structure-containing monomer (a1) and the aromatic ring-containing monomer (a2) as monomer units constituting the polymer. From the pressure-sensitive adhesive obtained from the pressure-sensitive adhesive composition containing the (meth) acrylic acid ester copolymer (A) and the crosslinking agent (B) and having a low molecular weight component content of 5% by mass or less An optical film with a pressure-sensitive adhesive layer is provided (Invention 1).

  According to the above invention (Invention 1), even when the optical film to be used is made thinner than the conventional product, it is excellent in durability when applied to a display panel, even under high temperature conditions and wet heat conditions. Occurrence of floating and peeling is suppressed. Moreover, the display panel using the said optical film with an adhesive layer does not warp easily also on high temperature conditions, and also it is hard to produce a thermal nonuniformity.

  In the said invention (invention 1), it is preferable that the outermost layer which contacts the said adhesive layer in the said optical film consists of an acrylic resin layer formed through extrusion molding (invention 2).

  In the said invention (invention 2), it is preferable that the said optical film was equipped with the phase difference plate which has the said acrylic resin layer and a phase difference expression layer at least (invention 3).

  In the said invention (invention 3), it is preferable that the said phase difference expression layer consists of styrene resin (invention 4).

  In the said invention (invention 3 and 4), it is preferable that the said phase difference plate has a 2nd acrylic resin layer in the surface side opposite to the surface at the said acrylic resin layer side in the said phase difference expression layer. (Invention 5).

  In the said invention (invention 3-5), it is preferable that the 2nd phase difference plate is further laminated | stacked on the surface side opposite to the surface at the side of the said adhesive layer in the said phase difference plate (invention 6). .

  In the said invention (invention 6), it is preferable that a said 2nd phase difference plate consists of cycloolefin type resin (invention 7).

  In the said invention (invention 6 and 7), it is preferable that the polarizing plate is further laminated | stacked on the surface side on the opposite side to the surface of the said phase difference plate side in a said 2nd phase difference plate (invention 8).

  In the said invention (invention 1-8), the said (meth) acrylic acid ester copolymer (A) further contains a hydroxyl-containing monomer (a3) as a monomer unit which comprises the said polymer, and a hydroxyl value is 5 It is preferable that it is -20 mgKOH / g (Invention 9).

  In the said invention (invention 1-9), it is preferable that the said crosslinking agent (B) is an isocyanate type crosslinking agent (invention 10).

  In the said invention (invention 1-10), it is preferable that the said adhesive composition further contains a silane coupling agent (C) (invention 11).

  In the said invention (invention 1-11), it is preferable that the said adhesive composition further contains an antistatic agent (D) (invention 12).

  According to the optical film with the pressure-sensitive adhesive layer according to the present invention, even when the optical film is thinned, the durability is excellent, the display panel is hardly warped, and further, heat unevenness is hardly generated.

It is sectional drawing of the optical film with an adhesive layer which concerns on one Embodiment of this invention. It is sectional drawing of the optical film with an adhesive layer which concerns on other embodiment of this invention. It is sectional drawing which shows the structural example of a phase difference plate. It is a figure (color) which shows the evaluation criteria of the heat-resistant unevenness test (visual observation) in an optical film with an adhesive layer.

Hereinafter, embodiments of the present invention will be described.
The optical film with an adhesive layer according to the present embodiment includes an optical film and an adhesive layer laminated on at least one surface of the optical film. The surface in contact with the pressure-sensitive adhesive layer in the optical film is composed of an acrylic resin, and the pressure-sensitive adhesive layer includes an alicyclic structure-containing monomer (a1) and an aromatic ring-containing monomer (a2) as monomer units constituting the polymer. A pressure-sensitive adhesive composition containing a (meth) acrylic acid ester copolymer (A) and a crosslinking agent (B) and having a low molecular weight component content of 5% by mass or less (hereinafter referred to as “pressure-sensitive adhesive composition”). It may be referred to as “product P”.). In this specification, (meth) acrylic acid ester means both acrylic acid ester and methacrylic acid ester. The same applies to other similar terms.

  Even if the optical film with the pressure-sensitive adhesive layer is used in a display panel even when the optical film to be used is made thinner than the conventional product, it is used under the durability conditions (as illustrated in the test examples described later). Under high temperature conditions, moist heat conditions or heat shocks, and also under high temperature environments and humid heat environments during actual use, etc. The same shall apply hereinafter unless otherwise noted) Is suppressed. Moreover, the display panel using the said optical film with an adhesive layer does not warp easily also on high temperature conditions, and also it is hard to produce a thermal nonuniformity.

  Here, the optical film includes a function-expressing layer that expresses optical performance such as polarization performance and retardation performance, and a protective layer for protecting the function-expressing layer and maintaining shape stability (for shape retention) Often consists of The present inventors have found that by using an acrylic resin for the protective layer, the optical performance of the function-expressing layer is not deteriorated and a thin film can be formed. However, when a conventional optical film with a pressure-sensitive adhesive layer is made thin by using an acrylic resin for the protective layer, the form retainability under durability conditions is insufficient, and the adhesion with the pressure-sensitive adhesive layer is also poor. As a result, the optical film with the pressure-sensitive adhesive layer using the optical film was not satisfactory in both durability and heat resistance unevenness. In addition, warping tends to be severe under high temperature conditions. On the other hand, in the optical film with the pressure-sensitive adhesive layer according to the present embodiment, the residual stress of the pressure-sensitive adhesive layer due to the shrinkage of the optical film under the durability condition is increased by increasing the stress relaxation property of the pressure-sensitive adhesive layer by the above-described composition. It was decided to eliminate.

  In addition, regarding the insufficient adhesion between the protective layer made of an acrylic resin and the pressure-sensitive adhesive layer, the present inventors have observed the interface between the protective layer and the pressure-sensitive adhesive layer after the endurance test. It has been found that there is a defect that some component is seen sucked out to the layer side. From this phenomenon, the low molecular weight component in the pressure-sensitive adhesive layer is sucked to the protective layer side under the durability condition, and the low molecular weight component is present at the interface between the protective layer and the pressure-sensitive adhesive layer. Therefore, it is inferred that it works like a lubricant and reduces the adhesion at the interface. Based on this reasoning, the glass transition temperature (Tg) of the main polymer of the pressure-sensitive adhesive layer is increased by the above-described composition, and the content of the low molecular weight component is suppressed to 5% by mass or less, so that the pressure-sensitive adhesive layer can be used under durable conditions. In addition to making it difficult for low molecular weight components to be sucked into optical films (parts composed of acrylic resin), it prevents them from acting like a lubricating oil because they are very small even if sucked. It was.

(Adhesive layer)
(1) (Meth) acrylic acid ester copolymer (A)
The (meth) acrylic acid ester copolymer (A) in this embodiment contains an alicyclic structure-containing monomer (a1) and an aromatic ring-containing monomer (a2) as monomer units constituting the polymer. By containing these alicyclic structure-containing monomer (a1) and aromatic ring-containing monomer (a2), the resulting pressure-sensitive adhesive can have both an appropriate cohesive force and stress relaxation properties, and can be used for an acrylic resin. Since adhesion becomes high, when used for a display panel, it is possible to exhibit excellent durability, warpage suppression, and heat resistance unevenness.

  The (meth) acrylic acid ester copolymer (A) includes a hydroxyl group-containing monomer in addition to the alicyclic structure-containing monomer (a1) and the aromatic ring-containing monomer (a2) as monomer units constituting the polymer. It is preferable to contain (a3), and it is particularly preferable to contain (meth) acrylic acid alkyl ester having 1 to 20 carbon atoms in the alkyl group. Moreover, you may contain another monomer if desired.

  Here, the hydroxyl value of the (meth) acrylic acid ester copolymer (A) is preferably 5 to 20 mgKOH / g, particularly preferably 8 to 18 mgKOH / g, and more preferably 10 to 16 mgKOH / g. It is preferable that When the hydroxyl value of the (meth) acrylic acid ester copolymer (A) is 5 mgKOH / g or more, the crosslinking point can be secured and the cohesive force can be kept high, and the resulting adhesive has excellent durability. It can be demonstrated effectively. Moreover, when the hydroxyl value of the (meth) acrylic acid ester copolymer (A) is 20 mgKOH / g or less, it is possible to prevent the crosslinking points from being increased excessively, and the resulting pressure-sensitive adhesive becomes flexible and has excellent stress. It is possible to effectively exhibit relaxation, excellent warpage suppression and heat unevenness.

  The acid value of the (meth) acrylic acid ester copolymer (A) is preferably 5 mgKOH / g or less, particularly preferably 2 mgKOH / g or less, and more preferably 1 mgKOH / g or less. preferable. When the acid value of the (meth) acrylic acid ester copolymer (A) is 5 mg KOH / g or less, the sticking target of the adhesive causes a problem due to the acid, for example, a transparent conductive film such as tin-doped indium oxide (ITO) Even in the case of a metal film or the like, it is possible to suppress those problems caused by acid. In particular, when the object to be pasted is a transparent conductive film, it is possible to suppress corrosion of the transparent conductive film or change of the resistance value of the transparent conductive film. In addition, since the lower limit of the acid value of (meth) acrylic acid ester copolymer (A) is so preferable that it is small, it is especially preferable that it is 0 mgKOH / g.

  Here, the hydroxyl value and acid value in the present specification are basically theoretical values derived from the blending ratio of the (meth) acrylic acid ester copolymer (A), and when the theoretical values cannot be derived, The measured value is based on JIS K0070.

  The (meth) acrylic acid ester copolymer (A) contains a (meth) acrylic acid alkyl ester having 1 to 20 carbon atoms in the alkyl group as a monomer unit constituting the polymer. Can be expressed. Examples of the (meth) acrylic acid alkyl ester having 1 to 20 carbon atoms in the alkyl group include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, and (meth) acrylic acid n-. Butyl, n-pentyl (meth) acrylate, n-hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, n-decyl (meth) acrylate, (meth) acrylic acid Examples include n-dodecyl, myristyl (meth) acrylate, palmityl (meth) acrylate, stearyl (meth) acrylate, and the like. Among these, from the viewpoint of further improving the adhesiveness, (meth) acrylic acid esters having 1 to 8 carbon atoms in the alkyl group are preferable, and (meth) acrylic acid n-butyl or (meth) acrylic acid 2-ethylhexyl is particularly preferable. . In addition, these may be used independently and may be used in combination of 2 or more type.

  The (meth) acrylic acid ester copolymer (A) contains 40 to 97.5 mass% of (meth) acrylic acid alkyl ester having 1 to 20 carbon atoms as the monomer unit constituting the polymer. In particular, it is preferably contained in an amount of 55 to 94% by mass, more preferably 65 to 83% by mass. If it contains 40 mass% or more of (meth) acrylic-acid alkylester, suitable adhesiveness can be provided to a (meth) acrylic-ester copolymer (A). Further, by making the (meth) acrylic acid alkyl ester 97.5% by mass or less, a desired amount of other monomer components can be introduced into the (meth) acrylic acid ester copolymer (A).

  The alicyclic carbocyclic ring in the alicyclic structure-containing monomer (a1) may have a saturated structure or may have an unsaturated bond in part. The alicyclic structure may be a monocyclic alicyclic structure or a polycyclic alicyclic structure such as a bicyclic ring or a tricyclic ring. From the viewpoint of making the distance between the obtained (meth) acrylic acid ester copolymer (A) appropriate and imparting stress relaxation to the pressure-sensitive adhesive, and the glass transition temperature (Tg) of the obtained copolymer (A) From the viewpoint of preventing the low molecular weight component in the pressure-sensitive adhesive from moving to the acrylic resin side and inhibiting the adhesion, the alicyclic structure is a polycyclic alicyclic structure (multiple Ring structure). Furthermore, considering the compatibility between the (meth) acrylic acid ester copolymer (A) and other components, the polycyclic structure is particularly preferably bicyclic to tetracyclic. In addition, from the viewpoint of imparting stress relaxation properties as described above, the carbon number of the alicyclic structure (refers to the total number of carbon atoms of the portion forming the ring, and when multiple rings exist independently) , Which means the total number of carbon atoms) is usually preferably 5 or more, and particularly preferably 7 or more. On the other hand, the upper limit of the number of carbon atoms in the alicyclic structure is not particularly limited, but it is preferably 15 or less and particularly preferably 10 or less from the viewpoint of compatibility as described above.

  Examples of the alicyclic structure include a cyclohexyl skeleton, dicyclopentadiene skeleton, adamantane skeleton, isobornyl skeleton, cycloalkane skeleton (cycloheptane skeleton, cyclooctane skeleton, cyclononane skeleton, cyclodecane skeleton, cycloundecane skeleton, cyclododecane skeleton, etc.) , Cycloalkene skeleton (cycloheptene skeleton, cyclooctene skeleton, etc.), norbornene skeleton, norbornadiene skeleton, cubane skeleton, basketn skeleton, Hausan skeleton, spiro skeleton, etc. are included, and among them, more excellent durability is exhibited. Those containing a dicyclopentadiene skeleton (carbon number of alicyclic structure: 10), adamantane skeleton (carbon number of alicyclic structure: 10) or isobornyl skeleton (carbon number of alicyclic structure: 7) are particularly preferable. Contains isobornyl skeleton Preference is.

  The alicyclic structure-containing monomer (a1) is preferably a (meth) acrylic acid ester monomer containing the skeleton, specifically, cyclohexyl (meth) acrylate, dicyclopentanyl (meth) acrylate, (Meth) acrylic acid adamantyl, (meth) acrylic acid isobornyl, (meth) acrylic acid dicyclopentenyl, (meth) acrylic acid dicyclopentenyloxyethyl, etc. are mentioned, among them, more excellent durability, ( Dicyclopentanyl (meth) acrylate, adamantyl (meth) acrylate or isobornyl (meth) acrylate is preferred, and isobornyl (meth) acrylate is particularly preferred. These may be used individually by 1 type and may be used in combination of 2 or more type.

  The (meth) acrylic acid ester copolymer (A) is an alicyclic monomer unit that constitutes the polymer from the viewpoint that the resulting pressure-sensitive adhesive exhibits excellent durability, warpage suppression, and heat unevenness. It is preferable to contain 1-20 mass% of structure containing monomers (a1). Furthermore, in addition to the above viewpoint, it is more preferable that the alicyclic structure-containing monomer (a1) is particularly preferably contained in an amount of 2 to 15% by mass from the viewpoint that the resulting pressure-sensitive adhesive exhibits excellent reworkability. % Content is particularly preferable.

  As the aromatic ring-containing monomer (a2), a (meth) acrylic acid ester having an aromatic ring is preferable. Examples of the aromatic ring include a benzene ring, a naphthalene ring, an anthracene ring, a biphenyl ring, and a fluorene ring, and among them, a benzene ring is preferable.

  Examples of the aromatic ring-containing monomer (a2) include phenyl (meth) acrylate, 2-phenylethyl (meth) acrylate, benzyl (meth) acrylate, naphthyl (meth) acrylate, and phenoxyethyl (meth) acrylate. , Phenoxybutyl (meth) acrylate, ethoxylated o-phenylphenol acrylate, phenoxydiethylene glycol (meth) acrylate, ethylene oxide modified cresol (meth) acrylate, ethylene oxide (EO) modified nonylphenol (meth) acrylate, and the like. From the viewpoint of improving cohesive strength, 2-phenylethyl (meth) acrylate is preferred. These may be used alone or in combination of two or more.

  The (meth) acrylic acid ester copolymer (A) preferably contains 1 to 30% by mass, particularly 3 to 25% by mass, of the aromatic ring-containing monomer (a2) as a monomer unit constituting the polymer. It is preferable to contain 12 to 22% by mass. When the content of the aromatic ring-containing monomer (a2) is within the above range, the obtained pressure-sensitive adhesive can exhibit excellent durability, warpage suppression, and heat unevenness.

  The (meth) acrylic acid ester copolymer (A) preferably contains a hydroxyl group-containing monomer (a3) as a monomer unit constituting the polymer. The hydroxyl group shows good reactivity with the crosslinking agent (B), and the (meth) acrylic acid ester copolymer (A) is crosslinked by the crosslinking agent (B) by their reaction. Due to this crosslinked structure, the resulting pressure-sensitive adhesive is excellent in durability.

  Examples of the hydroxyl group-containing monomer (a3) include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, and 2-hydroxybutyl (meth) acrylate. , (Meth) acrylic acid hydroxyalkyl esters such as (meth) acrylic acid 3-hydroxybutyl and (meth) acrylic acid 4-hydroxybutyl, among others, from the point of reactivity with the crosslinking agent (B) ( 2-hydroxyethyl (meth) acrylate or 4-hydroxybutyl (meth) acrylate is preferred, and 2-hydroxyethyl (meth) acrylate is particularly preferred. These may be used alone or in combination of two or more.

  The (meth) acrylic acid ester copolymer (A) preferably contains 0.5 to 10% by mass of the hydroxyl group-containing monomer (a3) as a monomer unit constituting the polymer, particularly 1 to 5% by mass. It is preferable to contain, Furthermore, it is preferable to contain 2-4 mass%. When the content of the hydroxyl group-containing monomer (a3) is in the above range, the hydroxyl value of the (meth) acrylic acid ester copolymer (A) easily enters the above range, and has excellent durability and warpage suppression. In addition, the heat unevenness can be effectively exhibited.

  The (meth) acrylic acid ester copolymer (A) preferably does not contain a carboxyl group-containing monomer as a monomer unit constituting the polymer so that the acid value is in the above-described range. The content is preferably 0.5% by mass or less, and particularly preferably 0.1% by mass or less.

  The (meth) acrylic acid ester copolymer (A) may contain a monomer other than the above-described monomers as a monomer unit constituting the polymer. The other monomer is preferably a monomer that does not contain a functional group having reactivity with the crosslinking agent (B) in order not to hinder the reaction between the hydroxyl group of the hydroxyl group-containing monomer (a3) and the crosslinking agent (B). .

  Examples of such other monomers include (meth) acrylic acid alkoxyalkyl esters such as methoxyethyl (meth) acrylate and ethoxyethyl (meth) acrylate, non-crosslinkable acrylamides such as acrylamide and methacrylamide, (meth) Examples include N, N-dimethylaminoethyl acrylate, (meth) acrylic acid ester having a non-crosslinkable tertiary amino group such as N, N-dimethylaminopropyl (meth) acrylate, and vinyl acetate. These may be used alone or in combination of two or more.

  The polymerization aspect of the (meth) acrylic acid ester copolymer (A) may be a random copolymer or a block copolymer.

  The weight average molecular weight of the (meth) acrylic acid ester copolymer (A) is preferably from 1.3 million to 3 million, particularly preferably from 1.5 million to 2.5 million, and more preferably from 1.6 million to 1.9 million. It is preferable. When the (meth) acrylic acid ester copolymer (A) has a weight average molecular weight of 1.3 million or more, the durability of the resulting pressure-sensitive adhesive can be ensured satisfactorily. Further, when the weight average molecular weight of the (meth) acrylic acid ester copolymer (A) is 3 million or less, the obtained pressure-sensitive adhesive has good stress relaxation properties, and is effective in suppressing warpage and heat resistance unevenness. Can be demonstrated.

  Here, the weight average molecular weight in this specification is a value in terms of standard polystyrene measured by a gel permeation chromatography (GPC) method.

  The polymerization aspect of the (meth) acrylic acid ester copolymer (A) may be a random copolymer or a block copolymer.

  In the adhesive composition P, the (meth) acrylic acid ester copolymer (A) may be used alone or in combination of two or more. Moreover, the adhesive composition P may further contain a (meth) acrylic acid ester polymer that does not contain the alicyclic structure-containing monomer (a1) or the aromatic ring-containing monomer (a2) as a constituent monomer unit.

(2) Crosslinking agent (B)
The crosslinking agent (B) may be any one that reacts with the functional group of the (meth) acrylic acid ester copolymer (A). For example, an isocyanate crosslinking agent, an epoxy crosslinking agent, an amine crosslinking agent, a melamine -Based crosslinking agents, aziridine-based crosslinking agents, hydrazine-based crosslinking agents, aldehyde-based crosslinking agents, oxazoline-based crosslinking agents, metal alkoxide-based crosslinking agents, metal chelate-based crosslinking agents, metal salt-based crosslinking agents, and ammonium salt-based crosslinking agents. It is done.

  When the (meth) acrylic acid ester copolymer (A) contains a hydroxyl group-containing monomer (a3) as a monomer unit constituting the polymer, the reactivity with the hydroxyl group derived from the hydroxyl group-containing monomer (a3) is increased. It is preferable to use an excellent isocyanate-based crosslinking agent. In addition, a crosslinking agent (B) can be used individually by 1 type or in combination of 2 or more types.

  The isocyanate-based crosslinking agent contains at least a polyisocyanate compound. Examples of the polyisocyanate compound include aromatic polyisocyanates such as tolylene diisocyanate, diphenylmethane diisocyanate and xylylene diisocyanate, aliphatic polyisocyanates such as hexamethylene diisocyanate, alicyclic polyisocyanates such as isophorone diisocyanate and hydrogenated diphenylmethane diisocyanate, etc. In addition to these biuret bodies, isocyanurate bodies, and adduct bodies that are reaction products with low molecular active hydrogen-containing compounds such as ethylene glycol, propylene glycol, neopentyl glycol, trimethylol propane, castor oil, etc. And may be referred to as “denatured”). Among these, from the viewpoint of durability of the obtained pressure-sensitive adhesive, a compound having an aromatic ring, that is, an aromatic polyisocyanate or a modified product thereof is preferable, and an organic group (for example, an alkylene chain is preferably included in the aromatic ring, 1 to 4 alkylene chains are particularly preferred.) Polyisocyanates having an isocyanate group bonded via each other or a modified product thereof are particularly preferred. Specifically, xylylene diisocyanate or a modified product thereof is more preferable, and trimethylolpropane-modified xylylene diisocyanate is most preferable. The said isocyanate type crosslinking agent can be used individually by 1 type or in combination of 2 or more types.

  The content of the crosslinking agent (B) in the adhesive composition P is preferably 0.01 to 10 parts by mass with respect to 100 parts by mass of the (meth) acrylic acid ester copolymer (A), and in particular. The amount is preferably 0.05 to 5 parts by mass, more preferably 0.1 to 0.4 parts by mass. When the content of the crosslinking agent (B) is in the above range, the obtained pressure-sensitive adhesive exhibits excellent cohesive force and stress relaxation properties, and is excellent in durability, warpage suppression, and heat resistance unevenness. .

(3) Silane coupling agent (C)
The adhesive composition P preferably contains a silane coupling agent (C) in addition to the (meth) acrylic acid ester copolymer (A) and the crosslinking agent (B), and is excellent in the resulting adhesive. From the viewpoint of imparting durability, it is particularly preferable to contain an epoxy group-containing silane coupling agent (C1) and / or a mercapto group-containing silane coupling agent (C2), and further, an epoxy group-containing silane coupling agent (C1). ) And a mercapto group-containing silane coupling agent (C2).

  The epoxy group-containing silane coupling agent (C1) is an organosilicon compound having at least one epoxy group (an organic group containing an epoxy group) and at least one alkoxysilyl group in the molecule, Those having good compatibility and having light transmission properties, for example, substantially transparent materials are preferred.

  Specific examples of the epoxy group-containing silane coupling agent (C1) include 3-glycidoxypropyltrialkoxysilane such as 3-glycidoxypropyltrimethoxysilane and 3-glycidoxypropyltriethoxysilane, and 3-glycidyl. 3-glycidoxypropylalkyldialkoxysilanes such as sidoxypropylmethyldiethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, methyltri (glycidyl) silane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane 2- (3,4-epoxycyclohexyl) ethyltrialkoxysilane such as 2- (3,4-epoxycyclohexyl) ethyltriethoxysilane. Among these, from the viewpoint of further improving durability, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 2- (3,4 epoxycyclohexyl) ) Ethyltrimethoxysilane is preferred, and 3-glycidoxypropyltrimethoxysilane is particularly preferred. These may be used individually by 1 type and may be used in combination of 2 or more type.

  The mercapto group-containing silane coupling agent (C2) is an organosilicon compound having at least one mercapto group (an organic group containing a mercapto group) and at least one alkoxysilyl group in the molecule, Those having good compatibility and having light transmission properties, for example, substantially transparent materials are preferred.

  Specific examples of mercapto group-containing silane coupling agents (C2) include mercapto group-containing low molecular weight silane couplings such as 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, and 3-mercaptopropyldimethoxymethylsilane. Agents: Mercapto group-containing silane compounds such as 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropyldimethoxymethylsilane, methyltriethoxysilane, ethyltriethoxysilane, methyltrimethoxysilane, ethyl Examples include mercapto group-containing oligomer type silane coupling agents such as co-condensates with alkyl group-containing silane compounds such as trimethoxysilane. Among these, from the viewpoint of achieving both durability and reworkability, a mercapto group-containing oligomer type silane coupling agent is preferable, and a cocondensate of a mercapto group-containing silane compound and an alkyl group-containing silane compound is particularly preferable. A cocondensate of mercaptopropyltrimethoxysilane and methyltriethoxysilane is preferred. These may be used individually by 1 type and may be used in combination of 2 or more type.

  As the silane coupling agent (C), in addition to the epoxy group-containing silane coupling agent (C1) and the mercapto group-containing silane coupling agent (C2), for example, an acryloyl-based silane coupling agent, Hydroxyl silane coupling agents, carboxyl group silane coupling agents, amino group silane coupling agents, amide group silane coupling agents, isocyanate group silane coupling agents, and the like may be used in combination.

  The total content of the silane coupling agent (C) in the adhesive composition P is 0.01 to 5 parts by mass with respect to 100 parts by mass of the (meth) acrylic acid ester copolymer (A). Particularly preferred is 0.1 to 2 parts by mass, and further preferred is 0.2 to 1 part by mass.

  Moreover, content of the epoxy group containing silane coupling agent (C1) in the adhesive composition P is 0.005-2.5 with respect to 100 mass parts of (meth) acrylic acid ester copolymers (A). The amount is preferably part by mass, particularly preferably 0.05 to 1 part by mass, and further preferably 0.1 to 0.5 part by mass. On the other hand, the content of the mercapto group-containing silane coupling agent (C2) in the adhesive composition P is 0.005 to 2.5 with respect to 100 parts by mass of the (meth) acrylic acid ester copolymer (A). The amount is preferably part by mass, particularly preferably 0.05 to 1 part by mass, and further preferably 0.1 to 0.5 part by mass.

(4) Antistatic agent (D)
The pressure-sensitive adhesive composition P preferably further contains an antistatic agent (D). The release sheet laminated on the pressure-sensitive adhesive layer, or optical members such as polarizing plates and composite polarizing plates are usually made of plastic materials, so they have high electrical insulation, and static electricity is generated when the release sheet is peeled off. Easy to do. If a polarizing plate, a composite polarizing plate, or the like is bonded to a liquid crystal cell with the generated static electricity remaining, the orientation of liquid crystal molecules may be disturbed. Causes problems such as sucking. Therefore, when the pressure-sensitive adhesive composition P contains the antistatic agent (D), the resulting pressure-sensitive adhesive (pressure-sensitive adhesive layer) exhibits antistatic properties, and the above problems can be solved.

  The antistatic agent (D) is not particularly limited as long as it can impart antistatic properties to the resulting pressure-sensitive adhesive, and examples thereof include ionic compounds and nonionic compounds, among which ionic compounds are preferred. . The ionic compound may be a liquid or a solid at room temperature, but is preferably a solid at room temperature from the viewpoint of easily exhibiting stable antistatic properties even when exposed to durability conditions. . Here, the ionic compound in this specification refers to a compound in which a cation and an anion are combined mainly by electrostatic attraction.

  As the ionic compound, a nitrogen-containing onium salt, a sulfur-containing onium salt, a phosphorus-containing onium salt, an alkali metal salt and an alkaline earth metal salt are preferable. From the viewpoint of excellent durability of the obtained adhesive, a nitrogen-containing onium salt is particularly preferable. preferable. The nitrogen-containing onium salt is preferably an ionic compound composed of a nitrogen-containing heterocyclic cation and its counter anion, and is particularly an ionic compound composed of a nitrogen-containing heterocyclic cation and a halogenated phosphate anion. It is preferably an ionic compound that is solid at room temperature and is composed of a nitrogen-containing heterocyclic cation and a halogenated phosphate anion. According to an ionic compound that is solid at room temperature and is composed of a nitrogen-containing heterocyclic cation and a halogenated phosphate anion, it is possible to achieve both antistatic properties and durability.

  As the nitrogen-containing heterocyclic skeleton of the nitrogen-containing heterocyclic cation, a pyridine ring, a pyrimidine ring, an imidazole ring, a triazole ring, an indole ring and the like are preferable, and a pyridine ring is particularly preferable. Moreover, as halogen of the halogenated phosphate anion, fluorine, chlorine, bromine and the like are preferable, and fluorine is particularly preferable.

  Specific examples of the antistatic agent (D) include N-butyl-4-methylpyridinium hexafluorophosphate, N-hexyl-4-methylpyridinium hexafluorophosphate, N-octylpyridinium hexafluorophosphate, and N-octyl-4. -Methylpyridinium hexafluorophosphate, N-dodecylpyridinium hexafluorophosphate, N-tetradecylpyridinium hexafluorophosphate, N-hexadecylpyridinium hexafluorophosphate, N-dodecyl-4-methylpyridinium hexafluorophosphate, N-tetradecyl-4 -Methylpyridinium hexafluorophosphate, N-hexadecyl-4-methylpyridinium hexafluorophosphate and the like. Among these, N-butyl-4-methylpyridinium hexafluorophosphate, N-hexyl-4-methylpyridinium hexafluorophosphate, and N- from the viewpoint of compatibility with the (meth) acrylic acid ester copolymer (A). Octyl-4-methylpyridinium hexafluorophosphate is preferred. The above antistatic agent (D) may be used individually by 1 type, and may be used in combination of 2 or more type.

  The content of the antistatic agent (D) in the adhesive composition P is preferably 0.1 to 15 parts by mass with respect to 100 parts by mass of the (meth) acrylic acid ester copolymer (A), In particular, the amount is preferably 0.5 to 10 parts by mass, and more preferably 1 to 5 parts by mass. When the content of the antistatic agent (D) is within the above range, the antistatic property can be exhibited effectively, and the deterioration of physical properties such as optical properties and durability can be prevented.

(5) Low molecular weight component The low molecular weight component in this specification does not correspond to any of the above components (B) to (D), and has a molecular weight (weight average molecular weight in the case of a polymer) of 10,000 or less. Say things. Examples of such low molecular weight components include acrylic polymers having a weight average molecular weight of 10,000 or less, styrene polymers, urethane polymers, silicones, etc .; hydrocarbons having a molecular weight of 1000 or less, such as stilbenes (cis stilbene, trans stilbene). , Benzyl benzoate, fluorene, diphenyl sulfide and the like, but are not limited thereto.

  Content of the low molecular weight component in the adhesive composition P is 5 mass% or less. When the content of the low molecular weight component is 5% by mass or less, the probability that the low molecular weight component in the pressure-sensitive adhesive layer is sucked out to the optical film side (part composed of acrylic resin) is reduced. Even if sucked out, the amount thereof is small, so that the low molecular weight component can be prevented from acting as a lubricating oil. Thereby, the adhesiveness with respect to the optical film of an adhesive layer becomes high, and when it uses for a display panel, the outstanding durability can be exhibited.

  From the above viewpoint, the content of the low molecular weight component in the adhesive composition P is preferably 3% by mass or less, particularly preferably 2% by mass or less, and further preferably 1.5% by mass or less. It is preferable. In addition, it is preferable that the lower limit of content of the low molecular weight component in the adhesive composition P is 0 mass%.

  In this embodiment, by using the (meth) acrylic acid ester copolymer (A) having the composition described above as the main component of the adhesive composition P, the (meth) acrylic acid ester copolymer (A ) Increases in the glass transition temperature (Tg), thereby suppressing the suction of the low molecular weight component from the pressure-sensitive adhesive layer to the optical film itself under the durable conditions.

(6) Various additives For the adhesive composition P, if desired, various additives usually used for acrylic pressure-sensitive adhesives, such as dispersants (for example, alkylene glycol dialkyl ethers), tackifiers, and antioxidants. An agent, an ultraviolet absorber, a light stabilizer, a softener, a filler, a refractive index adjusting agent, and the like can be added. Some of these additives correspond to the low molecular weight component, but in this case as well, the content of the low molecular weight component in the adhesive composition P needs to be 5% by mass or less. is there. In addition, the adhesive composition P represents a mixture of various components remaining in the adhesive layer as it is or in a reacted state, and is a component that is removed in a drying step or the like, for example, polymerization described later. Solvents and dilution solvents are not included in the adhesive composition P.

(7) Manufacturing method of adhesive composition Adhesive composition P manufactured (meth) acrylic acid ester copolymer (A), and obtained (meth) acrylic acid ester copolymer (A), It can manufacture by mixing a crosslinking agent (B) and a silane coupling agent (C), an antistatic agent (D), an additive, etc. depending on necessity.

  The (meth) acrylic acid ester copolymer (A) can be produced by polymerizing a mixture of monomer units constituting the polymer by an ordinary radical polymerization method. The polymerization of the (meth) acrylic acid ester copolymer (A) can be carried out by a solution polymerization method or the like using a polymerization initiator as desired. Examples of the polymerization solvent include ethyl acetate, n-butyl acetate, isobutyl acetate, toluene, acetone, hexane, methyl ethyl ketone, and the like. Two or more kinds may be used in combination.

  Examples of the polymerization initiator include azo compounds and organic peroxides, and two or more kinds may be used in combination. Examples of the azo compound include 2,2′-azobisisobutyronitrile, 2,2′-azobis (2-methylbutyronitrile), 1,1′-azobis (cyclohexane 1-carbonitrile), 2 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobis (2,4-dimethyl-4-methoxyvaleronitrile), dimethyl 2,2′-azobis (2-methylpropionate) 4,4′-azobis (4-cyanovaleric acid), 2,2′-azobis (2-hydroxymethylpropionitrile), 2,2′-azobis [2- (2-imidazolin-2-yl) Propane] and the like.

  Examples of organic peroxides include benzoyl peroxide, t-butyl perbenzoate, cumene hydroperoxide, diisopropyl peroxydicarbonate, di-n-propyl peroxydicarbonate, and di (2-ethoxyethyl) peroxy. Examples include dicarbonate, t-butyl peroxyneodecanoate, t-butyl peroxybivalate, (3,5,5-trimethylhexanoyl) peroxide, dipropionyl peroxide, diacetyl peroxide and the like.

  In addition, in the said superposition | polymerization process, the weight average molecular weight of the polymer obtained can be adjusted by mix | blending chain transfer agents, such as 2-mercaptoethanol.

  When the (meth) acrylic acid ester copolymer (A) is obtained, the solution of the (meth) acrylic acid ester copolymer (A) is added to the crosslinking agent (B), and optionally the silane coupling agent (C), An antistatic agent (D), an additive, a diluting solvent, and the like are added and mixed thoroughly to obtain an adhesive composition P (coating solution) diluted with a solvent.

  Examples of the dilution solvent for diluting the adhesive composition P to form a coating solution include aliphatic hydrocarbons such as hexane, heptane, and cyclohexane, aromatic hydrocarbons such as toluene and xylene, methylene chloride, ethylene chloride, and the like. Halogenated hydrocarbons, methanol, ethanol, propanol, butanol, alcohols such as 1-methoxy-2-propanol, acetone, methyl ethyl ketone, ketones such as 2-pentanone, isophorone, cyclohexanone, esters such as ethyl acetate and butyl acetate, ethyl A cellosolv solvent such as cellosolve is used.

  The concentration / viscosity of the coating solution thus prepared is not particularly limited as long as it can be coated, and can be appropriately selected depending on the situation. For example, it dilutes so that the density | concentration of the adhesive composition P may be 10-40 mass%. In addition, when obtaining a coating solution, addition of a dilution solvent etc. is not a necessary condition, and if a viscosity etc. which can be coated with the adhesive composition P are not necessary, a dilution solvent does not need to be added. In this case, the adhesive composition P becomes a coating solution using the polymerization solvent of the (meth) acrylic acid ester copolymer (A) as a dilution solvent.

(8) Adhesive The adhesive which comprises the adhesive layer in this embodiment is obtained from the adhesive composition P demonstrated above, and is specifically formed by bridge | crosslinking the adhesive composition P. is there. The pressure-sensitive adhesive composition P can be crosslinked by heat treatment. In addition, this heat processing can also serve as the drying process at the time of volatilizing the dilution solvent of the adhesive composition P, etc.

  When performing heat processing, it is preferable that heating temperature is 50-150 degreeC, and it is especially preferable that it is 70-120 degreeC. The heating time is preferably 30 seconds to 10 minutes, particularly preferably 50 seconds to 2 minutes. After the heat treatment, if necessary, a curing period of about 1 to 2 weeks may be provided at room temperature (for example, 23 ° C., 50% RH). When the curing period is necessary, after the curing period has elapsed, when the curing period is unnecessary, an adhesive layer having predetermined physical properties is formed after the heat treatment.

  By the heat treatment (and curing), the (meth) acrylic acid ester copolymer (A) is crosslinked by the crosslinking agent (B) to form a three-dimensional network structure.

  The degree of crosslinking of the pressure-sensitive adhesive, that is, the gel fraction, is preferably 40 to 90%, particularly preferably 60 to 85%, and more preferably 73 to 78%. When the gel fraction is 40% or more, the durability of the pressure-sensitive adhesive is more excellent. Moreover, when the gel fraction is 90% or less, the stress relaxation property of the pressure-sensitive adhesive becomes better, and the warpage suppressing property and the heat resistance unevenness become more excellent. In addition, the measuring method of the gel fraction of an adhesive is as showing to the test example mentioned later.

(9) Physical properties of the pressure-sensitive adhesive layer The thickness of the pressure-sensitive adhesive layer is preferably 5 to 100 μm, more preferably 10 to 60 μm, particularly preferably 10 to 50 μm, and 15 to 30 μm. Is more preferable.

  The haze value (value measured according to JIS K7136: 2000) of the pressure-sensitive adhesive layer is preferably 2% or less, and particularly preferably 1% or less. When the haze value is 2% or less, the transparency is very high, which is suitable for optical applications.

[Optical film]
The optical film in this embodiment may consist of a single layer or a plurality of layers. As an optical film, for example, a polarizer, a polarizing plate, a retardation plate, a polarizing plate with a retardation plate, a viewing angle compensation film, a brightness enhancement film, a contrast enhancement film, a liquid crystal polymer film, a diffusion film, a half Examples thereof include a transflective film and a laminate thereof. Among these, from the viewpoint that the polarizer easily contracts, has a large dimensional change, and requires durability, the optical film including the polarizer is suitable as the optical film of the optical film with the pressure-sensitive adhesive layer according to the present embodiment. In particular, the thin polarizing plate with the protective layer being thinned, and the composite polarizing plate using the polarizing plate have a weak ability to suppress the shrinkage of the polarizer with the protective layer, and thus are easily contracted by heat, etc. It is optimal as an optical film of the optical film with an adhesive layer according to the present embodiment.

  Here, the surface in contact with the pressure-sensitive adhesive layer in the optical film is made of an acrylic resin. By using an acrylic resin at the relevant part of the optical film, the film thickness can be reduced without deteriorating the predetermined optical performance. When the optical film is composed of a single layer, the optical film is composed of a single layer of an acrylic resin. When the optical film is composed of a plurality of layers, the outermost layer in contact with the pressure-sensitive adhesive layer is preferably composed of an acrylic resin layer formed through extrusion molding. Such an acrylic resin and a conventionally known pressure-sensitive adhesive layer have low adhesion and low durability. However, according to the pressure-sensitive adhesive layer in the present embodiment, the adhesive strength is high even for acrylic resins, and the stress relaxation property is excellent. Therefore, it is excellent in durability even under high temperature conditions, moist heat conditions, heat shocks, and the like. The “acrylic resin layer formed through extrusion molding” includes an acrylic resin layer obtained by stretching after extrusion molding.

  The optical film in the present embodiment is preferably provided with a retardation plate having at least an acrylic resin layer and a retardation development layer, and the retardation development layer has a reduced thickness and a retardation development. From the viewpoint of achieving both, it is preferably made of a styrene resin. Moreover, it is preferable that the said phase difference plate has a 2nd acrylic resin layer in the surface side on the opposite side to the surface at the side of the acrylic resin layer in the said phase difference expression layer. Thus, by having the acrylic resin layer and the retardation developing layer made of styrene resin, and further having the second acrylic resin layer, a liquid crystal display device, particularly an IPS (In-Place-Switching) is provided. ) In a mode liquid crystal display device, excellent viewing angle compensation performance can be exhibited.

  It is preferable that a second retardation plate is further laminated on the surface of the retardation plate opposite to the surface on the pressure-sensitive adhesive layer side, and the second retardation plate is made of cycloolefin resin. It is preferable to become. By having such a second retardation plate, and further having a second retardation plate made of a cycloolefin resin, the viewing angle compensation performance is further improved.

  Moreover, it is preferable that a polarizing plate is further laminated on the surface of the second retardation plate opposite to the surface of the retardation plate. Thereby, the composite polarizing plate which has the very outstanding viewing angle compensation performance can be provided.

[Specific example of optical film with adhesive layer]
1. Example of Optical Film as Polarizing Plate An example of the optical film with the pressure-sensitive adhesive layer according to this embodiment in the case where the optical film is a polarizing plate will be described with reference to FIG. As shown in FIG. 1, an optical film 10A with an adhesive layer according to this embodiment includes a polarizing plate 2A and an adhesive layer 1 laminated on one surface (the lower surface in FIG. 1) of the polarizing plate 2A. And is configured. Although not shown, a release sheet may be laminated on the surface of the pressure-sensitive adhesive layer 1 opposite to the polarizing plate 2A side until the optical film 10A with the pressure-sensitive adhesive layer is used.

  The pressure-sensitive adhesive layer 1 is made of a pressure-sensitive adhesive obtained from the pressure-sensitive adhesive composition P described above.

  The polarizing plate 2A in the present embodiment includes a polarizer 21, a first protective layer 22 laminated on one surface of the polarizer 21 (the upper surface in FIG. 1), and the other surface of the polarizer 21 (FIG. 1 is provided with a second protective layer 23 laminated on the lower surface). Although not shown, an adhesive layer may be interposed between the polarizer 21 and the first protective layer 22 and / or between the polarizer 21 and the second protective layer 23.

(1) Polarizer The polarizer 21 is preferably made of a polyvinyl alcohol-based resin film on which a dichroic dye is adsorbed and oriented.

  The polyvinyl alcohol resin constituting the polarizer 21 can be obtained by saponifying a polyvinyl acetate resin. Examples of the polyvinyl acetate resin include polyvinyl acetate, which is a homopolymer of vinyl acetate, and copolymers of vinyl acetate and other monomers copolymerizable therewith. Examples of other monomers copolymerized with vinyl acetate include unsaturated carboxylic acids, olefins, vinyl ethers, and unsaturated sulfonic acids.

  The degree of saponification of the polyvinyl alcohol resin is usually 85 to 100 mol%, preferably 98 to 100 mol%. The polyvinyl alcohol-based resin may be further modified, and for example, polyvinyl formal or polyvinyl acetal modified with aldehydes may be used. The degree of polymerization of the polyvinyl alcohol resin is usually 1,000 to 10,000, preferably 1,500 to 5,000.

  The polarizer 21 as described above includes a step of uniaxially stretching a polyvinyl alcohol-based resin film, a step of dyeing a polyvinyl alcohol-based resin film with a dichroic dye, and adsorbing the dichroic dye, It is preferably manufactured by passing the adsorbed polyvinyl alcohol resin film with a boric acid aqueous solution.

  Uniaxial stretching may be performed before dyeing with a dichroic dye, may be performed simultaneously with dyeing with a dichroic dye, or may be performed after dyeing with a dichroic dye. When uniaxial stretching is performed after dyeing with a dichroic dye, this uniaxial stretching may be performed before boric acid treatment or during boric acid treatment. Of course, it is also possible to perform uniaxial stretching in these plural stages. For uniaxial stretching, rolls having different peripheral speeds may be uniaxially stretched or uniaxially stretched using a hot roll. Moreover, the dry-type extending | stretching which extends | stretches in air | atmosphere may be sufficient, and the wet extending | stretching which extends | stretches in the state swollen with the solvent may be sufficient. The draw ratio is usually about 4 to 8 times.

  In order to dye the polyvinyl alcohol resin film with the dichroic dye, for example, the polyvinyl alcohol resin film may be immersed in an aqueous solution containing the dichroic dye. Specifically, iodine or a dichroic organic dye is used as the dichroic dye.

  When iodine is used as the dichroic dye, a method of dyeing a polyvinyl alcohol resin film by dipping it in an aqueous solution containing iodine and potassium iodide is usually employed. The content of iodine in this aqueous solution is usually about 0.01 to 0.5 parts by mass per 100 parts by mass of water, and the content of potassium iodide is usually about 0.5 to 10 parts by mass per 100 parts by mass of water. It is. The temperature of this aqueous solution is usually about 20 to 40 ° C., and the immersion time (dyeing time) in this aqueous solution is usually about 30 to 300 seconds.

  The boric acid treatment after dyeing with a dichroic dye is performed by immersing the dyed polyvinyl alcohol resin film in an aqueous boric acid solution. The boric acid content in the boric acid aqueous solution is usually about 2 to 15 parts by mass, preferably about 5 to 12 parts by mass per 100 parts by mass of water. When iodine is used as the dichroic dye, the aqueous boric acid solution preferably contains potassium iodide. The content of potassium iodide in the boric acid aqueous solution is usually about 2 to 20 parts by mass, preferably 5 to 15 parts by mass per 100 parts by mass of water. The immersion time in the boric acid aqueous solution is usually about 100 to 1,200 seconds, preferably about 150 to 600 seconds, and more preferably about 200 to 400 seconds. The temperature of the boric acid aqueous solution is usually 50 ° C. or higher, preferably 50 to 85 ° C.

  The polyvinyl alcohol resin film after the boric acid treatment is usually washed with water. The water washing treatment is performed, for example, by immersing a boric acid-treated polyvinyl alcohol resin film in water. After washing with water, a drying process is performed to obtain the polarizer 21. The temperature of water in the water washing treatment is usually about 5 to 40 ° C., and the immersion time is usually about 2 to 120 seconds. The drying process performed thereafter is usually performed using a hot air dryer or a far infrared heater. The drying temperature is usually 40 to 100 ° C. Moreover, the time of a drying process is about 120 to 600 seconds normally.

  The thickness of the polarizer 21 is preferably about 3 to 50 μm, and particularly about 3 to 15 μm when thinning is required.

(2) Protective layer The first protective layer 22 and the second protective layer 23 (hereinafter sometimes collectively referred to as "protective layers 22 and 23") are preferably made of a transparent resin film. The transparent resin film constituting the protective layers 22 and 23 may be either an unstretched film or a uniaxially or biaxially stretched film.

  The main component of the transparent resin film constituting the first protective layer 22 is preferably at least selected from the group consisting of polyester resins, polycarbonate resins, acrylic resins, amorphous polyolefin resins, and cellulose resins. One type of resin. Among the above, the first protective layer 22 is preferably made of a cellulose resin.

  The cellulose resin is a resin in which at least a part of hydroxyl groups in cellulose is acetate esterified, and a mixed ester in which part is acetated and partly esterified with another acid. Good. The cellulose resin is preferably a cellulose ester resin, and more preferably an acetyl cellulose resin. Specific examples of the acetyl cellulose resin include triacetyl cellulose, diacetyl cellulose, cellulose acetate propionate, and cellulose acetate butyrate. Examples of commercially available films made of such an acetyl cellulose resin include “Fujitac TD80”, “Fujitac TD80UF” and “Fujitac TD80UZ” manufactured by Fuji Film Co., Ltd., and “KC8UX2M” manufactured by Konica Minolta Opto Co., Ltd. "," KC2UA "," KC8UY "and the like.

  A cellulose resin film provided with an optical compensation function can also be used. As such an optical compensation film, for example, a film in which a compound having a retardation adjusting function is contained in a cellulose resin, a film in which a compound having a retardation adjusting function is applied to the surface of the cellulose resin, a cellulose resin is uniaxial or biaxial. Examples thereof include a film obtained by stretching on a shaft. Examples of commercially available optical compensation films of cellulose resin include “Wide View Film WV BZ 438” and “Wide View Film WV EA” manufactured by Fuji Film Co., Ltd., “Konica Minolta Opto Co., Ltd.” KC4FR-1 "and" KC4HR-1 ".

  Among the cellulose resins, the first protective layer 22 is more preferably made of a cellulose ester resin, particularly preferably an acetyl cellulose resin, and further preferably triacetyl cellulose.

  On the other hand, the main component of the transparent resin film constituting the second protective layer 23 is preferably an acrylic resin. In particular, the second protective layer 23 has a viewpoint that it can be easily thinned without impairing the polarization performance. Therefore, it is preferably made of an acrylic resin. In this case, in the case where the pressure-sensitive adhesive layer in contact with the second protective layer 23 is made of a conventional acrylic pressure-sensitive adhesive composition, the low molecular weight component in the pressure-sensitive adhesive is sucked out, and the second protective layer 23 and the pressure-sensitive adhesive layer It will reduce the adhesion at the interface. However, if it is the adhesive layer 1 formed from the adhesive composition P in this embodiment, the (meth) acrylic acid ester copolymer which has a glass transition temperature (Tg) high to such an extent that adhesive force will not become inadequate. While using (A) and suppressing the content of the low molecular weight component to 5% by mass or less, the suction of the low molecular weight component from the pressure-sensitive adhesive layer 1 to the second protective layer 23 can be effectively suppressed. . Thereby, the adhesive layer 1 has high adhesion to the second protective layer 23. Therefore, the optical film 10A with the pressure-sensitive adhesive layer has excellent durability even under high temperature conditions, wet heat conditions, heat shocks, and the like.

  The acrylic resin forming the second protective layer 23 is preferably a polymer having a methacrylic acid ester as a main monomer, and is a copolymer in which a small amount of other comonomer components are copolymerized. It is particularly preferred. This copolymer can be usually obtained by polymerizing a monofunctional monomer containing methyl methacrylate and methyl acrylate in the presence of a radical polymerization initiator and a chain transfer agent. The acrylic resin can be copolymerized with a third monofunctional monomer.

  Examples of the third monofunctional monomer that can be copolymerized with methyl methacrylate and methyl acrylate include, for example, ethyl methacrylate, butyl methacrylate, cyclohexyl methacrylate, phenyl methacrylate, benzyl methacrylate, 2-ethylhexyl methacrylate. , And methacrylates other than methyl methacrylate, such as 2-hydroxyethyl methacrylate; ethyl acrylate, butyl acrylate, cyclohexyl acrylate, phenyl acrylate, benzyl acrylate, 2-ethylhexyl acrylate, and acrylic acid 2 Acrylic esters such as hydroxyethyl; methyl 2- (hydroxymethyl) acrylate, methyl 2- (1-hydroxyethyl) acrylate, ethyl 2- (hydroxymethyl) acrylate, and 2- Hydroxyalkyl acrylates such as (hydroxymethyl) butyl acrylate; unsaturated acids such as methacrylic acid and acrylic acid; halogenated styrenes such as chlorostyrene and bromostyrene; substituted styrenes such as vinyltoluene and α-methylstyrene And unsaturated nitriles such as acrylonitrile and methacrylonitrile; unsaturated acid anhydrides such as maleic anhydride and citraconic anhydride; unsaturated imides such as phenylmaleimide and cyclohexylmaleimide. Each of these may be used alone, or a plurality of different types may be used in combination.

  When copolymerizing polyfunctional monomers, examples of polyfunctional monomers that can be copolymerized with methyl methacrylate and methyl acrylate include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, and triethylene. Glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, nonaethylene glycol di (meth) acrylate, tetradecaethylene glycol di (meth) acrylate, etc. Esterified with methacrylic acid; Propylene glycol or its oligomers hydroxylated at both terminal hydroxyl groups with acrylic acid or methacrylic acid; Neopentyl glycol di (meth) acrylate, One obtained by esterifying a hydroxyl group of a dihydric alcohol such as xanthdiol di (meth) acrylate and butanediol di (meth) acrylate with acrylic acid or methacrylic acid; bisphenol A, alkylene oxide adduct of bisphenol A, or halogens thereof Those obtained by esterifying the hydroxyl groups at both ends of the substituent with acrylic acid or methacrylic acid; those obtained by esterifying polyhydric alcohols such as trimethylolpropane and pentaerythritol with acrylic acid or methacrylic acid, and glycidyl acrylate or glycidyl at these terminal hydroxyl groups Ring-opening addition of an epoxy group of methacrylate; dibasic acids such as succinic acid, adipic acid, terephthalic acid, phthalic acid, and halogen-substituted products thereof, and alkylene oxy Id adducts as epoxy group of glycidyl acrylate or glycidyl methacrylate was ring-opening addition to the like; aryl (meth) acrylate; and aromatic divinyl compounds such as divinylbenzene. Among these, ethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, and neopentyl glycol dimethacrylate are preferably used.

  The acrylic resin having such a composition may be further modified by a reaction between functional groups of the copolymer. As the reaction, for example, demethanol condensation reaction in a polymer chain between a methyl ester group of methyl acrylate and a hydroxyl group of methyl 2- (hydroxymethyl) acrylate, a carboxyl group of acrylic acid and 2- (hydroxymethyl) acrylic Examples thereof include a dehydration condensation reaction in a polymer chain with a hydroxyl group of methyl acid.

  The glass transition temperature (Tg) of the acrylic resin is preferably in the range of 80 to 120 ° C. In order to adjust the glass transition temperature (Tg) of the acrylic resin to the above range, the polymerization ratio of the methacrylic acid ester monomer and the acrylic acid ester monomer, the carbon chain length of each ester group, and its For example, a method of appropriately selecting the type of the functional group to be possessed and the polymerization ratio of the polyfunctional acrylic monomer to the whole monomer is employed.

  The acrylic resin may contain a known additive as required. Known additives include, for example, lubricants, anti-blocking agents, heat stabilizers, antioxidants, antistatic agents, light resistance agents, impact resistance improvers, surfactants and the like. However, since transparency is required as a protective film laminated on the polarizer, it is preferable to keep the amount of these additives to a minimum.

  As a method for producing the acrylic resin film, any method such as a melt casting method, a melt extrusion method such as a T-die method or an inflation method, or a calendar method may be used. Among these, a method of forming a film by melting and extruding a raw material resin from, for example, a T die and bringing at least one surface of the obtained film-like material into contact with a roll or a belt is preferable in that a film having good surface properties can be obtained.

  The acrylic resin may contain acrylic rubber particles that are impact modifiers from the viewpoint of film-forming properties on the film and impact resistance of the film. The term “acrylic rubber particles” as used herein refers to particles containing an elastic polymer mainly composed of an acrylate ester as an essential component. The thing of the multilayered structure used as one layer is mentioned.

  An example of such an elastic polymer is a cross-linked elastic copolymer obtained by copolymerizing an alkyl acrylate as a main component with another vinyl monomer and a cross-linkable monomer copolymerizable therewith. Examples of the alkyl acrylate that is the main component of the elastic polymer include those having an alkyl group of about 1 to 8 carbon atoms, such as methyl acrylate, ethyl acrylate, butyl acrylate, and 2-ethylhexyl acrylate. An acrylate having an alkyl group of several 4 or more is preferably used. Examples of other vinyl monomers copolymerizable with the alkyl acrylate include compounds having one polymerizable carbon-carbon double bond in the molecule, and more specifically, methacrylic acid esters such as methyl methacrylate. And aromatic vinyl compounds such as styrene and vinylcyan compounds such as acrylonitrile. Examples of the crosslinkable monomer include a crosslinkable compound having at least two polymerizable carbon-carbon double bonds in the molecule, and more specifically, ethylene glycol di (meth) acrylate and butanediol. Examples include (meth) acrylates of polyhydric alcohols such as di (meth) acrylate, alkenyl esters of (meth) acrylic acid such as allyl (meth) acrylate, and divinylbenzene.

  Furthermore, a laminate of a film made of an acrylic resin not containing rubber particles and a film made of an acrylic resin containing rubber particles can be used as the protective layers 22 and 23. Commercially available acrylic resins can be easily obtained. For example, Sumipex (manufactured by Sumitomo Chemical Co., Ltd.), Acripet (manufactured by Mitsubishi Rayon Co., Ltd.), Delpet (Asahi Kasei) (Manufactured by Co., Ltd.), Parapet (manufactured by Kuraray Co., Ltd.), acryl viewer (manufactured by Nippon Shokubai Co., Ltd.) and the like.

  The protective layers 22 and 23 may contain an ultraviolet absorber. This is because the liquid crystal cell can be protected from deterioration due to ultraviolet rays by disposing a protective layer containing an ultraviolet absorber on the viewing side of the liquid crystal cell.

  Here, the 1st protective layer 22 and the 2nd protective layer 23 may consist of a transparent resin film of the same kind, and may consist of a transparent resin film of a different kind.

  Prior to bonding to the polarizer 21, the protective layers 22 and 23 may be subjected to easy adhesion treatment such as saponification treatment, corona treatment, primer treatment, and anchor coating treatment on the bonding surface. Moreover, you may have various process layers, such as a hard-coat layer, an antireflection layer, an anti-glare layer, in the surface on the opposite side to the bonding surface to the polarizer 21 of the protective layers 22 and 23. FIG.

  The thickness of the protective layers 22 and 23 is usually in the range of about 5 to 200 μm, preferably 10 to 120 μm, particularly preferably 10 to 85 μm, and more preferably 10 to 30 μm.

(3) Adhesive layer Adhesive constituting an adhesive layer that may be interposed between the polarizer 21 and the first protective layer 22 and / or between the polarizer 21 and the second protective layer 23. As such, an appropriate one can be used depending on the type and purpose of the adherend. For example, solvent type adhesives, emulsion type adhesives, water based adhesives, pressure sensitive adhesives, rewet adhesives, polycondensation type adhesives, solventless type adhesives, film adhesives, hot melt type adhesives, etc. Can be mentioned.

  One preferable adhesive constituting the adhesive is a water-based adhesive, and a typical example thereof is a polyvinyl alcohol resin as a main component. Examples of commercially available polyvinyl alcohol resins that can be used as water-based adhesives include “KL-318” manufactured by Kuraray Co., Ltd.

  The aqueous adhesive may contain a crosslinking agent. As the crosslinking agent, an amine compound, an aldehyde compound, a methylol compound, an epoxy compound, an isocyanate compound, a polyvalent metal salt and the like are preferable, and an epoxy compound is particularly preferable. Examples of commercially available cross-linking agents include Glyoxal and “Smilease Resin 650 (30)” which is an aqueous solution of a water-soluble epoxy compound sold by Sumika Chemtex Co., Ltd.

  Another preferred adhesive is an adhesive made of an epoxy resin composition containing an epoxy resin that is cured by irradiation with active energy rays or heating. When the adhesive is used, the adhesive between the films is applied by irradiating active energy rays or heating the adhesive layer interposed between the films to cure the curable epoxy resin contained in the adhesive. Can be done. Curing of the epoxy resin by irradiation with active energy rays or heating is preferably performed by cationic polymerization of the epoxy resin. In this specification, an epoxy resin means a compound having two or more epoxy groups in the molecule.

  From the viewpoint of weather resistance, refractive index, cationic polymerizability, etc., the epoxy resin contained in the curable epoxy resin composition that is an adhesive is preferably an epoxy resin that does not contain an aromatic ring in the molecule. Examples of such epoxy resins include hydrogenated epoxy resins, alicyclic epoxy resins, aliphatic epoxy resins, and the like.

(4) Manufacturing method of polarizing plate The manufacturing method of the polarizing plate 2A can be performed by an ordinary method. Hereinafter, as an example, a manufacturing method when a water-based adhesive is used as the adhesive will be described.

  First, an adhesive layer is formed on the bonding surface of the polarizer 21 or the bonding surfaces of the protective layers 22 and 23. For example, a bar coating method, a knife coating method, a roll coating method, a blade coating method, a die coating method, or a gravure coating method can be used for forming the adhesive layer. Moreover, it is also possible to adopt a method in which the polarizer 21 and the protective layers 22 and 23 are continuously supplied so that the bonding surfaces of the polarizer 21 and the protective layers 22 and 23 are inside, and an adhesive is cast between them. After the adhesive is applied, heat treatment is performed as necessary to evaporate moisture and dry the adhesive layer.

  The film thickness of the adhesive layer can be arbitrarily set by the characteristic design of the polarizing plate 2A, but from the viewpoint of reducing the adhesive material cost, a smaller one is preferable, and the viewpoint of suppressing defects such as air bubbles and foreign matters at the time of bonding. From the viewpoint of adhesion and durability, it is preferable to carry out within the optimum range determined for each combination of the adherend and the adhesive. In general, the thickness is 0.005 to 10 μm, preferably 0.01 to 5 μm, more preferably 0.03 to 1 μm.

  In adhering the polarizer 21 and the protective layers 22 and 23, a corona discharge treatment, a plasma treatment, a flame treatment, and a primer treatment are performed on one or both of the bonding surfaces before forming an adhesive coating layer. An easy adhesion treatment such as an anchor coating treatment may be performed.

  When the adhesive layer is formed as described above, the first protective layer 22 is bonded to one surface of the polarizer 21 through the adhesive layer, and the second protective layer 23 is bonded to the polarizer 21. Paste it on the other side. Thereby, the polarizing plate 2A formed by laminating the first protective layer 22, the polarizer 21, and the second protective layer 23 is obtained.

  The total thickness of the polarizing plate 2A is usually about 15 to 400 μm, and preferably 20 to 100 μm, and preferably 30 to 80 μm from the viewpoint of maintaining polarization performance while meeting the demand for thinning for mobile applications. Is particularly preferred.

(5) Method for producing optical film with pressure-sensitive adhesive layer As a preferred example of the method for producing optical film with pressure-sensitive adhesive layer 10A, first, a release sheet is provided on one or both sides of the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition P. To produce a pressure-sensitive adhesive sheet. Here, as an example, a pressure-sensitive adhesive sheet is manufactured by laminating release sheets on both sides of a pressure-sensitive adhesive layer.

  As the release sheet, for example, polyethylene film, polypropylene film, polybutene film, polybutadiene film, polymethylpentene film, polyvinyl chloride film, vinyl chloride copolymer film, polyethylene terephthalate film, polyethylene naphthalate film, polybutylene terephthalate film, Polyurethane film, ethylene vinyl acetate film, ionomer resin film, ethylene / (meth) acrylic acid copolymer film, ethylene / (meth) acrylic acid ester copolymer film, polystyrene film, polycarbonate film, polyimide film, fluororesin film, etc. Is used. These crosslinked films are also used. Furthermore, these laminated films may be sufficient.

  It is preferable that at least one surface of the release sheet (particularly the release surface in contact with the pressure-sensitive adhesive layer) is subjected to a release treatment. Examples of the release agent used for the release treatment include alkyd, silicone, fluorine, unsaturated polyester, polyolefin, and wax release agents. In addition, the release surface of the release sheet in this specification refers to a surface having peelability in the release sheet, and includes both a surface that has been subjected to a release treatment and a surface that exhibits peelability without being subjected to a release treatment. .

  When laminating release sheets on both sides of the pressure-sensitive adhesive layer, it is preferable that one release sheet is a heavy release release sheet having a large release force and the other release sheet is a light release release sheet having a low release force.

  Although there is no restriction | limiting in particular about the thickness of a peeling sheet, Usually, it is about 20-150 micrometers.

  As an example of the manufacturing method of the said adhesive sheet, after apply | coating the application | coating solution of the adhesive composition P to the peeling surface of a peeling sheet and performing heat processing, and forming a coating film, it separates into that coating film as needed. A release sheet (so that the release surface is in contact with the coating film) or a substrate is laminated. When the curing period is unnecessary, the coating film becomes an adhesive layer as it is, and when the curing period is necessary, the coating film becomes an adhesive layer after the curing period. The conditions for the heat treatment and curing are as described above.

  As a method for applying the coating solution, for example, a bar coating method, a knife coating method, a roll coating method, a blade coating method, a die coating method, a gravure coating method, or the like can be used.

  One release sheet (light release type release sheet) is released from the pressure-sensitive adhesive sheet obtained as described above. And the 2nd protective layer 23 of polarizing plate 2A is piled up on the exposed adhesive layer, and an adhesive sheet and polarizing plate 2A are crimped | bonded. Thereby, 10 A of said optical films with an adhesive layer (with a peeling sheet) are obtained.

  As another example of the manufacturing method of the optical film 10A with an adhesive layer, the solution (coating solution) containing the adhesive composition P mentioned above is apply | coated to the peeling surface of a peeling sheet, and it heat-processes and performs a coating film. After the formation, the second protective layer 23 of the polarizing plate 2A is overlaid on the coating film. When a curing period is required, a curing period is set, and when the curing period is unnecessary, the coating film becomes the pressure-sensitive adhesive layer 1 as it is. Thereby, 10 A of said optical films with an adhesive layer (with a peeling sheet) are obtained.

2. Example of Optical Film as Composite Polarizing Plate An example of the optical film with the pressure-sensitive adhesive layer according to this embodiment in the case where the optical film is a composite polarizing plate having a retardation plate will be described with reference to FIG. As shown in FIG. 2, the optical film 10B with the pressure-sensitive adhesive layer according to this embodiment includes a composite polarizing plate 2B and a pressure-sensitive adhesive laminated on one surface (the lower surface in FIG. 2) of the composite polarizing plate 2B. And a layer 1. In addition, although not shown in figure, the release sheet may be laminated | stacked until the optical film 10B with an adhesive layer is used for the surface on the opposite side to the composite polarizing plate 2B side in the adhesive layer 1. FIG.

  The pressure-sensitive adhesive layer 1 is made of a pressure-sensitive adhesive obtained from the pressure-sensitive adhesive composition P described above.

  The composite polarizing plate 2B in this embodiment includes a first retardation plate 24 that contacts the adhesive layer 1 and a second position that is located on the opposite side of the first retardation plate 24 from the adhesive layer 1 side. The phase difference plate 25, the second pressure-sensitive adhesive layer 26 interposed between the first phase difference plate 24 and the second phase difference plate 25, and the second pressure-sensitive adhesive layer 26 side of the second phase difference plate 25 The polarizer 21 is laminated on the opposite side of the polarizer 21, and the protective layer 27 is laminated on the opposite side of the polarizer 21 from the second retardation plate 25 side. Although not shown, an adhesive layer may be interposed between the polarizer 21 and the protective layer 27 and / or between the polarizer 21 and the second retardation plate 25. Such a composite polarizing plate 2B exhibits excellent viewing angle compensation performance.

(1) 1st phase difference plate The 1st phase difference plate 24 may consist of a single layer which expresses a phase difference, and may consist of a several layer containing a phase difference expression layer. As shown in FIG. 3, the first retardation plate 24 is preferably a retardation development layer 242 and a first layer laminated on one surface of the retardation development layer 242 (the lower surface in FIG. 3). 1 acrylic resin layer 241 and a second acrylic resin layer 243 laminated on the other surface (upper surface in FIG. 3) of the retardation developing layer 242. The retardation layer 242 preferably has a negative intrinsic birefringence and is made of a styrene resin from the viewpoint of easy thinning. Thus, it has the 1st phase plate 24 comprised including the 1st acrylic resin layer 241, the phase difference expression layer 242 which consists of a styrene resin, and the 2nd acrylic resin layer 243. The composite polarizing plate 2B is excellent in the viewing angle compensation performance of a liquid crystal display device, particularly an IPS (In-Place-Switching) mode liquid crystal display device. Moreover, since the phase difference expression layer 242 is protected by the first acrylic resin layer 241 and the second acrylic resin layer 243 existing on both surfaces thereof, the first phase difference plate 24 is composed of the phase difference expression layer 24. The optical performance of 242 is not impaired, and the mechanical strength and chemical resistance are excellent.

  Further, when the layer in contact with the pressure-sensitive adhesive layer 1 in the first retardation plate 24 is the first acrylic resin layer 241, the pressure-sensitive adhesive layer in contact with the first acrylic resin layer 241 is a conventional acrylic pressure-sensitive adhesive. In the layer made of the composition, the low molecular weight component in the pressure-sensitive adhesive is sucked out, and the adhesion at the interface between the first acrylic resin layer 241 and the pressure-sensitive adhesive layer is lowered. However, if it is the adhesive layer 1 formed from the adhesive composition P in this embodiment, the (meth) acrylic acid ester copolymer which has a glass transition temperature (Tg) high to such an extent that adhesive force will not become inadequate. While using (A) and suppressing the content of the low molecular weight component to 5% by mass or less, the suction of the low molecular weight component from the pressure-sensitive adhesive layer 1 to the first acrylic resin layer 241 is effectively suppressed. Can do. Thereby, the adhesive layer 1 has high adhesion to the first retardation plate 24. Therefore, the optical film 10B with the pressure-sensitive adhesive layer has excellent durability even under high temperature conditions, wet heat conditions, heat shocks, and the like.

  The first retardation plate 24 is preferably provided with in-plane retardation by stretching. Thereby, the viewing angle compensation performance is further improved.

  The styrene resin constituting the retardation layer 242 may be a homopolymer of styrene or a derivative thereof, or a binary or higher copolymer of styrene or a derivative thereof and another copolymerizable monomer. It may be a coalescence. Styrene derivatives are compounds in which other groups are bonded to styrene, such as o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, o-ethylstyrene, p-ethyl. Alkyl styrene such as styrene, hydroxy styrene, tert-butoxy styrene, vinyl benzoic acid, o-chloro styrene, p-chloro styrene, such as hydroxyl group, alkoxy group, carboxyl group and halogen are introduced into the benzene nucleus of styrene. Substituted styrene and the like.

  As the styrenic resin, a terpolymer as disclosed in JP2003-50316A or JP2003-207640A can also be used.

  The styrene resin constituting the retardation developing layer 242 is preferably a copolymer of styrene or a styrene derivative and at least one monomer selected from acrylonitrile, maleic anhydride, methyl methacrylate, and butadiene.

  Moreover, as a styrene resin which comprises the phase difference expression layer 242, the styrene resin which has heat resistance is preferable. The glass transition temperature (Tg) of the styrene resin is generally 100 ° C. or higher, but a styrene resin having a glass transition temperature (Tg) of 120 ° C. or higher is preferable.

  The thickness of the phase difference expression layer 242 is preferably 10 to 100 μm. When the thickness of the retardation developing layer 242 is 10 μm or more, a sufficient retardation value is exhibited by stretching. On the other hand, when the thickness of the retardation developing layer 242 is 100 μm or less, the impact strength is high, and the change in retardation due to external stress is small, so that when applied to a liquid crystal display device, heat unevenness or the like hardly occurs.

  The first acrylic resin layer 241 and the second acrylic resin layer 243 are preferably made of a (meth) acrylic resin composition in which rubber particles are blended with a (meth) acrylic resin. By blending the rubber particles, the impact resistance of the acrylic resin layer can be enhanced.

  Examples of the (meth) acrylic resin include a homopolymer of a methacrylic acid alkyl ester or an acrylic acid alkyl ester, a copolymer of a methacrylic acid alkyl ester and an acrylic acid alkyl ester, and the like. Examples of the alkyl methacrylate include methyl methacrylate, ethyl methacrylate, propyl methacrylate and the like. Examples of the alkyl acrylate ester include methyl acrylate, ethyl acrylate, and propyl acrylate. As such a (meth) acrylic resin, a commercially available (meth) acrylic resin can be used. Some (meth) acrylic resins include those called impact resistant (meth) acrylic resins, and high heat resistant (meth) acrylic resins having a glutaric anhydride structure or a lactone ring structure in the main chain. What is called is also included.

  The rubber particles blended in the (meth) acrylic resin are preferably acrylic. Acrylic rubber particles are particles having rubber elasticity obtained by polymerizing in the presence of a polyfunctional monomer mainly composed of an alkyl acrylate ester such as butyl acrylate or 2-ethylhexyl acrylate.

  The rubber particles may be made of a material having rubber elasticity uniformly in the form of particles, or may be a multilayer structure having at least one rubber elastic layer. As the acrylic rubber particles having a multilayer structure, particles having rubber elasticity as described above are used as cores, and the periphery thereof is covered with a hard alkyl methacrylate ester polymer, or a hard alkyl methacrylate ester polymer. The core is covered with an acrylic polymer having rubber elasticity as described above, and the hard core is covered with an acrylic polymer having rubber elasticity, and the surroundings are hard methacrylic acid. Examples thereof include those covered with an alkyl ester polymer.

  The average diameter of the rubber particles is preferably about 50 to 400 nm. The average diameter of the rubber particles can be measured by a laser diffraction scattering method.

  The content of the rubber particles in the (meth) acrylic resin composition constituting the first acrylic resin layer 241 and the second acrylic resin layer 243 is 5 to 100 parts by mass of the (meth) acrylic resin. The amount is preferably about 50 parts by mass.

  The (meth) acrylic resin composition constituting the first acrylic resin layer 241 and the second acrylic resin layer 243 is commercially available in a state where the (meth) acrylic resin and acrylic rubber particles are mixed. Can be used. Examples of commercially available products of (meth) acrylic resin ((meth) acrylic resin composition) containing acrylic rubber particles are “HT55X” sold by Sumitomo Chemical Co., Ltd. under the trade name. And “Technoloy S001”.

  The glass transition temperature (Tg) of the (meth) acrylic resin composition is generally 160 ° C. or lower, but a (meth) acrylic resin composition having a glass transition temperature (Tg) of 120 ° C. or lower is preferred, particularly 110 A (meth) acrylic resin composition at a temperature of 0 ° C. or lower is preferred. That is, it is preferable that the glass transition temperature (Tg) of the retardation developing layer 242 and the glass transition temperatures (Tg) of the first acrylic resin layer 241 and the second acrylic resin layer 243 do not overlap with each other. The layer 242 preferably has a glass transition temperature (Tg) higher than that of the first acrylic resin layer 241 and the second acrylic resin layer 243.

  The materials of the first acrylic resin layer 241 and the second acrylic resin layer 243 may be the same or different.

  The thicknesses of the first acrylic resin layer 241 and the second acrylic resin layer 243 are each preferably 10 to 100 μm. If the thickness is 10 μm or more, the film can be easily formed, and if the thickness is 100 μm or less, the retardation of the first acrylic resin layer 241 and the second acrylic resin layer 243 should be ignored. Can do. Note that the thickness of the first acrylic resin layer 241 and the thickness of the second acrylic resin layer 243 are preferably substantially the same.

  The surface on the second pressure-sensitive adhesive layer 26 side of the first retardation plate 24 may be subjected to a surface treatment such as a corona treatment.

  In order to manufacture the first retardation plate 24, for example, a styrene resin and a (meth) acrylic resin composition containing rubber particles may be coextruded and then stretched. Stretching can be performed by longitudinal uniaxial stretching, tenter transverse uniaxial stretching, simultaneous biaxial stretching, sequential biaxial stretching, or the like, and may be performed so as to obtain a desired retardation value. In addition to the above method, single-layer films (a retardation developing layer 242, a first acrylic resin layer 241 and a second acrylic resin layer 243) are prepared and then thermally fused by heat lamination. And the laminate may be stretched.

  The total thickness of the first retardation plate 24 after stretching is preferably 5 to 100 μm, and 10 to 50 μm from the viewpoint of meeting the demand for thinning in mobile applications while maintaining sufficient performance. Is more preferable, and it is especially preferable that it is 15-30 micrometers.

  In the first retardation plate 24, the surface in contact with the pressure-sensitive adhesive layer 1 is constituted by the first acrylic resin layer 241, but in this case as well, the pressure-sensitive adhesive layer 1 is in contact with the first acrylic resin layer 241. Adhesive strength is high, and thus the optical film 10B with a pressure-sensitive adhesive layer is excellent in durability even under high temperature conditions, wet heat conditions, under heat shock, and the like.

(2) Second retardation plate The second retardation plate 25 is preferably made of an olefin resin. The olefin resin is a chain aliphatic olefin such as ethylene and propylene, or a structural unit derived from an alicyclic olefin such as norbornene or a substituted product thereof (hereinafter collectively referred to as norbornene monomer). It is a resin. The olefin resin may be a copolymer using two or more kinds of monomers.

  Among them, as the olefin resin, a cyclic olefin resin that is a resin mainly containing a structural unit derived from an alicyclic olefin is preferably used. Typical examples of the alicyclic olefin constituting the cyclic olefin resin include a norbornene monomer. Norbornene is a compound in which one carbon-carbon bond of norbornane is a double bond, and according to IUPAC nomenclature, it is named bicyclo [2,2,1] hept-2-ene. is there. Examples of substituted norbornene include 3-substituted, 4-substituted, 4,5-disubstituted, etc., with the norbornene double bond position being 1,2-position. Cyclopentadiene, dimethanooctahydronaphthalene, and the like can also be used as monomers constituting the cyclic olefin resin.

  The cyclic olefin-based resin may or may not have a norbornane ring in its structural unit. Examples of the norbornene-based monomer that forms a cyclic olefin-based resin having no norbornane ring as a structural unit include, for example, those that become a 5-membered ring by ring opening, typically norbornene, dicyclopentadiene, 1- or 4- Examples thereof include methyl norbornene and 4-phenyl norbornene. When the cyclic olefin resin is a copolymer, the arrangement state of the molecules is not particularly limited, and may be a random copolymer, a block copolymer, or a graft copolymer. It may be a polymer.

  More specific examples of cyclic olefin resins include, for example, ring-opening polymers of norbornene monomers, ring-opening copolymers of norbornene monomers and other monomers, maleic acid addition and cyclopentadiene addition to them. Examples of the polymer-modified product, a polymer or copolymer obtained by hydrogenation of these, an addition polymer of a norbornene monomer, an addition copolymer of a norbornene monomer and another monomer, and the like. Examples of other monomers in the case of a copolymer include α-olefins, cycloalkenes, and non-conjugated dienes. Moreover, the cyclic olefin resin may be a copolymer using one or more of norbornene monomers and other alicyclic olefins.

  Among the above specific examples, as the cyclic olefin resin, a resin obtained by hydrogenating a ring-opening polymer using a norbornene monomer is preferably used. Such a cyclic olefin-based resin can be subjected to stretching treatment to obtain a retardation plate, and in addition to stretching, by applying a heat shrinking treatment by bonding a shrinkable film having a predetermined shrinkage rate, A retardation plate having high uniformity and a large retardation value can also be obtained.

  Commercially available products of cyclic olefin resins using norbornene-based monomers are trade names of “ZEONEX”, “ZEONOR” sold by Nippon Zeon Co., Ltd., and JSR Corp. “ Arton "etc. Commercially available products of these cyclic olefin-based resin films and stretched films thereof are also available, for example, “Zeonor Film” and JSR Co., Ltd., both of which are sold by Nippon Zeon Co., Ltd. There are “Arton Film” sold and “Essina” sold by Sekisui Chemical Co., Ltd.

  The second retardation plate 25 may be a film made of a mixed resin containing two or more types of olefin resins, or a film made of a mixed resin of an olefin resin and another thermoplastic resin. For example, the mixed resin containing two or more types of olefinic resins may include a mixture of the cyclic olefinic resin and the chain aliphatic olefinic resin as described above. When a mixed resin of an olefin resin and another thermoplastic resin is used, another thermoplastic resin is appropriately selected depending on the purpose. Specific examples include polyvinyl chloride resin, cellulose resin, polystyrene resin, acrylonitrile / butadiene / styrene copolymer resin, acrylonitrile / styrene copolymer resin, (meth) acrylic resin, polyvinyl acetate resin, polyvinyl chloride. Vinylidene resin, polyamide resin, polyacetal resin, polycarbonate resin, modified polyphenylene ether resin, polybutylene terephthalate resin, polyethylene terephthalate resin, polyphenylene sulfide resin, polysulfone resin, polyethersulfone resin, polyether Examples include ether ketone resins, polyarylate resins, liquid crystalline resins, polyamideimide resins, polyimide resins, polytetrafluoroethylene resins, and the like. A thermoplastic resin can be used individually by 1 type or in combination of 2 or more types. The thermoplastic resin may be used after any appropriate polymer modification. Examples of the polymer modification include copolymerization, crosslinking, molecular terminal modification, and stereoregularity imparting.

  When a mixed resin of an olefin resin and another thermoplastic resin is used, the content of the other thermoplastic resin is usually about 50% by mass or less and preferably about 40% by mass or less with respect to the entire resin. By setting the content of other thermoplastic resin within this range, the absolute value of the photoelastic coefficient is small, excellent wavelength dispersion characteristics are exhibited, and the retardation plate has excellent durability, mechanical strength and transparency. Can be obtained.

  The olefin-based resin can be formed by a casting method from a solution, a melt extrusion method, or the like. When forming a film from two or more kinds of mixed resins, the film forming method is not particularly limited. For example, a film is formed by a casting method using a uniform solution obtained by stirring and mixing resin components with a solvent at a predetermined ratio. A production method, a method in which a resin component is melt-mixed at a predetermined ratio, and a film is produced by a melt extrusion method, etc. are employed.

  The film made of the olefin resin may contain other components such as a residual solvent, a stabilizer, a plasticizer, an anti-aging agent, an antistatic agent, and an ultraviolet absorber as necessary. Moreover, a leveling agent can also be contained in order to reduce the surface roughness.

  The surface on the second pressure-sensitive adhesive layer 26 side of the second retardation plate 25 may be subjected to a surface treatment such as a corona treatment.

Second retardation plate 25 has an in-plane slow axis direction, and the refractive index in the in-plane fast axis direction and the thickness direction respectively n _x, and n _y and n _z, when the thickness of the film is d, the following Formula (1):
_{R e = (n x -n y} ) × d (1)
In-plane retardation value _{R e} in the definition is the wavelength 590nm is 30 to 150 nm, the following formula (2):
Nz factor _{= (n x -n z) /} (n x -n y) (2)
It is preferable that the Nz coefficient defined by the above has a refractive index anisotropy of more than 1 and less than 2.

  The second retardation plate 25 having the refractive index anisotropy as described above is obtained by longitudinal uniaxial stretching, tenter transverse uniaxial stretching, simultaneous biaxial stretching, sequential biaxial stretching, or the like of the film made of the olefin resin. In addition to adjusting the draw ratio and the draw speed appropriately, the desired refractive index difference can be determined by appropriately selecting various temperatures such as preheating temperature, drawing temperature, heat setting temperature, cooling temperature, and the like during drawing. You can get directionality.

  The thickness of the second retardation plate 25 is preferably in the range of 5 to 80 μm, more preferably in the range of 10 to 80 μm, and particularly preferably in the range of 10 to 30 μm.

(3) Second pressure-sensitive adhesive layer As the pressure-sensitive adhesive constituting the second pressure-sensitive adhesive layer 26, a known pressure-sensitive adhesive can be used, and a curable pressure-sensitive adhesive may be used. Although an adhesive may be used, it is preferable to use an active energy ray-curable adhesive from the viewpoint of suppressing dimensional changes due to thermal contraction of the polarizing plate.

  The active energy ray-curable pressure-sensitive adhesive may be mainly composed of a polymer having active energy ray curability, a polymer not having active energy ray curability, an active energy ray curable polyfunctional monomer, and The main component may be a mixture with / or oligomer. Further, it may be a mixture of a polymer having active energy ray curability and a polymer not having active energy ray curability, or a polymer having active energy ray curability and an active energy ray curable polyfunctional monomer and / or Alternatively, it may be a mixture with an oligomer or a mixture of these three.

  Among these, a mixture of a polymer having no active energy ray curability and an active energy ray curable polyfunctional monomer and / or oligomer from the viewpoint of easily obtaining an adhesive that exhibits cohesion while maintaining tackiness. Are preferred, and in particular, those comprising a mixture of a polymer having no active energy ray curability and an active energy ray curable polyfunctional monomer as the main component are preferred.

  As a polymer which does not have active energy ray-curable property, (meth) acrylic acid ester polymer which does not have an active energy ray-curable group (hereinafter may be referred to as “(meth) acrylic acid ester polymer (X)”). Is preferred. The (meth) acrylic acid ester polymer (X) preferably contains a (meth) acrylic acid alkyl ester having 1 to 20 carbon atoms in the alkyl group as a monomer constituting the polymer. Thereby, the obtained adhesive can express preferable adhesiveness. The (meth) acrylic acid ester polymer (X) is a monomer having a reactive functional group and a (meth) acrylic acid alkyl ester having 1 to 20 carbon atoms in the alkyl group (reactive functional group-containing monomer). And a copolymer with other monomer used as desired. By including a reactive functional group-containing monomer as a monomer constituting the polymer (meth) acrylic acid ester polymer (X), it is possible to improve the adhesion with a glass surface such as a liquid crystal cell, Moreover, it can react with a crosslinking agent (Z) described later to form a crosslinked structure.

  Examples of the (meth) acrylic acid alkyl ester having 1 to 20 carbon atoms in the alkyl group include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, and (meth) acrylic acid n-. Butyl, n-pentyl (meth) acrylate, n-hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, n-decyl (meth) acrylate, (meth) acrylic acid Examples include n-dodecyl, myristyl (meth) acrylate, palmityl (meth) acrylate, stearyl (meth) acrylate, and the like. Among these, from the viewpoint of further improving the adhesiveness, (meth) acrylic acid esters having 1 to 8 carbon atoms in the alkyl group are preferable, and n-butyl (meth) acrylate is particularly preferable. In addition, these may be used independently and may be used in combination of 2 or more type.

  The (meth) acrylic acid ester polymer (X) may contain 50 to 99% by mass of a (meth) acrylic acid alkyl ester having an alkyl group having 1 to 20 carbon atoms as a monomer unit constituting the polymer. It is preferable to contain 60-99 mass% especially, and it is preferable to contain 70-98 mass% further.

  As the reactive functional group-containing monomer, a monomer having a hydroxyl group in the molecule (hydroxyl group-containing monomer), a monomer having a carboxyl group in the molecule (carboxyl group-containing monomer), a monomer having an amino group in the molecule (amino group-containing) Monomer) and the like. One of these reactive functional group-containing monomers may be used alone, or two or more thereof may be used in combination.

  Examples of the hydroxyl group-containing monomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, (meth And (meth) acrylic acid hydroxyalkyl esters such as 3-hydroxybutyl acrylate and 4-hydroxybutyl (meth) acrylate.

  Examples of the carboxyl group-containing monomer include ethylenically unsaturated carboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, itaconic acid, and citraconic acid. Of these, acrylic acid is preferred from the viewpoint of the reactivity of the resulting (meth) acrylic acid ester polymer (X) with the crosslinking agent (Z) of the carboxyl group and the copolymerizability with other monomers. These may be used alone or in combination of two or more.

  Examples of the amino group-containing monomer include aminoethyl (meth) acrylate, n-butylaminoethyl (meth) acrylate, and the like. These may be used alone or in combination of two or more.

  The (meth) acrylic acid ester polymer (X) preferably contains 1 to 25% by mass of a reactive functional group-containing monomer as the monomer unit constituting the polymer, particularly 1 to 20% by mass. It is preferable to contain 2 to 5% by mass.

  The polymerization mode of the (meth) acrylic acid ester polymer (X) may be a random copolymer or a block copolymer.

  The weight average molecular weight of the (meth) acrylic acid ester polymer (X) is preferably 300,000 to 3,000,000, particularly preferably 1,000,000 to 2,500,000, and more preferably 1,600,000 to 2,200,000. preferable.

  In addition, in the adhesive composition P, (meth) acrylic acid ester polymer (X) may be used individually by 1 type, and may be used in combination of 2 or more type.

  As the active energy ray-curable polyfunctional monomer, a polyfunctional acrylate monomer having a molecular weight of 1000 or less and excellent in compatibility with the (meth) acrylic acid ester polymer (X) and the like is preferable.

  Examples of polyfunctional acrylate monomers having a molecular weight of 1000 or less include 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, and polyethylene glycol diene. (Meth) acrylate, neopentyl glycol adipate di (meth) acrylate, hydroxypivalate neopentyl glycol di (meth) acrylate, dicyclopentanyl di (meth) acrylate, caprolactone modified dicyclopentenyl di (meth) acrylate, ethylene oxide modified Bifunctional type such as di (meth) acrylate phosphate, di (acryloxyethyl) isocyanurate, allylated cyclohexyl di (meth) acrylate, etc .; trimethylolpropane tri (meth) acrylate , Dipentaerythritol tri (meth) acrylate, propionic acid modified dipentaerythritol tri (meth) acrylate, pentaerythritol tri (meth) acrylate, propylene oxide modified trimethylolpropane tri (meth) acrylate, tris (acryloxyethyl) Trifunctional types such as isocyanurate and ε-caprolactone modified tris- (2- (meth) acryloxyethyl) isocyanurate; tetrafunctional types such as diglycerin tetra (meth) acrylate and pentaerythritol tetra (meth) acrylate; propionic acid 5-functional type such as modified dipentaerythritol penta (meth) acrylate; dipentaerythritol hexa (meth) acrylate, caprolactone modified dipentaerythritol hexa (meth) acrylate 6 functional types such as These may be used individually by 1 type and may be used in combination of 2 or more type.

  The content of the active energy ray-curable compound (Y) is preferably 1 to 50 parts by mass, particularly 5 to 30 parts by mass with respect to 100 parts by mass of the (meth) acrylic acid ester polymer (X). It is preferable that it is 10 to 20 parts by mass.

  The active energy ray-curable pressure-sensitive adhesive preferably contains a crosslinking agent (Z). When the active energy ray-curable pressure-sensitive adhesive contains a (meth) acrylate polymer (X) containing a reactive functional group-containing monomer as a monomer unit constituting the polymer, and a crosslinking agent (Z), When the pressure-sensitive adhesive is heated, the crosslinking agent (Z) reacts with the reactive functional group of the reactive functional group-containing monomer constituting the (meth) acrylic acid ester polymer (X). Thereby, the structure by which (meth) acrylic acid ester polymer (X) was bridge | crosslinked with the crosslinking agent (Z) is formed, and the cohesion force of the adhesive obtained is improved.

  The crosslinking agent (Z) may be any one that reacts with the reactive functional group of the (meth) acrylic acid ester polymer (X). For example, an isocyanate crosslinking agent, an epoxy crosslinking agent, an amine crosslinking agent. , Melamine crosslinking agent, aziridine crosslinking agent, hydrazine crosslinking agent, aldehyde crosslinking agent, oxazoline crosslinking agent, metal alkoxide crosslinking agent, metal chelate crosslinking agent, metal salt crosslinking agent, ammonium salt crosslinking agent, etc. Is mentioned. As an isocyanate type crosslinking agent, the thing similar to the crosslinking agent (B) mentioned above can be used. In addition, a crosslinking agent (Z) can be used individually by 1 type or in combination of 2 or more types.

  The content of the crosslinking agent (Z) is preferably 0.01 to 10 parts by mass, particularly 0.05 to 5 parts by mass with respect to 100 parts by mass of the (meth) acrylic acid ester polymer (X). It is preferable that it is 0.1 to 1 part by mass.

  The active energy ray-curable pressure-sensitive adhesive may be optionally added with various additives such as a photopolymerization initiator, a silane coupling agent, a refractive index adjusting agent, an antistatic agent, a tackifier, an antioxidant, an ultraviolet absorber, and light. It may contain stabilizers, softeners, fillers and the like.

  When ultraviolet rays are used as the active energy ray for curing the active energy ray-curable pressure-sensitive adhesive, the active energy ray-curable pressure-sensitive adhesive preferably contains a photopolymerization initiator.

  Examples of the photopolymerization initiator include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-butyl ether, benzoin isobutyl ether, acetophenone, dimethylaminoacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1- [4- (methylthio) phenyl]- 2-morpholino-propan-1-one, 4- (2-hydroxyethoxy) phenyl-2- (hydroxy-2-propyl) ketone, benzophenone, p-phenylbenzophenone, 4,4′-diethylamino Benzophenone, dichlorobenzophenone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 2-aminoanthraquinone, 2-methylthioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2 , 4-diethylthioxanthone, benzyldimethyl ketal, acetophenone dimethyl ketal, p-dimethylaminobenzoate, oligo [2-hydroxy-2-methyl-1 [4- (1-methylvinyl) phenyl] propanone], 2,4 , 6-trimethylbenzoyl-diphenyl-phosphine oxide and the like. These may be used alone or in combination of two or more.

  The photopolymerization initiator is an amount in the range of 0.1 to 20 parts by mass, particularly 1 to 12 parts by mass with respect to 100 parts by mass of the active energy ray curable compound (Y) in the active energy ray curable adhesive. Is preferably used.

  Moreover, it is preferable that the said active energy ray-curable adhesive contains a silane coupling agent from a viewpoint of improving the adhesiveness to the film of the adhesive obtained. The silane coupling agent is preferably an organosilicon compound having at least one alkoxysilyl group in the molecule, having good compatibility with the adhesive component and having light transmittance.

  Examples of such silane coupling agents include, in addition to the above-described epoxy group-containing silane coupling agent (C1) and mercapto group-containing silane coupling agent (C2), vinyltrimethoxysilane, vinyltriethoxysilane, methacryloxypropyltrimethyl. Polymerizable unsaturated group-containing silicon compounds such as methoxysilane, 3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-amino Amino group-containing silicon compounds such as propylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, or at least one of these, methyltriethoxysilane, ethyltriethoxysilane, methyltrimethoxysilane Emissions, such as condensation products of alkyl group-containing silicon compounds such as ethyl trimethoxysilane. These may be used individually by 1 type and may be used in combination of 2 or more type.

  The content of the silane coupling agent is preferably 0.01 to 10 parts by mass, particularly 0.05 to 5 parts by mass with respect to 100 parts by mass of the (meth) acrylic acid ester polymer (X). It is preferably 0.1 to 1 part by mass.

  The polymer having active energy ray curability is a (meth) acrylic acid ester (co) polymer in which a functional group having active energy ray curability (active energy ray curable group) is introduced into the side chain. It is preferable.

  The thickness of the 2nd adhesive layer 26 is about 1-50 micrometers normally, Preferably it is 1-20 micrometers, Most preferably, it is 2-7 micrometers. If the pressure-sensitive adhesive layer is too thin, the tackiness is lowered, and if it is too thick, problems such as the pressure-sensitive adhesive protruding easily occur.

(4) Polarizer As the polarizer 21, the same one as the polarizer 21 of the polarizing plate 2A described above can be used.

(5) Protective layer The protective layer 27 is preferably made of a transparent resin film. As this protective layer 27, the thing similar to the 1st protective layer 22 in 2A of polarizing plates can be used.

(6) Adhesive Layer The adhesive layer that may be interposed between the polarizer 21 and the protective layer 27 and / or between the polarizer 21 and the second retardation plate 25 is the polarizing plate 2A described above. The same adhesive layer can be used.

(7) Manufacturing method of composite polarizing plate The composite polarizing plate 2B can be manufactured by a normal method. Hereinafter, as an example, a manufacturing method when a water-based adhesive is used as the adhesive will be described.

  First, an adhesive coating film constituting the second adhesive layer 26 is formed on the release surface of the release sheet. Specifically, the adhesive coating liquid constituting the second adhesive layer 26 is applied to the release surface of the release sheet and dried.

  On the other hand, an adhesive layer is formed on the bonding surface of the polarizer 21 or the bonding surfaces of the second retardation plate 25 and the protective layer 27. This adhesive layer can be formed in the same manner as in the method for manufacturing the polarizing plate 2A described above. The same applies to the thickness of the adhesive layer and the easy adhesion treatment.

  When the adhesive layer is formed as described above, the protective layer 27 is bonded to one surface of the polarizer 21 through the adhesive layer, and the second retardation plate 25 is attached to the other side of the polarizer 21. The laminated body which consists of the protective layer 27, the polarizer 21, and the 2nd phase difference plate 25 is obtained.

  Next, the coating film of the adhesive which comprises the 2nd adhesive layer 26 on the said peeling sheet is bonded to the surface at the side of the 2nd phase difference plate 25 of the obtained laminated body. And the active energy ray is irradiated through the said peeling sheet, the coating film of the said adhesive is hardened, and the said coating film is made into the 2nd adhesive layer 26. FIG.

  Here, active energy rays refer to those having energy quanta among electromagnetic waves or charged particle beams, and specific examples include ultraviolet rays and electron beams. Among active energy rays, ultraviolet rays that are easy to handle are particularly preferable.

Irradiation with ultraviolet rays can be performed by a high pressure mercury lamp, a metal halide lamp, a fusion H lamp, a xenon lamp or the like, and the irradiation amount of ultraviolet rays is preferably about 50 to 1000 mW / cm ^{2 in} illuminance. Further, the light quantity is preferably 50~10000mJ / cm ^2, more preferably 80~5000mJ / cm ^2, and particularly preferably 100~1000mJ / cm ^2. On the other hand, the electron beam irradiation can be performed by an electron beam accelerator or the like, and the electron beam irradiation amount is preferably about 10 to 1000 krad.

  Finally, the release sheet is peeled from the second pressure-sensitive adhesive layer 26 formed as described above, and the second acrylic resin layer 243 in the first retardation plate 24 is exposed to the exposed second pressure-sensitive adhesive layer 26. Adhere the side surface. Thus, the composite polarizing plate 2B formed by laminating the protective layer 27, the polarizer 21, the second retardation plate 25, the second pressure-sensitive adhesive layer 26, and the first retardation plate 24 is obtained.

  The total thickness of the composite polarizing plate 2B is preferably 20 to 300 μm, more preferably 30 to 150 μm, and particularly preferably 50 to 100 μm.

(8) Method for producing optical film with pressure-sensitive adhesive layer As a preferred example of the method for producing optical film 10B with pressure-sensitive adhesive layer, a release sheet is first formed on one or both sides of the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition P. To produce a pressure-sensitive adhesive sheet. Here, as an example, a pressure-sensitive adhesive sheet is manufactured by laminating release sheets on both sides of a pressure-sensitive adhesive layer. This pressure-sensitive adhesive sheet can be produced by the method described in the method for producing the pressure-sensitive adhesive layer-attached optical film 10A.

  One release sheet (light release type release sheet) is released from the pressure-sensitive adhesive sheet obtained as described above. And the 1st phase difference plate 24 of the composite polarizing plate 2B is piled up on the exposed adhesive layer, and an adhesive sheet and the composite polarizing plate 2B are pressure-bonded. Thereby, the said optical film 10B with an adhesive layer (with a peeling sheet) is obtained.

  As another example of the manufacturing method of the optical film 10B with an adhesive layer, after apply | coating the application | coating solution of the adhesive composition P mentioned above to the peeling surface of a peeling sheet and performing heat processing, forming a coating film, The first retardation plate 24 of the composite polarizing plate 2B is overlaid on the coating film. When a curing period is required, a curing period is set, and when the curing period is unnecessary, the coating film becomes the pressure-sensitive adhesive layer 1 as it is. Thereby, the said optical film 10B with an adhesive layer (with a peeling sheet) is obtained.

3. Physical properties of optical film with pressure-sensitive adhesive layer The pressure-sensitive adhesive strength of optical films 10A and 10B with pressure-sensitive adhesive layer according to this embodiment is preferably 0.5 to 20 N / 25 mm, particularly 1 It is preferable that it is-10N / 25mm. Thereby, the optical film with the pressure-sensitive adhesive layer is excellent in durability. Furthermore, it is preferable that the said adhesive force is 2-7 N / 25mm from a viewpoint which shall be excellent also about rework property. In addition, although the adhesive force here means the adhesive force measured by the 180 degree peeling method according to JIS Z0237: 2009, the measurement sample has a width of 25 mm and a length of 100 mm, and the measurement sample is attached. After being applied to the body by applying pressure at 0.5 MPa and 50 ° C. for 20 minutes, the sample was left for 24 hours under conditions of normal pressure, 23 ° C. and 50% RH, and then measured at a peeling rate of 300 mm / min. To do. When the adhesive strength is within the above range, it is possible to prevent floating or peeling when the adhesive is attached to the liquid crystal cell.

  Moreover, the optical films 10A and 10B with the pressure-sensitive adhesive layer according to the present embodiment are further adhered to the adherend after being left for 14 days under conditions of 23 ° C. and 50% RH (after 14 days of application). Is preferably 1 to 20 N / 25 mm, and particularly preferably 3 to 9 N / 25 mm. Thus, by suppressing the increase in adhesive strength over time, the optical films 10A and 10B with an adhesive layer according to the present embodiment are excellent in reworkability and can be easily reapplied even after being attached to a liquid crystal cell. be able to.

  Moreover, the optical films 10A and 10B with the pressure-sensitive adhesive layer according to this embodiment are further subjected to adhesive strength (50 ° C. 2) after being left on the adherend for 2 days under the conditions of 50 ° C. and 50% RH. The adhesive strength after the day is preferably 1 to 20 N / 25 mm from the viewpoint of durability, and more preferably 6 to 12 N / 25 mm from the viewpoint of reworkability.

The surface resistivity of the pressure-sensitive adhesive layer in the pressure-sensitive adhesive layer-attached optical films 10A and 10B according to the present embodiment is preferably 1.0 × 10 ¹² Ω / sq or less, particularly 5.0 × 10 ¹¹ Ω / sq. Or less, more preferably 5.0 × 10 ¹⁰ Ω / sq or less. When the surface resistivity is not more than the above value, sufficient antistatic properties can be exhibited in the display panel. Such surface resistivity can be achieved when the adhesive composition P contains the antistatic agent (D) described above. In addition, the measurement of the surface resistivity of an adhesive layer shall be performed according to JISK6911, and is specifically as shown in the test example mentioned later. The lower limit value of the surface resistivity is not particularly limited, but is about 5.0 × 10 ⁸ Ω / sq from the viewpoint of not adversely affecting durability and heat unevenness.

4). Use of optical film with pressure-sensitive adhesive layer By using the optical films 10A and 10B with pressure-sensitive adhesive layer, for example, a liquid crystal display device including a liquid crystal cell and an optical film (polarizing plate or composite polarizing plate) can be produced. it can.

  Specifically, the pressure-sensitive adhesive layer of the optical films 10A and 10B with the pressure-sensitive adhesive layer (the pressure-sensitive adhesive layer exposed by peeling the release sheet when the release sheet is laminated) What is necessary is just to superimpose on a surface and to crimp. Thereby, the liquid crystal display device provided with the liquid crystal cell and the polarizing plate 2A and / or the composite polarizing plate 2B is obtained.

  Since the pressure-sensitive adhesive layer 1 of the optical films 10A and 10B with the pressure-sensitive adhesive layer according to this embodiment is excellent in durability, the pressure-sensitive adhesive is obtained even under high-temperature conditions, wet heat conditions, or heat shocks. Occurrence of floating or peeling at the interface of the layer 1 is suppressed. For example, when a glass plate to which the optical films 10A and 10B with adhesive layers are attached is placed under a high temperature condition of 85 ° C. or a wet heat condition of 60 ° C./90% RH for 250 hours, Even when a shock is applied (each 30 minutes, 200 cycles), the occurrence of floating or peeling is suppressed.

  Further, since the pressure-sensitive adhesive layer 1 of the optical films 10A and 10B with the pressure-sensitive adhesive layer according to the present embodiment is also excellent in stress relaxation properties, the obtained liquid crystal display device is not easily warped even under high temperature conditions, and further, heat unevenness. Is unlikely to occur. For example, even when a glass plate to which the optical films 10A and 10B with pressure-sensitive adhesive layers are attached is kept under high temperature conditions (for example, 80 to 85 ° C.) for 250 hours, it is difficult to warp and heat unevenness hardly occurs. In particular, even if the polarizing plate 2A or the composite polarizing plate 2B is a thin film, the liquid crystal display device hardly warps, and even if the liquid crystal cell has a high definition, heat unevenness hardly occurs.

  A transparent conductive film may be present on the surface of the liquid crystal cell with which the pressure-sensitive adhesive layer 1 is in contact. Examples of such a transparent conductive film include metals such as platinum, gold, silver and copper, oxides such as tin oxide, indium oxide, cadmium oxide, zinc oxide and zinc dioxide, tin-doped indium oxide (ITO), and zinc oxide-doped oxide. Examples include composite oxides such as indium, fluorine-doped indium oxide, antimony-doped tin oxide, fluorine-doped tin oxide, and aluminum-doped zinc oxide, and non-oxidized compounds such as chalcogenide, lanthanum hexaboride, titanium nitride, and titanium carbide. It is done.

  The embodiment described above is described for facilitating understanding of the present invention, and is not described for limiting the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention.

  EXAMPLES Hereinafter, although an Example etc. demonstrate this invention further more concretely, the scope of the present invention is not limited to these Examples etc.

[Example 1]
1. Production of optical film (composite polarizing plate) (1) Production of polarizer Polyvinyl alcohol film having a thickness of 75 μm made of polyvinyl alcohol having an average polymerization degree of about 2,400 and a saponification degree of 99.9 mol% or more is obtained by a dry method. The film was uniaxially stretched about 5 times and immersed in pure water at 60 ° C. for 1 minute while maintaining the tension state. Then, it was immersed in an aqueous solution having a mass ratio of iodine / potassium iodide / water of 0.05 / 5/100 at 28 ° C. for 60 seconds. Subsequently, it was immersed in an aqueous solution having a mass ratio of potassium iodide / boric acid / water of 8.5 / 8.5 / 100 at 72 ° C. for 300 seconds. Next, after washing with pure water at 26 ° C. for 20 seconds, it was dried at 65 ° C. to obtain a polarizer in which iodine was adsorbed and oriented on polyvinyl alcohol.

(2) Production of Laminate Containing Protective Layer, Polarizer, and Second Retardant Plate 3 carboxyl group-modified polyvinyl alcohol (trade name “KL-318”, manufactured by Kuraray Co., Ltd.) is added to 100 parts by mass of water. Dissolve parts by mass and add a polyamide epoxy additive (made by Taoka Chemical Industry Co., Ltd., trade name “Smiles Resin 650 (30)”, aqueous solution with a solid content concentration of 30% by mass) that is a water-soluble epoxy resin to the aqueous solution. An epoxy adhesive added with 1.5 parts by mass was prepared. The said epoxy-type adhesive agent was apply | coated to one side of the polarizer obtained above.

  A 25 μm thick triacetylcellulose film (Konica Minolta Opto, trade name “KC2UA”) with a saponified surface is bonded as a protective layer to the epoxy adhesive coating layer. And the laminated body formed by laminating | stacking a protective layer and a polarizer was obtained.

  Next, an epoxy adhesive is applied to the other surface of the polarizer in the laminate in the same manner as described above, and a cyclic olefin resin having a thickness of 23 μm is applied to the applied layer as a second retardation plate. The zero phase difference film which consists of (Nippon ZEON Co., Ltd. make, brand name "ZEONOR") was bonded. Thereafter, the protective layer and the second retardation plate were adhered to the polarizer by drying at 80 ° C. for 5 minutes. After bonding, the total thickness obtained by curing at 40 ° C. for 168 hours and laminating a protective layer (layer thickness: 25 μm), a polarizer (stretching ratio: 5 times, layer thickness: 15 μm), and a second retardation plate (layer thickness: 23 μm) A 63 μm laminate was obtained.

(3) Formation of coating film of active energy ray-curable pressure-sensitive adhesive 95 parts by mass of n-butyl acrylate and 5 parts by mass of acrylic acid were copolymerized to prepare (meth) acrylic acid ester polymer (X). When the molecular weight of this (meth) acrylic acid ester polymer (X) was measured by the method described later, it was a weight average molecular weight (Mw) of 2,000,000.

  Tris (acryloxyethyl) isocyanurate (manufactured by Toa Gosei Co., Ltd., trade name “100 parts by mass of (meth) acrylic acid ester polymer (X)) and active energy ray-curable compound (Y) (polyfunctional monomer)” Aronix M-315 ") 15 parts by mass, as a crosslinking agent (Z), 0.3 parts by mass of trimethylolpropane-modified tolylene diisocyanate (trade name“ Coronate L ”, manufactured by Nippon Polyurethane Industry Co., Ltd.), and a polymerization initiator , 1.5 parts by mass of a mixture of benzophenone and 1-hydroxycyclohexyl phenyl ketone (Ciba Specialty Chemicals, trade name “Irgacure 500”) mixed at a mass ratio of 1: 1, Glycidoxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., trade name “KBM4 3 ") were mixed with 0.2 parts by mass, sufficiently stirred, by diluting with ethyl acetate to obtain a coating solution of the active energy ray-curable pressure-sensitive adhesive.

  On the release treatment surface of the release sheet (SP-PET3811, thickness: 38 μm, manufactured by Lintec Co., Ltd.), one side of the polyethylene terephthalate film was release-treated with a silicone release agent. After coating with a knife coater, heat treatment was performed at 90 ° C. for 1 minute to form a coating film of an active energy ray-curable adhesive.

(4) Production of first retardation plate Methacrylic resin (manufactured by Sumitomo Chemical Co., Ltd.) containing about 20% by mass of acrylic rubber particles having an average particle size of 200 nm constituting the first acrylic resin layer. A product name “Technoloy S001”), a styrene-maleic anhydride copolymer resin (manufactured by Nova Chemical Co., Ltd., product name “Dylark D332”) constituting the phase difference layer, and a second acrylic resin layer. A methacrylic resin (manufactured by Sumitomo Chemical Co., Ltd., trade name “Technoloy S001”) containing about 20% by mass of acrylic rubber particles having an average particle size of 200 nm is co-extruded in that order in three layers and has a three-layer structure. A laminated film was obtained. The obtained laminated film is stretched, and a first retardation plate having an in-plane retardation value of 60 nm and a thickness of 25 μm (first acrylic resin layer / retardation expressing layer / second acrylic resin layer) Got.

(5) Preparation of composite polarizing plate Coating film of active energy ray-curable pressure-sensitive adhesive obtained in step (3) on the surface on the second retardation plate side in the laminate obtained in step (2). And the ultraviolet-ray was irradiated on the following conditions through the said peeling sheet, the coating film of the said adhesive was hardened, and it was set as the 2nd adhesive layer. Thereafter, the release sheet is peeled from the obtained second pressure-sensitive adhesive layer, and the second surface of the first phase difference plate obtained in the step (4) is exposed to the exposed surface of the second pressure-sensitive adhesive layer. The surface on the acrylic resin layer side was bonded. Thus, a composite polarizing plate (optical film) having a total thickness of 93 μm formed by laminating the protective layer, the polarizer, the second retardation plate, the second pressure-sensitive adhesive layer, and the first retardation plate was obtained. . Note that the thickness of the formed second pressure-sensitive adhesive layer was 5 μm.
<Ultraviolet irradiation conditions>
・ Use of high pressure mercury lamp ・ Illuminance 300mW / cm ² , Light quantity 300mJ / cm ²
・ Uses UVGraph-A1 made by Eye Graphics as UV illuminance / light meter

2. Manufacture of optical film with adhesive layer (1) Preparation of (meth) acrylic acid ester copolymer 87 parts by mass of n-butyl acrylate, 5 parts by mass of isobornyl acrylate, 5 parts by mass of 2-phenylethyl acrylate and acrylic acid 2 parts by mass of 2-hydroxyethyl were copolymerized to prepare a (meth) acrylic acid ester copolymer (A). When the molecular weight of this (meth) acrylic acid ester copolymer (A) was measured by the method mentioned later, it was weight average molecular weight (Mw) 1.6 million. In addition, from the said mixing | blending, the hydroxyl value of the said (meth) acrylic acid ester copolymer (A) is calculated to 14.49 mgKOH / g, and an acid value is calculated to 0 mgKOH / g.

(2) Preparation of adhesive composition 100 parts by mass of the (meth) acrylic acid ester copolymer (A) obtained in the above step (1) and, as a crosslinking agent (B), trimethylolpropane-modified xylylene diisocyanate ( 0.2 parts by mass of Mitsui Chemicals, trade name “Takenate D110N”) and 3-glycidoxypropyltrimethoxysilane (trade name “Shin-Etsu Chemical Co., Ltd., trade name”) as an epoxy group-containing silane coupling agent (C1) KBM403 ") 0.2 parts by mass and, as a mercapto group-containing silane coupling agent (C2), a co-condensation product of 3-mercaptopropyltrimethoxysilane and methyltriethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., trade name" X -41-1810 ", mercapto equivalent: 450 g / mole) 0.2 parts by mass, and as antistatic agent (D), N-octyl-4-methyl A coating solution of the adhesive composition was obtained by mixing 2.0 parts by mass of rupyridinium hexafluorophosphate (ionic compound solid at room temperature), sufficiently stirring, and diluting with ethyl acetate. In this example, no low molecular weight components other than those described above were blended.

Here, Table 1 shows each composition (solid content converted value) of the adhesive composition when the (meth) acrylic acid ester copolymer (A) is 100 parts by mass (solid content converted value). Details of the abbreviations and the like described in Table 1 are as follows.
[(Meth) acrylic acid ester copolymer]
BA: n-butyl acrylate IBXA: isobornyl acrylate PhEA: 2-phenylethyl acrylate HEA: 2-hydroxyethyl acrylate CHA: cyclohexyl acrylate MA: methyl acrylate
[Isocyanate-based crosslinking agent]
XDI: trimethylolpropane-modified xylylene diisocyanate (Mitsui Chemicals, trade name “Takenate D110N”)
TDI: Trimethylolpropane-modified tolylene diisocyanate (manufactured by Nippon Polyurethane Industry Co., Ltd., trade name “Coronate L”)
[Antistatic agent]
Pry + PF6- (1): N-octyl-4-methylpyridinium hexafluorophosphate (ionic compound solid at room temperature)
Pry + PF6- (2): N-butyl-4-methylpyridinium hexafluorophosphate (ionic compound solid at room temperature)
[Low molecular weight component]
Transstilbene: Transstilbene (manufactured by Tokyo Chemical Industry Co., Ltd.)
Benzyl benzoate: Benzyl benzoate (Wako Pure Chemical Industries, Ltd.)
Acrylic polymer (1): Acrylic ester copolymer having a weight average molecular weight (Mw) of 10,000 obtained by copolymerizing 70 parts by mass of n-butyl acrylate and 30 parts by mass of 2-phenylethyl acrylate Acrylic polymer (2) : Acrylic polymer with a weight average molecular weight (Mw) of 3000 (manufactured by Toa Gosei Co., Ltd., trade name “ARUFON UP-1000”)

(3) Production of optical film with pressure-sensitive adhesive layer A release sheet (SP-PET3811, manufactured by Lintec Corporation, thickness) obtained by subjecting one side of a polyethylene terephthalate film to a release treatment using a silicone-based release agent. : 38 μm) was coated with a knife coater and then heat-treated at 90 ° C. for 1 minute to form a coating film of the adhesive composition.

  Next, the composite polarizing plate obtained above is bonded to the coating film so that the surface of the first acrylic resin layer in the first retardation plate is in contact with the exposed surface of the coating film, The optical film with an adhesive layer in which the adhesive layer was formed on the composite polarizing plate was obtained by curing for 7 days at 23 ° C. and 50% RH. The formed pressure-sensitive adhesive layer (first pressure-sensitive adhesive layer) had a thickness of 20 μm.

[Examples 2 to 21, Comparative Examples 1 to 4]
The type and ratio of each monomer constituting the (meth) acrylic acid ester copolymer (A), the weight average molecular weight (Mw) of the (meth) acrylic acid ester copolymer (A), the type of the crosslinking agent (B) and Except for changing the blending amount, the blending amount of the silane coupling agent (C), the kind of the antistatic agent (D), and the kind and blending amount of the low molecular weight component as shown in Table 1, the same manner as in Example 1 was performed. An optical film with an adhesive layer was produced.

Here, the above-mentioned weight average molecular weight (Mw) is a polystyrene-reduced weight average molecular weight measured under the following conditions (GPC measurement) using gel permeation chromatography (GPC).
<Measurement conditions>
GPC measurement device: manufactured by Tosoh Corporation, HLC-8020
GPC column (passed in the following order): TSK guard column HXL-H manufactured by Tosoh Corporation
TSK gel GMHXL (× 2)
TSK gel G2000HXL
・ Measurement solvent: Tetrahydrofuran ・ Measurement temperature: 40 ° C.

[Test Example 1] (Measurement of gel fraction)
In place of the optical film used for the production of the optical film with the pressure-sensitive adhesive layer in Examples and Comparative Examples, a release sheet obtained by peeling one side of a polyethylene terephthalate film with a silicone release agent (manufactured by Lintec Corporation, SP-PET 3801, thickness) S: 38 μm) was used to prepare an adhesive sheet. Specifically, the release treatment surface side contacts the release sheet on the exposed coating film of the composition comprising the release sheet / adhesive composition coating film obtained in the production process of the examples or comparative examples. And then cured under conditions of 23 ° C. and 50% RH for 7 days. This produced the adhesive sheet which consists of a structure of a peeling sheet (SP-PET3801) / adhesive layer (thickness: 20 micrometers) / release sheet (SP-PET3811).

  The obtained pressure-sensitive adhesive sheet is cut into a size of 80 mm × 80 mm, the pressure-sensitive adhesive layer is wrapped in a polyester mesh (mesh size 200), the mass is weighed with a precision balance, and the mass of the mesh alone is subtracted. Thus, the mass of only the pressure-sensitive adhesive was calculated. The mass at this time is M1.

  Next, the pressure-sensitive adhesive wrapped in the polyester mesh was immersed in ethyl acetate at room temperature (23 ° C.) for 24 hours. Thereafter, the pressure-sensitive adhesive was taken out, air-dried for 24 hours in an environment of a temperature of 23 ° C. and a relative humidity of 50%, and further dried in an oven at 80 ° C. for 12 hours. After drying, the mass was weighed with a precision balance, and the mass of the pressure sensitive adhesive alone was calculated by subtracting the mass of the mesh alone. The mass at this time is M2. The gel fraction (%) is represented by (M2 / M1) × 100. The results are shown in Table 2.

[Test Example 2] (Durability evaluation)
The optical film with an adhesive layer obtained in Examples and Comparative Examples was cut to prepare a sample having a size of 150 mm × 200 mm. The release sheet is peeled off from this sample and attached to an alkali-free glass (Corning Corp., Eagle XG) through the exposed adhesive layer, and then applied at 0.5 MPa and 50 ° C. for 20 minutes in an autoclave manufactured by Kurihara Seisakusho. Pressed.

Then, it put into the environment of the following three durability conditions, and the presence or absence of the float or peeling was confirmed using the 10 time loupe after 250 hours. The evaluation criteria are as follows. The results are shown in Table 2.
A: No lifting or peeling was confirmed.
○: Lifting or peeling of a size of 0.5 mm or less was confirmed.
(Triangle | delta): The float and peeling of a magnitude | size exceeding 0.5 mm and 1.0 mm or less were confirmed.
X: Floating and peeling of a size exceeding 1.0 mm were confirmed.
<Durability conditions>
・ Heat resistance: 85 ℃ dry
-Humid heat: 60 ° C, relative humidity 90% RH
・ H. S. : Heat shock test at -35 ° C to 70 ° C for 30 minutes each, 200 cycles

[Test Example 3] (Evaluation of warpage resistance)
The optical films with pressure-sensitive adhesive layers obtained in Examples and Comparative Examples were cut so as to be 200 mm long and 150 mm wide. The release sheet is peeled off from the optical film with the pressure-sensitive adhesive layer, and the exposed pressure-sensitive adhesive layer is placed in the center of 250 mm long, 175 mm wide, 0.5 mm thick non-alkali glass (trade name “Eagle-XG” manufactured by Corning). This was attached to the part and used as a sample. This sample was allowed to stand for 250 hours at 85 ° C. in a dry atmosphere. After that, the sample is taken out in an environment of 25 ° C. and 50% RH, placed on a horizontal table with the polarizing plate side up, and the amount of warpage of each sample corner (four points) from the table (distance between the corner and the table) ) And the amount of warpage of each corner was summed. Based on the results, warpage resistance was evaluated as follows. The results are shown in Table 2.
◎: Total warpage amount is 10 mm or less ○: Total warpage amount is more than 10 mm, 15 mm or less △: Total warpage amount is more than 15 mm, 20 mm or less ×: Total warpage amount is more than 20 mm

[Test Example 4] (Evaluation of heat resistance unevenness)
The optical film with an adhesive layer obtained in Examples and Comparative Examples was adjusted to a size of 200 mm × 150 mm using a cutting device (Super cutter, PN1-600 manufactured by Hadano Seisakusho Co., Ltd.). The release sheet was peeled off and attached to alkali-free glass (Corning Corp., Eagle XG) through the exposed adhesive layer, and then pressurized at 0.5 MPa and 50 ° C. for 20 minutes in an autoclave manufactured by Kurihara Seisakusho. In addition, the said bonding was performed so that a polarizing axis might be in a crossed nicols state (polarizing axis: ∠45 °, ∠135 °) on the front and back of non-alkali glass. In this state, it was allowed to stand for 250 hours in an 80 ° C. dry environment, and then left for 2 hours in an environment of 23 ° C. and 50% RH. Using this as a sample, the heat resistance unevenness was evaluated by the following method. The results are shown in Table 2.

<Evaluation method>
The sample was placed on a flat illuminator (Dentsu Sangyo Co., Ltd., HF-SL-A312LC, illuminance: 26,000 Lux, luminance: 10,000 cd), and a two-dimensional color luminance meter (Konica Minolta, CA-2000). ) And converted into a luminance distribution image by analysis software (Konica Minolta, CA-S20w). The luminance distribution image of the obtained sample was evaluated based on FIG. 4 and the evaluation criteria shown below.
A: The luminance distribution is almost uniform. B: The luminance distribution on the four sides is slightly distorted. Δ: The luminance distribution on the four sides is clearly distorted. X: The luminance distribution on the four sides is severely distorted.

[Test Example 5] (Measurement of adhesive strength-reworkability evaluation)
Samples having a width of 25 mm and a length of 100 mm were cut out from the optical films with pressure-sensitive adhesive layers obtained in Examples and Comparative Examples, the release sheet was peeled off, and alkali-free glass (Corning Corp., Eagle) was exposed through the exposed pressure-sensitive adhesive layer. After being attached to XG), it was pressurized at 0.5 MPa and 50 ° C. for 20 minutes in an autoclave manufactured by Kurihara Seisakusho. Then, after leaving for 24 hours under conditions of 23 ° C. and 50% RH, using a tensile tester (Orientec Co., Ltd., Tensilon), the adhesive strength (adhesion) under the conditions of a peeling speed of 300 mm / min and a peeling angle of 180 degrees. The adhesive strength after 1 day; N / 25 mm) was measured. Conditions other than those described here were measured according to JIS Z 0237: 2009. The results are shown in Table 2.

  Further, after being left for 14 days under conditions of 23 ° C. and 50% RH, the adhesive strength (adhesive strength after 14 days of application; N / 25 mm) was measured in the same manner as described above. Separately, it was allowed to stand for 2 days under conditions of 50 ° C. and 50% RH, and then the adhesive strength (adhesive strength after 2 days at 50 ° C .; N / 25 mm) was measured in the same manner as described above. The results are shown in Table 2.

Based on the adhesive strength after 14 days from the pasting, reworkability was evaluated according to the following criteria. The results are shown in Table 2.
◎: Adhesive strength after 14 days of application is 8.8 N / 25 mm or less ○: Adhesive strength after 14 days of application is more than 8.8 N / 25 mm and less than 10 N / 25 mm △: Adhesive strength after 14 days of application is 10 N / 25 mm or more, 20 N / Less than 25 mm x: Adhesive strength after 14 days of application is 20 N / 25 mm or more

[Test Example 6] (Measurement of surface resistivity of adhesive layer)
The optical films with pressure-sensitive adhesive layers obtained in Examples and Comparative Examples were cut into a size of 50 mm × 50 mm, and the obtained samples were allowed to stand at a temperature of 23 ° C. and a humidity of 50% RH for 24 hours. Thereafter, the release sheet is peeled off, and the exposed adhesive layer surface is subjected to surface resistivity (Ω / sq) according to JIS K6911 using a resistivity meter (manufactured by Mitsubishi Chemical Analytech Co., Ltd., Hiresta UP MCP-HT450 type). ) Was measured. The results are shown in Table 2.

  As can be seen from Table 2, the optical film with the pressure-sensitive adhesive layer obtained in the examples was excellent in durability, hardly warped even at high temperatures, and hardly caused heat unevenness. Moreover, the optical film with an adhesive layer obtained in the Example had a low surface resistivity of the adhesive layer and had a small adverse effect on liquid crystal cells and the like. Furthermore, the optical film with an adhesive layer obtained in Examples 1 to 20 was excellent in reworkability.

  The optical film with an adhesive layer according to the present invention is suitable for laminating a thinned polarizing plate or a composite polarizing plate and a liquid crystal cell.

DESCRIPTION OF SYMBOLS 10A, 10B ... Optical film 1 with an adhesive layer ... Adhesive layer 2A ... Polarizing plate 2B ... Composite polarizing plate 21 ... Polarizer 22 ... 1st protective layer 23 ... 2nd protective layer 24 ... 1st phase difference plate DESCRIPTION OF SYMBOLS 241 ... 1st acrylic resin layer 242 ... Retardation expression layer 243 ... 2nd acrylic resin layer 25 ... 2nd phase difference plate 26 ... 2nd adhesive layer 27 ... Protective layer

Claims (12)

An optical film;
An optical film with an adhesive layer comprising an adhesive layer laminated on at least one side of the optical film,
The surface in contact with the pressure-sensitive adhesive layer in the optical film is composed of an acrylic resin,
The pressure-sensitive adhesive layer is
(Meth) acrylic acid ester copolymer (A) containing an alicyclic structure-containing monomer (a1) and an aromatic ring-containing monomer (a2) as monomer units constituting the polymer;
An optical film with an adhesive layer, comprising an adhesive obtained from an adhesive composition containing a crosslinking agent (B) and having a low molecular weight component content of 5% by mass or less.   2. The optical film with an adhesive layer according to claim 1, wherein the outermost layer in contact with the adhesive layer in the optical film is an acrylic resin layer formed through extrusion molding.   The optical film with an adhesive layer according to claim 2, wherein the optical film includes a retardation plate having at least the acrylic resin layer and a retardation developing layer.   The optical film with a pressure-sensitive adhesive layer according to claim 3, wherein the retardation layer is made of a styrene resin.   The said phase difference plate has a 2nd acrylic resin layer in the surface side on the opposite side to the surface by the side of the said acrylic resin layer in the said phase difference expression layer, The Claim 3 or 4 characterized by the above-mentioned. Optical film with adhesive layer.   6. The second retardation plate is further laminated on the surface of the retardation plate opposite to the surface on the pressure-sensitive adhesive layer side. 6. Optical film with adhesive layer.   The optical film with an adhesive layer according to claim 6, wherein the second retardation plate is made of a cycloolefin-based resin.   8. The optical with an adhesive layer according to claim 6, wherein a polarizing plate is further laminated on the surface of the second retardation plate opposite to the surface on the retardation plate side. 9. the film. The (meth) acrylic acid ester copolymer (A) is
As a monomer unit constituting the polymer, further containing a hydroxyl group-containing monomer (a3),
A hydroxyl value is 5-20 mgKOH / g, The optical film with an adhesive layer as described in any one of Claims 1-8 characterized by the above-mentioned.   The said crosslinking agent (B) is an isocyanate type crosslinking agent, The optical film with an adhesive layer as described in any one of Claims 1-9 characterized by the above-mentioned.   The said adhesive composition further contains a silane coupling agent (C), The optical film with an adhesive layer as described in any one of Claims 1-10 characterized by the above-mentioned.   The said adhesive composition further contains an antistatic agent (D), The optical film with an adhesive layer as described in any one of Claims 1-11 characterized by the above-mentioned.

Images