JP6550251B2 - Adhesive film with optical film - Google Patents

Description

  The present invention relates to an optical film with a pressure-sensitive adhesive layer, and more particularly to an optical film with a pressure-sensitive 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, a touch panel which doubles as a display device and an input unit is often used as a display panel of various electronic devices. There are mainly resistive film type, electrostatic capacity type, optical type and ultrasonic type as the type of touch panel, analog resistive film type and matrix resistive film type as resistive film type, and surface as capacitive type There is a type and a projection type.

  In the touch panels of mobile electronic devices such as smartphones and tablet terminals that are recently attracting attention, many of projected capacitive type are used. As a projected capacitive touch panel in such mobile electronic devices, for example, a liquid crystal display (LCD), an adhesive layer, a transparent conductive film (tin-doped indium oxide: ITO), a glass substrate, a transparent conductive film What laminated | stacked protective plates, such as ITO) and tempered glass, is proposed.

  As an optical component which comprises the said liquid crystal display device, a liquid crystal cell is generally used. The liquid crystal cell is generally arranged with the alignment layer of the two transparent electrode substrates on which the alignment layer is formed inside, at a predetermined distance by the spacer, and the periphery is sealed to form the two transparent electrode substrates. A liquid crystal material is held between the two. Usually, a polarizing plate and a composite polarizing plate having a retardation plate are adhered to the outside of the two transparent electrode substrates in the liquid crystal cell via an adhesive.

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

JP, 2009-242786, A

  Here, with the recent demand for thinner mobile electronic devices, it is also required to reduce the thickness of an optical film such as a polarizing plate. However, the thin film polarizing plate has a high shrinkage ratio due to heat, etc., and the conventional pressure sensitive adhesive as disclosed in Patent Document 1 or the like causes the display panel to warp or floats or peels under high temperature conditions or moist heat conditions. It will Furthermore, it is pointed out that light leakage (so-called heat unevenness) occurs due to the shift of the optical axis of the optical film due to the stress at the time of thermal contraction of the optical film.

  Moreover, when priority is given to thinning of the optical film, the adhesion with the pressure-sensitive adhesive is deteriorated, and the adhesion at the interface between the optical film and the pressure-sensitive adhesive is insufficient with the conventional pressure-sensitive adhesive of Patent Document 1 and the like. , Durability tends to be further deteriorated.

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

  In order to achieve the above object, firstly, the present invention is an optical film with a pressure-sensitive adhesive layer comprising an optical film and a pressure-sensitive adhesive layer laminated on at least one surface of the optical film, The surface in contact with the pressure-sensitive adhesive layer is composed of an acrylic resin, and the pressure-sensitive adhesive layer contains an alicyclic structure-containing monomer (a1) and an aromatic ring-containing monomer (a2) as monomer units constituting a polymer. A pressure-sensitive adhesive layer-carrying optical film comprising a pressure-sensitive adhesive obtained from a pressure-sensitive adhesive composition containing a (meth) acrylic acid ester copolymer (A) and a crosslinking agent (B) (Invention 1).

  According to the invention (Invention 1), the (meth) acrylic acid ester is mainly used even when the surface of the optical film in contact with the pressure-sensitive adhesive layer is made of an acrylic resin and the optical film is thinned. The copolymer (A) is composed of the above composition to improve the stress relaxation property and raise the glass transition temperature (Tg), whereby it is excellent in durability when used in a display panel, and the display panel It is difficult to warp, and furthermore, thermal unevenness hardly occurs.

  In the said invention (invention 1), it is preferable that the outermost layer which touches 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 an at least said acrylic resin layer and a phase difference expression layer (invention 3).

  In the said invention (invention 3), it is preferable that the said phase difference expression layer consists of styrenic 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 by the side of the said acrylic resin layer in the said phase difference expression layer (Invention 5).

  In the above inventions (Inventions 3 to 5), it is preferable that a second retardation plate be further laminated on the side opposite to the surface on the pressure-sensitive adhesive layer side in the retardation plate (Invention 6) .

  In the above invention (Invention 6), the second retardation plate preferably comprises a cycloolefin resin (Invention 7).

  In the above inventions (Inventions 6 and 7), it is preferable that a polarizing plate is further laminated on the side opposite to the surface on the side of the retardation plate in the second retardation plate (Invention 8).

  In the above inventions (Inventions 1 to 8), the (meth) acrylic acid ester copolymer (A) further contains a hydroxyl group-containing monomer (a3) as a monomer unit constituting the polymer, and has a hydroxyl value of 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 pressure-sensitive adhesive layer-attached optical film of the present invention, even when the optical film is made thin, the durability is excellent, the display panel is not easily warped, and furthermore, the heat unevenness hardly occurs.

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 an evaluation standard of a heat-resistant non-uniformity examination (visual observation) in an optical film with an adhesive layer.

Hereinafter, embodiments of the present invention will be described.
The pressure-sensitive adhesive layer-carrying optical film according to the present embodiment is configured to include an optical film and a pressure-sensitive adhesive layer laminated on at least one side of the optical film. The surface of the optical film in contact with the pressure-sensitive adhesive layer is composed of an acrylic resin, and the pressure-sensitive adhesive layer contains an alicyclic structure-containing monomer (a1) and an aromatic ring-containing monomer (a2) as monomer units constituting a polymer. A pressure-sensitive adhesive obtained from a pressure-sensitive adhesive composition containing (meth) acrylic acid ester copolymer (A) and a crosslinking agent (B) (hereinafter sometimes referred to as “pressure-sensitive composition P”). It consists of In the present specification, (meth) acrylic acid ester means both acrylic acid ester and methacrylic acid ester. Other similar terms are also the same.

  The pressure-sensitive adhesive layer-carrying optical film is excellent in durability when applied to a display panel even when the optical film to be used is thinner than conventional products, and is under high temperature conditions, wet heat conditions or Even under heat shock, the occurrence of floating or peeling is suppressed. In addition, a display panel using the above-mentioned pressure-sensitive adhesive does not easily warp even under high temperature conditions, and furthermore, thermal unevenness hardly occurs.

  Here, the optical film has a functional expression layer that exhibits optical performance such as polarization performance and retardation performance, and a protective layer (for maintaining form) for protecting the functional expression layer and maintaining form stability. It often consists of The present inventors have found that use of an acrylic resin for the protective layer makes it possible to reduce the film thickness without reducing the optical performance of the functional layer. However, in the conventional pressure-sensitive adhesive layer-carrying optical film, when an acrylic resin is used for the protective layer to make it thin, durable conditions (high temperature conditions as exemplified in the test examples described later, wet heat conditions or heat shock In addition to the following, it includes high temperature environment and wet heat environment at the time of actual use, etc. In addition, the form retention in the following becomes the same unless otherwise noted, and adhesion to the pressure-sensitive adhesive layer As a result, the pressure-sensitive adhesive layer-carrying optical film using the optical film did not have satisfactory durability and heat resistance unevenness. Furthermore, the warp tends to be severe under high temperature conditions. On the other hand, in the pressure-sensitive adhesive layer-carrying optical film according to the present embodiment, the residual stress of the pressure-sensitive adhesive layer due to the optical film shrinkage under durable conditions is enhanced by enhancing the stress relaxation property of the pressure-sensitive adhesive layer by the composition described above. I decided to eliminate it.

  The inventors of the present invention carefully observed the interface between the protective layer and the pressure-sensitive adhesive layer after the durability test, regarding the insufficient adhesion between the protective layer made of acrylic resin and the pressure-sensitive adhesive layer. It has been found that there is a defect that some component seems to be sucked out to the layer side. From this found phenomenon, the low molecular weight component of the main ingredient polymer in the pressure-sensitive adhesive layer is attracted to the protective layer side made of the same acrylic resin from the same condition under the endurance condition, and the above-mentioned is formed at the interface between the protective layer and the pressure-sensitive adhesive layer. It was inferred that low molecular weight components were present, and because they are low molecular weight components, they act like lubricating oils and reduce the adhesion at the interface. Based on this inference, by raising the glass transition temperature (Tg) of the main component polymer of the pressure-sensitive adhesive layer by the above-described composition, suction of low molecular weight components from the pressure-sensitive adhesive layer to the protective layer under durable conditions is prevented. Even if a low molecular weight component is aspirated, it is intended to prevent it from acting like a lubricating oil.

[Adhesive layer]
(1) (meth) acrylic acid ester copolymer (A)
The (meth) acrylic acid ester copolymer (A) in the present embodiment contains an alicyclic structure-containing monomer (a1) and an aromatic ring-containing monomer (a2) as monomer units constituting the polymer. By containing the alicyclic structure-containing monomer (a1) and the aromatic ring-containing monomer (a2), the obtained pressure-sensitive adhesive can have appropriate cohesion and stress relaxation properties as well as an acrylic resin. Since the adhesion is high, when used in a display panel, it is possible to exhibit excellent durability, warpage suppressing property and heat unevenness.

  The (meth) acrylic acid ester copolymer (A) is, as a monomer unit constituting the polymer, a hydroxyl group-containing monomer in addition to the above-mentioned alicyclic structure-containing monomer (a1) and the aromatic ring-containing monomer (a2) It is preferable to contain (a3), and it is especially preferable to contain a (meth) acrylic acid alkyl ester having 1 to 20 carbon atoms in the alkyl group. Also, if desired, other monomers may be contained.

  Here, the hydroxyl value of the (meth) acrylate copolymer (A) is preferably 5 to 20 mg KOH / g, particularly preferably 8 to 18 mg KOH / g, and further 10 to 16 mg KOH / g Is preferred. When the hydroxyl value of the (meth) acrylic acid ester copolymer (A) is 5 mg KOH / g or more, the crosslinking point can be secured and the cohesion can be maintained high, and the resulting adhesive has excellent durability. It can be exhibited effectively. In addition, when the hydroxyl value of the (meth) acrylic acid ester copolymer (A) is 20 mg KOH / g or less, it is possible to prevent the crosslinking point from becoming too large, the obtained adhesive becomes flexible, and the stress is excellent. It is possible to effectively exhibit the relaxation property, the excellent warpage suppressing property and the heat non-uniformity due to it.

  The acid value of the (meth) acrylic acid ester copolymer (A) is preferably 5 mg KOH / g or less, particularly preferably 2 mg KOH / g or less, and further preferably 1 mg KOH / g or less preferable. When the acid value of the (meth) acrylic acid ester copolymer (A) is 5 mg KOH / g or less, a target to which the pressure-sensitive adhesive is to be attached causes a problem due to the acid, for example, a transparent conductive film such as tin-doped indium oxide (ITO) Also in the case of a metal film or the like, those defects caused by the acid can be suppressed. In particular, when the object to be attached 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 it is so preferable that the lower limit of the acid value of a (meth) acrylic acid ester copolymer (A) is small, it is especially preferable that it is 0 mgKOH / g.

  Here, the hydroxyl value and the acid value in the present specification are basically theoretical values derived from the blend ratio of the (meth) acrylic acid ester copolymer (A), and when the theoretical values can not be derived, It is a value measured based on JIS K 0070.

  The (meth) acrylic acid ester copolymer (A) is preferably adhesive because it 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 methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate and n- (meth) acrylate Butyl, n-pentyl (meth) acrylate, n-hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, n-decyl (meth) acrylate, (meth) acrylate n-dodecyl, myristyl (meth) acrylate, palmityl (meth) acrylate, stearyl (meth) acrylate and the like can be mentioned. Among them, from the viewpoint of further improving the adhesiveness, (meth) acrylic esters having 1 to 8 carbon atoms in the alkyl group are preferable, and n-butyl (meth) acrylate or 2-ethylhexyl (meth) acrylate is particularly preferable . These may be used alone or in combination of two or more.

  The (meth) acrylic acid ester copolymer (A) contains 40 to 97.5 mass% (meth) acrylic acid alkyl ester having 1 to 20 carbon atoms of an alkyl group as a monomer unit constituting the polymer. It is preferable to contain, and it is preferable to contain especially 55-94 mass%, and also it is preferable to contain 65-83 mass%. When the (meth) acrylic acid alkyl ester is contained at 40% by mass or more, the (meth) acrylic acid ester copolymer (A) can be provided with suitable adhesiveness. Further, by setting the (meth) acrylic acid alkyl ester to 97.5% by mass or less, a desired amount of another monomer component can be introduced into the (meth) acrylic acid ester copolymer (A).

  The carbon ring of the alicyclic structure 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 or tricyclic ring. From the viewpoint of making the distance between the obtained (meth) acrylic acid ester copolymers (A) suitable and giving stress relaxation to the adhesive, and the glass transition temperature (Tg) of the obtained copolymer (A) The above alicyclic structure is a polycyclic alicyclic structure (polycyclic structure) from the viewpoint of preventing the low molecular weight portion from migrating to the acrylic resin side and inhibiting the adhesion by raising the Is preferred. Furthermore, in view of the compatibility between the (meth) acrylic acid ester copolymer (A) and the other components, the polycyclic structure is particularly preferably a bicyclic to tetracyclic ring. In addition, from the viewpoint of imparting stress relaxation properties in the same manner as described above, the carbon number of the alicyclic structure (the carbon number of all the parts forming the ring is referred to, and plural rings are independently present) The total number of carbon atoms is preferably 5 or more, and particularly preferably 7 or more. On the other hand, the upper limit of the carbon number of 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.

  As an alicyclic structure, for example, cyclohexyl skeleton, dicyclopentadiene skeleton, adamantane skeleton, isobornyl skeleton, cycloalkane skeleton (cycloheptane skeleton, cyclooctane skeleton, cyclononane skeleton, cyclodecane skeleton, cycloundecane skeleton, cyclododecane skeleton, etc.) And cycloalkene skeletons (cycloheptene skeleton, cyclooctene skeleton, etc.), norbornene skeleton, norbornadiene skeleton, cubane skeleton, basquetan skeleton, housen skeleton, spiro skeleton, etc. Those containing a dicyclopentadiene skeleton (the carbon number of the alicyclic structure: 10), an adamantane skeleton (the carbon number of the alicyclic structure: 10) or an isobornyl skeleton (the carbon number of the alicyclic structure: 7) are preferred. Contains an isobornyl skeleton Preference is.

  As said alicyclic structure containing monomer (a1), the (meth) acrylic acid ester monomer containing said frame | skeleton is preferable, Specifically, (meth) acrylic acid cyclohexyl, (meth) acrylic acid dicyclopentanyl, (Meth) acrylic acid adamantyl, (meth) acrylic acid isobornyl, (meth) acrylic acid dicyclopentenyl, (meth) acrylic acid dicyclopentenyl oxyethyl and the like, and among them, it exhibits more excellent durability ( Dicyclopentanyl acrylate, adamantyl (meth) acrylate or isobornyl (meth) acrylate are preferred, and isobornyl (meth) acrylate is particularly preferred. One of these may be used alone, or two or more of these may be used in combination.

  The (meth) acrylic acid ester copolymer (A) is an alicyclic polymer as a monomer unit constituting the polymer from the viewpoint that the obtained adhesive exhibits excellent durability, warpage suppressing property and heat non-uniformity property. It is preferable to contain 1 to 20% by mass of the structure-containing monomer (a1). Furthermore, in addition to the above viewpoints, from the viewpoint that the obtained adhesive exhibits excellent reworkability, it is more preferable to particularly contain 2 to 15% by mass of the alicyclic structure-containing monomer (a1), and 3 to 9% % Is particularly preferable.

  As an aromatic ring containing monomer (a2), the (meth) acrylic acid ester which has an aromatic ring is preferable. As an aromatic ring, a benzene ring, a naphthalene ring, an anthracene ring, a biphenyl ring, a fluorene ring etc. are mentioned, A benzene ring is especially 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 And phenoxybutyl (meth) acrylate, ethoxylated o-phenylphenol acrylate, phenoxydiethylene glycol (meth) acrylate, ethylene oxide modified cresol (meth) acrylate, ethylene oxide (EO) modified nonylphenol (meth) acrylate, etc., among which And 2-phenylethyl (meth) acrylate is preferred from the viewpoint of improving the cohesive strength. 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 carry out, and also it is preferable to contain 12-22 mass%. When the content of the aromatic ring-containing monomer (a2) is in the above range, the resulting pressure-sensitive adhesive can exhibit excellent durability, warpage suppressing property, 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 exhibits 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. The crosslinked structure makes the obtained pressure-sensitive adhesive excellent in durability.

  As the hydroxyl group-containing monomer (a3), for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate And (meth) acrylic acid hydroxyalkyl esters such as 3-hydroxybutyl (meth) acrylic acid and 4-hydroxybutyl (meth) acrylic acid, and the like, and among them, from the viewpoint of reactivity with the crosslinking agent (B) Preferred are 2-hydroxyethyl (meth) acrylate or 4-hydroxybutyl (meth) acrylate, and in particular 2-hydroxyethyl (meth) acrylate. 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 a hydroxyl group-containing monomer (a3) as a monomer unit constituting the polymer, particularly 1 to 5% by mass It is preferable to contain, and also 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-mentioned range, and the excellent durability and the warpage suppressing property are obtained. And heat-resistant nonuniformity can be exhibited effectively.

  The (meth) acrylic acid ester copolymer (A) preferably does not contain a carboxyl group-containing monomer as a monomer unit constituting the polymer also in order to set the acid value to the above-mentioned range, and even if it contains it 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, as a monomer unit constituting the polymer, another monomer other than the monomers described above. As the other monomer, a monomer not containing a functional group having reactivity with the crosslinking agent (B) is also preferable in order not to prevent 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, and (meth) Examples thereof include (meth) acrylic acid esters having a non-crosslinkable tertiary amino group such as N, N-dimethylaminoethyl acrylate and N, N-dimethylaminopropyl (meth) acrylate, and vinyl acetate. These may be used alone or in combination of two or more.

  The polymerization mode 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 1,300,000 to 3,000,000, particularly preferably 1,500,000 to 2,500,000, and more preferably 1,600,000 to 1,900,000. Is preferred. When the weight average molecular weight of the (meth) acrylic acid ester copolymer (A) is 1,300,000 or more, the durability of the obtained pressure-sensitive adhesive can be favorably secured. In addition, when the weight average molecular weight of the (meth) acrylic acid ester copolymer (A) is 3,000,000 or less, the stress relaxation property of the obtained pressure-sensitive adhesive is favorably secured, and the warpage suppressing property and the heat non-uniformity resistance are effective. Can be demonstrated.

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

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

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

(2) Crosslinking agent (B)
The crosslinking agent (B) should just react with the functional group which a (meth) acrylic acid ester copolymer (A) has, for example, an isocyanate type crosslinking agent, an epoxy type crosslinking agent, an amine type crosslinking agent, melamine Type crosslinking agent, aziridine type crosslinking agent, hydrazine type crosslinking agent, aldehyde type crosslinking agent, oxazoline type crosslinking agent, metal alkoxide type crosslinking agent, metal chelate type crosslinking agent, metal salt type crosslinking agent, ammonium salt type crosslinking agent, etc. Be

  When the (meth) acrylate 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 It is preferred 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 crosslinking agent contains at least a polyisocyanate compound. Examples of polyisocyanate compounds include aromatic polyisocyanates such as tolylene diisocyanate, diphenylmethane diisocyanate, xylylene diisocyanate, aliphatic polyisocyanates such as hexamethylene diisocyanate, alicyclic polyisocyanates such as isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, and the like And adducts that are the reaction products with their biuret and isocyanurate, as well as low molecular weight active hydrogen-containing compounds such as ethylene glycol, propylene glycol, neopentyl glycol, trimethylolpropane and castor oil. It may be referred to as "denatured body". Among these, from the viewpoint of the durability of the adhesive obtained, compounds having an aromatic ring, that is, aromatic polyisocyanates or modified products thereof are preferable, and an aromatic group is preferably an organic group (for example, an alkylene chain is preferably mentioned. Particularly preferred is a polyisocyanate having an isocyanate group linked via an alkylene chain of 1 to 4), or a modified product thereof. 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, and more preferably 0.1 to 0.4 parts by mass. When the content of the crosslinking agent (B) is in the above-mentioned range, the obtained pressure-sensitive adhesive exhibits good cohesion and stress relaxation properties, and is excellent in durability, warpage suppressing property, and heat 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 was excellent in the adhesive obtained. 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 mercapto group-containing silane coupling agent (C2) are preferably contained.

  The epoxy group-containing silane coupling agent (C1) is an organic silicon compound having at least one epoxy group (organic group containing an epoxy group) and at least one alkoxysilyl group in the molecule, which is an adhesive component and And those having light transparency, such as those substantially transparent.

  Specific examples of the epoxy group-containing silane coupling agent (C1) include 3-glycidoxypropyltrialkoxysilane such as 3-glycidoxypropyltrimethoxysilane and 3-glycidoxypropyltriethoxysilane; 3-glycidoxypropylalkyldialkoxysilanes such as cidoxypropylmethyldiethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, methyltri (glycidyl) silane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane And 2- (3,4-epoxycyclohexyl) ethyltrialkoxysilane such as 2- (3,4-epoxycyclohexyl) ethyltriethoxysilane and the like. Among them, from the viewpoint of further improving the durability, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 2- (3,4 epoxycyclohexyl ) Ethyltrimethoxysilane is preferred, in particular 3-glycidoxypropyltrimethoxysilane. One of these may be used alone, or two or more of these may be used in combination.

  The mercapto group-containing silane coupling agent (C2) is an organic silicon compound having at least one mercapto group (organic group containing a mercapto group) and at least one alkoxysilyl group in the molecule, which is an adhesive component and And those having light transparency, such as those substantially transparent.

  Specific examples of the mercapto group-containing silane coupling agent (C2) include mercapto group-containing low molecular weight silane couplings such as 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropyldimethoxymethylsilane, etc. Mercapto group-containing silane compounds such as 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropyldimethoxymethylsilane and the like, methyltriethoxysilane, ethyltriethoxysilane, methyltrimethoxysilane, ethyl Mercapto-group containing oligomer type | mold silane coupling agents, such as a cocondensate with alkyl-group containing silane compounds, such as a trimethoxysilane, etc. are mentioned. Among them, from the viewpoint of achieving both durability and reworkability, mercapto group-containing oligomer type silane coupling agents are preferable, and in particular, a co-condensate of a mercapto group-containing silane compound and an alkyl group-containing silane compound is preferable. Preferred are co-condensates of mercaptopropyltrimethoxysilane and methyltriethoxysilane. One of these may be used alone, or two or more of these may be used in combination.

  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, if necessary A hydroxyl group based silane coupling agent, a carboxyl group based silane coupling agent, an amino group based silane coupling agent, an amide group based silane coupling agent, an isocyanate group based silane coupling agent or 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) It is preferable that it is especially preferable that it is 0.1-2 mass parts, and it is further more preferable that it is 0.2-1 mass part.

  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). It is preferable that it is a mass part, it is preferable that it is especially 0.05-1 mass part, and it is more preferable that it is 0.1-0.5 mass part. 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 based on 100 parts by mass of the (meth) acrylic acid ester copolymer (A). It is preferable that it is a mass part, it is preferable that it is especially 0.05-1 mass part, and it is more preferable that it is 0.1-0.5 mass part.

(4) Antistatic agent (D)
The adhesive composition P preferably further contains an antistatic agent (D). Since the release sheet to be laminated on the pressure-sensitive adhesive layer, or an optical film such as a polarizing plate or a composite polarizing plate is usually made of a plastic material, it has high electrical insulation and generates static electricity when peeling the release sheet, etc. Easy to do. If a polarizing plate, a composite polarizing plate, or the like is attached to a liquid crystal cell in a state in which the generated static electricity remains, there is a possibility that the alignment of liquid crystal molecules may be disturbed. It causes problems such as suctioning. Then, when the adhesive composition P contains an antistatic agent (D), the adhesive (adhesive layer) obtained exhibits an antistatic property, and the above problems can be eliminated.

  The antistatic agent (D) may be any one that can impart antistatic properties to the obtained adhesive, and examples thereof include ionic compounds and nonionic compounds, among which ionic compounds are preferred. . The ionic compound may be liquid or solid at room temperature, but is preferably solid at room temperature from the viewpoint that it tends to exhibit stable antistatic properties even when exposed to durability conditions. . Here, the ionic compound in the present specification refers to a compound in which a cation and an anion are mainly combined by electrostatic attraction.

  As the ionic compound, nitrogen-containing onium salts, sulfur-containing onium salts, phosphorus-containing onium salts, alkali metal salts and alkaline earth metal salts are preferable, and from the viewpoint of excellent durability of the obtained adhesive, nitrogen-containing onium salts are 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 in particular an ionic compound composed of a nitrogen-containing heterocyclic cation and a halogenated phosphate anion. It is preferably an ionic compound which is solid at room temperature and is composed of a nitrogen-containing heterocyclic cation and a halogenated phosphate anion. According to the ionic compound which 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 of the antistatic property and the durability.

  The nitrogen-containing heterocyclic skeleton of the nitrogen-containing heterocyclic cation is preferably a pyridine ring, a pyrimidine ring, an imidazole ring, a triazole ring, an indole ring, etc., among which a pyridine ring is preferable. Further, as the halogen of the halogenated phosphate anion, fluorine, chlorine, bromine and the like are preferable, and among them, fluorine is 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 -Methyl pyridinium hexafluorophosphate, N-hexadecyl 4-methyl pyridinium hexafluorophosphate, etc. are mentioned. Among these, from the viewpoint of compatibility with the (meth) acrylate copolymer (A), N-butyl-4-methylpyridinium hexafluorophosphate, N-hexyl-4-methylpyridinium hexafluorophosphate and N- Octyl-4-methylpyridinium hexafluorophosphate is preferred. The above antistatic agents (D) may be used alone or in combination of two or more.

  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 in the above range, the antistatic property can be effectively exhibited, and deterioration of physical properties such as optical characteristics and durability can be prevented.

(5) Various Additives In the adhesive composition P, various additives generally used in acrylic pressure-sensitive adhesives, for example, dispersants (for example, alkylene glycol dialkyl ether), tackifiers, oxidation prevention, if desired Additives, UV absorbers, light stabilizers, softeners, fillers, refractive index modifiers and the like can be added. The adhesive composition P represents a mixture of various components remaining in the pressure-sensitive adhesive layer as it is or in a reacted state, and is a component to be removed in a drying step or the like, for example, polymerization described later. The solvent and the dilution solvent are not included in the adhesive composition P.

(6) Method for Producing Adhesive Composition The adhesive composition P produces a (meth) acrylic acid ester copolymer (A), and the obtained (meth) acrylic acid ester copolymer (A), It can manufacture by mixing a crosslinking agent (B) and the silane coupling agent (C), an antistatic agent (D), an additive, etc. as needed.

  The (meth) acrylic acid ester copolymer (A) can be produced by polymerizing a mixture of monomer units constituting the polymer by a conventional 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, if desired. As a polymerization solvent, ethyl acetate, n-butyl acetate, isobutyl acetate, toluene, acetone, hexane, methyl ethyl ketone etc. are mentioned, for example, You may use 2 or more types together.

  As a polymerization initiator, an azo compound, an organic peroxide, etc. are mentioned, You may use 2 or more types together. As an azo compound, for example, 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-methyl propionate) 4,4'-azobis (4-cyanovaleric acid), 2,2'-azobis (2-hydroxymethylpropionitrile), 2,2'-azobis [2- (2-imidazolin-2-yl) Propane] and the like.

  As the organic peroxide, for example, benzoyl peroxide, t-butyl perbenzoate, cumene hydroperoxide, diisopropyl peroxy dicarbonate, di-n-propyl peroxy dicarbonate, di (2-ethoxyethyl) peroxy Dicarbonate, t-butyl peroxy neodecanoate, t-butyl peroxy bivalate, (3,5,5-trimethylhexanoyl) peroxide, dipropionyl peroxide, diacetyl peroxide and the like can be mentioned.

  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-mercapto ethanol.

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

  Examples of the dilution solvent for diluting the adhesive composition P to obtain 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, 2-pentanone, isophorone, ketones such as cyclohexanone, esters such as ethyl acetate and butyl acetate, ethyl Cellosolv solvents such as cellosolve are used.

  The concentration / viscosity of the coating solution prepared in this manner 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 viscosity etc. which the adhesive composition P can coat, it is not necessary to add a dilution solvent. In this case, the adhesive composition P is a coating solution in which the polymerization solvent of the (meth) acrylic acid ester copolymer (A) is used as a dilution solvent as it is.

(7) Pressure-sensitive adhesive The pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer in this embodiment is obtained from the pressure-sensitive adhesive composition P described above, and specifically, is formed by crosslinking the pressure-sensitive adhesive composition P is there. Crosslinking of the adhesive composition P can be carried out by heat treatment. In addition, this heat processing can also serve as the drying processing at the time of volatilizing the dilution solvent etc. of the adhesive composition P.

  When heat-processing, it is preferable that heating temperature is 50-150 degreeC, and it is preferable that it is especially 70-120 degreeC. The heating time is preferably 30 seconds to 10 minutes, and more 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 normal temperature (for example, 23 ° C., 50% RH). When this curing period is required, after the curing period, when the curing period is unnecessary, after the heat treatment is completed, a pressure-sensitive adhesive layer having predetermined physical properties is formed.

  By the above 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%, more preferably 60 to 85%, and still more preferably 73 to 78%. When the gel fraction is 40% or more, the durability of the pressure-sensitive adhesive becomes 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 non-uniformity become more excellent. In addition, the measuring method of the gel fraction of an adhesive is as showing to the test example mentioned later.

(8) Physical Properties of 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 preferably 15 to 30 μm. Is more preferred.

  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 as an optical application.

[Optical film]
The optical film in the present embodiment may be composed of a single layer or may be composed of a plurality of layers. Examples of optical films include composite polarizing plates such as polarizers, polarizing plates, retardation plates, and polarizing plates with retardation plates, viewing angle compensation films, brightness enhancement films, contrast enhancement films, liquid crystal polymer films, diffusion films, Transmissive reflective films, laminates thereof and the like can be mentioned. Among them, the polarizer is easily shrunk, the dimensional change is large, and the optical film including the polarizer is suitable as the optical film of the pressure-sensitive adhesive layer-attached optical film according to the present embodiment from the viewpoint of requiring durability. In particular, a thin polarizing plate having a thin protective layer and a composite polarizing plate using the polarizing plate are easily shrunk by heat or the like because the protective layer is weak in suppressing the shrinkage of the polarizer, and It is optimum as an optical film of the pressure-sensitive adhesive layer-carrying optical film according to the present embodiment.

  Here, the surface of the optical film in contact with the pressure-sensitive adhesive layer is made of an acrylic resin. By using an acrylic resin in the relevant portion of the optical film, it is possible to make the film thickness thinner without impairing the predetermined optical performance. When the optical film consists of a single layer, the optical film consists of a single layer of 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. The adhesion between the acrylic resin and the conventionally known pressure-sensitive adhesive layer was low, and the durability was also low. However, according to the pressure-sensitive adhesive layer in the present embodiment, adhesion to acrylic resins is high, and stress relaxation is excellent. Therefore, the durability is excellent even under high temperature conditions, wet heat conditions, heat shock conditions, and the like. The “acrylic resin layer formed through extrusion molding” also includes an acrylic resin layer obtained by performing stretching processing after extrusion molding.

  It is preferable that the optical film in the present embodiment is provided with a retardation plate having at least an acrylic resin layer and a retardation expression layer, and the retardation expression layer has a reduced thickness and an expression of retardation. It is preferable to consist of a styrene resin from a compatible viewpoint. Moreover, 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 side of the acrylic resin layer in the said phase difference expression layer. As described above, the liquid crystal display device, particularly the IPS (In-Place-Switching) device, has the acrylic resin layer and the phase difference developing layer composed of the styrene resin, and further has the second acrylic resin layer. In the 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 side opposite to the surface on the pressure-sensitive adhesive layer side in the retardation plate, and the second retardation plate is made of cycloolefin resin. It is preferable that By having such a second retardation plate and further having a second retardation plate made of a cycloolefin resin, the viewing angle compensation performance becomes more excellent.

  In addition, it is preferable that a polarizing plate is further laminated on the side opposite to the surface on the side of the retardation plate in the second retardation plate. This makes it possible to provide a composite polarizing plate having very excellent viewing angle compensation performance.

[Specific Example of Optical Film Having Pressure-Sensitive Adhesive Layer]
1. Example of Optical Film: Polarizing Plate An example of the pressure-sensitive adhesive layer-carrying optical film according to the present embodiment in the case where the optical film is a polarizing plate will be described with reference to FIG. As shown in FIG. 1, the pressure-sensitive adhesive layer-carrying optical film 10A according to the present embodiment includes a polarizing plate 2A and a pressure-sensitive adhesive layer 1 laminated on one side of the polarizing plate 2A (the lower side in FIG. 1). 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 until the pressure-sensitive adhesive layer-carrying optical film 10A 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 (upper surface in FIG. 1) of the polarizer 21, and the other surface of the polarizer 21 (see FIG. 1) and the 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 in which a dichroic dye is adsorbed and oriented.

  The polyvinyl alcohol-type resin which comprises the polarizer 21 is obtained by saponifying polyvinyl acetate type resin. Examples of polyvinyl acetate resins include polyvinyl acetate, which is a homopolymer of vinyl acetate, and copolymers of vinyl acetate and other monomers copolymerizable therewith. As another monomer copolymerized by vinyl acetate, unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids etc. are mentioned, for example.

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

  The polarizer 21 as described above uniaxially stretches a polyvinyl alcohol-based resin film, dyes a polyvinyl alcohol-based resin film with a dichroic dye, and adsorbs the dichroic dye, and the dichroic dye It is preferably manufactured by passing through the process of treating 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 or during the boric acid treatment. Of course, it is also possible to perform uniaxial stretching in these multiple stages. In order to uniaxially stretch, uniaxial stretching may be performed between rolls having different peripheral speeds, or uniaxial stretching may be performed using a heat 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 stretching ratio is usually about 4 to 8 times.

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

  When using iodine as a dichroic dye, the method of immersing and dye | staining a polyvinyl-alcohol-type resin film the aqueous solution containing an iodine and potassium iodide is employ | adopted normally. 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 (staining time) in this aqueous solution is usually about 30 to 300 seconds.

  The boric acid process after dyeing | staining with a dichroic dye is performed by immersing the dyed polyvinyl alcohol-type resin film in boric-acid aqueous solution. The content of boric acid in the aqueous boric acid 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, this aqueous boric acid solution preferably contains potassium iodide. The content of potassium iodide in the aqueous boric acid 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 boric acid treatment is usually washed with water. The water washing process is performed, for example, by immersing a boric acid-treated polyvinyl alcohol resin film in water. After washing with water, drying treatment is performed to obtain a 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 subsequent drying treatment 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 preferably about 3 to 15 μm when thin film formation 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. It is one kind of resin. Among the above, the first protective layer 22 is preferably made of a cellulose-based resin.

  A cellulose-based resin is a resin in which at least a part of hydroxyl groups in cellulose is acetate-esterified, and a mixed ester in which a part is acetate-esterified and a part is esterified with another acid Good. The cellulose-based resin is preferably a cellulose ester-based resin, and more preferably an acetyl cellulose-based resin. Specific examples of the acetyl cellulose-based resin include triacetyl cellulose, diacetyl cellulose, cellulose acetate propionate, and cellulose acetate butyrate. As a commercial item of the film which consists of such an acetyl cellulose type-resin, for example, "FUJITAC TD80" made by FUJIFILM Corporation, "FUJITAC TD80UF" and "FUJITAC TD80UZ", "KC8UX2M made by Konica Minolta Opto Co., Ltd." And "KC2UA" and "KC8UY" and the like.

  It is also possible to use a cellulose resin film provided with an optical compensation function. As such an optical compensation film, for example, a film in which a compound having a phase difference adjusting function is contained in a cellulose resin, a film in which a compound having a phase difference adjusting function is coated on the surface of a cellulose resin, a uniaxial or two cellulose resin The film etc. obtained by extending | stretching to an axis | shaft etc. are mentioned. As an example of the commercially available optical compensation film of a cellulose-based resin, "Wide View Film WV BZ 438" and "Wide View Film WV EA" manufactured by Fuji Film Co., Ltd., and "" manufactured by Konica Minolta Opto Co., Ltd. KC4FR-1 "and" KC4HR-1 ".

  Among the above-mentioned cellulose resins, the first protective layer 22 is more preferably made of a cellulose ester resin, particularly preferably made of an acetyl cellulose resin, and still more preferably made of 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, and in particular, the second protective layer 23 has a viewpoint of easy thinning without impairing the polarization performance. Therefore, it is preferable to be made of an acrylic resin. In this case, in the layer in which the pressure-sensitive adhesive layer in contact with the second protective layer 23 is composed of a conventional acrylic pressure-sensitive adhesive composition, low molecular weight components in the pressure-sensitive adhesive are absorbed and the second protective layer 23 and the pressure-sensitive adhesive layer The adhesion of the interface with the However, in the case of the pressure-sensitive adhesive layer 1 formed from the pressure-sensitive adhesive composition P in the present embodiment, a (meth) acrylic acid ester copolymer having a high glass transition temperature (Tg) such that the adhesion does not become insufficient. By using (A), the above suction phenomenon can be effectively prevented. Thereby, the adhesive layer 1 has high adhesion to the second protective layer 23. Therefore, the pressure-sensitive adhesive layer-carrying optical film 10A is excellent in durability even under high temperature conditions, wet heat conditions, heat shock conditions, 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 a copolymer in which a small amount of other comonomer component is copolymerized therewith Is particularly preferred. This copolymer can be generally obtained by polymerizing monofunctional monomers containing methyl methacrylate and methyl acrylate in the coexistence of a radical polymerization initiator and a chain transfer agent. In addition, the acrylic resin can copolymerize the third monofunctional monomer.

  As a third monofunctional monomer copolymerizable with methyl methacrylate and methyl acrylate, 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 acid esters such as hydroxyethyl; methyl 2- (hydroxymethyl) acrylate, methyl 2- (1-hydroxyethyl) acrylate, ethyl 2- (hydroxymethyl) acrylate, and 2- Hydroxyalkyl acrylic esters such as butyl (hydroxymethyl) acrylate; unsaturated acids such as methacrylic acid and acrylic acid; halogenated styrenes such as chlorostyrene and bromostyrene; substituted styrenes such as vinyl toluene and α-methylstyrene Unsaturated nitriles such as acrylonitrile and methacrylonitrile; unsaturated acid anhydrides such as maleic anhydride and citraconic anhydride; unsaturated imides such as phenyl maleimide and cyclohexyl maleimide; and the like. Each of these may be used alone, or two or more different types may be used in combination.

  When a polyfunctional monomer is copolymerized, examples of polyfunctional monomers copolymerizable with methyl methacrylate and methyl acrylate include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate and triethylene. Acrylic acid or both terminal hydroxyl groups of ethylene glycol or its oligomers such as glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, nona ethylene glycol di (meth) acrylate, and tetradecaethylene glycol di (meth) acrylate Esterified with methacrylic acid; Propylene glycol or its oligomer esterified with hydroxyl groups at both terminal ends with acrylic acid or methacrylic acid; Neopentyl glycol di (meth) acrylate, Esterified with hydroxyl group of 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 both terminal hydroxyl groups of a substituted compound 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-opened addition of epoxy group of methacrylate; dibasic acids such as succinic acid, adipic acid, terephthalic acid, phthalic acid, and their halogen-substituted products, and alkylene alkylene oxides thereof 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 them, 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 the reaction between functional groups possessed by the copolymer. As the reaction, for example, intramolecular demethanol condensation reaction of methyl ester group of methyl acrylate and hydroxyl group of methyl 2- (hydroxymethyl) acrylate, carboxyl group of acrylic acid and 2- (hydroxymethyl) acrylic Examples include intramolecular dehydration condensation reaction of methyl acid with hydroxyl group.

  It is preferable that the glass transition temperature (Tg) of the said acrylic resin is the range of 80-120 degreeC. In order to adjust the glass transition temperature (Tg) of the acrylic resin to the above range, usually, the polymerization ratio of the methacrylic acid ester monomer and the acrylic acid ester monomer, the carbon chain length of each ester group and the polymerization rate thereof The kind of functional group to have, and the method of selecting the polymerization ratio of the polyfunctional acryl monomer with respect to the whole monomer suitably are employ | adopted.

  The acrylic resin may contain known additives as required. Examples of known additives include lubricants, antiblocking agents, heat stabilizers, antioxidants, antistatic agents, light stabilizers, impact modifiers, surfactants and the like. However, since transparency is required as a protective film laminated on a polarizer, it is preferable to minimize the amount of these additives.

  As a method of 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 them, a method in which a raw material resin is melt-extruded from, for example, a T-die, and at least one surface of the obtained film is contacted with a roll or a belt to form a film is preferable in that a film with good surface properties is obtained.

  The acrylic resin may contain acrylic rubber particles, which are impact modifiers, from the viewpoint of film forming property to a film and impact resistance of the film. The acrylic rubber particles as referred to herein are particles containing an elastic polymer mainly composed of acrylic acid ester as an essential component, and those obtained by making the elastic polymer into particles uniformly or the elastic polymer The thing of the multilayer structure made into two layers is mentioned.

  As an example of such an elastic polymer, there may be mentioned a crosslinked elastic copolymer comprising an alkyl acrylate as a main component, and another vinyl monomer copolymerizable therewith and a crosslinking monomer copolymerized therewith. Examples of the alkyl acrylate which is the main component of the elastic polymer include those having about 1 to 8 carbon atoms in the alkyl group, such as methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, etc., particularly carbon An acrylate having an alkyl group of several or more is preferably used. Examples of other vinyl monomers copolymerizable with this alkyl acrylate include compounds having one polymerizable carbon-carbon double bond in the molecule, and more specifically, methacrylic esters such as methyl methacrylate And aromatic vinyl compounds such as styrene, and vinyl cyan compounds such as acrylonitrile. Further, as the crosslinkable monomer, a crosslinkable compound having at least two polymerizable carbon-carbon double bonds in the molecule can be mentioned, 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, under the trade names, Sumipex (Sumitomo Chemical Co., Ltd.), Acrypet (Mitsubishi Rayon Co., Ltd.), Delpet (Asahi Kasei) (Manufactured by Nippon Steel Co., Ltd.), Parapet (manufactured by Kuraray Co., Ltd.), Acrivia (manufactured by Nippon Shokubai Co., Ltd.), etc.

  The protective layers 22 and 23 may contain an ultraviolet absorber. By arranging a protective layer containing an ultraviolet light absorber on the viewing side of the liquid crystal cell, the liquid crystal cell can be protected from deterioration by ultraviolet light.

  Here, the first protective layer 22 and the second protective layer 23 may be made of the same kind of transparent resin film, or may be made of different kinds of transparent resin films.

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

  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 An adhesive constituting an adhesive layer which 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 appropriate, appropriate ones can be used according to the type and purpose of the adherend. For example, solvent-type adhesives, emulsion-type adhesives, water-based adhesives, pressure-sensitive adhesives, remoistenable adhesives, polycondensation-type adhesives, non-solvent-type adhesives, film adhesives, hot-melt adhesives, etc. It can be mentioned.

  One preferable adhesive constituting the above-mentioned adhesive is a water-based adhesive, and a representative example thereof is one having a polyvinyl alcohol-based resin as a main component. Examples of commercially available polyvinyl alcohol-based resins that can be water-based adhesives include "KL-318" manufactured by Kuraray Co., Ltd., and the like.

  The water-based adhesive can 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 crosslinking agents include Glyoxal and "Sumirez Resin 650 (30)", which is an aqueous solution of a water-soluble epoxy compound sold by Sumika Chemtex Co., Ltd.

  Another preferable adhesive is an adhesive made of an epoxy resin composition containing an epoxy resin which is cured by irradiation with active energy rays or heating. When the adhesive is used, the adhesion between the films is performed by irradiating the active energy ray to the adhesive layer interposed between the films or heating to cure the curable epoxy resin contained in the adhesive. It can be done by Curing of the epoxy resin by irradiation or heating of active energy rays is preferably carried out by cationic polymerization of the epoxy resin. In the present specification, the epoxy resin means a compound having two or more epoxy groups in the molecule.

  From the viewpoint of weatherability, refractive index, cationic polymerization and the like, the epoxy resin contained in the curable epoxy resin composition which is an adhesive is preferably an epoxy resin containing no aromatic ring in the molecule. A hydrogenated epoxy resin, an alicyclic epoxy resin, an aliphatic epoxy resin etc. can be illustrated as such an epoxy resin.

(4) Method of Manufacturing Polarizing Plate The polarizing plate 2A can be manufactured by a usual method. Hereinafter, the manufacturing method at the time of using a water-based adhesive as said adhesive agent is demonstrated as an example.

  First, an adhesive layer is formed on the bonding surface of the polarizer 21 or the bonding surface of the protective layers 22 and 23. For forming the adhesive layer, for example, a bar coat method, a knife coat method, a roll coat method, a blade coat method, a die coat method, a gravure coat method, or the like can be used. In addition, it is possible to adopt a method of casting the adhesive between the polarizer 21 and the protective layers 22 and 23 while continuously supplying the polarizer 21 and the protective layers 22 and 23 so that the bonding surfaces of both are on the inside. After the adhesive is applied, heat treatment is performed as needed to evaporate the water 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, the smaller one is preferable, and from the viewpoint of suppressing defects such as air bubbles and foreign substances during bonding. From the viewpoint of adhesion and durability, it is preferable to carry out in an optimum range determined for each combination of adherend and adhesive. Generally, it is 0.005 to 10 μm, preferably 0.01 to 5 μm, and more preferably 0.03 to 1 μm.

  Before bonding the polarizer 21 and the protective layers 22 and 23 to one or both of the bonding surfaces of the both, corona discharge treatment, plasma treatment, flame treatment, primer treatment before forming the coating layer of the adhesive An easy adhesion process such as an anchor coating process may be applied.

  After the adhesive layer is formed as described above, the first protective layer 22 is bonded to one surface of the polarizer 21 via the adhesive layer, and the second protective layer 23 is polarizer 21. Paste it on the other side of the 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, preferably 20 to 100 μm, and preferably 30 to 80 μm from the viewpoint of maintaining polarization performance while meeting the demand for thinning in mobile applications. Is particularly preferred.

(5) Method of Producing Optical Film Having Pressure-Sensitive Adhesive Layer As a preferable example of a method of producing the optical film 10A having pressure-sensitive adhesive layer, first, a release sheet is formed on one side or both sides of the pressure-sensitive adhesive layer formed from the adhesive composition P To produce a pressure-sensitive adhesive sheet. Here, as an example, a pressure-sensitive adhesive sheet formed by laminating a release sheet on both sides of a pressure-sensitive adhesive layer is manufactured.

  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, fluorine resin film, etc. Is used. Moreover, these crosslinked films are also used. Furthermore, these laminated films may be sufficient.

  It is preferable that the peeling process is performed to the at least one surface (especially the peeling surface which contact | connects an adhesive layer) of the said peeling sheet. Examples of the release agent used for the release treatment include alkyd-based, silicone-based, fluorine-based, unsaturated polyester-based, polyolefin-based and wax-based release agents. In addition, the peeling surface of the peeling sheet in this specification means the surface which has peelability in a peeling sheet, and includes both the surface which performed peeling processing, and the surface which shows peeling even if it does not perform peeling processing. .

  When laminating a release sheet on both sides of the pressure-sensitive adhesive layer, it is preferable to use one release sheet as a heavy release type release sheet with high release force and the other release sheet as a light release type release sheet with low release force.

  The thickness of the release sheet is not particularly limited, but is usually about 20 to 150 μm.

  As an example of the method for producing the pressure-sensitive adhesive sheet, a coating solution of the adhesive composition P is applied to the release surface of the release sheet, and heat treatment is performed to form a coating film. The release sheet (the release surface is in contact with the coating film) or the substrate is laminated. The above-mentioned coating film becomes an adhesive layer as it is when the curing period is unnecessary, and becomes an adhesive layer after the aging period when the curing period is necessary. The heat treatment and curing conditions are as described above.

  As a method of 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 and 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. Then, the second protective layer 23 of the polarizing plate 2A is superimposed on the exposed pressure-sensitive adhesive layer, and the pressure-sensitive adhesive sheet and the polarizing plate 2A are pressure-bonded. Thus, the pressure-sensitive adhesive layer-carrying optical film 10A (with a release sheet) is obtained.

  As another example of the method for producing the pressure-sensitive adhesive layer-carrying optical film 10A, a solution (coating solution) containing the above-mentioned pressure-sensitive adhesive composition P is applied to the release surface of the release sheet, and heat treatment is performed to form a coated film. After the formation, the second protective layer 23 of the polarizing plate 2A is superimposed on the coating film. When the curing period is required, the coating film becomes the pressure-sensitive adhesive layer 1 as it is when the curing period is unnecessary by setting the curing period. Thus, the pressure-sensitive adhesive layer-carrying optical film 10A (with a release sheet) is obtained.

2. Example of Optical Film: Composite Polarizing Plate An example of the pressure-sensitive adhesive layer-carrying optical film according to the present 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 pressure-sensitive adhesive layer-attached optical film 10B according to this embodiment is 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. Although not shown, a release sheet may be laminated on the surface of the pressure-sensitive adhesive layer 1 opposite to the side of the composite polarizing plate 2B until the pressure-sensitive adhesive layer-carrying optical film 10B 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 composite polarizing plate 2B in the present embodiment has a first retardation plate 24 in contact with the pressure-sensitive adhesive layer 1 and a second position on the opposite side of the first retardation plate 24 to the pressure-sensitive adhesive layer 1 side. The second pressure-sensitive adhesive layer 26 interposed between the retardation plate 25, the first retardation plate 24 and the second retardation plate 25, and the second pressure-sensitive adhesive layer 26 side of the second retardation plate 25 And the protective layer 27 laminated | stacked on the opposite side to the 2nd phase difference plate 25 side in the polarizer 21 comprised. 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. The composite polarizing plate 2B exhibits the performance of viewing angle compensation well.

(1) First Retardation Plate The first retardation plate 24 may be composed of a single layer that exhibits retardation, or may be composed of a plurality of layers including a retardation presentation layer. Preferably, as shown in FIG. 3, the first retardation plate 24 is formed by laminating a retardation expression layer 242 and one surface (a lower surface in FIG. 3) of the retardation expression layer 242. And the second acrylic resin layer 243 laminated on the other surface (the upper surface in FIG. 3) of the retardation expression layer 242. The phase difference developing layer 242 is preferably made of a styrene-based resin from the viewpoint of having a negative intrinsic birefringence and easy thinning. As described above, the first retardation plate 24 configured to include the first acrylic resin layer 241, the retardation expression layer 242 made of a styrene resin, and the second acrylic resin layer 243 is provided. The composite polarizing plate 2B is excellent in view angle compensation performance of a liquid crystal display device, particularly an IPS (In-Place-Switching) mode liquid crystal display device. Further, since the phase difference developing layer 242 is protected by the first acrylic resin layer 241 and the second acrylic resin layer 243 existing on both sides thereof, the first phase difference plate 24 is a phase difference developing layer. It does not impair the optical performance of 242 and is excellent in mechanical strength and chemical resistance.

  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, low molecular weight components in the pressure-sensitive adhesive are absorbed, and the adhesion at the interface between the first acrylic resin layer 241 and the pressure-sensitive adhesive layer is reduced. However, in the case of the pressure-sensitive adhesive layer 1 formed from the pressure-sensitive adhesive composition P in the present embodiment, a (meth) acrylic acid ester copolymer having a high glass transition temperature (Tg) such that the adhesion does not become insufficient. By using (A), the above suction phenomenon can be effectively prevented. Thereby, the adhesive layer 1 has high adhesion to the first retardation plate 24. Therefore, the pressure-sensitive adhesive layer-carrying optical film 10B is excellent in durability even under high temperature conditions, wet heat conditions, heat shock conditions, and the like.

  Preferably, the first retardation plate 24 is provided with in-plane retardation by stretching. This makes the performance of viewing angle compensation better.

  The styrene-based resin constituting the phase difference developing layer 242 may be a homopolymer of styrene or a derivative thereof, or a copolymer of two or more of styrene or a derivative thereof and another copolymerizable monomer. It may be combined. The styrene derivative is a compound in which another group is bonded to styrene, and is, for example, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, o-ethylstyrene, p-ethyl Hydroxyl group, alkoxy group, carboxyl group, halogen, etc. are introduced into the benzene nucleus of styrene such as alkylstyrene such as styrene, hydroxystyrene, tert-butoxystyrene, vinylbenzoic acid, o-chlorostyrene, p-chlorostyrene and the like Substituted styrene and the like.

  As a styrene resin, a ternary copolymer as disclosed in Japanese Patent Application Laid-Open Nos. 2003-50316 and 2003-207640 can also be used.

  It is preferable that the styrene resin which comprises the phase difference expression layer 242 is a copolymer of styrene or a styrene derivative, and at least 1 sort (s) of monomer chosen from an acrylonitrile, maleic anhydride, a 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 developing layer 242 is preferably 10 to 100 μm. When the thickness of the phase difference developing layer 242 is 10 μm or more, a sufficient retardation value is developed by stretching. On the other hand, when the thickness of the phase difference developing layer 242 is 100 μm or less, the impact strength is high, and the change in retardation due to external stress is small, and thermal unevenness hardly occurs when applied to a liquid crystal display.

  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 (meth) acrylic resins include homopolymers of methacrylic acid alkyl esters or acrylic acid alkyl esters, and copolymers of methacrylic acid alkyl esters and acrylic acid alkyl esters. Examples of the methacrylic acid alkyl ester include methyl methacrylate, ethyl methacrylate and propyl methacrylate. Moreover, as acrylic acid alkyl ester, methyl acrylate, ethyl acrylate, propyl acrylate etc. are mentioned. As such (meth) acrylic resins, those commercially available as general-purpose (meth) acrylic resins can be used. Among (meth) acrylic resins, 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 It also includes what is called.

  The rubber particles to be blended into the (meth) acrylic resin are preferably acrylic. Acrylic rubber particles are particles having rubber elasticity obtained by using an acrylic acid alkyl ester such as butyl acrylate or 2-ethylhexyl acrylate as a main component and polymerizing in the presence of a polyfunctional monomer.

  The rubber particles may be formed by uniformly granulating a material having rubber elasticity, or may be a multilayer structure having at least one rubber elastic layer. As the acrylic rubber particles having a multilayer structure, those having the above-described particles having rubber elasticity as a core and the periphery thereof covered with a hard methacrylic acid alkyl ester type polymer, a hard methacrylic acid alkyl ester type polymer A core is covered with an acrylic polymer having rubber elasticity as described above, and a hard core is covered with an acrylic polymer having rubber elasticity, and a hard methacrylic acid is further surrounded. What was covered by the alkyl ester type polymer etc. are mentioned.

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

  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 5 parts by mass per 100 parts by mass of the (meth) acrylic resin. It is preferably about 50 parts by mass.

  As a (meth) acrylic resin composition which comprises the 1st acrylic resin layer 241 and the 2nd acrylic resin layer 243, it is marketed in the state in which (meth) acrylic resin and acrylic rubber particles were mixed. Can be used. As an example of a commercial item of (meth) acrylic resin ((meth) acrylic resin composition) in which acrylic rubber particles are blended, "HT55X" sold by Sumitomo Chemical Co., Ltd. under the respective trade names And “Technoloi S 001”.

  The glass transition temperature (Tg) of the (meth) acrylic resin composition is generally 160 ° C. or less, but a (meth) acrylic resin composition having a glass transition temperature (Tg) of 120 ° C. or less is preferable, in particular 110 A (meth) acrylic resin composition having a temperature of not higher than ° C is preferred. That is, it is preferable that the glass transition temperature (Tg) of the retardation expression layer 242 and the glass transition temperature (Tg) of the first acrylic resin layer 241 and the second acrylic resin layer 243 do not overlap, and the retardation expression is 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 thickness of each of the first acrylic resin layer 241 and the second acrylic resin layer 243 is 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 is ignored. Can. 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 side of the second pressure-sensitive adhesive layer 26 in the first retardation plate 24 may be subjected to surface treatment such as 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 stretching may be performed so as to obtain a desired retardation value. In addition to the above method, after producing single-layer films (retardation layer 242, first acrylic resin layer 241 and second acrylic resin layer 243), they are 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 preferably 15 to 30 μm.

  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 also in this case, the pressure-sensitive adhesive layer 1 corresponds to the first acrylic resin layer 241. The adhesive power is high, and therefore, the pressure-sensitive adhesive layer-carrying optical film 10B is excellent in durability even under high temperature conditions, wet heat conditions, heat shock conditions, and the like.

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

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

  The cyclic olefin resin may or may not have a norbornane ring in its constituent unit. As a norbornene-based monomer which forms a cyclic olefin-based resin not having a norbornane ring in a constituent unit, for example, one which becomes a 5-membered ring by ring opening, typically norbornene, dicyclopentadiene, 1- or 4- Methyl norbornene, 4-phenyl norbornene, etc. are mentioned. When the cyclic olefin resin is a copolymer, the arrangement state of its molecules is not particularly limited, and it may be a random copolymer or a block copolymer, or a graft copolymer It may be a polymer.

  More specific examples of cyclic olefin-based resins include, for example, ring-opening polymers of norbornene-based monomers, ring-opening copolymers of norbornene-based monomers and other monomers, and addition of maleic acid and cyclopentadiene thereto. The modified polymers, polymers or copolymers obtained by hydrogenating them, addition polymers of norbornene monomers, addition copolymers of norbornene monomers and other monomers, and the like can be mentioned. As another monomer in the case of making it into a copolymer, (alpha) -olefins, cycloalkenes, nonconjugated dienes etc. are mentioned. The cyclic olefin resin may be a copolymer using one or more of a norbornene monomer and another alicyclic olefin.

  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 form a retardation plate, and in addition to stretching, a shrinkable film having a predetermined shrinkage ratio is attached and heat shrinkage treatment is performed, The retardation plate may have high uniformity and a large retardation value.

  As commercially available products of cyclic olefin resins using norbornene monomers, “Zeonex” and “Zeonor” sold by Nippon Zeon Co., Ltd., and “JSR Co., Ltd.” are all commercially available under the trade names. Arton etc. Films of these cyclic olefin resins and stretched films thereof can also be obtained as commercial products. For example, "Zeonor Film" sold by Nippon Zeon Co., Ltd. under the trade name, JSR Co., Ltd. There are "Arton film" sold and "essina" sold by Sekisui Chemical Co., Ltd.

  Further, as the second retardation plate 25, 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 can also be used. For example, as mixed resin containing 2 or more types of olefin resin, the mixture of the above cyclic olefin resin and chain | strand-shaped aliphatic olefin resin can be mentioned. In the case of using a mixed resin of an olefin resin and another thermoplastic resin, the other thermoplastic resin is appropriately selected depending on the purpose. Specific examples thereof include polyvinyl chloride resins, cellulose resins, polystyrene resins, acrylonitrile / butadiene / styrene copolymer resins, acrylonitrile / styrene copolymer resins, (meth) acrylic resins, polyvinyl acetate resins, and polychlorinated resins. Vinylidene resin, polyamide resin, polyacetal resin, polycarbonate resin, modified polyphenylene ether resin, polybutylene terephthalate resin, polyethylene terephthalate resin, polyphenylene sulfide resin, polysulfone resin, polyether sulfone resin, polyether Ether ketone resin, polyarylate resin, liquid crystalline resin, polyamide imide resin, polyimide resin, polytetrafluoroethylene resin, etc. may be mentioned. The thermoplastic resins can be used alone or in combination of two or more. The thermoplastic resin can also be used after any suitable polymer modification. Examples of the polymer modification include copolymerization, crosslinking, molecular end modification, stereoregularization and the like.

  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, preferably about 40% by mass or less, based on the entire resin. By setting the content of the other thermoplastic resin in this range, a retardation plate having a small absolute value of photoelastic coefficient, exhibiting good wavelength dispersion characteristics, and being excellent in durability, mechanical strength and transparency You can get

  The olefin resin can be formed into a film by a casting method from a solution, a melt extrusion method, or the like. When forming a film from two or more types 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 a resin component with a solvent at a predetermined ratio. The method of producing, the method of melt-mixing the resin component in a predetermined ratio, and the method of producing a film by the melt-extrusion method are adopted.

  The film made of the above-mentioned olefin resin may contain other components such as a residual solvent, a stabilizer, a plasticizer, an antiaging agent, an antistatic agent, and an ultraviolet light absorber as required. Moreover, in order to reduce surface roughness, it can also contain a leveling agent.

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

The second retardation plate 25 has refractive indices n _x , n _y and n _z in the in-plane slow axis direction, in-plane phase advance axis direction and thickness direction, respectively, and the film thickness is d. Formula (1):
R _e = (n _x −n _y ) × d (1)
The in-plane retardation value R _e at a wavelength of 590 nm defined by is 30 to 150 nm, and the following formula (2):
Nz factor _{= (n x -n z) /} (n x -n y) (2)
It is preferable that the Nz coefficient defined by is have 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, or sequential biaxial stretching of the film made of the above-mentioned olefin resin. In addition to appropriately adjusting the draw ratio and the draw speed, the desired refractive index difference can be obtained by appropriately selecting various temperatures such as the preheating temperature, the draw temperature, the heat setting temperature, the cooling temperature, and the like. You can get the 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, which may be a curable pressure-sensitive adhesive, or non-curable. The pressure-sensitive adhesive may be used, but it is preferable to use an active energy ray-curable pressure-sensitive adhesive from the viewpoint of suppressing dimensional change and the like due to heat contraction of the polarizing plate.

  The active energy ray-curable pressure-sensitive adhesive may be based on a polymer having an active energy ray-curable property, or a polymer having no active energy ray-curable property, an active energy ray-curable polyfunctional monomer, It may be based on a mixture with / or an oligomer. Alternatively, 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 a multifunctional monomer curable with active energy ray, and / Or a mixture with an oligomer, or a mixture of the three.

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

  As a polymer which does not have active energy ray curability, the (meth) acrylic acid ester polymer which does not have an active energy ray curable group (Hereinafter, it may be called "(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 of an alkyl group as a monomer constituting the polymer. Thereby, the obtained adhesive can express desirable adhesiveness. Moreover, the (meth) acrylic acid ester polymer (X) is an alkyl group having a carbon number of 1 to 20 (meth) acrylic acid alkyl ester, and a monomer having a reactive functional group (reactive functional group-containing monomer) It is particularly preferable that the copolymer is a copolymer with any other monomer optionally used. When the (meth) acrylic acid ester polymer (X) contains a reactive functional group-containing monomer as a monomer constituting the polymer, adhesion to a glass surface such as a liquid crystal cell can be improved, Moreover, it can also react with the crosslinking agent (Z) mentioned later, and can also form a crosslinked structure.

  Examples of the (meth) acrylic acid alkyl ester having 1 to 20 carbon atoms in the alkyl group include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate and n- (meth) acrylate Butyl, n-pentyl (meth) acrylate, n-hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, n-decyl (meth) acrylate, (meth) acrylate n-dodecyl, myristyl (meth) acrylate, palmityl (meth) acrylate, stearyl (meth) acrylate and the like can be mentioned. Among them, from the viewpoint of further improving the adhesiveness, (meth) acrylic acid ester having 1 to 8 carbon atoms in the alkyl group is preferable, and n-butyl (meth) acrylic acid is particularly preferable. These may be used alone or in combination of two or more.

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

  As said reactive functional group containing monomer, the monomer which has a hydroxyl group in a molecule (hydroxyl group containing monomer), the monomer which has a carboxyl group in a molecule (carboxyl group containing monomer), the monomer which has an amino group in a molecule (amino group containing) Monomers are preferably mentioned. 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 (iii) hydroxyalkyl esters of (meth) acrylic acid such as 3-hydroxybutyl acrylate and 4-hydroxybutyl (meth) acrylate.

  Examples of the carboxyl group-containing monomer include ethylenic unsaturated carboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, itaconic acid and citraconic acid. Among them, acrylic acid is preferable from the viewpoint of the reactivity of the carboxyl group in the obtained (meth) acrylic acid ester polymer (X) with the crosslinking agent (Z) 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 and n-butylaminoethyl (meth) acrylate. 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, and particularly preferably 1 to 20% by mass of a reactive functional group-containing monomer as a monomer unit constituting the polymer. Is more preferable, and further preferably 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 further 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 combining 2 or more types.

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

  As a polyfunctional acrylate monomer having a molecular weight of 1000 or less, for example, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, polyethylene glycol di (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 types such as phosphoric acid di (meth) acrylate, di (acryloxyethyl) isocyanurate, allylated cyclohexyl di (meth) acrylate, etc .; trimethylolpropane tri (meth) acrylate To, 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 type such as isocyanurate, ε-caprolactone modified tris- (2- (meth) acryloxyethyl) isocyanurate; tetrafunctional type such as diglycerin tetra (meth) acrylate or pentaerythritol tetra (meth) acrylate; propionic acid Pentafunctional type such as modified dipentaerythritol penta (meth) acrylate; dipentaerythritol hexa (meth) acrylate, caprolactone modified dipentaerythritol hexa (meth) acrolein 6-functional type such as G. One of these may be used alone, or two or more of these may be used in combination.

  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) And preferably 10 to 20 parts by mass.

  The active energy ray-curable pressure-sensitive adhesive also preferably contains a crosslinking agent (Z). When the active energy ray-curable pressure-sensitive adhesive contains a (meth) acrylic acid ester polymer (X) containing a reactive functional group-containing monomer as a monomer unit constituting a polymer, and a crosslinking agent (Z), When the adhesive is heated or the like, 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). As a result, a structure in which the (meth) acrylic acid ester polymer (X) is crosslinked by the crosslinking agent (Z) is formed, and the cohesion of the obtained adhesive is improved.

  The crosslinking agent (Z) may be any one that reacts with the reactive functional group possessed by the (meth) acrylic acid ester polymer (X). For example, an isocyanate crosslinking agent, an epoxy crosslinking agent, an amine crosslinking agent Melamine based crosslinking agent, Aziridine based crosslinking agent, Hydrazine based crosslinking agent, Aldehyde based crosslinking agent, Alkaline based crosslinking agent, Metal alkoxide based crosslinking agent, Metal chelate based crosslinking agent, Metal salt based crosslinking agent, Ammonium salt based crosslinking agent, etc. Can be 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, and particularly preferably 0.05 to 5 parts by mass, with respect to 100 parts by mass of the (meth) acrylic acid ester polymer (X). And preferably 0.1 to 1 part by mass.

  The above-mentioned active energy ray-curable pressure-sensitive adhesive optionally contains various additives such as a photopolymerization initiator, a silane coupling agent, a refractive index regulator, an antistatic agent, a tackifier, an antioxidant, an ultraviolet absorber, light Stabilizers, softeners, fillers and the like may be contained.

  When using an ultraviolet-ray as an active energy ray which hardens the said active energy ray curable adhesive, it is preferable that the said active energy ray curable adhesive contains a photoinitiator.

  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'-diethylamide Benzophenone, dichlorobenzophenone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 2-aminoanthraquinone, 2-methylthioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2 2,4-diethylthioxanthone, benzyl dimethyl ketal, acetophenone dimethyl ketal, p-dimethylaminobenzoic acid ester, oligo [2-hydroxy-2-methyl-1 [4- (1-methylvinyl) phenyl] propanone], 2,4 And 6-trimethylbenzoyl-diphenyl-phosphine oxide. These may be used alone or in combination of two or more.

  The photopolymerization initiator is used in an amount of 0.1 to 20 parts by mass, in particular 1 to 12 parts by mass, per 100 parts by mass of the active energy ray-curable compound (Y) in the active energy ray-curable adhesive It is preferable to be used in

  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 an organosilicon compound having at least one alkoxysilyl group in the molecule, which is preferably compatible with the adhesive component and has light transmittance.

  As such a silane coupling agent, for example, in addition to the above-mentioned epoxy group-containing silane coupling agent (C1) and mercapto group-containing silane coupling agent (C2), vinyltrimethoxysilane, vinyltriethoxysilane, methacryloxypropyltritriol 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-isocyanatepropyltriethoxysilane, or at least one of these, methyltriethoxysilane, ethyltriethoxysilane, methyltrimethoxysilane Emissions, such as condensation products of alkyl group-containing silicon compounds such as ethyl trimethoxysilane. One of these may be used alone, or two or more of these may be used in combination.

  The content of the silane coupling agent is preferably 0.01 to 10 parts by mass, and 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 more preferable that it is 0.1-1 mass part further.

  In addition, the polymer which has the said active energy ray curability is a (meth) acrylic acid ester (co) polymer in which the functional group (active energy ray curable group) which has active energy ray curability in the side chain was introduce | transduced Is preferred.

  The thickness of the second pressure-sensitive adhesive layer 26 is usually about 1 to 50 μm, preferably 1 to 20 μm, and particularly preferably 2 to 7 μm. When the pressure-sensitive adhesive layer is too thin, the tackiness is lowered, and when it is too thick, the pressure-sensitive adhesive is liable to cause problems such as extrusion.

(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 the protective layer 27, the same one as the first protective layer 22 in the polarizing plate 2A can be used.

(6) Adhesive Layer The adhesive layer which 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. An adhesive layer similar to the above can be used.

(7) Manufacturing Method of Composite Polarizing Plate The manufacturing of the composite polarizing plate 2B can be performed by a usual method. Hereinafter, the manufacturing method at the time of using a water-based adhesive as said adhesive agent is demonstrated as an example.

  First, a coating film of the pressure-sensitive adhesive that constitutes the second pressure-sensitive adhesive layer 26 is formed on the release surface of the release sheet. Specifically, the coating solution of the pressure-sensitive adhesive that constitutes the second pressure-sensitive 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 surface of the second retardation plate 25 and the protective layer 27. The formation of the adhesive layer can be carried out in the same manner as in the method of manufacturing the polarizing plate 2A described above. Further, the thickness of the adhesive layer and the easy adhesion treatment are also the same.

  After 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 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, a film of the pressure-sensitive adhesive constituting the second pressure-sensitive adhesive layer 26 on the release sheet is bonded to the surface of the obtained laminate on the second retardation plate 25 side. Then, an active energy ray is irradiated through the release sheet to cure the coating of the pressure-sensitive adhesive, and the coating is used as a second pressure-sensitive adhesive layer 26.

  Here, an active energy ray means what has an energy quantum in electromagnetic waves or a charged particle beam, and an ultraviolet ray, an electron beam, etc. are specifically mentioned. Among the active energy rays, ultraviolet rays which are easy to handle are particularly preferable.

The irradiation of ultraviolet light 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 light is preferably about 50 to 1000 mW / cm ^{2 of} 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 irradiation of the electron beam can be performed by an electron beam accelerator or the like, and the irradiation dose of the electron beam is preferably about 10 to 1000 krad.

  Finally, the release sheet is peeled off 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 removed from the exposed second pressure-sensitive adhesive layer 26. Paste the side surface. Thus, a 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 Having Pressure-Sensitive Adhesive Layer As a preferable example of a method for producing optical film 10B having pressure-sensitive adhesive layer, first, a release sheet is formed on one side or both sides of the pressure-sensitive adhesive layer formed from adhesive composition P To produce a pressure-sensitive adhesive sheet. Here, as an example, a pressure-sensitive adhesive sheet formed by laminating a release sheet on both sides of a pressure-sensitive adhesive layer is manufactured. This pressure-sensitive adhesive sheet can be manufactured by the method described in the method for manufacturing the pressure-sensitive adhesive layer-carrying optical film 10A.

  One release sheet (light release type release sheet) is released from the pressure-sensitive adhesive sheet obtained as described above. Then, the first retardation plate 24 of the composite polarizing plate 2B is stacked on the exposed pressure-sensitive adhesive layer, and the pressure-sensitive adhesive sheet and the composite polarizing plate 2B are pressure-bonded. Thus, the pressure-sensitive adhesive layer-carrying optical film 10B (with a release sheet) is obtained.

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

3. Physical Properties of Pressure-Sensitive Adhesive Layer-Containing Optical Film The pressure-sensitive adhesive power of the pressure-sensitive adhesive layer-containing optical films 10A and 10B according to this embodiment is preferably 0.5 to 20 N / 25 mm, particularly 1 It is preferable that it is -10 N / 25 mm. As a result, the pressure-sensitive adhesive layer-carrying optical film becomes excellent in durability. Furthermore, it is preferable that the said adhesive force is 2-7 N / 25 mm from a viewpoint of making it excellent also about rework property. In addition, although the adhesive force here means the adhesive force measured by the 180 degree tearing-off method basically based on JISZ0237: 2009, a measurement sample is made into 25 mm width and 100 mm length, and the said measurement sample is adhered. After applying pressure to the body for 20 minutes at 50 ° C with 0.5MPa, it is left for 24 hours under normal pressure, 23 ° C, 50% RH, and then measured at a peeling speed of 300 mm / min. Do. When the adhesive strength is in the above range, floating or peeling can be prevented when the liquid crystal cell is attached.

  In addition, the adhesive films with adhesive layer 10A and 10B according to the present embodiment, after being attached to the adherend, are further left to stand under conditions of 23 ° C. and 50% RH for 14 days (after 14 days of attachment (Adhesive force) is preferably 1 to 20 N / 25 mm, particularly preferably 3 to 9 N / 25 mm. Thus, the pressure-sensitive adhesive layer-carrying optical films 10A and 10B according to the present embodiment are excellent in reworkability by suppressing the increase in adhesive force with time, and they are easily attached again even after being attached to a liquid crystal cell. be able to.

  In addition, the pressure-sensitive adhesive layer-attached optical films 10A and 10B according to the present embodiment have adhesion (50 ° C. 2) after being left for 2 days under the conditions of 50 ° C. and 50% RH after being attached to the adherend. The adhesion after the day is preferably 1 to 20 N / 25 mm from the viewpoint of durability, and further 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-carrying optical films 10A and 10B according to the present embodiment is preferably 1.0 × 10 ¹² Ω / sq or less, and particularly preferably 5.0 × 10 ¹¹ Ω / sq. It is preferably not more than 5.0 × 10 ¹⁰ Ω / sq. When the surface resistivity is equal to or less than the above value, sufficient antistatic performance can be exhibited in the display panel. Such surface resistivity can be achieved by the adhesive composition P containing the above-described antistatic agent (D). In addition, the measurement of the surface resistivity of an adhesive layer shall be performed according to JISK6911, and is specifically as shown to 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 the durability and the heat unevenness.

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

  Specifically, the pressure-sensitive adhesive layer of the pressure-sensitive adhesive layer-carrying optical films 10A and 10B (when the release sheet is laminated, the pressure-sensitive adhesive layer exposed by peeling the release sheet) is a desired liquid crystal cell. It may be superimposed on the surface and crimped. Thus, a liquid crystal display device provided with the liquid crystal cell and the polarizing plate 2A and / or the composite polarizing plate 2B can be obtained.

  The pressure-sensitive adhesive layer 1 of the pressure-sensitive adhesive layer-containing optical films 10A and 10B according to the present embodiment is excellent in durability, and therefore, the obtained liquid crystal display is a pressure-sensitive adhesive even under high temperature conditions, wet heat conditions or heat shock. The occurrence of floating or peeling at the interface of layer 1 is suppressed. For example, when a glass plate to which the optical film 10A or 10B attached with an adhesive layer is attached under high temperature conditions of 85 ° C. or moist heat conditions of 60 ° C./90% RH for 250 hours, or heat of -35 ° C. to 70 ° C. Even when shocks (30 minutes each, 200 cycles) are given, the occurrence of floating or peeling is suppressed.

  In addition, since the pressure-sensitive adhesive layer 1 of the pressure-sensitive adhesive layer-containing optical films 10A and 10B according to the present embodiment is excellent in stress relaxation property, the obtained liquid crystal display device is hardly warped even under high temperature conditions, and further thermal unevenness Is less likely to occur. For example, even when the glass plate to which the pressure-sensitive adhesive layer-attached optical films 10A and 10B are attached is subjected to high temperature conditions (for example, 80 to 85 ° C.) for 250 hours, it hardly warps, and furthermore, thermal 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 is hardly warped, and even if the liquid crystal cell is high definition, thermal unevenness hardly occurs.

  A transparent conductive film may be present on the surface of the liquid crystal cell in contact with the pressure-sensitive adhesive layer 1. 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), zinc oxide-doped oxide Materials comprising composite oxides such as indium, fluorine-doped indium oxide, antimony-doped tin oxide, fluorine-doped tin oxide, aluminum-doped zinc oxide, chalcogenides, non-oxidized compounds such as lanthanum hexaboride, titanium nitride and titanium carbide Be

  The embodiments described above are described to facilitate the understanding of the present invention, and are not described to limit the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents that fall within the technical scope of the present invention.

  Hereinafter, the present invention will be more specifically described by way of examples and the like, but the scope of the present invention is not limited to these examples and the like.

Example 1
1. Production of Optical Film (Composite Polarizing Plate) (1) Production of Polarizer A 75 μm-thick polyvinyl alcohol film made of polyvinyl alcohol having an average degree of polymerization of about 2,400 and a degree of saponification of 99.9 mol% or more The film was uniaxially stretched about 5 times and further immersed in pure water at 60 ° C. for 1 minute while maintaining tension. Thereafter, it was immersed in an aqueous solution of iodine / potassium iodide / water at a mass ratio 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, the film was washed with pure water at 26 ° C. for 20 seconds and then dried at 65 ° C. to obtain a polarizer in which iodine was adsorbed and oriented to polyvinyl alcohol.

(2) Preparation of a layered product including a protective layer, a polarizer and a second retardation plate 3 parts of carboxyl group-modified polyvinyl alcohol (trade name "KL-318" manufactured by Kuraray Co., Ltd.) per 100 parts by mass of water It dissolves in parts by mass, and a polyamide epoxy-based additive (Taoka Chemical Industry Co., Ltd., trade name "Sumirez resin 650 (30), an aqueous solution having a solid content concentration of 30% by mass) which is a water-soluble epoxy resin is dissolved in the aqueous solution. An epoxy adhesive was prepared with 1.5 parts by mass added. 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 Co., Ltd., trade name “KC2UA”) with a surface saponified on the surface is pasted as a protective layer to the coating layer of the epoxy adhesive. Then, a laminate obtained by laminating the protective layer and the 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 23 μm-thick cyclic olefin resin is formed as a second retardation plate on the coated layer. A zero retardation film (manufactured by Nippon Zeon Co., Ltd., trade name “ZEONOR”) was laminated. Thereafter, the protective layer and the second retardation plate were adhered to a polarizer by drying at 80 ° C. for 5 minutes. After bonding, it is aged at 40 ° C for 168 hours, and the total thickness of the protective layer (layer thickness 25 μm), polarizer (stretching ratio 5 times, layer thickness 15 μm) and second retardation plate (layer thickness 23 μm) laminated A 63 μm laminate was obtained.

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

  100 parts by mass of the (meth) acrylic acid ester polymer (X) and tris (acryloxyethyl) isocyanurate (trade name: “Toa Gosei Co., Ltd.” as an active energy ray-curable compound (Y) (polyfunctional monomer) Alonics M-315 ") 15 parts by mass, and 0.3 parts by mass of trimethylolpropane-modified tolylene diisocyanate (trade name" Corronate L "manufactured by Nippon Polyurethane Industry Co., Ltd.) as a crosslinking agent (Z), and a polymerization initiator 1.5 parts by mass of a mixture of benzophenone and 1-hydroxycyclohexyl phenyl ketone at a mass ratio of 1: 1 (Ciba Specialty Chemicals, trade name “IRGACURE 500”), and as a silane coupling agent, Glycidoxypropyltrimethoxysilane (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-treated surface of a release sheet (Lintech Co., Ltd., SP-PET 3811, thickness: 38 μm) obtained by release-coating one side of a polyethylene terephthalate film with a coating solution of the obtained active energy ray-curable adhesive. 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) Preparation of first retardation plate A methacrylic resin (manufactured by Sumitomo Chemical Co., Ltd.), in which about 20% by mass of acrylic rubber particles having an average particle diameter of 200 nm constituting the first acrylic resin layer is blended. A second acrylic resin layer is configured with a trade name “Technolo S 001”, a styrene-maleic anhydride copolymer resin (trade name “Dylark D332”, manufactured by Nova Chemical Co., Ltd., which constitutes a retardation expression layer, and a second acrylic resin layer. Three-layer coextrusion with a methacrylic resin (trade name “Technoloi S 001” manufactured by Sumitomo Chemical Co., Ltd., trade name “Tekunoloy S001”), which contains about 20% by mass of acrylic rubber particles having an average particle diameter of 200 nm, in a three-layer structure The laminated film of 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 layer / second acrylic resin layer) I got

(5) Preparation of composite polarizing plate The coating film of the active energy ray-curable adhesive obtained in the step (3) on the surface on the second retardation plate side in the laminate obtained in the step (2) The ultraviolet ray was irradiated under the following conditions through the above-mentioned exfoliation sheet, the coating film of the above-mentioned adhesive was hardened, and it was considered as the 2nd adhesive layer. Thereafter, the release sheet is peeled off from the obtained second pressure-sensitive adhesive layer, and the surface of the exposed second pressure-sensitive adhesive layer is removed from the second retardation plate obtained in the step (4). The surface on the acrylic resin layer side was bonded. Thus, a composite polarizing plate (optical film) with a total thickness of 93 μm was obtained by laminating the protective layer, the polarizer, the second retardation plate, the second adhesive layer and the first retardation plate. . In addition, the thickness of the formed 2nd adhesive layer was 5 micrometers.
<UV irradiation conditions>
・ Use high pressure mercury lamp ・ Illumination 300mW / cm ² , light quantity 300mJ / cm ²
・ UV illumination and light quantity meter use "UVPF-A1" made by Eye Graphics Co., Ltd.

2. Production of pressure-sensitive adhesive layer-attached optical film (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 (Meth) acrylic acid ester copolymer (A) was prepared by copolymerizing 3 parts by mass of 2-hydroxyethyl. When the molecular weight of this (meth) acrylic acid ester copolymer (A) was measured by the method mentioned later, it was a weight average molecular weight (Mw) 1.6 million. In addition, the hydroxyl value of the said (meth) acrylic acid ester copolymer (A) is calculated with 14.49 mgKOH / g, and an acid value is calculated with 0 mgKOH / g from the said mixing | blending.

(2) Preparation of adhesive composition 100 parts by mass of the (meth) acrylic acid ester copolymer (A) obtained in the above step (1) and trimethylolpropane-modified xylylene diisocyanate as a crosslinking agent (B) Mitsui Chemicals, Inc., trade name "Takenate D110N" 0.2 parts by mass, and epoxy group-containing silane coupling agent (C1), 3-glycidoxypropyltrimethoxysilane (Shin-Etsu Chemical Co., Ltd., trade name " KBM 403 ′ ′) 0.2 part by mass, as a mercapto group-containing silane coupling agent (C2), a co-condensate of 3-mercaptopropyltrimethoxysilane and methyltriethoxysilane (Shin-Etsu Chemical Co., Ltd., trade name “X -41-1810 ", mercapto equivalent: 450 g / mol) and 0.2 parts by mass, and as an antistatic agent (D), N-octyl-4-methyl ester A coating solution of a tacky composition was obtained by mixing with 2.0 parts by mass of pyridinyl hexafluorophosphate (an ionic compound solid at room temperature), thoroughly stirring and diluting with ethyl acetate.

Here, each composition (solid content conversion value) of the adhesive composition at the time of setting a (meth) acrylic acid ester copolymer (A) to 100 mass parts (solid content conversion value) is shown in Table 1. The details of the abbreviations and the like described in Table 1 are as follows.
[(Meth) acrylic acid ester copolymer]
BA: n-butyl acrylate MA: methyl acrylate HEA: 2-hydroxyethyl acrylate IBXA: isobornyl acrylate PhEA: 2-phenylethyl acrylate CHA: cyclohexyl acrylate
[Isocyanate Crosslinker]
XDI: trimethylolpropane modified xylylene diisocyanate (manufactured by Mitsui Chemicals, Inc., trade name "Takenate D110N")
[Antistatic agent]
Pry + PF6-: N-octyl-4-methylpyridinium hexafluorophosphate (an ionic compound solid at room temperature)

(3) Preparation of pressure-sensitive adhesive layer-carrying optical film A release sheet (SP-PET 3811, manufactured by Lintec Corp., having a coating solution of the obtained adhesive composition peeled off with a silicone release agent on one side of a polyethylene terephthalate film). The composition was applied to a release-treated surface of 38 μm) with a knife coater and then heat-treated at 90 ° C. for 1 minute to form a coating of an adhesive composition.

  Then, 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, By curing for 7 days at 23 ° C. and 50% RH, an adhesive film with an adhesive layer was obtained, in which an adhesive layer was formed on the composite polarizing plate. The thickness of the formed pressure-sensitive adhesive layer (first pressure-sensitive adhesive layer) was 20 μm.

[Examples 2 to 13, Comparative Examples 1 to 2]
The types and proportions of the respective monomers constituting the (meth) acrylic acid ester copolymer (A), the weight average molecular weight of the (meth) acrylic acid ester copolymer (A), and the blending amount of the crosslinking agent (B) are shown in the table. A pressure-sensitive adhesive layer-carrying optical film was produced in the same manner as in Example 1 except for changing as shown in 1.

[Reference Example 1]
(1) Preparation of Polarizer A 75 μm-thick polyvinyl alcohol film consisting of polyvinyl alcohol having an average degree of polymerization of about 2,400 and a degree of saponification of 99.9 mol% or more is uniaxially stretched about 3 times in a dry state, While maintaining tension, it was immersed in pure water at 60 ° C. for 1 minute. Thereafter, it was immersed in an aqueous solution of iodine / potassium iodide / water at a mass ratio 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, the film was washed with pure water at 26 ° C. for 20 seconds and then dried at 65 ° C. to obtain a polarizer in which iodine was adsorbed and oriented to polyvinyl alcohol.

(2) Preparation of polarizing plate 3 parts by mass of carboxyl group-modified polyvinyl alcohol (manufactured by Kuraray Co., Ltd., trade name "KL-318") is dissolved in 100 parts by mass of water, and it is a water-soluble epoxy resin in its aqueous solution An epoxy-based adhesive was prepared by adding 1.5 parts by mass of a polyamide epoxy-based additive (product of Taoka Chemical Industry Co., Ltd., trade name “Sumilase resin 650 (30), solid content concentration of 30% by mass). . The said epoxy-type adhesive agent was apply | coated to one side of the polarizer obtained above.

  An 80 μm thick triacetyl cellulose film (Konica Minolta Opto Co., Ltd. product name, “KC8UYW”) having a surface treated with a saponification treatment as a first protective layer for the coating layer of the epoxy adhesive described above Pasted together. Similarly, as the second protective layer, an 80 μm thick triacetyl cellulose film (Konica Minolta Opto Co., Ltd., trade name “KC8UYW”) was bonded to the other surface of the polarizer.

  Then, the first protective layer and the second protective layer were adhered to the polarizer by drying at 80 ° C. for 5 minutes. After bonding, it is aged at 40 ° C for 168 hours, and a first protective layer (layer thickness 80 μm), a polarizer (stretching ratio 3 times, layer thickness 25 μm) and a second protective layer (layer thickness 80 μm) are laminated. A polarizing plate with a total thickness of 185 μm was obtained.

  Then, in the same manner as in Comparative Example 1, a pressure-sensitive adhesive layer was formed on one surface of the polarizing plate obtained in the above step. Thereby, the optical film with an adhesive layer which the surface which contact | connects an adhesive layer becomes from triacetyl cellulose was obtained.

Here, the weight average molecular weight (Mw) mentioned above is a weight average molecular weight of polystyrene conversion measured (GPC measurement) on the following conditions using gel permeation chromatography (GPC).
<Measurement conditions>
・ GPC measuring apparatus: Tosoh Corp. HLC-8020
・ GPC column (pass in the following order): Tosoh TSK guard column HXL-H
TSK gel GMHXL (x 2)
TSK gel G2000HXL
・ Measurement solvent: Tetrahydrofuran ・ Measurement temperature: 40 ° C

Test Example 1 (Measurement of Gel Fraction)
A release sheet (Lintech Co., Ltd., SP-) in which one side of a polyethylene terephthalate film is release-treated with a silicone release agent instead of the optical film used for producing the optical film with an adhesive layer in Examples, Comparative Examples and Reference Examples. A pressure-sensitive adhesive sheet was produced using PET 3801, thickness: 38 μm). Specifically, the release-treated side of the release sheet is in contact with the exposed coating film of the structure of the release sheet / adhesive composition obtained in the production process of the example or the comparative example. It was laminated as such and aged for 7 days under conditions of 23 ° C. and 50% RH. Thereby, the adhesive sheet which consists of a structure of a peeling sheet (SP-PET3801) / adhesive layer (thickness: 20 micrometers) / peeling sheet (SP-PET 3811) was produced.

  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 by a precision balance, and the mass of the mesh alone is subtracted The mass of only the adhesive was calculated by The mass at this time is M1.

  Next, the adhesive wrapped in the polyester mesh was immersed in ethyl acetate for 24 hours at room temperature (23 ° C.). After that, the adhesive was taken out, air-dried for 24 hours under an environment of temperature 23 ° C. and relative humidity 50%, and further dried for 12 hours in an oven at 80 ° C. After drying, the mass was weighed using a precision balance, and the mass of the 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 pressure-sensitive adhesive layer-carrying optical films obtained in Examples, Comparative Examples and Reference Examples were cut to prepare samples of 150 mm × 200 mm in size. After peeling off the release sheet from this sample and attaching it to an alkali-free glass (manufactured by Corning, Eagle XG) through the exposed pressure-sensitive adhesive layer, addition is carried out at 0.5 MPa and 50 ° C. for 20 minutes in an autoclave made by Kurihara Works. I pressed it.

After that, it was put into an environment of the following three endurance conditions, and after 250 hours, using a 10-fold loupe, the presence or absence of floating or peeling was confirmed. Evaluation criteria are as follows. The results are shown in Table 2.
◎: No floating or peeling was observed.
Good: A float or peel of a size of 0.5 mm or less was confirmed.
B: Lifting or peeling of a size of more than 0.5 mm and 1.0 mm or less was confirmed.
X: Lifting or peeling of a size of more than 1.0 mm was confirmed.
<Durability condition>
・ Heat resistant: 85 ° C dry
Humid heat: 60 ° C, relative humidity 90% RH
H. S. : Heat shock test for 30 minutes each at -35 ° C / 70 ° C, 200 cycles

[Test example 3] (warping resistance evaluation)
The pressure-sensitive adhesive layer-carrying optical films obtained in Examples, Comparative Examples and Reference Examples were cut into a length of 200 mm and a width of 150 mm. The release sheet is peeled off from the pressure-sensitive adhesive layer-attached optical film, and the exposed pressure-sensitive adhesive layer is the center of a 250 mm long, 175 mm wide, 0.5 mm thick non-alkali glass (manufactured by Corning, trade name "Eagle-XG") It stuck to a part and made this into a sample. The sample was left at 85 ° C. under a dry atmosphere for 250 hours. After that, take out under environment of 25 ° C, 50% RH, place it on the horizontal stand with the polarizing plate side up, and the amount of warpage from the stand of each corner (4 points) of the sample (distance between corner and stand) ) Was measured, and the amount of warpage of each corner was summed. Based on the results, the 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 Δ: 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 pressure-sensitive adhesive layer-carrying optical films obtained in Examples, Comparative Examples and Reference Examples were adjusted to a size of 200 mm × 150 mm using a cutting apparatus (Super Cutter, manufactured by Hino Manufacturing Co., Ltd., PN1-600). The release sheet was peeled off and attached to an alkali-free glass (manufactured by Corning, Eagle XG) through the exposed pressure-sensitive adhesive layer, and then pressurized at 0.5 MPa and 50 ° C. for 20 minutes in an autoclave made by Kurihara. The above bonding was performed on the front and back of the non-alkali glass so that the polarizing film in the pressure-sensitive adhesive layer was in a crossed Nicol state (polarization axis: ∠ 45 °, ∠ 135 °). In this state, after leaving for 250 hours in a dry environment at 80 ° C., it was left for 2 hours in an environment at 23 ° C. and 50% RH, and this was used as a sample to evaluate the heat non-uniformity resistance by the method shown below. The results are shown in Table 2.

<Evaluation method>
The above sample is placed on a flat illuminator (manufactured by Dentsu Sangyo Co., Ltd., HF-SL-A312LC, illuminance: 26,000 Lux, luminance: 10,000 cd), and a two-dimensional color luminance meter (manufactured by Konica Minolta, CA-2000) ) And converted into a luminance distribution image by analysis software (manufactured by Konica Minolta, CA-S20w). The luminance distribution image of the obtained sample was evaluated based on the evaluation criteria shown in FIG. 4 and the following.
◎: The luminance distribution is almost uniform.
○: There is a slight distortion in the luminance distribution on all sides.
Δ: There is a clear distortion in the luminance distribution on the four sides.
X: There is severe distortion in the luminance distribution on the four sides.

[Test Example 5] (Measurement of adhesive strength-evaluation of reworkability)
A sample 25 mm wide and 100 mm long is cut out from the optical film with an adhesive layer obtained in Examples, Comparative Examples and Reference Examples, the release sheet is peeled off, and non-alkali glass (Corning Co., Ltd.) via the exposed adhesive layer After sticking on a product, Eagle XG), it was pressurized at 0.5 MPa and 50 ° C. for 20 minutes with an autoclave manufactured by Kurihara Mfg. Co., Ltd. Then, after leaving it to stand for 24 hours under conditions of 23 ° C. and 50% RH, using a tensile tester (Tensilon, manufactured by Orientec Co., Ltd.), adhesive force (sticking under conditions of peeling speed 300 mm / min, peeling angle 180 ° The adhesion after 1 day; N / 25 mm) was measured. The conditions other than the conditions described here were measured in accordance with JIS Z 0237: 2009. The results are shown in Table 2.

  Furthermore, after left to stand under conditions of 23 ° C. and 50% RH for 14 days, the adhesive strength (adhesive strength 14 days after application; N / 25 mm) was measured in the same manner as described above. Separately, it was left for 2 days under the conditions of 50 ° C. and 50% RH, and the adhesion (adhesive force 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 14 days after the said sticking, rework property was evaluated by the following references | standards. The results are shown in Table 2.
:: Adhesive strength 14 days after application is 8.8 N / 25 mm or less ○: Adhesive strength 14 days after application is more than 8.8 N / 25 mm, less than 10 N / 25 mm Δ: Adhesive strength 14 days after application is 10 N / 25 mm or more, 20 N / Less than 25 mm ×: The adhesion after 14 days of application is 20 N / 25 mm or more

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

  As can be seen from Table 2, the pressure-sensitive adhesive layer-containing optical film obtained in the examples was excellent in durability, hardly warped even under high temperature, and hardly generated thermal unevenness. Moreover, the pressure-sensitive adhesive layer-attached optical film obtained in the examples had a low surface resistivity of the pressure-sensitive 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 1-12 was excellent also in rework property. On the other hand, as shown in Reference Example 1, it can be seen that there is no problem in any of the durability, the heat non-uniformity resistance and the warpage suppressing property even if the same polarizing plate as the comparative example 1 is used in the conventional polarizing plate. .

  The pressure-sensitive adhesive layer-carrying optical film according to the present invention is suitable for bonding a thin film polarizing plate or a composite polarizing plate with a liquid crystal cell.

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

Claims (12)

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 of the optical film in contact with the pressure-sensitive adhesive layer is made 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 a polymer,
Contains a crosslinking agent (B) ,
The adhesive composition, wherein the (meth) acrylic ester copolymer (A) contains 1 to 30% by mass of the aromatic ring-containing monomer (a2) as a monomer unit constituting the polymer. An optical film with a pressure-sensitive adhesive layer, characterized by comprising the obtained pressure-sensitive adhesive.   The pressure-sensitive adhesive layer-carrying optical film according to claim 1, wherein the outermost layer of the optical film in contact with the pressure-sensitive adhesive layer comprises an acrylic resin layer formed through extrusion.   The pressure-sensitive adhesive layer-carrying optical film according to claim 2, wherein the optical film comprises a retardation plate having at least the acrylic resin layer and a retardation expression layer.   The pressure-sensitive adhesive layer-carrying optical film according to claim 3, wherein the phase difference developing layer is made of a styrene resin.   The said phase difference plate has a 2nd acrylic resin layer in the surface side opposite to the surface by the side of the said acrylic resin layer in the said phase difference expression layer, The said Claim 3 or 4 characterized by the above-mentioned. Adhesive film with optical film.   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, It is described in any one of the Claims 3-5 characterized by the above-mentioned. Optical film with adhesive layer.   The pressure-sensitive adhesive layer-carrying optical film according to claim 6, wherein the second retardation plate is made of a cycloolefin resin.   The pressure-sensitive adhesive layer-carrying optical according to claim 6 or 7, wherein a polarizing plate is further laminated on the side opposite to the surface on the side of the retardation plate in the second retardation plate. the film. The (meth) acrylic acid ester copolymer (A) is
And a hydroxyl group-containing monomer (a3) as a monomer unit constituting the polymer.
The pressure-sensitive adhesive layer-carrying optical film according to any one of claims 1 to 8, which has a hydroxyl value of 5 to 20 mg KOH / g.   The pressure-sensitive adhesive layer-carrying optical film according to any one of claims 1 to 9, wherein the crosslinking agent (B) is an isocyanate-based crosslinking agent.   The pressure-sensitive adhesive layer-carrying optical film according to any one of claims 1 to 10, wherein the pressure-sensitive adhesive composition further contains a silane coupling agent (C).   The pressure-sensitive adhesive layer-carrying optical film according to any one of claims 1 to 11, wherein the pressure-sensitive adhesive composition further contains an antistatic agent (D).

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