KR20160107114A - Polarizing plate with adhesive layer - Google Patents

Abstract

Provide is a polarizing plate having an adhesive layer, which can have excellent durability even when the polarizing plate is a thin film, can prevent a display panel from being bent, and can prevent cracks from being generated due to heat. A polarizing plate (10A) having an adhesive layer (1) comprises: a polarizer (21); a first protective layer (22) stacked on one surface of the polarizer (21); a second protective layer (23) stacked on the other surface of the polarizer (21); and the adhesive layer (1) stacked on the surface opposite to the surface of the polarizer (21) on which the second protective layer (23) is stacked. The adhesive layer (1) contains, in monomer units forming a polymer, an alicyclic structure-containing monomer (a1), an aromatic ring-containing monomer (a2), and a hydroxyl group-containing monomer (a3). The adhesive layer (1) includes an adhesive obtained from a composition containing a (meth)acrylic acid ester copolymer (A) having a hydroxyl group value of 5 to 20 mgKOH/g, an acid value of less than or equal to 5 mgKOH/g, and a weight average molecular weight of 1,300,000 to 3,000,000, and an isocyanate-based cross-linking agent (B). The adhesive has a gel fraction of 60 to 89%. The second protective layer (23) includes cycloolefin-based resin or triacetyl cellulose. The thickness of the polarizer (21) is 1 to 20 m. The thickness of the second protective layer (23) is 5 to 30 m. A ratio of the thickness of the second protective layer (23) to the thickness of the polarizer (21) is 1.0 to 5.0.

Description

POLARIZING PLATE WITH ADHESIVE LAYER [0002]

The present invention relates to a polarizer plate with a pressure-sensitive adhesive layer.

2. Description of the Related Art Recently, a touch panel serving as both a display device and an input means has been widely used as a display panel of various electronic apparatuses. The types of touch panels are mainly resistive, capacitive, optical and ultrasonic. Resistive type is analog resistive type and matrix resistive type. Capacitive type is surface type and projection type.

BACKGROUND ART [0002] In a touch panel in a mobile electronic device such as a smart phone or a tablet terminal, which has recently attracted attention, a projection type capacitance type is widely used. As a projection type capacitive touch panel in such a mobile electronic device, for example, a liquid crystal display (LCD), a pressure sensitive adhesive layer, a transparent conductive film (tin-doped indium oxide: ITO) A transparent conductive film (ITO), and a protective plate such as tempered glass are stacked.

As an optical component constituting the liquid crystal display device, a liquid crystal cell is generally used. In the liquid crystal cell, the alignment layers of the two transparent electrode substrates on which the alignment layers are formed are arranged in the inner side, spaced apart from each other by a spacer, and the periphery thereof is sealed to form a liquid crystal material . Usually, a polarizing plate is adhered to the outside of two transparent electrode substrates in a liquid crystal cell through a pressure-sensitive adhesive.

As an optical pressure-sensitive adhesive, for example, one disclosed in Patent Document 1 is known. The pressure-sensitive adhesive is preferably a (meth) acrylic polymer comprising, as a monomer unit, 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, 0.02 to 2 parts by mass of peroxide and 0.005 to 5 parts by mass of an epoxy cross-linking agent as a cross-linking agent relative to 100 parts by mass of the (meth) acryl-based polymer.

Patent Document 1: JP-A-2009-242786

Here, in accordance with the recent demand for thinning of mobile electronic devices, it is required to make the polarizing plate thinner. However, since the polarizing plate of the thin film has a high shrinkage rate due to heat and the like, the conventional pressure sensitive adhesive such as Patent Document 1 causes a problem that the display panel is warped, and under the high temperature condition or the moist heat condition, . Further, when a monomer having a high glass transition point (Tg) is copolymerized as a component of the (meth) acryl-based polymer in order to improve the durability of the pressure-sensitive adhesive, a large shrinkage stress occurs under high temperature conditions, and the warpage of the display panel is increased. Further, it is pointed out that there is a problem that light leakage (so-called thermal unevenness) due to displacement of the optical axis of the polarizing plate occurs due to stress at the time of heat shrinkage of the polarizing plate.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described circumstances, and it is an object of the present invention to provide a polarizing plate with a pressure-sensitive adhesive layer which is excellent in durability even when a polarizing plate is a thin film,

In order to achieve the above object, first, the present invention provides a polarizing element comprising a polarizer, a first protective layer laminated on one surface side of the polarizer, a second protective layer laminated on the other surface side of the polarizer, And a pressure-sensitive adhesive layer laminated on a side of the protective layer opposite to the polarizer side, wherein the pressure-sensitive adhesive layer comprises a monomer (a1) having an alicyclic structure as a monomer unit constituting the polymer, , An aromatic ring-containing monomer (a2), and a hydroxyl group-containing monomer (a3) and having a hydroxyl value of 5 to 20 mgKOH / g, an acid value of 5 mgKOH / g or less and a weight average molecular weight of 1.3 to 3 million (A) and an isocyanate-based crosslinking agent (B), and the second protective layer is composed of a cycloolefin-based resin or an isocyanate-based crosslinking agent Triacetyl Wherein the thickness of the polarizer is 1 to 20 占 퐉, the thickness of the second protective layer is 5 to 30 占 퐉, and the ratio of the thickness of the second protective layer to the thickness of the polarizer is 1.0 to 5.0 (Invention 1).

According to the polarizing plate with a pressure-sensitive adhesive layer according to the invention (Invention 1), the polarizing plate is thinner than the conventional one. Nevertheless, when the polarizing plate with a pressure-sensitive adhesive layer is applied to a display panel, the polarizing plate with the pressure-sensitive adhesive layer has excellent durability, the display panel does not bend well, and heat unevenness does not occur easily.

In the above invention (Invention 1), the thickness of the first protective layer is preferably 5 to 120 탆, and the ratio of the thickness of the first protective layer to the thickness of the polarizer is preferably 1.0 to 6.0 (Invention 2) .

In the above invention (Invention 1 or 2), it is preferable that the first protective layer is made of triacetylcellulose (Invention 3).

In the above invention (Invention 1 to 3), it is preferable that the alicyclic structure in the alicyclic structure-containing monomer (a1) is a polycyclic alicyclic structure (Invention 4).

In the above invention (Invention 1 to 4), it is preferable that the adhesive composition further contains an epoxy group-containing silane coupling agent (Cl) (Invention 5).

In the above invention (Inventions 1 to 5), it is preferable that the adhesive composition further contains a mercapto group-containing silane coupling agent (C2) (Invention 6).

In the above invention (Invention 1 to 6), it is preferable that the adhesive composition further contains an antistatic agent (D) (Invention 7).

In the above invention (invention 7), it is preferable that the antistatic agent (D) is an ionic compound composed of a nitrogen-containing heterocyclic cation and a halogenated phosphoric acid anion as a solid at room temperature (invention 8).

In the above invention (Invention 1 to 8), it is preferable that the isocyanate crosslinking agent (B) is a compound having an aromatic ring (Invention 9).

In the above invention (Invention 1 to 9), it is preferable that the (meth) acrylic acid ester copolymer (A) does not contain a carboxyl group-containing monomer as a monomer unit constituting the polymer (invention 10).

In the above invention (Invention 1 to 10), the (meth) acrylic acid ester copolymer (A) contains 1 to 40 mass% of the alicyclic structure-containing monomer (a1) as a monomer unit constituting the polymer (Invention 11).

In the above invention (Invention 1 to 11), the (meth) acrylic acid ester copolymer (A) preferably contains 1 to 40 mass% of the aromatic ring-containing monomer (a2) as a monomer unit constituting the polymer (Invention 12).

In the above invention (Invention 1 to 12), the (meth) acrylic acid ester copolymer (A) preferably contains 0.5 to 10 mass% of the hydroxyl group-containing monomer (a3) as the monomer unit constituting the polymer (Invention 13).

In the invention (Invention 1 to 13), the surface resistivity of the pressure-sensitive adhesive layer is preferably 1.0 × 10 ¹² Ω / sq or less (Invention 14).

According to the polarizing plate with a pressure-sensitive adhesive layer according to the present invention, even if the polarizing plate is a thin film, durability is excellent, the display panel does not bend well, and thermal unevenness does not occur easily.

1 is a cross-sectional view of a polarizing plate with a pressure-sensitive adhesive layer according to a first embodiment of the present invention.
2 is a cross-sectional view of a polarizing plate with a pressure-sensitive adhesive layer according to a second embodiment of the present invention.
3 is a cross-sectional view showing a configuration example of a retardation plate.
4 is a drawing (color) showing evaluation criteria of a heat resistance non-uniformity test (visual observation) in a polarizer with a pressure-sensitive adhesive layer.

Hereinafter, an embodiment of the present invention will be described.

[First Embodiment]

1, the polarizer 10A with a pressure-sensitive adhesive layer according to the first embodiment of the present invention comprises a polarizer 21 and a first polarizer 21 laminated on one side (upper side in Fig. 1) of the polarizer 21, A second protective layer 23 laminated on the other surface side (lower side in Fig. 1) of the polarizer 21 and a second protective layer 23 laminated on the side of the polarizer 21 in the second protective layer 23, And a pressure-sensitive adhesive layer 1 laminated on a surface side (lower side in Fig. 1) opposite to the surface. In this embodiment, the laminate of the first protective layer 22, the polarizer 21 and the second protective layer 23 constitutes the polarizing plate 2A. Although not shown, a release sheet may be laminated on the surface of the pressure-sensitive adhesive layer 1 opposite to the polarizing plate 2A side until the polarizing plate 10A with a pressure-sensitive adhesive layer is used.

The pressure-sensitive adhesive layer (1) contains a monomer unit (a1) containing an alicyclic structure, a monomer (a2) having an aromatic ring, and a hydroxyl group-containing monomer (a3) as a monomer unit constituting the polymer, (hereinafter referred to as " pressure-sensitive adhesive composition (A) ") containing an acrylic acid ester copolymer (A) having an acid value of 5 mgKOH / g or less and a weight average molecular weight of 1,300 to 3,000,000 and an isocyanate crosslinking agent Composition (P) ") having a gel fraction of 60 to 89%. In the present specification, the term "(meth) acrylate" means both of an acrylate ester and a methacrylate ester. The same is true of other similar terms.

The thickness of the polarizer 21 is 1 to 20 占 퐉, the thickness of the second protective layer 23 is 5 to 30 占 퐉, and the thickness of the second protective layer 23 is 5 to 30 占 퐉. The second protective layer 23 is made of cycloolefin resin or triacetyl cellulose. And the ratio of the thickness of the second protective layer 23 to the thickness of the polarizer 21 is 1.0 to 5.0.

In the polarizing plate 10A with a pressure-sensitive adhesive layer that satisfies the above requirements, the polarizing plate 2A is made thinner than the conventional polarizing plate 2A, and the display panel can be made thin. Nevertheless, when the polarizing plate 10A with a pressure-sensitive adhesive layer is applied to a display panel, the polarizing plate 10A with a pressure-sensitive adhesive layer is excellent in durability and can be lifted even under a high temperature condition, Peeling is suppressed. In addition, the display panel using the polarizing plate 10A with a pressure-sensitive adhesive layer does not bend well under high-temperature conditions, and heat unevenness does not occur easily.

1. Adhesive layer

(1) Properties

As described above, the hydroxyl value of the (meth) acrylic acid ester copolymer (A) contained in the adhesive composition (P) for constituting the pressure sensitive adhesive layer (1) in this embodiment is 5 to 20 mgKOH / g, The acid value is 5 mgKOH / g or less, and the weight average molecular weight is 1.3 to 3 million. The gel fraction of the pressure-sensitive adhesive obtained from the pressure-sensitive adhesive composition (P) is 60 to 89%.

When the hydroxyl group value of the (meth) acrylic acid ester copolymer (A) is less than 5 mgKOH / g, the crosslinking point is too small to lower the cohesive strength and the resulting pressure-sensitive adhesive does not exhibit excellent durability. When the hydroxyl value of the (meth) acrylic acid ester copolymer (A) is more than 20 mgKOH / g, the crosslinking point is excessively large, the resulting pressure-sensitive adhesive is not flexible and the stress relaxation property is lowered, The display panel may be warped, or heat may be uneven.

From the above viewpoints, the lower limit of the hydroxyl value of the (meth) acrylic acid ester copolymer (A) is preferably 8 mgKOH / g or more, particularly preferably 10 mgKOH / g or more. The upper limit of the hydroxyl value of the (meth) acrylic acid ester copolymer (A) is preferably 18 mgKOH / g or less, particularly preferably 16 mgKOH / g or less.

On the other hand, when the acid value of the (meth) acrylic acid ester copolymer (A) is 5 mgKOH / g or less, the object to which the adhesive is to be applied is a transparent conductive material such as tin- Even in the case of a film or a metal film, these problems due to the acid can be suppressed. In particular, when the object to be pasted is a transparent conductive film, it is possible to inhibit the transparent conductive film from being corroded or changing the resistance value of the transparent conductive film.

From the above viewpoint, the upper limit of the acid value of the (meth) acrylic acid ester copolymer (A) is preferably 2 mgKOH / g or less, particularly preferably 1 mgKOH / g or less. The lower limit of the acid value of the (meth) acrylic acid ester copolymer (A) is preferably as small as possible, and is particularly preferably 0 mgKOH / g.

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

If the weight average molecular weight of the (meth) acrylic ester copolymer (A) is less than 1.3 million, the durability of the pressure-sensitive adhesive layer (1) in this embodiment is deteriorated. When the weight average molecular weight of the (meth) acrylic acid ester copolymer (A) exceeds 3,000,000, the stress relaxation property of the pressure-sensitive adhesive layer (1) in the present embodiment is lowered and the display panel is warped under high temperature conditions Or heat unevenness occurs.

From the above viewpoints, the lower limit of the weight average molecular weight of the (meth) acrylic acid ester copolymer (A) is preferably 1.5 million or more, and particularly preferably 1.6 million or more. The upper limit of the weight average molecular weight of the (meth) acrylic acid ester copolymer (A) is preferably 2.5 million or less, and particularly preferably 1.9 million or less.

Here, the weight average molecular weight in the present specification is a value in terms of standard polystyrene measured by Gel Permeation Chromatography (GPC).

When the gel fraction of the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer (1) is less than 60%, the durability of the pressure-sensitive adhesive is deteriorated. On the other hand, if the gel fraction of the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer 1 exceeds 89%, the stress relaxation property of the pressure-sensitive adhesive layer 1 is lowered, and the display panel is warped under high temperature conditions, do.

In view of the above, the lower limit of the gel fraction of the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer (1) is preferably 65% or more, particularly preferably 70% or more. The upper limit of the gel fraction of the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer (1) is preferably 85% or less, more preferably 78% or less. The method of measuring the gel fraction of the pressure-sensitive adhesive is as shown in the test examples described later.

The pressure-sensitive adhesive layer (1) in the present embodiment preferably has a haze value (value measured in accordance with JIS K7136: 2000) of 2% or less, particularly preferably 1% or less. When the haze value is 2% or less, the transparency is extremely high and is preferable for optical use.

(2) The (meth) acrylic acid ester copolymer (A)

The (meth) acrylic acid ester copolymer (A) in the present embodiment is obtained by copolymerizing an alicyclic structure-containing monomer (a1), an aromatic ring-containing monomer (a2), and a hydroxyl group- ). By containing the alicyclic structure-containing monomer (a1) and the aromatic ring-containing monomer (a2) among these monomers, the resulting pressure-sensitive adhesive can have both appropriate cohesive force and stress relaxation property, It is possible to exhibit excellent durability, deflection suppression property and heat resistance non-uniformity when used in a display panel.

(Meth) acrylic acid ester copolymer (A) may contain, as monomer units constituting the polymer, the alicyclic structure-containing monomer (a1), the aromatic ring-containing monomer (a2) and the hydroxyl group- (Meth) acrylic acid alkyl ester having 1 to 20 carbon atoms. In addition, other monomers may be contained as desired.

(Meth) acrylic acid ester copolymer (A) can exhibit favorable tackiness by containing a (meth) acrylic acid alkyl ester having 1 to 20 carbon atoms in the alkyl group as a monomer unit constituting the polymer. 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, n-butyl (Meth) acrylate, n-hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl Myristyl, palmityl (meth) acrylate, stearyl (meth) acrylate, and the like. Among them, (meth) acrylic acid 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 from the viewpoint of further improving the tackiness. These may be used alone or in combination of two or more.

The (meth) acrylic acid ester copolymer (A) preferably contains 40 to 97.5 mass% of a (meth) acrylic acid alkyl ester having 1 to 20 carbon atoms in the alkyl group as the monomer unit constituting the polymer, By mass to 94% by mass, and more preferably 65 to 83% by mass. When the (meth) acrylic acid alkyl ester is contained in an amount of 40 mass% or more, the (meth) acrylic acid ester copolymer (A) can be given favorable tackiness. In addition, by making the (meth) acrylic acid alkyl ester 97.5% by mass or less, a desired amount of other monomer components can be introduced into the (meth) acrylic acid ester copolymer (A).

The 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 a part thereof. The alicyclic structure may be a monocyclic alicyclic structure or a multicyclic alicyclic structure such as two or three rings. From the viewpoint of making the distance between the obtained (meth) acrylic acid ester copolymer (A) appropriately and imparting stress relieving property to the pressure-sensitive adhesive, the alicyclic structure is preferably a polycyclic alicyclic structure desirable. In consideration of compatibility of the (meth) acrylic acid ester copolymer (A) with other components, it is particularly preferable that the above-mentioned polycyclic structure is 2 to 4 rings. Also, from the viewpoint of imparting stress relaxation property as described above, the number of carbon atoms of the alicyclic structure (the total number of carbon atoms in the part forming the ring, when plural rings are present independently, refers to the total number of carbon atoms) , Usually 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 from the viewpoint of compatibility as described above, it is preferably 15 or less, and particularly preferably 10 or less.

Examples of the alicyclic structure include a cyclohexyl skeleton, a dicyclopentadiene skeleton, an adamantane skeleton, an isobornyl skeleton, a cycloalkane skeleton (a cycloheptane skeleton, a cyclooctane skeleton, a cyclononane skeleton, a cyclodecane skeleton, Cyclopentene skeleton, cyclohexene skeleton, cyclododecane skeleton, etc.), cycloalkene skeleton (cycloheptene skeleton, cyclooctene skeleton, etc.), norbornene skeleton, norbornadiene skeleton, cubhenain skeleton, (10 carbon atoms in the alicyclic structure), an adamantane skeleton (the number of carbon atoms in the alicyclic structure: 10), or a dicyclopentadiene skeleton An isobornyl skeleton (the number of carbon atoms in the alicyclic structure: 7), and particularly preferably an isobornyl skeleton.

As the alicyclic structure-containing monomer (a1), a (meth) acrylic acid ester monomer containing the above skeleton is preferable. Specific examples thereof include cyclohexyl (meth) acrylate, dicyclopentanyl (meth) acrylate, (Meth) acrylate dicyclopentenyl acrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, and the like. Among them, Dicyclopentanyl acrylate, adamantyl (meth) acrylate or isobornyl (meth) acrylate is preferable, and isobornyl (meth) acrylate is particularly preferable. These may be used singly or in combination of two or more kinds.

(Meth) acrylic acid ester copolymer (A) is preferably a monomer having an alicyclic structure (a1) as a monomer unit constituting the polymer from the viewpoint of exhibiting excellent durability, flexural inhibition property and heat resistance non- By mass, more preferably from 2 to 30% by mass, and particularly preferably from 3 to 20% by mass. In addition to the above viewpoints, it is more preferable that the obtained pressure-sensitive adhesive contains 2 to 15 mass%, particularly 3 to 9 mass%, of the alicyclic structure-containing monomer (a1) desirable.

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

Examples of the aromatic ring-containing monomer (a2) include phenyl (meth) acrylate, 2-phenylethyl (meth) acrylate, benzyl (meth) acrylate, naphthyl (meth) acrylate, phenoxyethyl (Meth) acrylate, phenoxydiethylene glycol (meth) acrylate, ethylene oxide modified cresol (meth) acrylate, ethylene oxide (EO) modified nonylphenol (meth) acrylate, etc. Among them, 2-phenylethyl (meth) acrylate is preferable in terms of improving the cohesion. These may be used alone or in combination of two or more.

(Meth) acrylic acid ester copolymer (A) preferably contains 1 to 40 mass% of the aromatic ring-containing monomer (a2) as a monomer unit constituting the polymer, more preferably 2 to 30 mass% By mass, particularly preferably 3 to 25% by mass, and more preferably 12 to 22% by mass. When the content of the aromatic ring-containing monomer (a2) is within the above range, the resulting pressure-sensitive adhesive can exhibit excellent durability, flexural restraining property and heat resistance non-uniformity.

(Meth) acrylic acid ester copolymer (A) contains a hydroxyl group-containing monomer (a3) as a monomer unit constituting the polymer. The hydroxyl group is highly reactive with the isocyanate group of the isocyanate crosslinking agent (B), and the (meth) acrylic acid ester copolymer (A) is crosslinked by the isocyanate crosslinking agent (B). By the crosslinking structure, the resulting pressure-sensitive adhesive is excellent in durability.

Examples of the hydroxyl group-containing monomer (a3) include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) (Meth) acrylic acid hydroxyalkyl esters such as butyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate. Among them, the reactivity with the isocyanate crosslinking agent 2-hydroxyethyl (meth) acrylate or 4-hydroxybutyl (meth) acrylate is preferable, and 2-hydroxyethyl (meth) acrylate is particularly preferable. 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 mass%, more preferably 1 to 5 mass%, of the hydroxyl group-containing monomer (a3) as the monomer unit constituting the polymer By mass, more preferably from 2 to 4% by mass. When the content of the hydroxyl group-containing monomer (a3) is within the above range, the hydroxyl value of the (meth) acrylic acid ester copolymer (A) tends to fall within the above-mentioned range and the durability, deflection suppression and heat non- .

(Meth) acrylic acid ester copolymer (A) preferably does not contain a carboxyl group-containing monomer as a monomer unit constituting the polymer in order to keep the acid value within the above-mentioned range, and even if it contains 0.5 mass% By mass, and particularly preferably 0.1% by mass or less.

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

Examples of such other monomers include non-crosslinkable acrylamides such as (meth) acrylic acid alkoxyalkyl esters such as methoxyethyl (meth) acrylate and ethoxyethyl (meth) acrylate, acrylamide and methacrylamide, (Meth) acrylate, N, N-dimethylaminoethyl, (meth) acrylic acid N, N-dimethylaminopropyl and the like. These may be used alone or in combination of two or more.

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

In the adhesive composition (P), the (meth) acrylic acid ester copolymer (A) may be used singly or in combination of two or more kinds. The adhesive composition (P) may further contain a (meth) acrylic acid ester polymer containing no alicyclic structure-containing monomer (a1), an aromatic ring-containing monomer (a2) or a hydroxyl group- do.

(3) Isocyanate Crosslinking Agent (B)

The isocyanate-based crosslinking agent (B) has an advantage of excellent reactivity with the hydroxyl group (derived from the hydroxyl group-containing monomer (a3)) of the (meth) acrylic acid ester copolymer (A).

The isocyanate-based crosslinking agent (B) comprises at least a polyisocyanate compound. Examples of the polyisocyanate compound include aromatic polyisocyanates such as tolylene diisocyanate, diphenylmethane diisocyanate and xylylene diisocyanate, aliphatic polyisocyanates such as hexamethylene diisocyanate, isophorone diisocyanate, hydrogenated diphenylmethane Alicyclic polyisocyanates such as diisocyanate and the like, and reaction products thereof with low-molecular-weight active hydrogen-containing compounds such as burette, isocyanurate and further ethylene glycol, propylene glycol, neopentyl glycol, trimethylolpropane, And a needle duct body (sometimes referred to as a " denatured body " in some cases). Among them, a compound having an aromatic ring, that is, an aromatic polyisocyanate or a modified product thereof is preferable from the viewpoint of the durability of the resulting pressure-sensitive adhesive. An aromatic compound (preferably an alkylene chain, And particularly preferably an alkylene chain of 1 to 4 carbon atoms, may be particularly preferably used), or an isocyanate group-modified isocyanate or a modified product thereof. More specifically, xylylenediisocyanate or a modified product thereof is more preferable, and trimethylolpropane-modified xylylene diisocyanate is most preferable. The isocyanate-based crosslinking agent (B) may be used singly or in combination of two or more.

The content of the isocyanate crosslinking agent (B) in the adhesive composition (P) is preferably 0.01 to 10 parts by mass, more preferably 0.05 to 5 parts by mass, per 100 parts by mass of the (meth) acrylic acid ester copolymer (A) And more preferably 0.1 to 0.4 parts by mass. When the content of the isocyanate cross-linking agent (B) is in the above range, the gel fraction of the pressure-sensitive adhesive easily falls within the above-mentioned range, and a pressure-sensitive adhesive excellent in durability, deflection suppression property and heat resistance non-uniformity tends to be obtained.

(4) Silane coupling agent (C)

The sticky composition (P) preferably contains a silane coupling agent (C) in addition to the (meth) acrylic acid ester copolymer (A) and the isocyanate crosslinking agent (B), and from the viewpoint of imparting excellent durability to the obtained pressure- Containing silane coupling agent (C1) and / or a mercapto group-containing silane coupling agent (C2), and more preferably an epoxy group-containing silane coupling agent (C1) and a mercapto group-containing silane coupling agent ). ≪ / RTI >

The epoxy group-containing silane coupling agent (C1) is preferably an organosilicon compound having at least one epoxy group (an organic group containing an epoxy group) in the molecule and at least one alkoxysilyl group, and is excellent in compatibility with a pressure- For example, substantially transparent.

Specific examples of the epoxy group-containing silane coupling agent (C1) include 3-glycidoxypropyltrialkoxysilane such as 3-glycidoxypropyltrimethoxysilane and 3-glycidoxypropyltriethoxysilane, 3- 3-glycidoxypropylalkyldialkoxysilane such as propylmethyldiethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, methyltri (glycidyl) silane, 2- (3,4-epoxycyclohexyl 2- (3,4-epoxycyclohexyl) ethyltrialkoxysilane such as ethyltrimethoxysilane and 2- (3,4-epoxycyclohexyl) ethyltriethoxysilane. Among them, from the viewpoint of further improving durability, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 2- (3,4 -Epoxycyclohexyl) ethyltrimethoxysilane is preferable, and 3-glycidoxypropyltrimethoxysilane is particularly preferable. These may be used singly or in combination of two or more kinds.

The mercapto group-containing silane coupling agent (C2) is preferably an organosilicon compound having at least one mercapto group (an organic group containing a mercapto group) and at least one alkoxysilyl group in the molecule, and has compatibility with a pressure- And it is also preferable that it has optical transparency, for example, substantially transparent.

Specific examples of the mercapto group-containing silane coupling agent (C2) include mercapto groups such as 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane and 3-mercaptopropyldimethoxymethylsilane, Containing low molecular weight silane coupling agent; A mercapto group-containing silane compound such as 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, and 3-mercaptopropyldimethoxymethylsilane, and a mercapto group-containing silane compound such as methyltriethoxysilane, ethyltriethoxysilane Containing oligomer-type silane coupling agents such as co-condensates of alkyl group-containing silane compounds such as methyltrimethoxysilane and ethyltrimethoxysilane. Among them, a mercapto group-containing oligomer-type silane coupling agent is preferable from the standpoint of achieving both durability and reworkability, and a cocondensation product of a mercapto group-containing silane compound and an alkyl group-containing silane compound is particularly preferable. - cocondensates of mercaptopropyltrimethoxysilane and methyltriethoxysilane are preferred. These may be used singly or in combination of two or more kinds.

Examples of the silane coupling agent (C) include, in addition to the epoxy group-containing silane coupling agent (C1) and the mercapto group-containing silane coupling agent (C2), an acryloyl silane coupling agent, , A carboxyl group silane coupling agent, an amino silane coupling agent, an amide silane coupling agent, and an isocyanate silane coupling agent may be used in combination.

The total content of the silane coupling agent (C) in the viscous composition (P) is preferably 0.01 to 5 parts by mass, more preferably 0.1 to 2 parts by mass, per 100 parts by mass of the (meth) acrylic acid ester copolymer (A) , More preferably from 0.2 to 1 part by mass.

The content of the epoxy group-containing silane coupling agent (C1) in the adhesive composition (P) is preferably 0.005 to 2.5 parts by mass, more preferably 0.05 to 5 parts by mass, per 100 parts by mass of the (meth) acrylic acid ester copolymer (A) 1 part by mass, more preferably 0.1 to 0.5 part by mass. On the other hand, the content of the mercapto group-containing silane coupling agent (C2) in the adhesive composition (P) is preferably 0.005 to 2.5 parts by mass relative to 100 parts by mass of the (meth) acrylic acid ester copolymer (A) It is preferably 0.05 to 1 part by mass, more preferably 0.1 to 0.5 part by mass.

(5) Antistatic agent (D)

The sticky composition (P) preferably further contains an antistatic agent (D). Since the release sheet or the polarizing plate laminated on the pressure-sensitive adhesive layer 1 is usually composed of a plastic material, the electrical insulation is high and static electricity is liable to be generated when the release sheet is peeled off. When the polarizing plate is attached to the liquid crystal cell in the state where the static electricity thus generated remains, there is a fear that the orientation of the liquid crystal molecules may be confused. In addition, the presence of the static electricity causes problems such as sucking dust and dirt. Thus, when the adhesive composition (P) contains the antistatic agent (D), the resulting pressure-sensitive adhesive (pressure-sensitive adhesive layer (1)) exhibits antistatic properties and can solve the above problems.

The antistatic agent (D) may be any one capable of imparting antistatic properties to the resulting pressure-sensitive adhesive. Examples of the antistatic agent (D) include an ionic compound and a nonionic compound. Among them, an ionic compound is preferable. The ionic compound may be a liquid at room temperature or a solid, but is preferably a solid at room temperature from the viewpoint of easily developing stable antistatic property even when exposed to the durability conditions. Herein, the ionic compound in the present specification refers to a compound in which cations and anions are mainly bonded by an electrostatic attractive force.

As the ionic compound, a nitrogen-containing onium salt, a sulfur onium salt, a zinc onium salt, an alkali metal salt and an alkaline earth metal salt are preferable, and a nitrogen-containing onium salt is particularly preferable from the viewpoint of excellent durability of the obtained pressure- The nitrogen-containing onium salt is preferably an ionic compound composed of a nitrogen-containing heterocyclic cation and a counter anion, and is preferably an ionic compound composed of a nitrogen-containing heterocyclic cation and a halogenated phosphoric anion , And more preferably an ionic compound composed of a nitrogen-containing heterocyclic cation and a halogenated phosphoric acid anion as a solid at room temperature. According to an ionic compound composed of a nitrogen-containing heterocyclic cation and a halogenated phosphoric anion as a solid at room temperature, it is possible to achieve both antistatic property and 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 or an indole ring. Of these, a pyridine ring is preferable. The halogen of the halogenated phosphoric anion is preferably fluorine, chlorine, bromine or the like, and fluorine is particularly preferable.

Specific examples of the antistatic agent (D) include N-butyl-4-methylpyridinium hexafluorophosphate, N-hexyl-4-methylpyridinium hexafluorophosphate, N-octylpyridinium hexafluorophosphate, 4-methylpyridinium hexafluorophosphate, N-dodecylpyridinium hexafluorophosphate, N-tetradecylpyridinium hexafluorophosphate, N-hexadecylpyridinium hexafluorophosphate, N -Dodecyl-4-methylpyridinium hexafluorophosphate, N-tetradecyl-4-methylpyridinium hexafluorophosphate, and N-hexadecyl-4-methylpyridinium hexafluorophosphate. Among them, from the viewpoint of compatibility with the (meth) acrylic acid ester copolymer (A), preferred are N-butyl-4-methylpyridinium hexafluorophosphate, N-hexyl-4-methylpyridinium hexafluorophosphate, -4-methylpyridinium hexafluorophosphate are preferable. 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 viscous composition (P) is preferably 0.1 to 15 parts by mass, more preferably 0.5 to 10 parts by mass, per 100 parts by mass of the (meth) acrylic acid ester copolymer (A) And further preferably 1 to 5 parts by mass. When the content of the antistatic agent (D) is within the above range, the antistatic property can be effectively exhibited and the deterioration of physical properties such as optical properties and durability can be prevented.

(6) Various additives

The pressure-sensitive adhesive composition (P) may contain various additives conventionally used in acrylic pressure-sensitive adhesives, such as a dispersant (e.g., an alkylene glycol dialkyl ether), a tackifier, an antioxidant, , A softening agent, a filler, a refractive index adjusting agent, and the like. Further, the adhesive composition (P) represents a mixture of various components remaining in the pressure-sensitive adhesive layer as it is or remains in the pressure-sensitive adhesive layer, and components such as a polymerization solvent and a diluting solvent , And is not included in the sticky composition (P).

(7) Production of sticky composition and pressure-sensitive adhesive

The sticky composition (P) can be obtained by preparing a (meth) acrylic acid ester copolymer (A) and reacting the obtained (meth) acrylic acid ester copolymer (A), an isocyanate crosslinking agent (B) and a silane coupling agent C), an antistatic agent (D), an additive, and the like.

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 as desired. As the polymerization solvent, for example, ethyl acetate, n-butyl acetate, isobutyl acetate, toluene, acetone, hexane, methyl ethyl ketone and the like may be used.

Examples of the polymerization initiator include an azo compound, an organic peroxide, and the like, and two or more types may be used in combination. Examples of the azo compound include azo compounds such as 2,2'-azobisisobutyronitrile, 2,2'-azobis (2-methylbutyronitrile), 1,1'-azobis (cyclohexane- (2,4-dimethylvaleronitrile), 2,2'-azobis (2,4-dimethyl-4-methoxy valeronitrile), dimethyl 2,2 ' Azobis (2-methylpropionate), 4,4'-azobis (4-cyanovaleric acid), 2,2'-azobis (2-hydroxymethylpropionitrile) -Azobis [2- (2-imidazolin-2-yl) propane].

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

In addition, the weight average molecular weight of the resulting polymer can be controlled by blending a chain transfer agent such as 2-mercaptoethanol in the polymerization step.

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

Examples of the diluting agent for diluting the adhesive composition (P) into a coating solution include aliphatic hydrocarbons such as hexane, heptane and cyclohexane, aromatic hydrocarbons such as toluene and xylene, halogenated compounds such as methylene chloride and ethylene chloride Alcohols such as methanol, ethanol, propanol, butanol and 1-methoxy-2-propanol; ketones such as acetone, methyl ethyl ketone, 2-pentanone, isophorone and cyclohexanone; Ester solvents, cellosolve solvents such as ethyl cellosolve, and the like.

The concentration and viscosity of the coating solution thus prepared are not particularly limited and may be appropriately selected according to the circumstances. For example, it is diluted such that the concentration of the sticky composition (P) is 10 to 40% by mass. In addition, when obtaining the coating solution, it is not necessary to add a diluting solvent or the like, and a diluting solvent may not be added if the viscosity of the adhesive composition (P) is such that it is a coating. In this case, the adhesive composition (P) becomes a coating solution containing the polymerization solvent of the (meth) acrylic acid ester copolymer (A) as it is as a diluting solvent.

The pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer (1) in the present embodiment is obtained from the pressure-sensitive adhesive composition (P), specifically, the pressure-sensitive adhesive composition (P) is crosslinked. The crosslinking of the viscous composition (P) can be carried out by a heat treatment. This heat treatment may also be used in the drying treatment for volatilizing the diluting solvent or the like of the adhesive composition (P).

When the heat treatment is carried out, the heating temperature is preferably 50 to 150 占 폚, particularly preferably 70 to 120 占 폚. The heating time is preferably 30 seconds to 10 minutes, particularly preferably 50 seconds to 2 minutes. After the heat treatment, if necessary, a curing period of about 1 to 2 weeks may be formed at room temperature (for example, 23 DEG C, 50% RH). When the curing period is necessary, after the curing period, if the curing period is not necessary, the pressure-sensitive adhesive layer (1) having a predetermined physical property is formed after the heat treatment is finished.

The (meth) acrylic acid ester copolymer (A) is crosslinked by the isocyanate crosslinking agent (B) by the above heat treatment (and curing) to form a three-dimensional mesh structure.

(8) Thickness of the pressure-sensitive adhesive layer

The thickness of the pressure-sensitive adhesive layer 1 is usually in the range of 5 to 100 占 퐉, preferably 10 to 60 占 퐉. From the viewpoint of exerting the excellent durability, the bending inhibition property and the heat resistance non-uniformity by the pressure- To 50 m, and particularly preferably 15 to 30 m.

2. Polarizer

(1) Configuration

The polarizing plate 2A in the present embodiment has a configuration in which a first protective layer 22, a polarizer 21 and a second protective layer 23 are laminated in this order as shown in Fig. By having such a configuration, the polarizing plate 2A is excellent in mechanical strength and chemical resistance. 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.

(2) 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-based resin constituting the polarizer 21 is obtained by saponifying a polyvinyl acetate-based resin. Examples of the polyvinyl acetate-based resin include polyvinyl acetate, which is a homopolymer of vinyl acetate, and copolymers of vinyl acetate and other monomers copolymerizable therewith. Examples of other monomers copolymerized with vinyl acetate include unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, and the like.

The degree of saponification of the polyvinyl alcohol-based resin is usually 85 to 100 mol%, preferably 98 to 100 mol%. The polyvinyl alcohol-based resin may also be modified. For example, polyvinyl formal or polyvinyl acetal modified with aldehydes may 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 described above is a step of uniaxially stretching a polyvinyl alcohol based resin film, a step of dying a polyvinyl alcohol type resin film with a dichroic dye, a step of adsorbing the dichroic dye, a step of dichroic dye adsorption Is subjected to a step of treating the polyvinyl alcohol-based resin film with an aqueous solution of boric acid.

The uniaxial stretching may be carried out before dyeing with a dichroic dye, or simultaneously with dyeing with a dichroic dye, or after dyeing with a dichroic dye. In the case where uniaxial stretching is carried out after dyeing with a dichroic dye, the uniaxial stretching may be carried out before the boric acid treatment or during the boric acid treatment. Of course, it is also possible to perform uniaxial stretching in these plural stages. In the case of uniaxial stretching, the uniaxial stretching may be performed between rolls having different circumferential speeds, or may be uniaxially stretched using a heat roll. In addition, it may be dry stretching in which stretching is performed in the atmosphere, or wet stretching in which stretching is performed in a state of being swollen with a solvent. The stretching magnification is usually about 4 to 8 times.

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. As the dichroic dye, iodine or a dichroic organic dye is specifically used.

When iodine is used as the dichroism dye, a method is generally employed in which a polyvinyl alcohol-based resin film is dipped in an aqueous solution containing iodine and potassium iodide for dyeing. 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. The temperature of the aqueous solution is usually about 20 to 40 占 폚, and the immersion time (dyeing time) for the aqueous solution is usually about 30 to 300 seconds.

The boric acid treatment after dyeing with the dichroic dye is carried out by immersing the dyed polyvinyl alcohol resin film in an aqueous solution of boric acid. The content of boric acid in the aqueous solution of boric acid 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, it is preferable that the aqueous solution of boric acid contains potassium iodide. The content of potassium iodide in the aqueous solution of boric acid is usually about 2 to 20 parts by mass, preferably 5 to 15 parts by mass, per 100 parts by mass of water. The immersing time in the boric acid aqueous solution is usually about 100 to 1,200 seconds, preferably about 150 to 600 seconds, more preferably about 200 to 400 seconds. The temperature of the boric acid aqueous solution is usually 50 占 폚 or higher, preferably 50 to 85 占 폚.

The polyvinyl alcohol-based resin film after treatment with boric acid is usually washed with water. The water washing treatment is carried out, for example, by immersing the 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 the water in the water washing treatment is usually about 5 to 40 캜, and the immersing time is usually about 2 to 120 seconds. The drying treatment to be performed thereafter is usually carried out using a hot-air dryer or a far-infrared heater. The drying temperature is usually 40 to 100 占 폚. The drying treatment time is usually about 120 to 600 seconds.

The thickness of the polarizer 21 in this embodiment is 1 to 20 占 퐉 and is thinner than a usual polarizer. When the thickness of the polarizer 21 is less than 1 m, sufficient polarization performance can not be exhibited. If the thickness of the polarizer 21 is more than 20 占 퐉, the display panel may have warpage or thermal non-uniformity beyond the effect of deflection suppression / heat-insulating non-uniformity by the pressure-sensitive adhesive layer (1). From this point of view, the thickness of the polarizer 21 is preferably 3 to 18 占 퐉, particularly preferably 5 to 15 占 퐉.

(3) Protective layer

The first protective layer 22 is preferably made of a transparent resin film. The transparent resin film constituting the first protective layer 22 may be a film which is not stretched or a film which is uniaxially or biaxially stretched.

The main component of the transparent resin film is preferably at least one resin selected from the group consisting of a polyester resin, a polycarbonate resin, an acrylic resin, an amorphous polyolefin resin and a cellulose resin.

The amorphous polyolefin-based resin used for the first protective layer 22 is preferably a cycloolefin-based resin. As the cycloolefin-based resin, ring-opening metathesis polymerization is carried out using, for example, cyclopentadiene and olefins, using norbornene or a derivative thereof obtained by the Diels-Alder reaction as a monomer, followed by hydrogenation A resin to be obtained; A resin obtained by carrying out ring-opening metathesis polymerization using tetracyclododecene or a derivative thereof obtained by a Diels-Alder reaction from dicyclopentadiene, olefins or methacrylic acid esters as a monomer, followed by hydrogenation; Norbornene, tetracyclododecene and derivatives thereof, and other cyclic polyolefin monomers to carry out ring-opening metathesis copolymerization, followed by hydrogenation; Norbornene, tetracyclododecene or a derivative thereof and an aromatic compound having a vinyl group. Examples of commercially available amorphous polyolefin resins include "ATON" manufactured by JSR Corporation, "ZEONEX" and "ZEONOR" manufactured by Nippon Zeon Co., Ltd., "APO" and "APEL" manufactured by Mitsui Chemicals, Inc. . When an amorphous polyolefin-based resin is formed into a film, known methods such as a solvent casting method and a melt extrusion method are suitably used for the film formation.

As the cellulose-based resin, a mixed ester in which at least a part of the hydroxyl groups in cellulose is converted into an acetic acid ester and a part thereof is converted into acetic acid ester and partly esterified with another acid may be used. The cellulose-based resin is preferably a cellulose ester-based resin, more preferably an acetylcellulose-based resin. Specific examples of the acetylcellulose-based resin include triacetylcellulose, diacetylcellulose, cellulose acetate propionate, and cellulose acetate butyrate. Examples of the commercially available film of such an acetylcellulose resin film include "Fujitak TD80", "Fujitak TD80UF", and "Fujitac TD80UZ" manufactured by Fuji Film Co., Ltd., manufactured by Konica Minolta Opto Co., KC8U2M ", " KC2UA ", and " KC8UY "

A cellulose resin film imparted with an optical compensation function may be used. Examples of such an optical compensation film include a film containing a compound having a retardation adjusting function in a cellulose resin, a film coated with a compound having a phase difference adjusting function on the surface of the cellulose resin, a cellulose resin having a single- , And the like. Examples of commercially available optical compensation films for cellulose resins include "Wide View Film WV BZ 438" and "Wide View Film WV EA" manufactured by Fuji Film Co., Ltd., "KC4FR- 1 " and " KC4HR-1 ".

The first protective layer 22 is preferably made of a cellulose resin, more preferably a cellulose ester resin, particularly preferably an acetylcellulose resin, more preferably a triacetylcellulose resin Do. Since the first protective layer 22 is made of triacetylcellulose, the resulting display panel does not bend better under high temperature conditions, and is less likely to generate heat unevenness.

The thickness of the first protective layer 22 is preferably 5 to 120 占 퐉, more preferably 10 to 120 占 퐉, particularly preferably 10 to 85 占 퐉, and still more preferably 10 to 30 占 퐉. If the thickness of the first protective layer 22 is 5 占 퐉 or more, the polarizer 21 can be sufficiently protected. If the thickness of the first protective layer 22 is 120 占 퐉 or less, the effect of suppressing the warping and the uneven heat resistance of the pressure-sensitive adhesive layer 1 is sufficiently exhibited.

The ratio of the thickness of the first protective layer 22 to the thickness of the polarizer 21 is preferably 1.0 to 6.0, more preferably 1.4 to 4.0, further preferably 1.6 to 3.8. When the ratio is within the above range, the effect of suppressing the warpage and the uneven heat resistance of the pressure-sensitive adhesive layer 1 can be sufficiently exhibited.

On the other hand, the second protective layer 23 in the present embodiment is composed of a cycloolefin resin or triacetylcellulose, and is usually composed of a cycloolefin resin or a transparent resin film containing triacetylcellulose as a main component. The transparent resin film may be a film that is not stretched or a film that is uniaxially or biaxially stretched.

The second protective layer 23 adjacent to the pressure-sensitive adhesive layer 1 is made of a cycloolefin resin or triacetylcellulose excellent in optical isotropy. Thus, the resulting polarizing plate 2A can suppress the deterioration of the optical performance to the minimum. From the standpoint of achieving thinning while maintaining optical performance, the second protective layer 23 is more preferably made of a cycloolefin-based resin.

As the cycloolefin-based resin constituting the second protective layer 23, the cycloolefin-based resin exemplified in the first protective layer 22 may be used. Among them, a dicyclopentadiene resin is preferable. As a commercially available product of such a cycloolefin-based resin, "ZEONOR" manufactured by Nippon Zeon Co., Ltd. is particularly preferable.

As a commercially available product of triacetylcellulose constituting the second protective layer 23, "KC2UA" manufactured by Konica Minolta Opto Co., Ltd. is particularly preferable.

The first protective layer 22 and the second protective layer 23 may be made of the same kind of material (transparent resin film) or different kinds of materials (transparent resin film).

The thickness of the second protective layer 23 in this embodiment is 5 to 30 占 퐉. If the thickness of the second protective layer 23 is less than 5 mu m, it is difficult to cause difficulties in the handling property of the second protective layer 23 in the manufacturing process of the polarizing plate 2A and to protect the polarizer 21 The ability also drops. If the thickness of the second protective layer 23 exceeds 30 mu m, the polarizing plate 2A obtained can not satisfy the request for thinning. From this viewpoint, the thickness of the second protective layer 23 is preferably 10 to 25 占 퐉, particularly preferably 12 to 24 占 퐉.

The ratio of the thickness of the second protective layer 23 to the thickness of the polarizer 21 is 1.0 to 5.0. If the ratio is less than 1.0, the function of maintaining the polarizer 21 against heat shrinkage becomes insufficient. If the ratio exceeds 5.0, the polarizing plate 21 can not cope with thinning of the polarizing plate 2A. From this point of view, the ratio of the thickness of the second protective layer 23 to the thickness of the polarizer 21 is preferably 1.3 to 4.0, particularly preferably 1.5 to 3.6.

The ratio of the total thickness of the first protective layer 22 and the second protective layer 23 to the thickness of the polarizer 21 is preferably 3.0 or more from the viewpoint of preventing heat shrinkage of the polarizer 21. The upper limit is not particularly limited, but it is preferable that the upper limit is about 8.0 or less, considering the request for thinning of the polarizing plate 2A.

The first protective layer 22 and the second protective layer 23 (collectively referred to as " protective layers 22 and 23 " in some cases) may contain an ultraviolet absorber. This is because the liquid crystal cell can be protected from deterioration by ultraviolet rays by disposing the protective layer containing the ultraviolet absorber on the visible side of the liquid crystal cell.

The adhesion layers may be subjected to easy adhesion treatment such as saponification treatment, corona treatment, primer treatment, and anchor coating treatment before the bonding to the polarizer 21. The surface of the protective layers 22 and 23 on the opposite side of the surface to which the polarizer 21 is adhered may have various treatment layers such as a hard coat layer, an antireflection layer, and an antiglare layer.

(4) Adhesive layer

As the adhesive constituting the 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, Accordingly, a suitably appropriate one can be used. For example, a solvent type adhesive, an emulsion type adhesive, an aqueous adhesive, a pressure-sensitive adhesive, a moisture-resisting adhesive, a polycondensation adhesive, a solventless adhesive, a film-

One preferable adhesive constituting the adhesive is an aqueous adhesive, and a typical example thereof is a polyvinyl alcohol-based resin as a main component. Commercially available polyvinyl alcohol-based resins that can be water-based adhesives include, for example, " KL-318 " manufactured by Kuraray Co.,

The aqueous adhesive may contain a crosslinking agent. As the crosslinking agent, an amine compound, an aldehyde compound, a methylol compound, an epoxy compound, an isocyanate compound, a polyvalent metal salt and the like are preferable, and an epoxy compound is particularly preferable. Commercially available products of the crosslinking agent include, for example, glyoxal and "Sumireze Resin 650 (30)" which is an aqueous solution of a water-soluble epoxy compound sold by Sumika-Chemtech.

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

From the viewpoints of weatherability, refractive index, cationic polymerization, and the like, the epoxy resin contained in the curable epoxy resin composition as the adhesive is preferably an epoxy resin which does not contain aromatic rings in the molecule. Examples of such epoxy resins include hydrogenated epoxy resins, alicyclic epoxy resins, aliphatic epoxy resins, and the like.

(5) Production method of polarizing plate

The polarizing plate 2A can be produced by a conventional method. Hereinafter, as an example, a manufacturing method in the case of using an aqueous adhesive as the adhesive will be described.

First, an adhesive layer is formed on the concave surface of the polarizer 21 or on the concave 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 and the like can be used. It is also possible to employ a method in which the polarizer 21 and the protective layers 22 and 23 are continuously supplied so that the concave surfaces of the polarizer 21 and the protective layers 22 and 23 are inwardly and the adhesive is plied therebetween. When the adhesive is applied, heat treatment is carried out if necessary to evaporate the moisture, and the adhesive layer is dried.

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 film thickness is preferably small, and from the viewpoint of suppressing defects such as bubbles and foreign substances at the time of co- From the viewpoints of adhesion and durability, it is preferable to carry out in an optimum range determined for each combination of adherend and adhesive. In general, it is 0.005 to 10 mu m, preferably 0.01 to 5 mu m, more preferably 0.03 to 1 mu m.

In the bonding of the polarizer 21 and the protective layers 22 and 23, a corona discharge treatment, a plasma treatment, a flame treatment, a primer treatment, an anchor An easy adhesion treatment such as a coating treatment may be performed.

When the adhesive layer is formed as described above, the first protective layer 22 is bonded to one surface of the polarizer 21 via the adhesive layer, and the second protective layer 23 is bonded to the polarizer 21 To the other side of the substrate. Thereby, a polarizing plate 2A is obtained in which the first protective layer 22, the polarizer 21 and the second protective layer 23 are laminated.

The total thickness of the polarizing plate 2A is preferably from 15 to 170 탆 and more preferably from 20 to 100 탆 and from 30 to 80 탆 in view of maintaining the polarizing performance in correspondence with the thinning requirement in mobile applications Is particularly preferable.

3. Peel sheet

A release sheet may be laminated on the surface (the lower surface in Fig. 1) opposite to the polarizing plate 2A of the pressure-sensitive adhesive layer 1 in the present embodiment.

Examples of the peeling sheet include a polyethylene film, a polypropylene film, a polybutene film, a polybutadiene film, a polymethylpentene film, a polyvinyl chloride film, a vinyl chloride copolymer film, a polyethylene terephthalate film, a polyethylene naphthalate film, (Meth) acrylate copolymer film, an ethylene / (meth) acrylate copolymer film, a polystyrene film, a polycarbonate film, a polyimide film, a polyimide film, a polyimide film, a polybutylene terephthalate film, A film, a fluororesin film, or the like is used. These crosslinked films are also used. Further, these laminated films may be used.

It is preferable that at least one surface of the release sheet (in particular, a release surface in contact with the pressure-sensitive adhesive layer) is subjected to a release treatment. As the releasing agent used in the peeling treatment, for example, an alkyd type, a silicone type, a fluorine type, an unsaturated polyester type, a polyolefin type, and a wax type releasing agent may be mentioned. The release face of the release sheet in the present specification means a face having release properties in the release sheet and includes both the face subjected to the exfoliation treatment and the face exhibiting the exfoliating property without performing the exfoliation treatment.

When the release sheet is laminated on both surfaces of the pressure-sensitive adhesive layer, it is preferable that one of the release sheets is a heavy-duty release sheet having a large stripping force and the other release sheet is a light-

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

4. Production method of polarizing plate with pressure-sensitive adhesive layer

As an example of the production method of the polarizing plate 10A with a pressure-sensitive adhesive layer, first, 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. Then, a separate release sheet (with the release surface contacting the coating film) is laminated on the coated film to obtain a pressure-sensitive adhesive sheet. When the curing period is not necessary, the coating film is directly a pressure-sensitive adhesive layer, and when a curing period is required, it becomes a pressure-sensitive adhesive layer after the curing period has elapsed. The conditions of the heat treatment and curing are as described above.

As the 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.

Subsequently, one of the release sheets (the thin release type release sheet) is peeled from the obtained pressure-sensitive adhesive sheet. 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 bonded. Thus, the polarizing plate 10A with a pressure-sensitive adhesive layer (with a release sheet) is obtained.

Another example of the production method of the polarizing plate 10A with a pressure-sensitive adhesive layer is a method in which a solution (coating solution) containing the above-described sticky composition (P) is applied to the release surface of the release sheet and heat treatment is performed to form a coating film The second protective layer 23 of the polarizing plate 2A is superimposed on the coated film. When a curing period is required, a curing period is provided, and when the curing period is unnecessary, the coating film becomes the pressure-sensitive adhesive layer (1). Thus, the polarizing plate 10A with a pressure-sensitive adhesive layer (with a release sheet) is obtained.

[Second Embodiment]

Next, a polarizing plate with a pressure-sensitive adhesive layer according to a second embodiment of the present invention will be described. The polarizing plate in this embodiment is a so-called composite polarizing plate having a polarizer and a retarder. 2, the polarizing plate 10B with a pressure-sensitive adhesive layer according to the present embodiment is composed of a composite polarizing plate 2B and a pressure-sensitive adhesive layer (laminated layer) 2 laminated on one surface (lower surface in Fig. 2) (1). Although not shown, a release sheet may be laminated on the surface of the pressure-sensitive adhesive layer 1 opposite to the composite polarizing plate 2B side until the polarizing plate 10B with a pressure-sensitive adhesive layer is used.

The pressure-sensitive adhesive layer (1) is formed from the pressure-sensitive adhesive relating to the present embodiment described above.

The composite polarizing plate 2B according to the present embodiment has a first retardation plate 24 in contact with the pressure sensitive adhesive layer 1 and a second retardation film 24 on the opposite side of the pressure sensitive adhesive layer 1 side of the first retardation plate 24 And a second pressure sensitive adhesive layer 26 interposed between the first retardation plate 24 and the second retardation plate 25, and a second pressure sensitive adhesive layer 26 interposed between the first retardation plate 24 and the second retardation plate 25, A polarizer 21 laminated on the side opposite to the side of the second pressure sensitive adhesive layer 26 in the second retardation plate 25 and a polarizer 21 laminated on the side opposite to the side of the second retardation plate 25 in the polarizer 21 And a protective layer 27 (corresponding to the first protective layer in the present invention) laminated on the protective layer 27. 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 retarder 25. This composite polarizing plate 2B exerts a satisfactory viewing angle compensation performance.

(1) The first retardation plate

The first retardation plate 24 may be composed of a single layer exhibiting a retardation or a plurality of layers including a retardation layer. 3, the first retardation plate 24 preferably includes a retardation layer 242 and a retardation layer 242 laminated on one surface (lower surface in FIG. 3) of the retardation layer 242 A first acrylic resin layer 241 and a second acrylic resin layer 243 laminated on the other surface (upper surface in FIG. 3) of the retardation developing layer 242. The phase difference-generating layer 242 is preferably made of a styrene-based resin. As described above, the complex polarizing plate 24 having the first retardation plate 24 having the first acrylic resin layer 241, the phase difference manifestation layer 242 made of the styrene resin, and the second acrylic resin layer 243, (2B) is excellent in the performance of compensating the viewing angle of a liquid crystal display device, in particular, an IPS (In-Place-Switching) mode liquid crystal display device. Since the retardation developing layer 242 is protected by the first acrylic resin layer 241 and the second acrylic resin layer 243 present on both sides of the retardation developing layer 242, the first retardation film 24 is excellent in mechanical strength and chemical resistance Is excellent.

It is preferable that the first retardation plate 24 is provided with in-plane retardation by stretching. As a result, the performance of the viewing angle compensation becomes better.

The styrene resin constituting the retardation developing layer 242 may be a homopolymer of styrene or a derivative thereof, or may be a binary or a copolymer of styrene or a derivative thereof and another copolymerizable monomer. The styrene derivative is a compound in which other groups are bonded to styrene, and examples thereof include alkyls such as o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, Substituted styrenes such as styrene, hydroxystyrene, tert-butoxystyrene, vinylbenzoic acid, o-chlorostyrene, p-chlorostyrene, etc. in which a benzene nucleus of styrene has a hydroxyl group, an alkoxy group, a carboxyl group, .

As the styrene resin, it is also possible to use a ternary copolymer as disclosed in Japanese Unexamined Patent Application Publication No. 2003-50316 or Japanese Unexamined Patent Publication No. 2003-207640.

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

As the styrene resin constituting the phase difference-generating layer 242, a styrene resin having heat resistance is preferable. The glass transition temperature (Tg) of the styrenic resin is generally 100 ° C or higher, but it is preferably a styrenic resin having a glass transition temperature (Tg) of 120 ° C or higher.

The thickness of the phase difference-generating layer 242 is preferably 10 to 100 mu m. When the thickness of the retardation developing layer 242 is 10 占 퐉 or more, a sufficient retardation value is expressed by stretching. On the other hand, when the thickness of the retardation developing layer 242 is 100 占 퐉 or less, the impact strength is high, the retardation change due to external stress is small, and heat unevenness or the like hardly occurs when applied to a liquid crystal display device.

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

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

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

The rubber particles may be a homogeneous material having rubber elasticity, or a multilayer structure having at least one rubber elastic layer. Examples of the acrylic rubber particles having a multilayer structure include those having rubber elastic particles as the nucleus and covering the periphery thereof with a hard methacrylic acid alkyl ester polymer and hard acrylic methacrylic acid alkyl ester polymers as nuclei And the periphery thereof is covered with an acrylic polymer having rubber elasticity as described above and that the periphery of the hard core is covered with an acrylic polymer having rubber elasticity and the periphery thereof is covered with a hard methacrylic acid alkyl ester polymer And the like.

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

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

As the (meth) acrylic resin composition constituting the first acrylic resin layer 241 and the second acrylic resin layer 243, those commercially available in a mixed state of a (meth) acrylic resin and acrylic rubber particles can be used . Examples of commercially available products of (meth) acrylic resin ((meth) acrylic resin composition) in which acrylic rubber particles are blended are "HT55X" and "Technoloy S001" sold by Sumitomo Chemical Co., .

(Meth) acryl-based resin composition having a glass transition temperature (Tg) of 160 ° C or lower, but a glass transition temperature (Tg) of 120 ° C or lower is preferable, An acrylic resin composition is preferable. That is, it is preferable that the glass transition temperature (Tg) of the retardation developing layer 242 does not overlap with the glass transition temperature (Tg) of the first acrylic resin layer 241 and the second acrylic resin layer 243, It is preferable that the layer 242 has a higher glass transition temperature (Tg) than 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.

It is preferable that the thicknesses of the first acrylic resin layer 241 and the second acrylic resin layer 243 are each 10 to 100 탆. If the thickness is 10 mu m or more, the film formation can be performed easily. If the thickness is 100 mu m or less, the retardation of the first acrylic resin layer 241 and the second acrylic resin layer 243 can be ignored. 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 of the first retardation plate 24 on the side of the second pressure sensitive adhesive layer 26 may be subjected to surface treatment such as corona treatment.

In order to manufacture the first retarder 24, for example, a styrene resin and a (meth) acrylic resin composition containing rubber particles may be co-extruded and then stretched. The stretching can be performed by longitudinal uniaxial stretching, tenter transverse uniaxial stretching, simultaneous biaxial stretching, or sequential biaxial stretching, and stretching can be performed to obtain a desired retardation value. (A phase difference manifestation layer 242, a first acrylic resin layer 241, and a second acrylic resin layer 243) are formed by heat lamination by heat lamination in addition to the above method, The sieve may be stretched.

The total thickness of the first retardation plate 24 after stretching is preferably 5 to 100 占 퐉, more preferably 10 to 50 占 퐉, from the viewpoint of meeting the demand for thinning in mobile applications while maintaining sufficient performance And particularly preferably 15 to 30 탆.

The surface of the first retardation plate 24 which is in contact with the pressure sensitive adhesive layer 1 is constituted by the first acrylic resin layer 241. In this case as well, the pressure sensitive adhesive layer 1 is composed of the first acrylic resin layer 241 ). Therefore, the polarizing plate 10B with a pressure-sensitive adhesive layer is excellent in durability under a high-temperature condition, under a humid condition, under heat shock, and the like.

(2) The second retardation plate

The second retarder 25 in the present embodiment corresponds to the second protective layer in the present invention. As the second retardation plate 25, the same material as the second protective layer 23 in the first embodiment can be used.

(3) Second pressure-sensitive adhesive layer

As a pressure-sensitive adhesive constituting the second pressure-sensitive adhesive layer 26, a known pressure-sensitive adhesive may be used, it may be a curable pressure-sensitive adhesive, or may be a non-curable pressure-sensitive adhesive. However, from the viewpoint of suppressing dimensional changes due to heat shrinkage of the polarizing plate, It is preferable to use an energy radiation curable pressure sensitive adhesive.

The active energy ray-curable pressure-sensitive adhesive may contain a polymer having an active energy ray curable property as a main component or a mixture of a polymer having no active energy ray curable property and a mixture of an active energy ray curable multifunctional monomer and / It is acceptable. A mixture of a polymer having active energy ray curability and a polymer having no active energy ray curability may be a mixture of a polymer having active energy ray curability and an active energy ray curable multifunctional monomer and / It may be a mixture of species.

Above all, from the viewpoint of easily obtaining a pressure-sensitive adhesive exhibiting cohesive strength while maintaining adhesiveness, it is preferable that a main component is a mixture of a polymer having no active energy ray-curable property and an active energy ray-curable polyfunctional monomer and / In particular, it is preferable to use as a main component a mixture of a polymer having no active energy ray curability and an active energy ray-curable multifunctional monomer.

(Meth) acrylic acid ester polymer (hereinafter sometimes referred to as "(meth) acrylic acid ester polymer (X)") having no active energy ray-curable group is preferable as the polymer having no active energy ray curability. The (meth) acrylic acid ester polymer (X) preferably contains a (meth) acrylic acid alkyl ester having 1 to 20 carbon atoms in the alkyl group as a monomer constituting the polymer. As a result, the obtained pressure-sensitive adhesive can exhibit desirable tackiness. The (meth) acrylic acid ester polymer (X) is obtained by polymerizing a (meth) acrylic acid alkyl ester having an alkyl group of 1 to 20 carbon atoms, a monomer having a reactive functional group (a reactive functional group containing monomer) Is particularly preferable. (Meth) acrylic acid ester polymer (X) contains a reactive functional group-containing monomer as a monomer constituting the polymer, it is possible to improve adhesion to a glass surface of a liquid crystal cell or the like, To 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, n-butyl (Meth) acrylate, n-hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl Myristyl, palmityl (meth) acrylate, stearyl (meth) acrylate, and the like. Among them, (meth) acrylic esters having an alkyl group of 1 to 8 carbon atoms are preferable, and n-butyl (meth) acrylate is particularly preferable from the viewpoint of further improving the tackiness. These may be used alone or in combination of two or more.

The (meth) acrylic acid ester polymer (X) preferably contains 50 to 99 mass% of a (meth) acrylic acid alkyl ester having 1 to 20 carbon atoms in the alkyl group as the monomer unit constituting the polymer, By mass, more preferably from 70 to 98% by mass.

Examples of the reactive functional group-containing monomer include a monomer having a hydroxyl group in the molecule (a hydroxyl group-containing monomer), a monomer having a carboxyl group in the molecule (a carboxyl group-containing monomer), a monomer having an amino group in the molecule (an amino group-containing monomer) . These reactive functional group-containing monomers may be used singly or in combination of two or more.

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

Examples of the carboxyl group-containing monomer include ethylenically unsaturated carboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, itaconic acid and citraconic acid. Among them, acrylic acid is preferable in view of the reactivity of the carboxyl group in the resulting (meth) acrylic acid ester polymer (X) with the crosslinking agent (Z) and the copolymerization 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 mass%, more preferably 1 to 20 mass%, of the monomer having a reactive functional group as the monomer unit constituting the polymer, It is preferably contained in an amount of 2 to 5% by mass.

The polymerization 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 from 300,000 to 3,000,000, particularly preferably from 1,000,000 to 2,500,000, and more preferably from 1,600,000 to 2,200,000.

The (meth) acrylic acid ester polymer (X) may be used singly or in combination of two or more kinds.

Examples of the active energy ray-curable multifunctional monomer (hereinafter also referred to as "active energy ray-curable compound (Y)") include polyfunctional acrylates having a molecular weight of 1,000 or less and excellent compatibility with (meth) acrylic acid ester polymer A rate-based monomer is preferred.

Examples of the polyfunctional acrylate monomer having a molecular weight of 1000 or less include 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (Meth) acrylate, dicyclopentanyl di (meth) acrylate, caprolactone denatured (meth) acrylate, hydroxypivalic acid neopentyl glycol di Bifunctional types such as dicyclopentenyl (meth) acrylate, ethylene oxide modified di (meth) acrylate, di (acryloxyethyl) isocyanurate and allyl cyclohexyldi (meth) acrylate; (Meth) acrylate, dipentaerythritol tri (meth) acrylate, propionic acid modified dipentaerythritol tri (meth) acrylate, pentaerythritol tri (meth) acrylate, propylene oxide modified trimethylol propane Trifunctional types such as tri (meth) acrylate, tris (acryloxyethyl) isocyanurate, and ε-caprolactone modified tris- (2- (meth) acryloxyethyl) isocyanurate; Tetrafunctional types such as diglycerin tetra (meth) acrylate and pentaerythritol tetra (meth) acrylate; Pentafunctional type such as propionic acid-modified dipentaerythritol penta (meth) acrylate; And hexafunctional types such as dipentaerythritol hexa (meth) acrylate and caprolactone-modified dipentaerythritol hexa (meth) acrylate. These may be used singly or in combination of two or more kinds.

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

It is also preferable that the active energy ray-curable pressure-sensitive adhesive contains a cross-linking agent (Z). When the active energy ray-curable pressure-sensitive adhesive contains the (meth) acrylic acid ester polymer (X) containing the reactive functional group-containing monomer as the monomer unit constituting the polymer and the crosslinking agent (Z) (Z) reacts with the reactive functional group of the reactive functional group-containing monomer constituting the (meth) acrylic acid ester polymer (X). Thereby, a structure in which the (meth) acrylic acid ester polymer (X) is crosslinked is formed by the crosslinking agent (Z), and the cohesive force of the obtained pressure sensitive adhesive is improved.

The crosslinking agent (Z) is not particularly limited as long as it can react with the reactive functional group possessed by the (meth) acrylic acid ester polymer (X), and examples thereof include isocyanate crosslinking agents, epoxy crosslinking agents, amine crosslinking agents, melamine crosslinking agents, aziridine crosslinking agents, Based crosslinking agent, an aldehyde-based crosslinking agent, an oxazoline-based crosslinking agent, a metal alkoxide-based crosslinking agent, a metal chelating-type crosslinking agent, a metal salt-based crosslinking agent, and an ammonium salt-based crosslinking agent. As the isocyanate crosslinking agent, the same isocyanate crosslinking agent (B) as mentioned above can be used. The crosslinking agent (Z) may be used singly or in combination of two or more kinds.

The content of the crosslinking agent (Z) is preferably 0.01 to 10 parts by mass, more preferably 0.05 to 5 parts by mass, further preferably 0.1 to 1 part by mass relative to 100 parts by mass of the (meth) acrylic acid ester polymer (X) desirable.

The active energy ray-curable pressure-sensitive adhesive may contain various additives such as a photopolymerization initiator, a silane coupling agent, a refractive index adjusting agent, an antistatic agent, a tackifier, an antioxidant, an ultraviolet absorber, a light stabilizer, a softening agent, You can.

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

Examples of the photopolymerization initiator include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-butyl ether, benzoin isobutyl ether, acetophenone, dimethylaminoacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one, 4- (2-hydroxyethoxy) -Propyl ketone, benzophenone, p-phenylbenzophenone, 4,4'-diethylaminobenzophenone, dichlorobenzophenone, 2-methyl anthraquinone, 2-ethyl anthraquinone, 2- tertiary- 2-methylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, benzyldimethylketal, Acetophenone dimethyl ketal, p-dimethyl Methylbenzyl-phenyl] propanone], 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, and the like can be given as examples of the aminobenzoic acid ester, oligo [2-hydroxy- have. These may be used alone or in combination of two or more.

The photopolymerization initiator is preferably used in an amount in the range of 0.1 to 20 parts by mass, particularly 1 to 12 parts by mass, based on 100 parts by mass of the active energy ray-curable compound (Y) in the above active energy ray-

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

Examples of such a silane coupling agent include, in addition to the aforementioned epoxy group-containing silane coupling agent (C1) and mercapto group-containing silane coupling agent (C2), vinyltrimethoxysilane, vinyltriethoxysilane, methacryloxypropyl (2-aminoethyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, 3-aminopropylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane, 3-isocyanatepropyltriethoxysilane, or a combination of at least one of these with methyltriethoxysilane, ethyltriethoxy And condensates of alkyl group-containing silicon compounds such as silane, methyltrimethoxysilane and ethyltrimethoxysilane. These may be used singly or in combination of two or more kinds.

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

The polymer having the active energy ray curability is preferably a (meth) acrylic acid ester (co) polymer to which a functional group having an active energy ray curable property (active energy radiation curable group) is introduced into the side chain.

The thickness of the second pressure sensitive adhesive layer 26 is usually about 1 to 50 占 퐉, preferably 1 to 20 占 퐉, and particularly preferably 2 to 7 占 퐉. When the pressure-sensitive adhesive layer is too thin, the pressure-sensitive adhesive property is deteriorated. When the pressure-sensitive adhesive layer is too thick, the pressure-sensitive adhesive is likely to be discharged.

(4) Polarizer

As the polarizer 21, the same polarizer 21 as the polarizer 2A described above can be used.

(5) Protective layer

The protective layer 27 in this embodiment corresponds to the first protective layer in the present invention. As the protective layer 27, the same material as the first protective layer 22 in the first embodiment can be used.

(6) Adhesive layer

The adhesive layer that may be interposed between the polarizer 21 and the protective layer 27 and / or between the polarizer 21 and the second retarder 25 may be the same as the adhesive layer of the polarizing plate 2A have.

(7) Method for producing a composite polarizing plate

The composite polarizing plate 2B can be produced by a conventional method. Hereinafter, as an example, a manufacturing method in the case of using an aqueous adhesive as the adhesive will be described.

First, a coating film of a pressure-sensitive adhesive constituting the second pressure-sensitive adhesive layer 26 is formed on the release surface of the release sheet. Specifically, the application liquid of the pressure-sensitive adhesive constituting the second pressure-sensitive adhesive layer 26 is coated on the release surface of the release sheet and dried.

On the other hand, an adhesive layer is formed on the concave surface of the polarizer 21 or on the concave surface of the second retardation plate 25 and the protective layer 27. This adhesive layer can be formed in the same manner as in the method for producing the polarizing plate 2A described above. In addition, the thickness of the adhesive layer and the easy adhesive treatment are also the same.

When the adhesive layer is formed as described above, the protective layer 27 is adhered to one surface of the polarizer 21 via the adhesive layer and the second retardation plate 25 is fixed to one side of the polarizer 21 (Polarizing plate) composed of the protective layer 27, the polarizer 21 and the second retardation plate 25 is obtained.

Next, a coating film of a pressure-sensitive adhesive constituting the second pressure-sensitive adhesive layer (26) on the release sheet is applied to the surface of the obtained laminate on the side of the second retardation plate (25). Then, the coating film of the pressure-sensitive adhesive is cured by irradiating an active energy ray over the peeling sheet to form the coated film as a second pressure-sensitive adhesive layer (26).

Here, the active energy ray refers to an energy having both energy in an electromagnetic wave or a charged particle beam, and specifically, ultraviolet rays, electron rays, and the like can be mentioned. Of the active energy rays, ultraviolet rays which are easy to handle are particularly preferable.

The irradiation with ultraviolet rays can be performed by a high-pressure mercury lamp, a metal halide lamp, a fusion H lamp, a xenon lamp, etc., and the irradiation amount of ultraviolet rays is preferably about 50 to 1000 mW / cm ² . The amount of light, 50 ~ 10000 mJ / cm ² is not preferred, and more preferred 80 to a 5000 mJ / cm ² and is, particularly preferably 100 ~ 1000 mJ / 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 in the above, and the second acrylic resin layer 243 of the first retardation plate 24 is exposed to the exposed second pressure- Side surface. In this manner, a composite polarizing plate 2B obtained 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 탆, more preferably 30 to 150 탆, and particularly preferably 50 to 100 탆.

(8) Production method of a polarizing plate with a pressure-sensitive adhesive layer

As an example of the method for producing the polarizing plate 10B with a pressure-sensitive adhesive layer, a pressure-sensitive adhesive sheet comprising a pressure-sensitive adhesive layer laminated on both sides of a pressure-sensitive adhesive layer as a pressure-sensitive adhesive sheet according to the present embodiment is prepared, and a pressure- Sheet) is peeled off. Then, the first retardation plate 24 of the composite polarizing plate 2B is superimposed on the exposed pressure-sensitive adhesive layer, and the adhesive sheet and the composite polarizing plate 2B are pressed together. Thus, the polarizing plate 10B with a pressure-sensitive adhesive layer (with a release sheet) is obtained.

Another example of the production method of the polarizing plate 10B with a pressure-sensitive adhesive layer is a method in which a coating solution of the above-mentioned sticking composition (P) is applied to the release surface of the release sheet and a heat treatment is performed to form a coating film, The first retardation plate 24 of the composite polarizing plate 2B is superimposed. When a curing period is required, a curing period is provided, and when the curing period is unnecessary, the coating film becomes the pressure-sensitive adhesive layer (1). Thus, the polarizing plate 10B with a pressure-sensitive adhesive layer (with a release sheet) is obtained.

5. Properties of Polarizer with Adhesive Layer

The adhesive force of the polarizer plates 10A, 10B with a pressure-sensitive adhesive layer according to the present embodiment is preferably 0.5 to 20 N / 25 mm, particularly preferably 1 to 10 N / 25 mm, . Thus, the polarizing plate with a pressure-sensitive adhesive layer is excellent in durability. Further, from the viewpoint of being excellent also in the reworkability, the adhesive force is preferably 1.5 to 7 N / 25 mm. The adhesive force referred to here is basically the adhesive force measured by the 180 deg. Peel method in accordance with JIS Z0237: 2009, wherein the sample to be measured has a width of 25 mm and a length of 100 mm, and the sample to be measured is 0.5 MPa at 50 DEG C for 20 minutes, and then left at rest under the conditions of normal pressure, 23 DEG C, and 50% RH for 24 hours, and then measured at a peeling rate of 300 mm / min. When the adhesive force is within the above range, lifting, peeling, and the like can be prevented when the liquid crystal cell is attached to the liquid crystal cell.

The polarizing plates 10A and 10B with a pressure-sensitive adhesive layer according to the present embodiment had the adhesive force (adhesive force after 14 days of application) after 14 days of standing under the conditions of 23 DEG C and 50% RH from the attachment to the adherend , Preferably 1 to 20 N / 25 mm, and more preferably 3 to 9 N / 25 mm. As described above, the pressure-sensitive adhesive layer-attached polarizing plates 10A, 10B according to the present embodiment are excellent in reheat workability by suppressing an increase in adhesive force with time, and can be easily reattached even after they are attached to the liquid crystal cell.

The polarizing plates 10A and 10B with a pressure-sensitive adhesive layer according to the present embodiment had the adhesive force (adhesive force after 2 days at 50 占 폚) after leaving for 2 days under the condition of 50 占 폚 and 50% RH from the adherend to the adherend, Is preferably 1 to 20 N / 25 mm from the viewpoint of durability, and further preferably 6 to 12 N / 25 mm in view of the reworkability.

The surface resistivity of the pressure-sensitive adhesive layer in the polarizer plates 10A and 10B with a pressure-sensitive adhesive layer according to the present embodiment is preferably 1.0 x 10 ¹² ? / Sq or less, more preferably 5.0 x 10 ¹¹ ? / Sq or less, Is preferably 7.0 x 10 < 10 ^> OMEGA / sq or less. When the surface resistivity is equal to or less than the above value, sufficient antistatic property can be exhibited in the display panel. This surface resistivity can be attained by containing the above-described antistatic agent (D) in the adhesive composition (P). The surface resistivity of the pressure-sensitive adhesive layer is measured in accordance with JIS K6911, specifically as shown in the following test examples. The lower limit of the surface resistivity is not particularly limited, but is about 5.0 × 10 ⁸ Ω / sq from the viewpoint of not adversely affecting durability and heat resistance non-uniformity.

6. Use of Polarizer with Adhesive Layer

By using the polarizer plates 10A and 10B with a pressure-sensitive adhesive layer, for example, a liquid crystal display device including a liquid crystal cell and a polarizer plate can be manufactured.

More specifically, the pressure-sensitive adhesive layer 1 (the pressure-sensitive adhesive layer 1 exposed by peeling off the release sheet when the release sheet is laminated) of the polarizer plates 10A and 10B with the pressure-sensitive adhesive layer is fixed on the desired surface of the liquid- And then pressed. Thereby, a liquid crystal display device including the liquid crystal cell and the polarizing plate 2A or the composite polarizing plate 2B is obtained.

Since the polarizing plates 10A and 10B with a pressure-sensitive adhesive layer according to the present embodiment have excellent durability, even if the obtained liquid crystal display device is placed under a high temperature condition under a humid condition or under a heat shock, Peeling is suppressed. For example, when a glass plate to which the polarizing plates 10A and 10B with a pressure-sensitive adhesive layer are attached is placed under a high temperature condition of 85 DEG C for 250 hours under a wet heat condition of 60 DEG C and 90% RH or a heat shock of -35 DEG C to 70 DEG C 200 minutes, 200 minutes, 30 minutes, and 200 cycles), the occurrence of lifting or peeling is suppressed.

In addition, the polarizing plates 10A, 10B with a pressure-sensitive adhesive layer according to the present embodiment are also excellent in stress relaxation property, so that the resulting liquid crystal display device does not bend well under high temperature conditions, and thermal unevenness does not occur easily. For example, even when a glass plate to which the polarizer plates 10A and 10B with a pressure-sensitive adhesive layer are attached is placed under a high-temperature condition (for example, at a temperature of 80 to 85 ° C) for 250 hours, the glass plate does not bend well, It does not happen. Particularly, even if the polarizing plate 2A or the composite polarizing plate 2B is a thin film, the liquid crystal display does not bend well, and even if the liquid crystal cell is high-precision, heat unevenness does not occur easily.

Here, there is a case where a transparent conductive film exists on the surface of the liquid crystal cell which is adhered to the pressure-sensitive adhesive layer 1. In this case, it is also suppressed that the transparent conductive film is corroded or the resistance value of the transparent conductive film is changed.

Examples of the 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, indium tin oxide (ITO) A non-oxidizing compound such as chalcogenide, lanthanum pentoxide, titanium nitride, titanium carbide, or the like, which is a composite oxide such as indium tin oxide, indium tin oxide, indium tin oxide, indium tin oxide, indium tin oxide, indium tin oxide, indium tin oxide, indium tin oxide, indium tin oxide, indium tin oxide, .

The above-described embodiments are described for the purpose of facilitating understanding of the present invention, and are not described for limiting the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design modifications and equivalents falling within the technical scope of the present invention.

Example

Hereinafter, the present invention will be described in more detail with reference to Examples and the like, but the scope of the present invention is not limited to these Examples and the like.

[Example 1]

1. Preparation of Polarizer

(1) Production of polarizer

A polyvinyl alcohol film having a thickness of 75 탆 and composed of polyvinyl alcohol having an average degree of polymerization of about 2,400 and a degree of saponification of 99.9 mol% or more was uniaxially stretched by about 5 times in a dry state and maintained at a stretching temperature of 1 Lt; / RTI > Thereafter, it was immersed in an aqueous solution having a mass ratio of iodine / potassium iodide / water of 0.05 / 5/100 at 28 ° C for 60 seconds. Subsequently, the substrate 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. Subsequently, the film was washed with pure water at 26 DEG C for 20 seconds, and then dried at 65 DEG C to obtain a polarizer in which iodine was adsorbed and oriented on polyvinyl alcohol. The thickness of this polarizer was 15 탆.

(2) Production of Polarizer

3 parts by mass of a carboxyl group-modified polyvinyl alcohol (trade name: "KL-318", manufactured by Kuraray Co., Ltd.) was dissolved in 100 parts by mass of water. To the aqueous solution was added a polyamide epoxy additive 1.5 parts by mass of an aqueous solution having a solid content concentration of 30% by mass (trade name, Sumirei Resin 650 (30), manufactured by Kankuchi Kogyo Co., Ltd.) was prepared. The epoxy adhesive was applied to one surface of the polarizer obtained above.

As the first protective layer, a triacetyl cellulose film (trade name "KC2UA", manufactured by Konica Minolta Opto Co., Ltd.) having a thickness of 25 μm and subjected to saponification treatment was applied to the coating layer of the epoxy adhesive.

Next, an epoxy adhesive was applied to the other surface of the polarizer as described above, and a zero-phase retardation film made of a cyclic olefin resin having a thickness of 23 占 퐉 (Trade name " ZEONOR ", manufactured by Nippon Zeon Co., Ltd.). And then dried at 80 DEG C for 5 minutes to adhere the first protective layer and the second protective layer to the polarizer. After adhering, the protective layer was cured at 40 占 폚 for 168 hours to obtain a total of a protective layer (layer thickness of 25 占 퐉), a polarizer (stretching magnification of 5 times, layer thickness of 15 占 퐉) and a second protective layer A polarizing plate having a thickness of 63 탆 was obtained. The ratio of the thickness of the first protective layer to the thickness of the polarizer was 1.67, and the ratio of the thickness of the second protective layer to the thickness of the polarizer was 1.53. The ratio of the total thickness of the first protective layer and the second protective layer to the thickness of the polarizer was 3.2.

2. Fabrication of Composite Polarizer

(1) Formation of coating film of active energy ray-curable pressure-sensitive adhesive

95 parts by mass of n-butyl acrylate and 5 parts by mass of acrylic acid were copolymerized to prepare a (meth) acrylic acid ester polymer (X). The molecular weight of the (meth) acrylic acid ester polymer (X) was measured by a method described later, and as a result, the weight average molecular weight (Mw) was 2,000,000.

100 parts by mass of the above-mentioned (meth) acrylic acid ester polymer (X) and 30 parts by mass of tris (acryloxyethyl) isocyanurate (trade name: Aronix M- 315 "), 0.3 part by mass of trimethylolpropane-modified tolylene diisocyanate (trade name " Coronate L ", trade name, manufactured by Nippon Polyurethane Industry Co., Ltd.) as a crosslinking agent (Z), and 0.1 part by mass of benzophenone and 1-hydroxycyclo 1.5 parts by mass of a mixture of hexyl phenyl ketone in a mass ratio of 1: 1 (manufactured by Chiba Specialty Chemicals Co., Ltd., trade name "Irgacure 500") and 3 parts by mass of 3-glycidoxypropyltrimethoxysilane Manufactured by Kagaku Kogyo K.K., trade name " KBM403 ") were mixed and sufficiently stirred and diluted with ethyl acetate to obtain a coating solution of the active energy ray-curable pressure-sensitive adhesive.

The coating solution of the obtained active energy ray-curable pressure-sensitive adhesive was coated with a knife coater on the release surface of a release sheet (SP-PET3811, manufactured by Lin Tec Co., Ltd., thickness: 38 占 퐉) in which one side of the polyethylene terephthalate film was peeled off with a silicone- Thereafter, the film was heat-treated at 90 ° C for 1 minute to form a coating film of an active energy ray-curable pressure-sensitive adhesive.

(2) Fabrication of first retardation plate

(Manufactured by Sumitomo Chemical Co., Ltd., trade name: " Technoloy S001 ") in which about 20 mass% of acrylic rubber particles having an average particle diameter of 200 nm constituting the first acrylic resin layer was blended, and a retardation- (Trade name " Dairak D332 ", trade name, manufactured by Nova Chemical Co., Ltd.) and about 20 mass% of acrylic rubber particles having an average particle diameter of 200 nm constituting the second acrylic resin layer Resin (trade name: "Technoloy S001", manufactured by Sumitomo Chemical Co., Ltd.) was co-extruded in this order to obtain a laminated film having a three-layer structure. The resulting laminated film was stretched to obtain a first retardation plate (first acrylic resin layer / phase retardation layer / second acrylic resin layer) having an in-plane retardation value of 60 nm and a thickness of 25 占 퐉.

(3) Fabrication of composite polarizer

Initially, the above-mentioned polarizing plate was prepared. The first protective layer and the second protective layer in the polarizing plate correspond to the protective layer and the second retardation plate in the composite polarizing plate to be produced here, respectively. That is, a polarizing plate comprising a protective layer, a polarizer and a second retardation plate laminated was prepared.

A coating film of the active energy ray-curable pressure-sensitive adhesive obtained in the above-mentioned step (1) is applied to the surface of the polarizing plate on the side of the second retarder, and ultraviolet rays are irradiated onto the peeling sheet under the following conditions to harden the coating film of the pressure- To form a second pressure-sensitive adhesive layer. Thereafter, the release sheet was peeled from the obtained second pressure-sensitive adhesive layer, and the surface of the first retardation plate obtained in the step (2) on the side of the second acrylic resin layer was bonded to the surface of the exposed second pressure- Respectively. Thus, a composite polarizing plate having a total thickness of 93 탆 was obtained by laminating a protective layer (first protective layer), a polarizer, a second retardation plate (second protective layer), a second pressure-sensitive adhesive layer and a first retardation plate. The thickness of the formed second pressure sensitive adhesive layer was 5 mu m.

<Ultraviolet irradiation condition>

· Using high pressure mercury lamp

Illumination 300 mW / cm ² , light quantity 300 mJ / cm ²

· UV illuminance · "UVPF-A1" manufactured by Eye Graphics Co., Ltd.

3. Preparation of Polarizer with Adhesive Layer

(1) Preparation of (meth) acrylic acid ester copolymer

87 parts by mass of n-butyl acrylate, 5 parts by mass of isobornyl acrylate, 5 parts by mass of 2-phenylethyl acrylate and 3 parts by mass of 2-hydroxyethyl acrylate were copolymerized to prepare a (meth) acrylic ester copolymer (A) . The molecular weight of the (meth) acrylic acid ester copolymer (A) was measured by a method described later, and as a result, the weight average molecular weight (Mw) was 1.6 million. From the above blending, the hydroxyl value of the (meth) acrylic acid ester copolymer (A) is calculated to be 14.49 mgKOH / g and the acid value to be 0 mgKOH / g.

(2) Preparation of adhesive composition

100 parts by mass of the (meth) acrylic acid ester copolymer (A) obtained in the above step (1) and 0.2 parts by mass of trimethylolpropane-modified xylylene diisocyanate (trade name: Takenate D110N, manufactured by Mitsui Chemicals, Inc.) as an isocyanate crosslinking agent (B) , 0.2 part by mass of 3-glycidoxypropyltrimethoxysilane (trade name: KBM403, manufactured by Shin-Etsu Chemical Co., Ltd.) as the epoxy group-containing silane coupling agent (C1) and 0.2 part by mass of the mercapto group- , 0.2 part by mass of a co-condensate of 3-mercaptopropyltrimethoxysilane and methyltriethoxysilane (trade name: "X-41-1810" manufactured by Shin-Etsu Chemical Co., Ltd., mercapto equivalent: 450 g / mol) 2.0 parts by mass of N-octyl-4-methylpyridinium hexafluorophosphate (ionic compound which is solid at room temperature) as a component (D) were sufficiently mixed and stirred and diluted with ethyl acetate to obtain To obtain a capsule solution.

Table 1 shows the respective blend (solid content conversion value) of the adhesive composition when the (meth) acrylic acid ester copolymer (A) was changed to 100 parts by mass (solid content conversion value). Details of the abbreviations and the like in Table 1 are as follows.

[(Meth) acrylic acid ester copolymer]

BA: n-butyl acrylate

HEA: 2-hydroxyethyl acrylate

IBXA: isobornyl acrylate

PhEA: 2-phenylethyl acrylate

CHA: cyclohexyl acrylate

MA: methyl acrylate

[Isocyanate-based crosslinking agent]

XDI: trimethylolpropane-modified xylylene diisocyanate (trade name &quot; Takenate D110N &quot;, manufactured by Mitsui Chemicals, Inc.)

[Antistatic Agent]

Pry + PF6-: N-octyl-4-methylpyridinium hexafluorophosphate (ionic compound which is solid at room temperature)

(3) Production of Polarizer with Adhesive Layer

The coating solution of the obtained sticky composition was applied to a release treatment surface of a release sheet (SP-PET3811, manufactured by Lin Tec Co., Ltd., thickness: 38 占 퐉) having one surface of a polyethylene terephthalate film peeled off with a silicone-based release agent by a knife coater, Followed by heat treatment at 90 占 폚 for 1 minute to form a coating film of the adhesive composition.

Subsequently, the polarizing plate obtained above was laminated with the coating film so that the surface of the second protective layer and the exposed surface of the coating film were in contact with each other, and cured at 23 DEG C and 50% RH for 7 days to form a pressure- Sensitive adhesive layer with a first pressure-sensitive adhesive layer. The thickness of the pressure-sensitive adhesive layer thus formed was 20 占 퐉.

The composite polarizing plate thus obtained was laminated with the coating film so that the surface of the first acrylic resin layer in the first retardation plate and the exposed surface of the coating film were in contact with each other, By curing, a polarizing plate with a second pressure-sensitive adhesive layer having a pressure-sensitive adhesive layer formed on the composite polarizing plate was obtained. The thickness of the pressure-sensitive adhesive layer thus formed was 20 占 퐉.

[Examples 2 to 13 and Comparative Examples 1 to 7]

The type and ratio of each monomer 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 isocyanate crosslinking agent (B) The polarizing plate with the first and second pressure-sensitive adhesive layers was prepared in the same manner as in Example 1, except that the polarizing plates were similarly changed.

The weight average molecular weight (Mw) described above is a weight average molecular weight in terms of polystyrene measured by gel permeation chromatography (GPC) under the following conditions (GPC measurement).

<Measurement Conditions>

GPC measurement apparatus: HLC-8020 manufactured by Toso Co., Ltd.

· GPC Column (Pass in the following order): Toso Co., Ltd.

  TSK guard column HXL-H

  TSK gel GMHXL (× 2)

  TSK gel G2000HXL

Measurement solvent: tetrahydrofuran

· Measuring temperature: 40 ℃

[Test Example 1] (Measurement of gel fraction)

(SP-PET3801, manufactured by Lin Tec Corp., thickness: 38 占 퐉) in which one side of the polyethylene terephthalate film was peeled off with a silicone-based releasing agent was used instead of the optical film used in the production of the polarizing plate with a pressure- To prepare a pressure-sensitive adhesive sheet. Specifically, the release sheet was laminated on the coated film on which the constitution made of the coating film of the release sheet / adhesive composition obtained in the manufacturing process of the example or the comparative example was exposed so that the release treatment side was in contact with the surface, % RH for 7 days. Thus, a pressure-sensitive adhesive sheet having the constitution of a release sheet (SP-PET3801) / a pressure-sensitive adhesive layer (thickness: 20 占 퐉) / release sheet (SP-PET3811) was produced.

The pressure-sensitive adhesive sheet thus obtained was cut into a size of 80 mm x 80 mm, the pressure-sensitive adhesive layer was wrapped in a polyester mesh (mesh size 200), the mass thereof was weighed with a precision balance and the mass of the mesh alone was subtracted, And the mass of each of them was calculated. The mass at this time is denoted by M1.

Next, the pressure-sensitive adhesive wrapped in the polyester mesh was immersed in ethyl acetate at room temperature (23 DEG C) for 24 hours. Thereafter, the pressure-sensitive adhesive was taken out and air-dried for 24 hours under an environment of a temperature of 23 ° C and a relative humidity of 50%, and further dried in an oven at 80 ° C for 12 hours. After drying, the mass was weighed with a precision balance, and the mass of the mesh alone was subtracted to calculate the mass of the adhesive alone. The mass at this time is M2. The gel fraction (%) is expressed by (M2 / M1) x100. The results are shown in Tables 2 and 3.

[Test Example 2] (Evaluation of durability)

The polarizer with a pressure-sensitive adhesive layer obtained in Examples and Comparative Examples was cut to prepare a sample having a size of 150 mm x 200 mm. The release sheet was peeled off from the sample and attached to an alkali-free glass (Eagle XG, manufactured by Corning Incorporated) through the exposed pressure-sensitive adhesive layer, followed by pressurization at 0.5 MPa and 50 ° C for 20 minutes with an autoclave manufactured by Kurihara Seisakusho .

Thereafter, the mixture was put under the conditions of the following three durability conditions, and after 250 hours, a 10-fold loupe was used to confirm whether or not it was lifted or peeled off. The evaluation criteria are as follows. The results of the polarizing plate with the first pressure-sensitive adhesive layer related to Examples 1 to 12 and Comparative Examples 1 to 5 are shown in Table 2, and the results of the polarizing plates with the second pressure-sensitive adhesive layer related to Examples 1 to 13 and Comparative Examples 1 to 7 Are shown in Table 3.

◎: No peeling or peeling was observed.

○: The size of peeling or peeling of 0.5 mm or less was confirmed.

[Delta]: Excoriation or exfoliation of not less than 0.5 mm and not more than 1.0 mm was confirmed.

X: Exfoliation or peeling of a size exceeding 1.0 mm was confirmed.

&Lt; Durability condition &

· Heat resistance: 85 ℃ dry

· Humidity: 60 ℃, relative humidity 90% RH

H.S. : Heat shock test for 30 minutes at -35 ° C to 70 ° C, 200 cycles

[Test Example 3] (Evaluation of warpage resistance)

The polarizing plate with a pressure-sensitive adhesive layer obtained in Examples and Comparative Examples was cut to a length of 200 mm and a width of 150 mm. The release sheet was peeled from the polarizing plate with a pressure-sensitive adhesive layer and the exposed pressure-sensitive adhesive layer was laminated to the center of a non-alkali glass (trade name "Eagle-XG", manufactured by Corning Incorporated) having a length of 250 mm, a width of 175 mm and a thickness of 0.5 mm, This was taken as a sample. This sample was allowed to stand in a dry atmosphere at 85 캜 for 250 hours. Thereafter, the sample was taken out under an environment of 25 DEG C and 50% RH, placed on a horizontal surface with the polarizing plate side up, and the amount of bending (distance between the corner and the stand) from each corner of the sample (4 points) And the deflection of the corner was added. Based on the results, the warpage resistance was evaluated as follows. The results of the polarizing plate with the first pressure-sensitive adhesive layer related to Examples 1 to 12 and Comparative Examples 1 to 5 are shown in Table 2, and the results of the polarizing plates with the second pressure-sensitive adhesive layer related to Examples 1 to 13 and Comparative Examples 1 to 7 Are shown in Table 3.

?: The total amount of deflection is not more than 10 mm

○: The total amount of deflection is more than 10 mm and not more than 15 mm

?: The total amount of deflection is more than 15 mm and not more than 20 mm

X: The total amount of deflection exceeds 20 mm

[Test Example 4] (Evaluation of heat non-uniformity)

The polarizer with a pressure-sensitive adhesive layer obtained in Examples and Comparative Examples was adjusted to a size of 200 mm x 150 mm using a cutting apparatus (Super Cutter, manufactured by Oji Paper Manufacturing Co., Ltd., PN1-600). The release sheet was peeled off and pasted to an alkali-free glass (Eagle XG, manufactured by Corning) through the exposed pressure-sensitive adhesive layer, followed by pressurization at 0.5 MPa and 50 占 폚 for 20 minutes with an autoclave manufactured by Kurihara Seisakusho. The bonding was performed so that the polarization axis of the polarizing plate with a pressure-sensitive adhesive layer was in the cross-Nicol state (polarizing axis: 45 deg., 135 deg.) On the front and back of the alkali-free glass. In this state, the sample was allowed to stand in a dry environment at 80 占 폚 for 250 hours, then left in an environment of 23 占 폚 and 50% RH for 2 hours. Using the sample as a sample, the thermal non-uniformity was evaluated by the following method. The results of the polarizing plate with the first pressure-sensitive adhesive layer related to Examples 1 to 12 and Comparative Examples 1 to 5 are shown in Table 2, and the results of the polarizing plates with the second pressure-sensitive adhesive layer related to Examples 1 to 13 and Comparative Examples 1 to 7 Are shown in Table 3.

<Evaluation method>

The sample was placed on a flat illuminator (HF-SL-A312LC, illuminance: 26,000 Lux, luminance: 10,000 cd, manufactured by Dentsu Ind.) And photographed with a two-dimensional color intensity meter (CA-2000 manufactured by Konica Minolta Co., And converted into a luminance distribution image by analysis software (CA-S20w, manufactured by Konica Minolta Co., Ltd.). The luminance distribution image of the obtained sample was evaluated based on Fig. 4 and the following evaluation criteria.

⊚: luminance distribution is almost uniform

○: There are slight variations in the luminance distribution of the four sides

?: There is a clear variation in the luminance distribution of the four sides

X: There is a severe deformation in the luminance distribution of four sides.

[Test Example 5] (Adhesive strength measurement - Evaluation of reworkability)

Samples having a length of 25 mm and a length of 100 mm were cut out from the polarizing plate with a pressure-sensitive adhesive layer obtained in Examples and Comparative Examples, and the release sheet was peeled off. The adhesive was applied to an alkali- And then pressurized at 0.5 MPa and 50 DEG C for 20 minutes with an autoclave manufactured by Kurihara Corporation. Thereafter, the film was allowed to stand under the conditions of 23 ° C and 50% RH for 24 hours, and then the film was peeled off with a tensile tester (Tencilon, Orientec Co., Ltd.) N / 25 mm) was measured. Conditions other than those described herein were measured in accordance with JIS Z 0237: 2009.

The adhesive strength (adhesive strength after 14 days of application; N / 25 mm) was measured in the same manner as above after being left under the conditions of 23 캜 and 50% RH for 14 days. Separately, the polarizing plate with a second pressure-sensitive adhesive layer related to Examples 1 to 13 and Comparative Examples 1 to 7 was allowed to stand for two days under the conditions of 50 ° C and 50% RH, and then the adhesive force N / 25 mm) was measured.

Based on the adhesive strength after 14 days of the application, the evaluation of the reworkability was carried out according to the following criteria.

⊚: Adhesion after 14 days of application is 8.8 N / 25 mm or less

○: Adhesive strength after 14 days of application exceeding 8.8 N / 25 mm, less than 10 N / 25 mm

?: Adhesive strength after 14 days of application of 10 N / 25 mm or more, less than 20 N / 25 mm

X: Adhesive strength after 14 days of application is 20 N / 25 mm or more

The results of the polarizing plate with the first pressure-sensitive adhesive layer related to Examples 1 to 12 and Comparative Examples 1 to 5 are shown in Table 2, and the results of the polarizing plates with the second pressure-sensitive adhesive layer related to Examples 1 to 13 and Comparative Examples 1 to 7 Are shown in Table 3.

[Test 6] (Measurement of surface resistivity of pressure-sensitive adhesive layer)

The polarizing plate with a pressure-sensitive adhesive layer obtained in Examples and Comparative Examples was cut into a size of 50 mm x 50 mm, and the obtained sample was left for 24 hours at a temperature of 23 캜 and a humidity of 50% RH. Thereafter, the release sheet was peeled off and the surface resistivity (Ω / sq) was measured according to JIS K6911 using a resistivity meter (Hiresta UP MCP-HT450 type, manufactured by Mitsubishi Chemical Co., ) Were measured. The results of the polarizing plate with the first pressure-sensitive adhesive layer related to Examples 1 to 12 and Comparative Examples 1 to 5 are shown in Table 2, and the results of the polarizing plates with the second pressure-sensitive adhesive layer related to Examples 1 to 13 and Comparative Examples 1 to 7 Are shown in Table 3.

As can be seen from Tables 2 and 3, the polarizing plate with a pressure-sensitive adhesive layer obtained in the Examples was excellent in durability, was not bent well even at a high temperature, and was not thermally uneven. In the polarizing plate with a pressure-sensitive adhesive layer obtained in Examples, the surface resistivity of the pressure-sensitive adhesive layer was low and the adverse effect on the liquid crystal cell was small. In addition, the polarizer with a pressure-sensitive adhesive layer obtained in Examples 1 to 12 was also excellent in workability.

The polarizing plate with a pressure-sensitive adhesive layer according to the present invention is suitable for bonding a polarizing plate and a liquid crystal cell, in particular, a liquid crystal cell having a transparent conductive film on the concave surface.

10A, 10B: Polarizer with a pressure-sensitive adhesive layer
1: pressure-sensitive adhesive layer
2A: polarizer
2B: Composite polarizer
21: Polarizer
22: First protective layer
23: Second protective layer
24: First retardation plate
241: a first acrylic resin layer
242: phase difference developing layer
243: a second acrylic resin layer
25: Second phase difference plate (second protective layer)
26: second pressure-sensitive adhesive layer
27: protective layer (first protective layer)

Claims (14)

A polarizer,
A first protective layer stacked on one side of the polarizer,
A second protective layer laminated on the other surface side of the polarizer,
A pressure-sensitive adhesive layer laminated on a surface of the second protective layer opposite to the surface on the polarizer side,
Sensitive adhesive layer-attached polarizer plate,
The pressure-
(A1), an aromatic ring-containing monomer (a2), and a hydroxyl group-containing monomer (a3) as a monomer unit constituting the polymer and having a hydroxyl value of 5 to 20 mgKOH / g and an acid value of 5 (meth) acrylic acid ester copolymer (A) having a weight-average molecular weight of 1,000 to 3,000,000,
The isocyanate-based crosslinking agent (B)
Of a pressure-sensitive adhesive composition having a gel fraction of 60 to 89%
Wherein the second protective layer comprises a cycloolefin resin or triacetyl cellulose,
The thickness of the polarizer is 1 to 20 占 퐉,
The thickness of the second protective layer is 5 to 30 탆,
Wherein the ratio of the thickness of the second protective layer to the thickness of the polarizer is 1.0 to 5.0. The method according to claim 1,
The thickness of the first protective layer is 5 to 120 탆,
Wherein a ratio of a thickness of the first protective layer to a thickness of the polarizer is 1.0 to 6.0. The method according to claim 1,
The polarizing plate with a pressure-sensitive adhesive layer, wherein the first protective layer is made of triacetyl cellulose. The method according to claim 1,
Wherein the alicyclic structure in the alicyclic structure-containing monomer (a1) is a polycyclic alicyclic structure. The method according to claim 1,
The polarizing plate with a pressure-sensitive adhesive layer, wherein the adhesive composition further comprises an epoxy group-containing silane coupling agent (C1). The method according to claim 1,
The polarizing plate with a pressure-sensitive adhesive layer, wherein the pressure-sensitive adhesive composition further comprises a mercapto group-containing silane coupling agent (C2). The method according to claim 1,
The polarizing plate with a pressure-sensitive adhesive layer, wherein the pressure-sensitive adhesive composition further contains an antistatic agent (D). 8. The method of claim 7,
The antistatic agent (D) is an ionic compound composed of a nitrogen-containing heterocyclic cation and a halogenated phosphoric acid anion as a solid at room temperature. The method according to claim 1,
The polarizing plate with a pressure-sensitive adhesive layer, wherein the isocyanate-based crosslinking agent (B) is a compound having an aromatic ring. The method according to claim 1,
The polarizing plate with a pressure-sensitive adhesive layer, wherein the (meth) acrylic acid ester copolymer (A) does not contain a carboxyl group-containing monomer as a monomer unit constituting the polymer. The method according to claim 1,
The polarizing plate with a pressure-sensitive adhesive layer, wherein the (meth) acrylic acid ester copolymer (A) contains 1 to 40 mass% of the alicyclic structure-containing monomer (a1) as a monomer unit constituting the polymer. The method according to claim 1,
The polarizing plate with a pressure-sensitive adhesive layer, wherein the (meth) acrylic acid ester copolymer (A) contains 1 to 40 mass% of the aromatic ring-containing monomer (a2) as a monomer unit constituting the polymer. The method according to claim 1,
The polarizing plate with a pressure-sensitive adhesive layer, wherein the (meth) acrylic acid ester copolymer (A) contains 0.5 to 10 mass% of the hydroxyl group-containing monomer (a3) as a monomer unit constituting the polymer. The method according to claim 1,
Wherein the pressure-sensitive adhesive layer has a surface resistivity of 1.0 10 ¹² ? / Sq or less.

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