JP6969564B2 - Polarizing plate and liquid crystal display device - Google Patents

Description

The present invention relates to a polarizing plate and a liquid crystal display device.

Liquid crystal display devices are widely used as liquid crystal displays for televisions, notebook computers, smartphones, and the like. A liquid crystal display device usually includes a liquid crystal cell and a pair of polarizing plates that sandwich the liquid crystal cell; the polarizing plate includes a polarizing element and a pair of protective films that sandwich the polarizing element.

As the protective film, a film containing cellulose acylate as a main component is generally used. Specifically, a laminated film including an inner layer containing cellulose acylate and second inorganic particles and a pair of outermost layers containing cellulose acylate and first inorganic fine particles sandwiching the inner layer is proposed (for example). Patent Document 1).

However, the film containing cellulose acylate as a main component has a problem of low moisture resistance. As a result, the polarizing plate containing a film containing cellulose acylate as a main component as a protective film has a problem that deterioration due to moisture of the polarizing element under high temperature and high humidity cannot be sufficiently suppressed. Therefore, instead of a film containing cellulose acylate as a main component, a film containing a cycloolefin resin as a main component is being studied.

A film containing a cycloolefin resin as a main component has higher hydrophobicity than a film containing cellulose acylate as a main component, and therefore has high moisture resistance. By laminating a film containing such a cycloolefin resin as a main component and a polarizing element via a water glue (PVA-based adhesive) or an ultraviolet curable adhesive, a polarizing plate with less deterioration of the polarizing element can be obtained. It is thought that it can be done.

However, since the film containing a cycloolefin resin as a main component has high hydrophobicity, it is difficult to be compatible with water glue (PVA-based adhesive) or an ultraviolet curable adhesive, and it is difficult to obtain adhesiveness with a polarizing element. There was a problem.

On the other hand, there has been proposed a polarizing plate obtained by providing an easy-adhesion layer on a film containing a cycloolefin resin as a main component and bonding it with a polarizing element (for example, Patent Document 2).

Japanese Unexamined Patent Publication No. 2014-149325 Japanese Unexamined Patent Publication No. 2006-171707

However, a liquid crystal display device provided with a polarizing plate obtained by providing an easy-adhesion layer on a film containing a cycloolefin resin as a main component has a problem that optical unevenness is likely to occur under high temperature and high humidity. Optical unevenness under high temperature and high humidity was particularly likely to occur when the thickness of the film containing a cycloolefin resin as a main component was thin.

The cause of this is not clear, but it is presumed as follows. That is, the easy-adhesion layer is obtained by coating and forming on a film containing a cycloolefin resin as a main component, but coating unevenness is likely to occur during the coating formation. In particular, since a thin film has no stiffness, coating unevenness is more likely to occur. As a result, the adhesiveness between the easy-adhesive layer and the film containing the cycloolefin resin as a main component tends to be uneven, and in the portion where the adhesiveness is weak, the moisture in the outside air easily enters the polarizing element. As a result, it is considered that the polarizing element is decolorized and deteriorated by moisture, causing optical unevenness.

The present invention has been made in view of such circumstances, and a polarizing plate having good adhesion to a polarizing element even if the protective film is thin, and a liquid crystal display containing the same, in which optical unevenness is suppressed. The purpose is to provide the device.

（一般式（Ｉ）のｎは、１以上の整数である）

（一般式（ＩＩ）中、
Ｒ^１は、アルキル基を表し、
Ｒ^２は、ポリエーテル基、ポリエステル基又はアラルキル基を表し、
ｍ、ｘ及びｙは、それぞれ１以上の整数を表す）

（一般式（ＩＩＩ）中、
Ｒ^３は、ポリエーテル基、ポリエステル基又はアラルキル基を表し、
ｍは、１以上の整数を表す）
［５］ 前記糊浸透促進剤Ｘは、無機粒子である、［１］〜［４］のいずれかに記載の偏光板。
［６］ 前記糊浸透促進剤Ｘの含有量は、前記シクロオレフィン系樹脂の全質量に対して０．１〜２．５質量％である、［１］〜［５］のいずれかに記載の偏光板。
［７］ 前記糊浸透促進剤Ｘと前記重合体Ｙの含有質量比は、前記重合体Ｙ／前記糊浸透促進剤Ｘ＝０．１〜２である、［２］に記載の偏光板。
［８］ 前記シクロオレフィン系樹脂の４０℃９０％ＲＨにおける透湿度は、１０〜３５０ｇ／ｍ^２・ｄａｙである、［１］〜［７］のいずれかに記載の偏光板。
［９］ 前記保護フィルムの厚みが１０〜３０μｍである、［１］〜［８］のいずれかに記載の偏光板。
［１０］ 液晶セルと、それを挟持する一対の偏光板とを含み、前記一対の偏光板の少なくとも一方が、［１］〜［９］のいずれかに記載の偏光板である、液晶表示装置。
［１１］［１］〜［９］のいずれかに記載の偏光板に含まれる保護フィルムは、前記液晶セルと接している、［１０］に記載の液晶表示装置。[1] Between a polyvinyl alcohol-based film, a polarizing element containing an adsorption-oriented bicolor dye thereof, a protective film provided on at least one surface of the polarizing element, and the polarizing element and the protective film. A polarizing plate including an adhesive layer provided in the above, wherein the protective film contains a cycloolefin-based resin and a glue permeation accelerator X having an adsorbed water content of 1% by mass or more and less than 2% by mass. The abundance of the glue permeation accelerator X in the region 0.5 to 3 μm from the surface of the protective film provided with the adhesive layer is 0. A polarizing plate having a thickness of 1 to 10 atom%, the adhesive constituting the adhesive layer permeates the inside of the protective film, and the permeation depth D of the adhesive is 0.5 to 3 μm. ..
[2] The polarizing plate according to [1], wherein the region of the protective film further contains a polymer Y having a polysiloxane-containing group or a fluorinated alkylene-containing group.
[3] The polarizing plate according to [2], wherein the LogP value of the polysiloxane-containing group or the fluorinated alkylene-containing group is 0.5 or more and 6.0 or less.
[4] The polymer Y is a polysiloxane-based compound represented by the following general formula (I) or a modified polysiloxane-based compound represented by the general formula (II) or (III), [2] or [ 3] The polarizing plate according to the above.

(N in the general formula (I) is an integer of 1 or more)

(In general formula (II),
R ¹ represents an alkyl group
R ² represents a polyether group, a polyester group or an aralkyl group.
m, x and y each represent an integer of 1 or more)

(In general formula (III),
R ³ represents a polyether group, a polyester group or an aralkyl group.
m represents an integer of 1 or more)
[5] The polarizing plate according to any one of [1] to [4], wherein the glue permeation accelerator X is an inorganic particle.
[6] The content of the glue permeation accelerator X is 0.1 to 2.5% by mass with respect to the total mass of the cycloolefin resin, according to any one of [1] to [5]. Polarizer.
[7] The polarizing plate according to [2], wherein the content mass ratio of the glue permeation accelerator X and the polymer Y is the polymer Y / the glue permeation accelerator X = 0.1 to 2.
[8] The polarizing plate according to any one of [1] to [7], wherein the cycloolefin resin has a moisture permeability of 10 to 350 g / m ^{2 · day at 40 ° C. and 90% RH.}
[9] The polarizing plate according to any one of [1] to [8], wherein the protective film has a thickness of 10 to 30 μm.
[10] A liquid crystal display device including a liquid crystal cell and a pair of polarizing plates sandwiching the liquid crystal cell, wherein at least one of the pair of polarizing plates is the polarizing plate according to any one of [1] to [9]. ..
[11] The liquid crystal display device according to [10], wherein the protective film contained in the polarizing plate according to any one of [1] to [9] is in contact with the liquid crystal cell.

According to the present invention, it is possible to provide a polarizing plate having good adhesiveness to a polarizing element even if the protective film is thin, and a liquid crystal display device containing the same and suppressing optical unevenness.

It is a schematic diagram which shows an example of the structure of the polarizing plate of this invention. It is a schematic diagram which shows an example of the basic structure of the liquid crystal display device of this invention.

The present inventors include a glue permeation accelerator X having an adsorbed water content in a specific range in a region of a protective film containing a cycloolefin resin as a main component, which includes at least a surface on which an adhesive layer is provided. Therefore, it has been found that good and uniform adhesiveness with a polarizing element can be obtained without providing an easy-adhesion layer.

Although the reason for this is not clear, the glue permeation accelerator X having an adsorbed water content in a specific range enhances the affinity of the protective film with the water-based adhesive and the ultraviolet curable adhesive within a range that does not impair the moisture resistance. This is considered to be because the adhesive can easily penetrate into the surface layer region of the protective film.

Further, by further combining the polymer Y having a polysiloxane-containing group or a fluorinated alkylene-containing group in addition to the glue permeation accelerator X, the adhesive component permeated into the surface layer region of the protective film by the glue permeation accelerator X can be obtained. It can be easily expanded in a network. As a result, it is possible to highly suppress optical unevenness that tends to occur particularly when the thickness of the protective film containing a cycloolefin resin as a main component is thin. The present invention has been made based on such findings.

As described above, the protective film of Patent Document 1 is a laminated film containing cellulose acylate as a main component and an outer layer containing inorganic particles. As described above, Patent Document 1 combines the "hydrophilic cellulose acylate" with the "hydrophilic inorganic particles" from the viewpoint of being easily compatible with the "hydrophilic cellulose acylate" and easily suppressing the aggregation of the inorganic particles. That is, when the resin is a "hydrophobic cycloolefin resin", it is suggested to add "hydrophobic inorganic particles" from the viewpoint of being easily compatible with the resin and easily suppressing the aggregation of the inorganic particles. ..
On the other hand, in the present invention, the "hydrophobic cycloolefin resin" is combined with the "hydrophilic glue permeation accelerator X" from the viewpoint of imparting the permeability of the adhesive. As described above, it can be seen that the idea and composition of the present invention are different from the idea and composition of Patent Document 1.

1. 1. Polarizing Plate The polarizing plate of the present invention includes a polarizing element, a protective film provided on at least one surface thereof, and an adhesive layer provided between the polarizing element and the protective film.

FIG. 1 is a cross-sectional view showing an example of the polarizing plate of the present invention. As shown in FIG. 1, the polarizing plate 10 of the present invention has an adhesive provided between the polarizing element 11, the protective film 13A and the protective film 13B sandwiching the polarizing element 11, and the polarizing element 11 and the protective film 13A. It includes a layer 15A and an adhesive layer 15B provided between the polarizing element 11 and the protective film 13B. Since at least the protective film 13A is a specific protective film containing the glue permeation accelerator X, the adhesive constituting the adhesive layer 15A has appropriately penetrated into the surface layer region of the protective film 13A.

1-1. Polarizer 11
The polarizing element 11 is an element that allows only light on a plane of polarization in a certain direction to pass through, and is usually a polyvinyl alcohol-based polarizing film. The polyvinyl alcohol-based polarizing film includes a polyvinyl alcohol-based film and a dichroic dye that is adsorbed and oriented thereof.

The polyvinyl alcohol-based polarizing film may be a film obtained by uniaxially stretching a polyvinyl alcohol-based film and then dyeing it with a dichroic dye (containing iodine); after dyeing the polyvinyl alcohol-based film with a dichroic dye. , It may be a uniaxially stretched film. The absorption axis of the stator 11 is usually parallel to the maximum stretching direction.

For example, the ethylene unit content described in JP-A-2003-248123, JP-A-2003-342322, etc. has a content of 1 to 4 mol%, a degree of polymerization of 2000 to 4000, and a degree of saponification of 99.0 to 99.99 mol%. Ethylene-modified polyvinyl alcohol is used. Of these, an ethylene-modified polyvinyl alcohol film having a hot water cutting temperature of 66 to 73 ° C. is preferably used.

The thickness of the polarizing element 11 is preferably 5 to 30 μm, and more preferably 5 to 25 μm in order to reduce the thickness of the polarizing plate.

1-2. Protective film 13A (specific protective film)
The protective film 13A contains a cycloolefin-based resin and a glue permeation accelerator X having an adsorbed water content of 1% by mass or more and less than 2% by mass.

1-2-1. Cycloolefin resin The cycloolefin resin is a polymer of a cycloolefin monomer (norbornene-based monomer) having a norbornene skeleton, or a copolymer of a norbornene-based monomer and other copolymerizable monomers. Is.

The norbornene-based monomer preferably contains a norbornene-based monomer represented by the following general formula (A-1).

^{R 1} of the general formula (A-1) represents a hydrogen atom, a hydrocarbon group having 1 to 5 carbon atoms, or an alkylsilyl group having an alkyl group having 1 to 5 carbon atoms. Of these, a hydrocarbon group having 1 to 5 carbon atoms is preferable, and a hydrocarbon group having 1 to 3 carbon atoms is more preferable.

^{R 2} of the general formula (A-1) is a polar group selected from the group consisting of a carboxy group, a hydroxy group, an alkoxycarbonyl group, an allyloxycarbonyl group, an amino group, an amide group, and a cyano group, or a halogen atom (fluorine). Represents an atom, a chlorine atom, a bromine atom or an iodine atom). Of these, a polar group is preferable, a carboxy group, a hydroxy group, an alkoxycarbonyl group and an aryloxycarbonyl group are preferable, and an alkoxycarbonyl group and an aryloxycarbonyl group are more preferable from the viewpoint of ensuring solubility at the time of solution film formation.

P in the general formula (A-1) represents an integer of 0 to 2. p is preferably 1 or 2.

The norbornene-based monomer represented by the general formula (A-1) has an asymmetric structure. In other words, the general formula (A-1) substituent norbornene monomer represented by R ¹ and R ^2, since it is replaced only to a ring-constituting carbon atoms of the one side of the axis of symmetry of the molecule, the molecule The symmetry of is low. In the cycloolefin monomer having such an asymmetric structure, even if the main chains are arranged in the x direction, the side chains are oriented not only in the xy plane but also in various other directions, so that only Ro is likely to be expressed. , It is considered that Rt is unlikely to increase.

The content ratio of the norbornene-based monomer represented by the general formula (A-1) is, for example, 50 mol% or more, preferably 60 mol% or more, based on the total of all norbornene-based monomers constituting the cycloolefin resin. % Or more, more preferably 80 mol% or more. A cycloolefin-based resin containing a certain amount or more of a monomer represented by the general formula (A-1) tends to lower the Rt of the protective film 13A.

The norbornene-based monomer may further contain other norbornene-based monomers other than the norbornene-based monomer represented by the general formula (A-1), if necessary. Examples of other norbornene-based monomers include norbornene-based monomers represented by the following formula (A-2).

^{R 3 to} R ⁶ of the general formula (A-2) independently represent a hydrogen atom, a hydrocarbon group having 1 to 30 carbon atoms, or a polar group. However, ^{except when all of R 3 to} R ⁶ become hydrogen atoms, it is assumed that R ³ and R ⁴ do not become hydrogen atoms at the same time, or R ⁵ and R ⁶ do not become hydrogen atoms at the same time.

The hydrocarbon group having 1 to 30 carbon atoms is preferably a hydrocarbon group having 1 to 10 carbon atoms, and more preferably a hydrocarbon group having 1 to 5 carbon atoms. The hydrocarbon group having 1 to 30 carbon atoms may further have a linking group containing a halogen atom, an oxygen atom, a nitrogen atom, a sulfur atom or a silicon atom. Examples of such linking groups include divalent polar groups such as carbonyl groups, imino groups, ether bonds, silyl ether bonds, thioether bonds and the like. Examples of the hydrocarbon group having 1 to 30 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group and the like.

Examples of polar groups include carboxy groups, hydroxy groups, alkoxy groups, alkoxycarbonyl groups, allyloxycarbonyl groups, amino groups, amide groups and cyano groups. Of these, a carboxy group, a hydroxy group, an alkoxycarbonyl group and an aryloxycarbonyl group are preferable, and an alkoxycarbonyl group and an aryloxycarbonyl group are preferable from the viewpoint of ensuring solubility during solution film formation.

P in the general formula (A-2) represents an integer of 0 to 2. p is preferably 1 or 2.

Specific examples of the norbornene-based monomer represented by the general formula (A-1) are shown in the exemplary compounds 15 to 34, and specific examples of the norbornene-based monomer represented by the general formula (A-2) are exemplified compounds. 1 to 14 are shown.

Examples of other norbornene-based monomers include dicyclopentadiene, dihydrodicyclopentadiene and the like.

Examples of the copolymerizable monomer copolymerizable with the norbornene-based monomer include a copolymerizable monomer capable of ring-opening copolymerization with the norbornene-based monomer and an addition copolymerizable with the norbornene-based monomer. Copolymerizable monomer is included.

Examples of open-ring copolymerizable copolymerizable monomers include non-norbornene-based monomers such as cyclobutene, cyclopentene, cycloheptene, cyclohexene, cyclooctene, cyclopentadiene, cyclohexadiene, cycloheptadiene and cyclooctadiene. Cycloolefin is included.

Examples of copolymerizable monomers include unsaturated double bond-containing compounds, vinyl cyclic hydrocarbon monomers and (meth) acrylates. Examples of unsaturated double bond-containing compounds are olefin compounds having 2 to 12 (preferably 2 to 8) carbon atoms, and examples thereof include ethylene, propylene and butene. Examples of vinyl-based cyclic hydrocarbon monomers include vinyl cyclopentene-based monomers such as 4-vinylcyclopentene and 2-methyl-4-isopropenylcyclopentene. Examples of (meth) acrylates include alkyl (meth) acrylates having 1 to 20 carbon atoms such as methyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and cyclohexyl (meth) acrylate.

The content ratio of the norbornene-based monomer in the cycloolefin-based resin may be, for example, 50 to 100 mol%, preferably 60 to 100 mol%, based on the total of all the monomers constituting the cycloolefin-based resin.

As described above, the cycloolefin resin is a polymer obtained by polymerizing or copolymerizing a norbornene monomer, preferably a norbornene monomer represented by the general formula (A-1) or (A-2). And examples include:
(1) A ring-opening polymer of a norbornene-based monomer (2) A ring-opening copolymer of a norbornene-based monomer and a copolymerizable monomer that can be ring-opened and copolymerizable (3) The above (1) or (2) Hydrogenated ring-opened (co) polymer (4) The ring-opened (co) polymer of (1) or (2) above was cyclized by the Friedelcrafts reaction and then hydrogenated (co-). ) Polymer (5) Additive copolymer of norbornene-based monomer and unsaturated double bond-containing compound (6) Addition copolymer of norbornene-based monomer with vinyl-based cyclic hydrocarbon monomer and its Hydrogen additive (7) Addition polymer of norbornene-based monomer and (meth) acrylate

Among them, (1) to (3) are preferable, and (3) is more preferable. That is, the cycloolefin-based resin has a structural unit represented by the following general formula (B-1) in that the glass transition temperature of the obtained cycloolefin-based resin can be increased and the light transmittance can be increased. It is preferable to include at least one of the structural units represented by the following general formula (B-2). The structural unit represented by the general formula (B-1) is a structural unit derived from a ring-opened product of the norbornene-based monomer represented by the above-mentioned general formula (A-1), and is a structural unit derived from the general formula (B-2). ) Is a structural unit derived from a ring-opened product of the norbornene-based monomer represented by the above-mentioned general formula (A-2).

X in the general formula (B-1) is −CH = CH − _{or −CH 2 CH 2−.}

^R 1 to R ⁴ and p in general formula (B-1) are respectively and ^R 1 to R ⁴ and p of formula (A-1) synonymous.

X in the general formula (B-2) is −CH = CH − _{or −CH 2 CH 2−.}

^R 5 to R ⁶ and p in the general formula (B-2) are respectively and ^R 5 to R ⁶ and p in the general formula (A-2) synonymous.

The cycloolefin-based resin can be obtained by any known method, for example, the methods described in JP-A-2008-107534, JP-A-2005-227606, and Japanese Patent No. 4466272. For example, in the polymer of (3), the monomer is solution-polymerized, and then the double bond of the main chain of the obtained ring-opening polymer is hydrogenated. The catalyst is removed (decatalyzed) from the polymer obtained after hydrogenation, and the mixture is further dried under reduced pressure to remove the solvent (desolvent) to obtain the polymer of (3).

Intrinsic viscosity [η] inh of cycloolefin resin is preferably 0.2~5cm ³ / g, more preferably 0.3~3cm ³ / g, 0.4~1.5cm ³ It is more preferably / g.

The number average molecular weight Mn of the cycloolefin resin is preferably 8000 to 100000, more preferably 1000 to 80000, and further preferably 12000 to 50000. The weight average molecular weight Mw of the cycloolefin resin is preferably 20000 to 30000, more preferably 30,000 to 250,000, and even more preferably 40,000 to 200,000. The number average molecular weight Mn and the weight average molecular weight Mw of the cycloolefin resin can be measured by the same method as described above.

Moisture permeability at 40 ° C. 90% RH cycloolefin resin (moisture permeability at 40 ° C. 90% RH of the film thickness of 20μm consisting of cycloolefin resin) may for example 10~500g ^/ m 2 · day. When the moisture permeability of the cycloolefin resin at 40 ° C. and 90% RH is 10 g / m ² · day or more, the moisture taken into the protective film 13A is easily released, so that the deterioration of the polarizing element is easily suppressed. When it is 500 g / m ² · day or less, it is easy to suppress the deterioration of the polarizing element due to the permeated moisture. The moisture permeability of the cycloolefin resin at 40 ° C. and 90% RH is more preferably ^{10 to 350 g / m 2 · day.}

For the moisture permeability of the cycloolefin resin at 40 ° C. 90% RH, a film having a thickness of 20 μm made of the cycloolefin resin was produced by solution film formation, and the moisture permeability of the obtained film at 40 ° C. 90% RH was determined by JIS Z 0208. It can be measured and obtained by a method (cup method) based on.

The content of the cycloolefin resin in the protective film 13A may be 50% by mass or more, preferably 70% by mass or more, based on the total mass of the protective film 13A.

1-2-2. Glue penetration accelerator X
The glue permeation accelerator X can be added for the purpose of facilitating the permeation of the adhesive constituting the adhesive layer 15A into the protective film 13A.

The glue permeation accelerator X is preferably fine particles having an adsorbed water content of 1.0% by mass or more and less than 2.0% by mass. When the adsorbed water content is 1.0% by mass or more, appropriate hydrophilicity can be imparted to the surface layer region of the protective film 13A, so that the water-based adhesive or the like can easily penetrate into the inside of the protective film 13A. When the amount of adsorbed water is less than 2.0% by mass, the hydrophilicity of the surface layer region of the protective film 13A does not increase too much and the moisture resistance is not easily impaired. It is easy to suppress the deterioration of the child.

The adsorbed water content of the glue permeation accelerator X can be measured by the following procedure.
1) After immersing the polarizing plate 11 in water at room temperature to peel off the protective film 13A, the obtained protective film 13A is dissolved in a good solvent (methylene chloride or the like), and the glue permeation accelerator X is added by a centrifuge. Isolate.
2) The adsorbed water content of the glue permeation accelerator X obtained by isolation is measured using a high-precision steam adsorption amount measuring device BELSORP-aqua3 (manufactured by Nippon Bell Co., Ltd.). The high-precision steam adsorption amount measuring device BELSORP-aqua3 reaches a solid-gas equilibrium under the condition that only the target gas (water in the present invention) is present, and measures the solid mass and the vapor pressure at this time. be. The specific measurement conditions and procedures are the same as those in the examples described later.

The amount of adsorbed water can be adjusted by adjusting the material of the fine particles, the average particle size, the specific surface area, and the like. In order to increase the amount of adsorbed water, for example, the material of the fine particles may be a material having a high affinity with water (for example, silica), the average particle size may be reduced, or the specific surface area may be increased.

The glue permeation accelerator X having an adsorbed water content within the above range may be organic fine particles or inorganic fine particles.

Examples of organic fine particles include acrylic fine particles. Examples of commercially available organic fine particles include Epostal MX series (manufactured by Nippon Shokubai Co., Ltd.).

Examples of inorganic fine particles include silicon dioxide (SiO ₂ ), titanium dioxide (TiO ₂ ), aluminum oxide (Al ₂ O ₃ ), tin oxide (SnO ₂ ), cobalt oxide (CoO), and iron oxide (Fe ₂ O _3). ) And fine particles such as yttrium oxide (Y ₂ O _3). Examples of commercially available products of inorganic fine particles include NanoTek SiO ₂ and NanoTek Al ₂ O ₃ . Among them, highly hydrophilic adhesives and highly polar sites such as hydroxy groups (OH groups) on the surface of silica fine particles and oxygen atoms (Si-O-Si, O = Si = O) contained in siloxane bonds. _{Fine particles of silicon dioxide (SiO 2} ) are preferable from the viewpoint of interaction with each other.

The average primary particle size of the organic fine particles or the inorganic fine particles is preferably 5 to 50 nm. When the average primary particle size is 5 nm or more, it is easy to appropriately increase the amount of adsorbed water, and when it is 50 nm or less, it is easy to suppress the increase in haze. The average primary particle size of the organic fine particles or the inorganic fine particles is more preferably 5 to 30 nm.

The average primary particle size of the organic fine particles or the inorganic fine particles in the protective film 13A can be measured by the following method.
That is, the polarizing plate is tomographically cut with a microtome (EM UC6 manufactured by Leica), and the film cross section of the protective film 13A is photographed with a scanning electron microscope (SEM) at an appropriate magnification. Then, the primary particle diameters of 100 particles included in the tomographic cut photograph are measured, and the average value thereof is taken as the average primary particle diameter. When the cross section of the particle is circular, the primary particle diameter is the diameter, and when the cross section is not circular, the area is calculated and converted into a circular shape. As a scanning electron microscope (SEM), JSM-6060LA (JEOL: JEOL Ltd.) can be used.

The specific surface area of the organic fine particles or the inorganic fine particles is preferably 10 to ^{400 m 2 / g.} When the specific surface area is 10 m ² / g or more, the adsorbed water content is likely to be appropriately increased, and when the ^{specific surface area is 400 m 2} / g or less, the adsorbed water content is not too large, so that the moisture resistance of the protective film 13A is not easily impaired. The specific surface area of the organic fine particles or inorganic fine particles, more preferably from 20 to 200 m ² / g, and more preferably 30 to 150 m ² / g. The specific surface area of the organic fine particles or the inorganic fine particles can be measured by the BET method.

The glue permeation accelerator X is a region of the protective film 13A in the thickness direction including at least a surface on which the adhesive layer 15A is provided, preferably a region R of 0.5 to 3.0 μm from the surface on which the adhesive layer 15A is provided. It suffices if it is included in. That is, as long as the glue permeation accelerator X is contained in the region R, the glue permeation accelerator X may be uniformly dispersed in the thickness direction of the protective film 13A, and includes a surface on which the adhesive layer is provided. It may be unevenly distributed only in the surface layer region.

The abundance of the glue permeation accelerator X in the region R is preferably 0.1 to 10 atom% with respect to the total number of atoms of all the atoms constituting the protective film 13A. When the abundance rate of the glue permeation accelerator X in the region R is 0.1 atom% or more, the hydrophilicity of the surface layer region of the protective film 13A can be appropriately increased, so that the adhesive can be easily permeated and the content is 10 atom% or less. The hydrophilicity of the surface layer region of the protective film 13A does not increase too much, and the moisture resistance is not easily impaired. The abundance of the glue permeation accelerator X in the region R is more preferably 0.1 to 5.0 atom% with respect to the total number of atoms of all the atoms constituting the protective film 13A.

The abundance of the glue permeation accelerator X is determined by elemental analysis of the surface of the protective film 13A on which the adhesive layer 15A is provided by X-ray photoelectron spectroscopy (XPS), and a specific atom peculiar to the glue permeation accelerator X (for example, Si). It can be identified by measuring the concentration of (atoms).
The concentration of a specific atom peculiar to the glue permeation accelerator X is the ratio of the number of atoms of the specific atom when the total of the quantitative values of the total number of atoms constituting the protective film 13A measured by XPS is 100 atom%. expressed. The XPS measurement conditions are the same as in the examples described later.
The surface of the protective film 13A on which the adhesive layer 15A is provided can be obtained by peeling off the protective film 13A from the polarizing plate by, for example, the same method as described above.

The device used for XPS measurement is not particularly limited, but for example, a model "QUANTERASXM" manufactured by ULVAC-PHI can be used.

The content of the glue permeation accelerator X in the protective film 13A may be set so that the abundance of the glue permeation accelerator X in the region R is within the above range, and is, for example, 0 with respect to the total mass of the cycloolefin resin. It can be 1-5% by weight. When the content of the glue permeation accelerator X is 0.1% by mass or more, it is easy to promote the permeation of the adhesive into the surface layer region of the protective film 13A, and when it is 5% by mass or less, the haze of the protective film 13A It is easy to suppress the increase. The content of the glue permeation accelerator X in the protective film 13A is more preferably 0.1 to 2.5% by mass with respect to the total mass of the cycloolefin resin.

1-2-3. Other components The protective film 13A may further contain components other than the above, if necessary. Examples of other components include polymer Y having a polysiloxane-containing group or a fluorinated alkylene-containing group, an ultraviolet absorber, an antioxidant and the like.

1-2-3-1. Polymer Y
The polymer Y is a polymer having a polysiloxane-containing group or a fluorinated alkylene-containing group.

The ClogP value of the polysiloxane-containing group or the fluorinated alkylene-containing group contained in the polymer Y is preferably 0.5 or more and 6.0 or less. When the ClogP value of these groups is 0.5 or more, the hydrophilicity is not too high, so that the moisture resistance of the protective film 13A is not easily impaired, and when it is 6 or less, the adhesive exhibits appropriate hydrophilicity. It is easy to promote the penetration of.

The ClogP value is a value obtained by calculation of the common logarithm logP of 1-octanol and the partition coefficient P to water. In the present invention, the computational chemistry integrated platform SCIGRESS manufactured by Fujitsu Limited is used as the method and software used for calculating the LogP value.

Subject to the provisions of ClogP value "polysiloxane-containing group", a polysiloxane compound represented by the general formula (I) ~ (III) to be described later - the repeating unit - [- _SiR 2 -O] In the polymer containing a structural unit derived from a monomer represented by the general formula (1) described later, it means a polysiloxane-containing group represented by L. The "fluorinated alkylene-containing group" subject to the regulation of the ClogP value is a fluorinated alkylene represented by L in a polymer containing a structural unit derived from a monomer represented by the general formula (1) described later. Refers to the containing group.

The polysiloxane-containing group or the fluorinated alkylene-containing group may be in the molecular main chain or the molecular side chain of the polymer Y.

Examples of the polymer Y having a polysiloxane-containing group or a fluorinated alkylene-containing group in the molecular main chain include a polysiloxane-based compound, a modified product of a polysiloxane-based compound (modified polysiloxane-based compound), and a polysiloxane at the molecular terminal. Acrylic polymers having a contained group and the like are included.

The polysiloxane-based compound is a linear polymer having a siloxane bond, and examples thereof include tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane, methyltochiethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, and γ. -Glysidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ Hydrolytic silyls such as −methacryloxypropyltriethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-acryloxypropyltrimethoxysilane, γ-acryloxypropylmethyldimethoxysilane Includes a partial hydrolyzate of a silane compound having a group.

Above all, the polysiloxane compound is preferably a compound represented by the following general formula (I).

N in the general formula (I) is a repetition number and is an integer of 1 or more.

The modified polysiloxane-based compound may be a compound in which the side chain or the terminal of the polysiloxane-based compound is replaced with a non-reactive organic group or a reactive organic group. Examples of non-reactive organic groups include polyether groups, aralkyl groups, long-chain alkyl groups, phenyl groups, and polyester groups. Examples of reactive organic groups include amino groups, epoxy groups, alicyclic epoxy groups, mercapto groups, carboxyl groups, and (meth) acryloyl groups. The ClogP value of the polysiloxane-containing group can be adjusted by replacing (modifying) the side chain or the terminal of the polysiloxane compound with these groups.

Above all, the modified polysiloxane compound is preferably a compound in which n of the general formula (I) or the type of the modification site is changed. Such examples include compounds represented by the following general formula (II) and compounds represented by the following general formula (III).

^{R 1} of the general formula (II) is an alkyl group (for example, a methyl group, an ethyl group, etc.).

M in the general formula (II) is an integer of 1 or more. R ² is a polyether group, a polyester group or an aralkyl group.

X in the general formula (II) is the ^{number of repetitions of the structural unit including R 1} , and is an integer of 1 or more. y is the ^{number of repetitions of the structural unit including R 2} , and is an integer of 1 or more.

The compound having the structure represented by the general formula (II) is a ^{copolymer containing a structural unit containing R 1} and a structural unit containing R ² , and these structural units are bonded in any order. It may be, for example, any of a block copolymer, a graft copolymer, and a random copolymer, but a block copolymer or a graft copolymer is more preferable. For example, examples of the compound having the structure represented by formula (II), structural units containing R ^2, structural units containing R ^1, include polymer bound in the order of structural units containing R ^2.

R ³ and m in the general formula (III) are synonymous with ^{R 2 and m in the general formula (II), respectively.}

Examples of compounds having a structure represented by the general formula (II) or the general formula (III) include alkyl-modified polydimethylsiloxane, carboxy-modified polydimethylsiloxane, amino-modified polydimethylsiloxane, epoxy-modified polydimethylsiloxane, and fluorine-modified. Includes polydimethylsiloxane, (meth) acrylate-modified polydimethylsiloxane, and the like.

Examples of polysiloxane-based compounds or modified polysiloxane-based compounds other than the above include GL series (GL-01, GL-02R, GL-03, GL-04R) and KL series (KL401, KL402) manufactured by Kyoeisha Chemical Co., Ltd. , KL403, KL404, see formula (X) below); Silface SAG002, Silface SAG005, Silface SAG008, Silface SAG503A manufactured by Nisshin Chemical Industry Co., Ltd .; FA-600, KC- manufactured by Shinetsu Chemical Industry Co., Ltd. 89S, KR-500, KR-516, X-40-9296, KR-513, X-22-161A, X-22-162C, X-22-163, X-22-163A, X-22-164, X-22-164A, X-22-173BX, X-22-174ASX, X-22-176DX, X-22-343, X-22-2046, X-22-2445, X-22-3939A, X- 22-4039, X-22-4015, X-22-4272, X-22-4741, X-22-4952, X-22-6266, KF-50-100cs, KF-96L-1cs, KF-101, KF-102, KF-105, KF-351, KF-352, KF-353, KF-354L, KF-355A, KF-393, KF-615A, KF-618, KF-857, KF-859, KF- 860, KF-862, KF-877, KF-889, KF-945, KF-1001, KF-1002, KF-1005, KF-2012, KF-2201, X-22-2404, X-22-2426, X-22-3710, KF-6004, KF-6011, KF-6015, KF-6123, KF-8001, KF-8010, KF-8012, X-22-9002; DOWN CORNING 100F manufactured by Dow Corning Co., Ltd. ADDITIVE, DOWN CORNING 11 ADDITIVE, DOWN CORNING 3037 INTERMEDIATE, DOWN CORNING 56 ADDITIVE, DOWN CORNING TORAY Z-6094, DOWN CORNING TORAY

Examples of the acrylic polymer having a polysiloxane-containing group at the molecular terminal include the polymerizable resin described in JP-A-2015-168719.

Examples of the polymer Y having a polysiloxane-containing group or a fluorinated alkylene-containing group in the molecular side chain include a homopolymer of a (meth) acrylate monomer having a polysiloxane-containing group or a fluorinated alkylene-containing group, or a copolymer thereof. Includes copolymers with polymerizable monomers. The homopolymer or copolymer contains a structural unit derived from a monomer represented by the following general formula (1).

R in the general formula (1) represents a hydrogen atom or a methyl group.

L of the general formula (1) is a polysiloxane-containing group or a fluorinated alkylene-containing group.

The polysiloxane-containing group represented by L is a group represented by the following general formula (2).

M in the general formula (2) is a carbon atom or a silicon atom.

_{R 1 to} R ₆ of the general formula (2) are a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or a fluorine atom, respectively. A is a hydrogen atom, an alkyl group having 1 to 3 carbon atoms which may be substituted, a fluorine atom, or a polymerizable group. Examples of polymerizable groups include (meth) acryloyl groups.

M in the general formula (2) is an integer of 1 or more, preferably 4 to 15.

Examples of the monomer in which L of the general formula (1) is a polysiloxane-containing group include Syrahplane FM-0711, Syrahplane FM-0721, and Syrahplane FM-0725 (all, product names of Chisso Corporation; Syrah). Plain is a registered trademark of Chisso Co., Ltd.), polysiloxane-containing (meth) acrylates such as X-22-174DX, X-22-2426, X-22-2475 (hereinafter, product name of Shin-Etsu Chemical Co., Ltd.), And the compound represented by the following formula (1)'is included.

The fluorinated alkylene-containing group represented by L is represented by -OR ₇ or -NR ₈ R ₉ .

R ₇ in -OR ₇ is optionally substituted fluorinated alkylene containing alkyl group.
The fluorinated alkylene-containing alkyl group which may be substituted is a fluorinated alkylene-containing alkyl group having 1 to 20 carbon atoms which may be substituted. The fluorinated alkylene moiety is one in which at least a part of the hydrogen atom of the alkylene moiety is replaced with a fluorine atom. Fluorinated alkylene containing alkyl group may be a fluorinated alkyl group; fluorinated alkyl group is -NHCO -, - O-or -NRSO 2 _- an alkyl group attached via a binding site, such as May be good.
Examples of "substituents" in the optionally substituted fluorinated alkylene-containing groups include hydroxyl groups.

-NR ₈ R R ₈ in ₉ and R ₉ are each substituted alkyl which may fluorinated alkylene containing optionally groups or (a group other than a fluorine atom) optionally substituted alkyl group. However, _{at least one of R 8} and R ₉ is a fluorinated alkylene-containing group which may be substituted.
The optionally substituted fluorinated alkylene-containing alkyl group is synonymous with the above-mentioned optionally substituted fluorinated alkylene-containing alkyl group. The alkyl group which may be substituted (with a group other than the fluorine atom) is an alkyl group having 1 to 10 carbon atoms which may be substituted.

Examples of the monomer in which L of the general formula (1) is a fluorinated alkyl-containing group include the following.

Examples of other monomers copolymerizable with the monomer represented by the general formula (1) include (meth) acrylic acid C1-20 alkyl esters (eg, methyl (meth) acrylate, ethyl (meth). ) Acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, tert-butyl (meth) acrylate, n-octyl (meth) acrylate, 2-ethylhexyl (Meta) acrylate, isononyl (meth) acrylate, isodecyl (meth) acrylate, etc.); hydroxyl group-containing (meth) acrylic acid alkyl esters (eg, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-Hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, monomer having ε-caprolactone added to (meth) acrylate having a hydroxyl group (for example, Praxel FM) Series), etc.); Blocked isocyanate group-containing (meth) acrylates (for example, 2-isocyanatoethyl (meth) acrylate with ethyl alcohol, isopropyl alcohol, caprolactam, MEK-oxime, dimethylpyrazole, diethyl malonate, etc. as blocking agents. (Reacted); (meth) acrylic acid alicyclic alkyl esters (cyclohexyl (meth) acrylate, 2-methylcyclohexyl (meth) acrylate, tricyclo [5.2.1.02,6] decane-8-yl (Meta) acrylates, tricyclo [5.2.1.02,6] decane-8-yloxyethyl (meth) acrylates, isobolonyl (meth) acrylates, etc.); (meth) acrylamides (eg, dimethylaminopropyl (meth) acrylates) ) Acrylate, isopropyl (meth) acrylamide, (meth) acryloylmorpholine, diacetone acrylamide, (meth) acrylamide-tert-butylsulfonic acid, (meth) acrylamide-tert-butylsulfonic acid organic salt, (meth) acrylamide-tert- Butylsulfonic acid inorganic salt, etc.); hydroxyl group-containing (meth) acrylamides (eg, N-hydroxyethylacrylamide, N-hydroxymethylacrylamide, etc.); Vinyl group-containing compounds (eg, N-vinylpyrrolidone, n-butylvinyl ether, a) Sobutyl vinyl ether, cyclohexyl vinyl ether, lauryl vinyl ether, etc.) are included.

The content ratio of the structural unit derived from the monomer represented by the formula (1) in the polymer containing the structural unit derived from the monomer represented by the general formula (1) is the total structure constituting the polymer. It is preferably 30% by mass or more with respect to the total of the units. When the content ratio is 30% by mass or more, the content ratio of the polysiloxane-containing group and the fluorinated alkylene-containing group in the polymer is increased, so that the adhesive that has penetrated into the surface layer region of the protective film 13A can be more easily diffused. obtain.

The polymer containing the structural unit derived from the monomer represented by the general formula (1) is, for example, the monomer represented by the formula (1) or the monomer represented by the formula (1) and other simple polymers. The monomer can be obtained by radical polymerization in the presence of a radical polymerization initiator and, if necessary, a chain transfer agent.

The weight average molecular weight of the polymer Y is preferably 1500 to 50000. When the weight average molecular weight of the polymer Y is 1500 or more, the molecular chain has an appropriate length, so that it is easy to form a network in which the molecules of the polymer connect between the glue penetration promoters, and the protective film. It is easy to diffuse the adhesive that has penetrated into the surface layer region of 13A. When the weight average molecular weight of the polymer Y is 50,000 or less, the compatibility with the cycloolefin resin is less likely to be impaired and the haze is less likely to increase. The weight average molecular weight of the polymer Y is preferably 2500 to 20000.

The abundance of the polymer Y in the region R is, for example, 0.5 to 20.0 atom% and 1.0 to 15.0 atom% with respect to the total number of atoms of all the atoms constituting the protective film 13A. Is preferable.

The measurement of the abundance of the polymer Y in the region R can be confirmed by the same method as the abundance of the glue permeation accelerator X in the region R described above. _{When SiO 2} particles are used as the additive 1 and a polysiloxane skeleton-containing polymer is used as the additive 2, the Si atom is a specific atom in each case. In that case, whether the detected Si atom is derived from the glue permeation accelerator X or the polymer Y can be determined by the binding energy of 2p electrons.

The content mass ratio of the glue permeation accelerator X and the polymer Y (polymer Y / glue permeation accelerator X) is preferably 0.1 to 2. When the content mass ratio is 0.1 or more, the content mass ratio of the polymer Y is constant or more, so that the permeated adhesive is easily diffused, and when it is 2 or less, the content ratio of the glue permeation accelerator X is easy. Is above a certain level, so it is easy for the adhesive to penetrate.

The content of the polymer Y in the protective film 13A is preferably 0.1 to 2% by mass with respect to the total mass of the cycloolefin resin, for example. When the content of the polymer Y is 2% by mass or less, it is easy to suppress the increase in haze. The content of the polymer Y in the protective film 13A is more preferably 0.1 to 1% by mass with respect to the total mass of the cycloolefin resin.

1-2-3-2. Ultraviolet absorber The ultraviolet absorber may be added for the purpose of improving the weather resistance of the protective film 13A. Examples of such UV absorbers include benzotriazole-based UV absorbers, benzophenone-based UV absorbers, salicylic acid ester-based UV absorbers, cyanoacrylate-based UV absorbers, and triazine-based UV absorbers.

Examples of benzotriazole-based ultraviolet absorbers include 5-chloro-2- (3,5-di-sec-butyl-2-hydroxylphenyl) -2H-benzotriazole, (2-2H-benzotriazole-2-yl). ) -6- (Linear and side chain dodecyl) -4-methylphenol is included. Examples of commercially available benzotriazole-based UV absorbers include the TINUVIN series such as TINUVIN109, TINUVIN171, TINUVIN234, TINUVIN326, TINUVIN327, TINUVIN328, and TINUVIN928, all of which are commercially available products manufactured by BASF.

Examples of benzophenone-based ultraviolet absorbers include 2-hydroxy-4-benzyloxybenzophenone, 2,4-benzyloxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, and 2-hydroxy-4-methoxy-5-. Sulfobenzophenone, bis (2-methoxy-4-hydroxy-5-benzoylphenylmethane) and the like are included.

Examples of the salicylic acid ester-based ultraviolet absorber include phenyl salicylate, p-tert-butyl salicylate and the like.

Examples of cyanoacrylate-based UV absorbers include 2'-ethylhexyl-2-cyano-3,3-diphenylacrylate, ethyl-2-cyano-3- (3', 4'-methylenedioxyphenyl) -acrylate and the like. Is included.

Examples of triazine-based ultraviolet absorbers include 2- (2'-hydroxy-4'-hexyloxyphenyl) -4,6-diphenyltriazine and the like. Examples of commercially available triazine-based UV absorbers include TINUVIN477.

Among these, a benzotriazole-based ultraviolet absorber and a benzophenone-based ultraviolet absorber are preferable, and a benzotriazole-based ultraviolet absorber is more preferable, in that a phase difference is less likely to be developed by stretching and the ultraviolet absorption performance is good.

The content of the ultraviolet absorber is preferably 0.1 to 10% by mass with respect to the total mass of the cycloolefin resin. When the content of the ultraviolet absorber is 0.1% by mass or more, the weather resistance of the protective film 13A can be sufficiently enhanced, and when it is 10% by mass or less, the transparency of the obtained protective film 13A is not easily impaired. The content of the ultraviolet absorber is more preferably 0.5 to 10% by mass with respect to the total mass of the cycloolefin resin.

1-2-3-3. Antioxidant Antioxidant is intended to suppress deterioration of the protective film 13A contained in a liquid crystal display device placed under high humidity and high temperature; specifically, halogen or phosphoric acid in the residual solvent amount in the protective film 13A. It can be added for the purpose of delaying or suppressing the decomposition of the resin due to phosphoric acid or the like of the plasticizer.

As the antioxidant, a hindered phenolic compound is preferably used, and examples thereof include 2,6-di-t-butyl-p-cresol and pentaerythrityl-tetrakis [3- (3,5-di). -T-butyl-4-hydroxyphenyl) propionate], triethylene glycol-bis [3- (3-t-butyl-5-methyl-4-hydroxyphenyl) propionate], 1,6-hexanediol-bis [3 -(3,5-di-t-butyl-4-hydroxyphenyl) propionate], 2,4-bis- (n-octylthio) -6- (4-hydroxy-3,5-di-t-butylanilino)- 1,3,5-triazine, 2,2-thio-diethylenebis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,5-di-t) -Butyl-4-hydroxyphenyl) propionate, N, N'-hexamethylenebis (3,5-di-t-butyl-4-hydroxy-hydrocinnamamide), 1,3,5-trimethyl-2,4 , 6-Tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene, Tris- (3,5-di-t-butyl-4-hydroxybenzyl) -isocyanurate and the like. Among them, 2,6-di-t-butyl-p-cresol, pentaerythrityl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], triethylene glycol-bis [3 -(3-T-Butyl-5-methyl-4-hydroxyphenyl) propionate] is preferred.

The content of the antioxidant is preferably 1% by mass to 1.0% by mass with respect to the total mass of the cycloolefin resin.

1-2-4. Film properties (phase difference Ro and Rt)
The in-plane phase difference Ro and the thickness direction phase difference Rth measured in an environment of a measurement wavelength of 550 nm and 23 ° C. 55% RH of the protective film 13A are retardation films in IPS and VA liquid crystal display devices. From the viewpoint of use as a λ / 4 film of an organic EL display device, for example, 0 nm ≦ Ro ≦ 300 nm and −200 nm ≦ Rth ≦ 200 nm are preferable, and 0 nm ≦ Ro ≦ 200 nm and −10 nm ≦ Rth ≦ 200 nm. Is more preferable.

Ro and Rt of the protective film 13A are defined by the following formulas, respectively.
Equation (1a): Ro = (nx-ny) × d
Equation (1b): Rt = ((nx + ny) /2-nz) × d
(During the ceremony,
nx is the refractive index in the direction x (in-plane slow phase axial direction) at which the refractive index becomes maximum in the in-plane direction of the film.
ny is the refractive index in the direction y orthogonal to the direction x (in-plane slow phase axis direction) in the in-plane direction of the film.
nz is the refractive index in the thickness direction of the film.
d is the film thickness (nm) of the film)

The Ro and Rt of the protective film 13A can be measured by the following method.
1) The protective film 13A is humidity-controlled for 24 hours in an environment of 23 ° C. and 55% RH.
2) The retardation Ro and Rt of the protective film 13A after humidity control at a measurement wavelength of 550 nm are measured in an environment of 23 ° C. and 55% RH using an automatic birefringence meter Axoscan manufactured by Axomethorics.

The phase difference Ro and Rt of the protective film 13A can be adjusted mainly by the draw ratio. In order to reduce the phase difference Ro and Rt of the protective film 13A, it is preferable to reduce the draw ratio.

(Haze)
The haze of the protective film 13A is preferably 0.01 to 2.0. When the haze of the protective film 13A is 2.0 or less, the contrast of the display image of the liquid crystal display device can be increased. The haze of the protective film 13A is more preferably 0.01 to 1.0. The haze of the protective film 13A can be measured by a haze meter (model NDH 2000, manufactured by Nippon Denshoku Co., Ltd.).

The haze of the protective film 13A can be adjusted mainly by the content of the glue permeation accelerator X and the polymer Y. In order to reduce the haze of the protective film 13A, for example, the content of the glue permeation accelerator X and the polymer Y is preferably set to a certain level or less.

(Thickness)
The thickness of the protective film 13A may be, for example, 5 to 100 μm, preferably 5 to 60 μm, and more preferably 10 to 30 μm.

The protective film 13A is preferably a single-layer film from the viewpoint of reducing the thickness of the polarizing plate and producing efficiency.

1-2-5. Method for Producing Protective Film 13A Protective film 13A may be manufactured by any method, for example, it may be manufactured by a solution casting film forming method. That is, the protective film 13A has 1) a step of obtaining a dope containing at least the above-mentioned cycloolefin resin, a glue permeation accelerator X, and a solvent, and 2) casting the obtained dope onto a metal support. It can be produced through a step of obtaining a film-like substance by drying and peeling, and a step of 3) stretching the obtained film-like substance.

Regarding the step 1), the solvent used for the dope preferably contains an organic solvent (good solvent) capable of dissolving the above-mentioned cycloolefin resin and other components. Examples of such good solvents include chlorine-based organic solvents such as methylene chloride (methylene chloride); non-chlorine-based organic solvents such as methyl acetate, ethyl acetate, acetone and tetrahydrofuran. Of these, methylene chloride (methylene chloride) is preferable.

The solvent used for the dope may further contain a poor solvent. Examples of poor solvents include straight-chain or branched-chain aliphatic alcohols having 1 to 4 carbon atoms. The higher the proportion of alcohol in the dope, the easier it is for the film to gel and the easier it is to peel off from the metal support.

Examples of the linear or branched aliphatic alcohol having 1 to 4 carbon atoms include methanol, ethanol, n-propanol, iso-propanol, n-butanol, sec-butanol, and tert-butanol. Of these, ethanol is preferable because of its stability of doping, relatively low boiling point, and good drying property.

The dope obtained in step 2) is cast on a metal support. Dope casting can be performed by discharging from a casting die.

The solvent in the dope cast on the metal support is then evaporated and dried. The dried dope is stripped from the metal support to give a film. The residual solvent amount of the dope when peeling from the metal support (residual solvent amount S ₀ at the time of peeling) is 50 to 120% by mass in terms of facilitating the reduction of the phase difference Ro and Rt of the obtained protective film 13A. It is preferable to have. When the residual solvent amount S ₀ at the time of peeling is 50% by mass or more, the thermoplastic resin easily flows during drying or stretching and tends to be non-oriented, so that Ro and Rt of the obtained protective film 13A can be easily reduced. When the residual solvent amount S ₀ at the time of peeling is 120% by mass or less, the force required for peeling the dope is unlikely to be excessively large, so that it is easy to suppress the breaking of the dope.

The amount of residual solvent in the dope is defined by the following formula. The same applies to the following.
Residual solvent amount of dope (mass%) = (mass before heat treatment of dope-mass after heat treatment of dope) / mass after heat treatment of dope × 100
The heat treatment for measuring the amount of residual solvent means a heat treatment at 120 ° C. for 60 minutes.

About the step 3) The obtained film-like material is stretched while being dried. Stretching can be done in at least one direction. The stretching direction may be any of the longitudinal direction of the film-like material (MD direction), the width direction orthogonal to the longitudinal direction of the film-like object (TD direction), and the diagonal direction with respect to the longitudinal direction of the film-like object. good.

The draw ratio is set according to the required optical performance, but from the viewpoint of making the protective film 13A function as a λ / 4 film or a retardation film for VA, it is set to, for example, 1.31 to 5.0 times. From the viewpoint of functioning as a retardation film for IPS, it can be, for example, 1.01 to 1.3 times. The stretch ratio is defined as (the size of the film after stretching in the stretching direction) / (the size of the film before stretching in the stretching direction). In the present invention, the protective film 13A is preferably stretched. The reason for this is not clear, but when it is stretched, minute gaps (claws) are likely to occur around the glue permeation accelerator, which becomes a path for the adhesive, and the adhesive permeates more than in the unstretched state. It is presumed that this is because it becomes easier.

The stretching temperature is preferably (Tg-30) ° C. to (Tg + 60) ° C., preferably (Tg-10) ° C. to (Tg + 50) ° C., where Tg is the glass transition temperature of the cycloolefin resin. More preferred. When the stretching temperature is (Tg-30) ° C. or higher, the tension applied to the film-like material during drying or stretching is unlikely to be excessively increased, so that the Ro and Rt of the obtained protective film 13A are unlikely to be excessively increased. When the stretching temperature is (Tg + 60) ° C. or lower, it is easy to highly suppress the generation of bubbles due to the vaporization of the solvent in the film-like material. Specifically, the stretching temperature can be 140 to 220 ° C.

_{The residual solvent amount S 1 in} the film-like material at the start of stretching is preferably 5 to 20% by mass. When the residual solvent amount S ₁ at the start of stretching is 5% by mass or more, the substantial Tg of the film-like substance at the time of stretching is lowered due to the plasticizing effect of the residual solvent, so that the Ro and Rt of the protective film 13A are increased. Hard to increase. When the residual solvent amount S ₁ at the start of stretching is 20% by mass or less, the generation of bubbles due to the vaporization of the solvent in the film-like material can be highly suppressed. _{The amount of residual solvent S 1 in} the film-like material at the start of stretching is more preferably 8 to 15% by mass.

Stretching of the film-like material in the MD direction can be performed, for example, by a method (roll method) in which a peripheral speed difference is applied to a plurality of rolls and the roll peripheral speed difference is used between them. Stretching of the film-like object in the TD direction can be performed, for example, by fixing both ends of the film-like object with clips or pins and widening the distance between the clips or pins in the traveling direction (tenter method).

1-3. Protective film 13B (other protective film)
The protective film 13B is not particularly limited and may be the same as or different from the above-mentioned protective film 13A. When the protective film 13B is different from the above-mentioned protective film 13A, the protective film 13B includes a known protective film such as a commercially available cellulose acylate film (for example, Konica Minolta Tuck KC8UX, KC5UX, KC4UX, KC8UCR3, KC4SR, KC4BR, etc. KC4CR, KC4DR, KC4FR, KC4KR, KC8UY, KC6UY, KC4UY, KC4UE, KC8UE, KC8UY-HA, KC2UA, KC4UA, KC6UA, KC2UAH, KC4UAH, KC2UAH, KC4UAH, KC6UAH (Polyethylene terephthalate film, etc.), cycloolefin-based resin film, acrylic-based resin film, etc. can be used.

The thickness of the protective film 13B is not particularly limited, but is preferably 1 to 100 μm, more preferably 5 to 60 μm, and particularly preferably 10 to 60 μm.

1-4. Adhesive layers 15A and 15B
The adhesive layers 15A and 15B are composed of a cured product of a water-based adhesive or an active energy ray-curable adhesive. The adhesive layers 15A and 15B may be the same as each other or may be different from each other.

The water-based adhesive contains a polyvinyl alcohol-based resin or a urethane resin as a main component.

The active energy ray-curable adhesive may be a photoradical polymerization type composition containing a photoradical polymerizable compound as a main component, a photocationic polymerization type composition containing a photocationic polymerizable compound as a main component, or a photoradical polymerizable compound. It may be a hybrid type composition in combination with a photocationic polymerizable compound.

The photoradical polymerization type composition contains a radically polymerizable compound containing a polar group such as a hydroxy group or a carboxy group described in JP-A-2008-09329 and a radically polymerizable compound not containing a polar group in a specific ratio. It can be a radical. The radically polymerizable compound is preferably a compound having a radically polymerizable ethylenically unsaturated bond, and more preferably a compound having a (meth) acryloyl group. Examples of the compound having a (meth) acryloyl group include N-substituted (meth) acrylamide-based compounds and (meth) acrylate-based compounds. (Meta) acrylamide means acryamide or methamide.

The photocationic polymerization type composition can be used for (α) cationically polymerizable compound, (β) photocationic polymerization initiator, and (γ) light having a wavelength longer than 380 nm, as disclosed in JP-A-2011-028234. It may be a composition containing each component of a photosensitizer exhibiting maximum absorption and a (δ) naphthalene-based photosensitizer.

In the present invention, as described above, the glue permeation accelerator X is contained in the region R including the surface of the protective film 13A on which the adhesive layer 15A is provided. Therefore, since the adhesive constituting the adhesive layer 15A easily penetrates into the surface layer region of the protective film 13A, the protective film 13A may have good adhesiveness to the polarizing element 11 via the adhesive layer 15A. In particular, since the water-based adhesive has high hydrophilicity, it is usually difficult to be compatible with a protective film containing a hydrophobic cycloolefin-based resin as a main component. Even in such a case, good adhesiveness to the polarizing element 11 can be obtained via the adhesive layer 15A.

The penetration depth D (see FIG. 1) of the adhesive layer 15A into the protective film 13A is preferably 0.5 to 3 μm from the surface of the protective film 13A on which the adhesive layer 15A is provided. When the penetration depth D is 0.5 μm or more, the adhesive layer 15A sufficiently penetrates into the surface layer region of the protective film 13A, so that good adhesion to the polarizing element 11 can be easily obtained. When the penetration depth D is 3 μm or less, the moisture resistance of the protective film 13A is not easily impaired, so that deterioration of the polarizing element 11 due to moisture absorption by the protective film 13A under high temperature and high humidity can be suppressed. The penetration depth D of the adhesive layer 15A into the protective film 13A makes it easy to obtain further adhesiveness with the polarizing element, and can further suppress an increase in haze due to the penetration of the adhesive. Therefore, the protective film 13A It is more preferably 0.7 μm or more and 2.5 μm or less from the surface on which the adhesive layer 15A is provided.

The penetration depth D of the adhesive layer 15A into the protective film 13A is an atom peculiar to the adhesive in the protective film 13A (for example, when a polyvinyl-based water-based adhesive is used, m / z 43 (for example) in the cross section of the polarizing plate 10. by checking the state of existence of C ₂ H ₃ O)), can be identified. The existence state of the specific structure in the thickness direction of the protective film 13A is analyzed by a time-of-flight secondary ion mass spectrometer (TOF-SIMS) on the surface of the protective film 13A on which the adhesive layer 15A is provided in the cross section of the polarizing plate 10. It can be confirmed by doing.

The time-of-flight secondary ion mass spectrometry method can measure chemical information of atoms and molecules on a solid sample with a sensitivity of one molecular layer or less, and can observe the distribution of specific atoms or molecules with spatial resolution of 100 nm or less. It is a mass spectrometry method. The flight time type secondary ion mass spectrometry is a kind of secondary ion mass spectrometry (SIMS), in which a solid sample is irradiated with a primary ion beam, and ions emitted from the outermost surface of the sample ( It is done by detecting secondary ions). Since a time-of-flight mass spectrometer (TOF-MS) is used as a mass spectrometer, it is called TOF-SIMS. The specific measurement / analysis conditions of the TOF-SIMS analysis are the same as those of the examples described later.

The above analysis is performed on the cross section of the protective film 13A, and the abundance rate (atom%) of the specific atom is calculated from the integrated value of the obtained peaks. This measurement is repeated while moving the measurement region in the thickness direction (depth direction) of the protective film 13A until the abundance rate of the specific atom is no longer confirmed. Then, the depth from the surface of the protective film 13A on which the adhesive layer 15A is provided until the abundance of specific atoms is no longer confirmed in the thickness direction is determined. A series of these operations is performed at several points in the plane direction, and the average value thereof is defined as "penetration depth D".

The penetration depth D of the adhesive layer 15A into the protective film 13A can be adjusted by the type of the glue penetration accelerator X and the polymer Y and the abundance (or content in the film) in the surface layer region of the film. In order to increase the penetration depth D of the adhesive layer 15A into the protective film 13A, for example, the abundance (or content) of the glue penetration promoter X or the polymer Y may be increased, or the glue penetration promoter X may be used. It is preferable to combine the polymer Y or adjust the ClogP value of the polysiloxane-containing group or the fluorinated alkylene-containing group contained in the polymer Y to a predetermined range.

1-5. Method for manufacturing a polarizing plate 10 The polarizing plate 10 of the present invention can be obtained through a step of adhering a protective film 13A on one surface of a polarizing element 11 and a protective film 13B on the other surface via an adhesive. .. The adhesive used is the above-mentioned water-based adhesive or active energy ray-curable adhesive.

For example, a method for manufacturing a polarizing plate 10 using an active energy ray-curable adhesive is as follows: 1) At least one of the bonding surfaces between the polarizing element 11 and the protective film 13A, and the bonding surface between the polarizing element 11 and the protective film 13B. A step of applying an active energy ray-curable adhesive to at least one of them, 2) a protective film 13A on one surface of the polarizing element 11 and a protective film 13B on the other surface via the obtained adhesive layer, respectively. Step of bonding 3) With the protective film 13A bonded to one surface of the polarizing element 11 and the protective film 13B bonded to the other surface via the adhesive layer, the adhesive layer is irradiated with active energy rays. The present invention includes a step of obtaining a polarizing plate 10 by curing the film, and 4) a step of punching (cutting) the obtained polarizing plate 10 into a predetermined shape. Before the step 1), if necessary, a step of 5) an easy-adhesion treatment (corona treatment, plasma treatment, etc.) on the surface to which the polarizing element 11 of the protective film 13A or 13B is bonded may be carried out.

In the step 1), the active energy ray-curable adhesive is preferably applied so that the thickness of the adhesive layer after curing is, for example, 0.01 to 10 μm, preferably 0.5 to 5 μm.

In the step 3), visible light, ultraviolet rays, X-rays, electron beams and the like can be used as the activation energy rays to be irradiated. Generally, it is preferable to use ultraviolet rays because it is easy to handle and the curing speed is sufficient. The ultraviolet irradiation conditions may be any conditions that can cure the adhesive. For example, the irradiation amount of ultraviolet rays is preferably from 50~1500mJ / cm ² in accumulated light quantity, it is more preferably 100 to 500 mJ / cm ^2.

2. 2. Image Display Device The image display device of the present invention has the polarizing plate of the present invention. Examples of the image display device include a liquid crystal display device and an organic EL display device, preferably a liquid crystal display device.

The liquid crystal display device of the present invention includes a liquid crystal cell and a pair of polarizing plates sandwiching the liquid crystal cell. Then, at least one of the pair of polarizing plates, preferably the polarizing plate on the viewing side, is the polarizing plate of the present invention. Since the polarizing plate of the present invention can satisfactorily suppress optical unevenness, it is preferable that a specific protective film (protective film 13A in FIG. 1) is provided so as to be in contact with the liquid crystal cell.

FIG. 2 is a schematic diagram showing an example of a basic configuration of a liquid crystal display device. As shown in FIG. 2, the liquid crystal display device 20 of the present invention includes a liquid crystal cell 30, a first polarizing plate 40 and a second polarizing plate 50 sandwiching the liquid crystal cell 30, and a backlight 60.

The display mode of the liquid crystal cell 30 is not particularly limited, and may be any of, for example, TN (Twisted Nematic), VA (Visual Organnment), IPS (In Plane Switching), and the like. The liquid crystal cell for mobile devices is preferably in IPS mode, for example, and the liquid crystal cell for medium and large size applications is preferably in VA mode, for example.

The first polarizing plate 40 is the polarizing plate of the present invention and is arranged on the surface of the liquid crystal cell 30 on the viewing side, which is opposite to the liquid crystal cell of the first polarizing element 41 and the first polarizing element 41. The protective film 43B (F1) arranged on the side surface, the protective film 43A (F2) arranged on the surface of the first polarizing element 41 on the liquid crystal cell side, the first polarizing element 41 and the protective film 43B ( Includes adhesive layers 45B and 45A provided between F1) or 43A (F2). The protective film 43A (F2) corresponds to a specific protective film (protective film 13A in FIG. 1); the protective film 43B (F1) corresponds to another protective film (protective film 13B in FIG. 1).

The second polarizing plate 50 is arranged on the surface of the liquid crystal cell 30 on the backlight side, and the second polarizing element 51 and the protective film 53A arranged on the surface of the second polarizing element 51 on the liquid crystal cell side. (F3), a protective film 53B (F4) arranged on a surface opposite to the liquid crystal cell of the second polarizing element 51, and a second polarizing element 51 and a protective film 53A (F3) or 53B (F4). Includes adhesive layers 55A and 55B provided between and. It is preferable that the absorption axis of the second polarizing element 51 is orthogonal to the absorption axis of the first polarizing element 41.

As described above, in the first polarizing plate 40, the protective film 43A (F2) and the adhesive layer 55A are well and uniformly adhered to each other. As a result, the liquid crystal display device 20 including the first polarizing plate 40 is highly suppressed in optical unevenness caused by adhesion unevenness.

Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited thereto.

得られた重合体溶液の４０００質量部をオートクレーブに入れ、この重合体溶液にＲｕＨＣｌ（ＣＯ）［Ｐ（Ｃ₆Ｈ₅）₃］₃を０．４８質量部加え、水素ガス圧を１０ＭＰａ、反応温度１６０℃の条件で３時間加熱攪拌して、水素添加反応を行った。
得られた反応溶液を冷却した後、水素ガスを放圧し、この反応溶液を大量のメタノール中に注いで凝固物を分離回収した。回収した凝固物を乾燥させて、シクロオレフィン系樹脂１を得た。得られたシクロオレフィン系樹脂１の重量平均分子量は、１４００００であった。1. 1. Material of specific protective film <Cycloolefin resin>
<Synthesis of cycloolefin resin 1>
Reaction in which 100 parts by mass of the exemplary compound 27 of the general formula (A-1) as a norbornene-based monomer, 3.6 parts by mass of 1-hexene as a molecular weight regulator, and 200 parts by mass of toluene were substituted with nitrogen. It was charged in a container and heated to 80 ° C. To this, 0.17 parts by mass of a toluene solution of triethylaluminum ((C ₂ H ₅ ) ₃ Al) 1.5 mol / l as a polymerization catalyst and tungsten hexachloride (WCl) modified with t-butanol and methanol were added. _{6 ) is contained, and 1.0 part by mass of a WCl 6} solution (concentration: 0.05 mol / l) containing t-butanol: methanol: tungsten = 0.35: 0.3: 1 (molar ratio) is added. The mixture was heated and stirred at 80 ° C. for 3 hours to carry out a ring-opening polymerization reaction to obtain a polymer solution. The polymerization conversion rate in this polymerization reaction was 98%.

4000 parts by mass of the obtained polymer solution was placed in an autoclave, _{0.48 parts by mass of RuHCl (CO) [P (C 6} H ₅ ) ₃ ] ₃ was added to this polymer solution, hydrogen gas pressure was 10 MPa, and the reaction was carried out. The hydrogenation reaction was carried out by heating and stirring at a temperature of 160 ° C. for 3 hours.
After cooling the obtained reaction solution, hydrogen gas was released and the reaction solution was poured into a large amount of methanol to separate and recover the coagulated product. The recovered coagulated product was dried to obtain a cycloolefin resin 1. The weight average molecular weight of the obtained cycloolefin resin 1 was 140000.

A film having a thickness of 20 μm made of the obtained cycloolefin resin 1 was produced by a solution film forming method. The moisture permeability of the film at 40 ° C. and 90% RH was measured by a method (cup method) based on JIS Z 0208, and as a result, ^{it was 300 g / m 2} · day.

<Cellulose acylate>
Konica Minolta Tack KC6UA (Cellulose Triacetate Film, manufactured by Konica Minolta, thickness 56 μm, indicated as TAC in the table)

<Glue penetration accelerator X>
Particles X1 and X2 were prepared as the glue permeation accelerator X. On the other hand, particles R1 and R2 were prepared for comparison. The average primary particle size and the amount of adsorbed water of these particles were measured by the following methods, respectively.

(Average primary particle size)
After preparing a specific protective film as described later, the average primary particle size of the particles in the film was measured by the following method.
The prepared specific protective film was tom-cut with a microtome (EM UC6 manufactured by Leica); the obtained film cross section was photographed with a scanning electron microscope JSM-6060LA (JEOL: JEOL Ltd.) at an appropriate magnification. Then, the primary particle diameters of 100 particles included in the tomographic cut photograph were measured, and the average value thereof was taken to obtain the average primary particle diameter.
The primary particle diameter was defined as the diameter when the cross section of the particle was circular, and when the cross section was not circular, the area was calculated and converted into a circular shape.

(Amount of adsorbed water)
The adsorbed water content of the particles X1 to X2 and R1 to R2 was measured using a high-precision steam adsorption amount measuring device BELSORP-aqua3 (manufactured by Nippon Bell Co., Ltd.). Specifically, first, about 1 g of additive 1 (particles) in Table 3 described later was introduced into a sample cell, and degassed at room temperature of 100 Pa or less for 24 hours. Then, after the degassing was completed, the sample weight was precisely weighed, set in the main body of the apparatus, and measured under the following conditions.
・ Air constant temperature bath temperature: 80.0 ℃
・ Adsorption temperature: 30.0 ° C
・ Adsorbent name: H ₂ O
Equilibrium time: 500 sec
・ Waiting for temperature: 60min
-Saturated vapor pressure: 4.245 kPa
・ Sample tube exhaust speed: Normal ・ Introduction pressure Initial introduction amount: 0.20 cm ³ (STP) ・ g ^-1
-Measured relative pressure P / P0 (measurement of adsorption process → desorption process): 0.05, 0.15, 0.25, 0.35, 0.45, 0.55, 0.65, 0.75, 0 .85, 0.90, 0.95
The measurement was performed under the above conditions, and a temperature line for moisture absorption / desorption at a temperature of 30 ° C. was drawn. The adsorbed water content (mg / g) at a humidity of 90% RH in the obtained adsorption process was calculated, and the adsorbed water content (mass%) was determined.

The composition and physical properties of the particles X1 to X2 and R1 to R2 are shown in Table 1.

<Polymer Y>
Polymers Y1 to Y5 shown in Table 2 below were prepared as the polymer Y having a polysiloxane-containing group or a fluorinated alkylene-containing group. The ClogP value of the polysiloxane-containing group or the fluorinated alkylene-containing group contained in the polymer Y was calculated by using the computational chemistry integration platform SCIGRESS manufactured by Fujitsu Limited.

2. 2. Fabrication of specific protective film <Preparation of protective film 101>
(Preparation of dispersion of particles X1)
10 parts by mass of particles X1 (NanoTeckK SiO ₂ ) and 80 parts by mass of ethanol were stirred and mixed with a dissolver for 30 minutes and then dispersed with Manton Gorlin to prepare a dispersion liquid of particles X1. 80 parts by mass of dichloromethane is added to the prepared dispersion of particles X1 with stirring, and after stirring and mixing with a dissolver for 30 minutes, a fine particle dispersion diluted solution filter (Advantech Toyo Co., Ltd .: Polypropylene Wind Cartridge Filter TCW-PPS) A dispersion of particles X1 was prepared by filtering with -1N).

(Preparation of doping)
The following components were put into a closed container, heated, and completely dissolved while stirring to obtain Azumi Filter Paper No. 1 manufactured by Azumi Filter Paper Co., Ltd. 24 was filtered to prepare a dope.
Cycloolefin resin 1 (denoted as COP in the table): 120 parts by mass Dispersion solution of particles X1: 1.05 parts by mass Dichloromethane: 357 parts by mass Ethanol: 19 parts by mass

(Film formation)
The obtained dope was kept at 40 ° C. and uniformly cast on a stainless steel belt, which is an endless metal support kept at 40 ° C. The cast dope was dried until the residual solvent amount became 80% by mass, and then peeled off from the stainless steel belt to obtain a film-like substance. The obtained film-like substance was dried at 40 ° C. until the residual solvent amount became 5% by mass, and then stretched in the width direction at a stretching ratio of 1.3 times (30%). The obtained film-like material was further dried at 120 ° C. while being conveyed by a large number of rolls to obtain a protective film 101 having a thickness of 20 μm and a width of 1.3 m.

<Manufacturing of protective films 102 to 106>
Protective films 102 to 106 were obtained in the same manner as the protective film 101 except that the content of the additive 1 (or the abundance of the additive 1) was changed as shown in Table 3.

<Manufacturing of protective films 107 to 109>
Protective films 107 to 109 were obtained in the same manner as the protective film 101 except that the type of the additive 1 was changed to that shown in Table 3.

<Manufacturing of protective film 110-114>
Protective films 110 to 114 were obtained in the same manner as the protective film 101 except that the type and amount of the additive 2 shown in Table 3 were further added.

<Manufacturing of protective film 115>
A protective film 115 was obtained in the same manner as the protective film 101 except that the additive 1 was not contained and only the type and amount of the additive 2 shown in Table 3 were contained.

<Making protective films 116-118, 123>
Protective films 116 to 118 and 123 were obtained in the same manner as the protective film 101 except that the content ratios of the additive 1 and the additive 2 were changed as shown in Table 3.

<Preparation of protective film 119>
A protective film 119 was obtained in the same manner as the protective film 101 except that the cycloolefin resin 1 was changed to Konica Minolta Tuck KC6UA.

<Manufacturing of protective film 120>
A protective film 120 was obtained in the same manner as the protective film 101 except that the additive 1 was not contained.

<Manufacturing of protective film 121>
A protective film 121 was obtained in the same manner as the protective film 104 except that the thickness was changed to 10 μm.

<Manufacturing of protective film 122>
(Adhesive adjustment)
KBM-603 (amino-based silane coupling agent) manufactured by Shin-Etsu Chemical Co., Ltd. was dissolved in 1-methoxy-2-propanol to obtain a composition 1 for an easy-adhesion layer having a concentration of 10% by weight.

(Formation of easy adhesive layer)
A base film was obtained in the same manner as the protective film 120 except that the thickness was changed to 10 μm. The obtained base film was subjected to a corona discharge treatment. The electron irradiation amount in the corona discharge was 500 W / m ² / min. The prepared composition 1 for an easily adhesive layer was applied to the corona-treated surface of the obtained base film with a bar coater so that the thickness after drying was 0.8 μm, and then dried at 80 ° C. for 5 minutes. An easy-adhesion layer was formed. As a result, a protective film 122 containing a base film and an easy-adhesion layer was obtained.

The abundance of the additive 1 in the vicinity of the surface layer of the obtained protective films 101 to 123 was measured by the following method.

(Presence rate of Additive 1 and Additive 2)
The surface of the obtained protective film on which the adhesive layer was provided was subjected to elemental analysis under the following conditions by X-ray photoelectron spectroscopy (XPS), and specific atoms peculiar to additive 1 (for example, particles X1 were used). In the case of using a Si atom, in the case of using the particles X2, an Al atom) and in the case of using a specific atom peculiar to the additive 2 (for example, in the case of using the polymers Y1 and Y2, a Si atom, and in the case of using the polymers Y3 to Y5). The concentration of F atom) was measured respectively.
(Measurement condition)
Measuring device: QUANTERASXM (manufactured by ULVAC FI Co., Ltd.)
X-ray source: Monochromatic Al-Kα
Measurement area: Si2p, C1s, N1s, O1s
Spatter ion: Ar (2keV)
Depth profile: Repeat measurement after sputtering for 1 minute Data processing: MultiPak (manufactured by ULVAC PHI Co., Ltd.)
Quantification: The background was determined by the Schillley method, and the obtained peak area was quantified by the relative sensitivity coefficient method.

When the particles X1 (SiO ₂ ) are used as the additive 1 and the polymers Y1 and Y2 (polysiloxane skeleton-containing polymer) are used as the additive 2, the Si atom is a specific atom in each case. In that case, whether the detected Si atom is derived from the particle X or the polymer Y is determined by the binding energy of the 2p electron (for example, the 2p electron of the Si atom of the _{particle X1 (SiO 2).} The binding energy is 103.4 eV, and the binding energy of the 2p electron of the Si atom of the polysiloxane skeleton-containing polymer is 101.4 eV).

Table 3 shows the configurations and evaluation results of the protective films 101 to 123.

3. 3. Fabrication and evaluation of polarizing plate <Other protective film (opposite film)>
Konica Minolta Tack KC6UA (Cellulose Triacetate Film, manufactured by Konica Minolta, thickness 56 μm, indicated as TAC in the table)
Technoroy S000 (Acrylic resin film, manufactured by Sumitomo Chemical Co., Ltd., thickness 75 μm, indicated as Ac in the table)
Cosmo Shine A4100 (polyethylene terephthalate film, manufactured by Toyobo Co., Ltd., thickness 75 μm, indicated as PET in the table)
Pure Ace T-138 (Polycarbonate film, manufactured by Teijin, thickness 70 μm, indicated as PC in the table)

<Manufacturing of polarizing plate 201>
(Making a polarizing element)
A 25 μm-thick polyvinyl alcohol film was swollen with water at 35 ° C. The obtained film was immersed in an aqueous solution consisting of 0.075 g of iodine, 5 g of potassium iodide and 100 g of water for 60 seconds, and further immersed in an aqueous solution of 45 ° C. consisting of 3 g of potassium iodide, 7.5 g of boric acid and 100 g of water. .. The obtained film was uniaxially stretched under the conditions of a stretching temperature of 55 ° C. and a stretching ratio of 5 times. This uniaxially stretched film was washed with water and then dried to obtain a polarizing element having a thickness of 7 μm.

(Preparation of polarizing plate)
Konica Minolta Tack KC6UA (thickness 56 μm, manufactured by Konica Minolta Co., Ltd.) was prepared as a counter film and subjected to alkali saponification treatment under the following conditions. Specifically, KC6UA was immersed in a 1.5N sodium hydroxide aqueous solution at 55 ° C. for 30 seconds, and then washed in a water washing bath at room temperature. The obtained KC6UA was dried with warm air at 30 ° C.

Next, on one surface of the prepared polarizing element, the prepared protective film 101 was passed through a 3% by mass aqueous solution of polyvinyl alcohol (PVA-117H manufactured by Kuraray) (referred to as water glue in the table) as a water-based adhesive. Lamination; Konica Minolta Tuck KC6UA, which had been subjected to alkali saponification treatment, was laminated to the other surface of the polarizing element via the water-based adhesive to obtain a laminate. The protective film 101 and the polarizing element were bonded together so that the slow axis of the protective film 101 and the absorption axis of the polarizing element were 90 °. Then, the obtained laminate was dried at 60 ° C. for 5 minutes to obtain a polarizing plate 201.

<Polarizer 202-219-228-230>
Polarizing plates 202 to 219 and 228 to 230 were obtained in the same manner as the polarizing plate 201 except that the protective film 101 was changed to that shown in Table 4.

<Polarizer 220>
A polarizing plate 220 was obtained in the same manner as the polarizing plate 201 except that the combination of the specific protective film and the other protective film (opposing film) was changed as shown in Table 4.

<Polarizer 221>
(Preparation of active energy ray-curable adhesive)
After mixing each of the following components, defoaming was performed to prepare an active energy ray-curable adhesive. The triarylsulfonium hexafluorophosphate was used as a 50% by mass propylene carbonate solution, and in the following configuration, the triarylsulfonium hexafluorophosphate was indicated as the solid content.
3,4-Epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate: 45 parts by mass Epolide GT-301 (alicyclic epoxy resin manufactured by Daicel Chemical Co., Ltd.): 40 parts by mass 1,4-butanediol diglycidyl ether: 15 parts by mass Triarylsulfonium hexafluorophosphate: 2.3 parts by mass 9,10-dibutoxyanthracene: 0.1 parts by mass 1,4-diethoxynaphthalene: 2.0 parts by mass

(Preparation of polarizing plate)
The surface of the protective film 111 produced above was subjected to a corona discharge treatment. The conditions for the corona discharge treatment were a corona output strength of 2.0 kW and a line speed of 18 m / min. Next, the above-prepared active energy ray-curable adhesive was applied to the corona discharge-treated surface of the protective film 111 with a bar coater so that the film thickness after curing was about 3 μm to form an adhesive layer. The above-prepared polarizing element was attached to the obtained adhesive layer. The bonding was performed so that the slow axis of the protective film 111 and the absorption axis of the polarizing element were at 90 °.

Further, as the facing film, the protective film 111 produced above was prepared. This was subjected to a corona discharge treatment under the same conditions as described above. Next, the above-prepared active energy ray-curable adhesive was applied to the corona discharge-treated surface of the protective film 111 with a bar coater so that the cured film thickness was about 3 μm to form an adhesive layer. ..

Then, the adhesive layer of the protective film 111 and the polarizing element to which the prepared protective film 111 is bonded to one side are bonded to each other, and the protective film 111 / adhesive layer / polarizing element / adhesive layer / A laminate having a laminated structure of the protective film 111 produced above was obtained.
From both sides of the obtained laminate, use an ultraviolet irradiation device with a belt conveyor (the lamp uses a D-bulb manufactured by Fusion UV Systems) to irradiate ultraviolet rays so ^{that the integrated light amount is 750 mJ / cm 2.} , Each adhesive layer was cured to obtain a polarizing plate 221.

<Polarizer 222-227>
A polarizing plate 222-227 was obtained in the same manner as the polarizing plate 221 except that the combination of the protective film and the facing film was changed to that shown in Table 4.

(Adhesive penetration depth D)
The penetration depth D of the adhesive was measured by TOF-SIMS. Specifically, the obtained polarizing plate was cut with a microtome to obtain a cut surface. On the cut surface of the obtained polarizing plate, a TOF-SIMS analysis was performed on the surface layer region including the surface provided with the adhesive layer of the protective film under the following conditions, and atoms peculiar to the adhesive (for example, polyvinyl-based water-based adhesion) were performed. When the agent was used, _{the abundance of m / z 43 (C 2} H ₃ O)) was measured.
(Measurement condition)
Measuring device: 2100TRIFT2 (manufactured by Physical Electricals)
Measurement mode: Cooling measurement (temperature range -105 to -95 ° C)
Primary ion: Ga (15 kV)
Measurement area: 60 μm square Integration time: 2 minutes

The measurement and analysis were performed with WIN-Cadence Ver4.0.0.14 manufactured by Physical Electricals.

The above analysis was performed on the cross section of the protective film 13A, and the abundance rate (atom%) of the specific atom was calculated from the integrated value of the obtained peaks. This measurement was repeated while moving the measurement region in the thickness direction (depth direction) of the protective film until the abundance of specific atoms was no longer confirmed. Then, the depth from the surface of the protective film 13A on which the adhesive layer 15A is provided until the abundance of specific atoms is no longer confirmed in the thickness direction was determined. A series of these operations was performed at several points in the plane direction, and the average value thereof was taken as "penetration depth D".

(Adhesiveness)
The obtained polarizing plate was left to stand in an environment of 23 ° C. and 55% RH for 24 hours. After that, when the adhesive surface between the polarizing element of the obtained polarizing plate and the protective film was peeled off by hand, the presence or absence of material breakage on the protective film and the degree of peeling were visually observed and according to the following evaluation criteria. Adhesion was evaluated. If it is ○ △ or higher, it is judged that there is no problem in practical use.
◎: Does not peel off ○: There is no problem with the adhesive force between the protective film and the polarizing element, and when trying to peel off the protective film, the material (base) is applied to the part exceeding at least half of at least one end of the protective film and the polarizing element. Material) Destruction occurs ○ △: There is no problem with the adhesive force between the protective film and the polarizing element, and when the protective film is to be peeled off, the material is applied to at least half of one end of the protective film and the polarizing element. (Base material) Destruction occurs Δ: Part of the interface between the protective film and the polarizing element is peeled off ×: All the interface between the protective film and the polarizing element is peeled off

Table 4 shows the configurations and evaluation results of the polarizing plates 2001 to 230.

As shown in Table 4, the polarizing plates 202 to 205, 208, 210 to 214, 216 to 218, 220 to 226, and 228 of the examples all have good adhesion between the polarizing element and the protective film. I understand.

In particular, the polarizing plate 210 to 214 using the protective film 110 to 114 further added with the polymer Y having the ClogP value of the polysiloxane-containing group or the fluorinated alkylene-containing group in a specific range does not contain the polymer Y. It can be seen that the adhesive penetrates the protective film more easily than the polarizing plate 204 using the protective film 104, and the adhesiveness is further good (comparison between the polarizing plate 204 and 210-214).

Further, when the polymer Y / glue permeation accelerator X is 1.3 or less, the permeation depth D of the adhesive can be particularly deepened, so that it is easy to obtain good adhesiveness (polarizing plate). Comparison of 214 with 212 and 216-218).

On the other hand, it can be seen that the polarizing plates 215 and 227 of the comparative example using the protective films 115 and 120 containing no glue permeation accelerator X are not permeated with the adhesive and have low adhesiveness. Further, the polarizing plate 201 of the comparative example using the protective film 101 having a low presence rate of the glue permeation accelerator X has almost no adhesive permeation (penetration depth D is shallow) and has low adhesiveness. Recognize. Further, it can be seen that the polarizing plate 207 of the comparative example using the protective film 107 containing the particles 2 having a low adsorbed water content has a shallow adhesive depth D and low adhesiveness.

Further, the penetration depth D (0.03 μm) of the adhesive of the polarizing plate 219 of the comparative example using the protective film 119 containing TAC as the main component is the same as that of the example using the protective film 111 containing COP as the main component. It can be seen that the depth of penetration of the adhesive of the polarizing plate 211 is significantly shallower than the penetration depth D (2.5 μm), and the adhesive hardly penetrates.

4. Manufacturing and evaluation of liquid crystal display device <Manufacturing of liquid crystal display device 301>
As a liquid crystal display device, an IPS type LG Electronics liquid crystal television (model number: 43UF6900) was prepared. The polarizing plate on the visual recognition side was peeled off from this device, and the polarizing plate 201 produced above was attached to the surface on the visual recognition side of the liquid crystal cell to obtain a liquid crystal display device 301.
When the polarizing plate 201 is attached, the protective film 101 (protective film F2) is on the liquid crystal cell side, the absorption axis of the polarizing element and the slow axis of the protective film 101 are orthogonal to each other, and the visual recognition side before peeling from the liquid crystal cell. This was done so as to coincide with the absorption axis of the polarizing plate.

<Manufacturing of liquid crystal displays 302 to 330>
Liquid crystal displays 302 to 330 were obtained in the same manner as the liquid crystal display devices 301 except that the polarizing plate 201 was changed to that shown in Table 5.

The optical unevenness of the obtained liquid crystal display devices 301 to 230 was evaluated by the following method.

(Optical unevenness)
A black image was displayed on the obtained liquid crystal display device at 80 ° C. and 90% RH, and visual observation was performed. If the protective film has optical unevenness, the phase difference changes only in that portion, so that light leakage like a white mist occurs in the black image portion, which appears as optical unevenness. Optical unevenness was evaluated based on the following criteria. If it is ○ △ or higher, it is judged that there is no practical problem.
◎: No unevenness is observed in both the bright room and the dark room.
○: Not observed at all in the bright room, but slight unevenness is observed in the dark room ○ △: Not observed at all in the bright room, but slightly uneven is observed in the dark room △: Not noticeable in the bright room, but in the dark room Unevenness is observed in ×: Unevenness is observed in both bright and dark rooms, which is a practical problem.

The evaluation results of the liquid crystal display devices 301 to 230 are shown in Table 5.

As shown in Table 5, the display devices 302 to 305, 308, 310-314, 316 to 318, 320 to 326, and 328 of the Examples all show good display characteristics with suppressed optical unevenness. Recognize.

In particular, the display device 311 using the protective film 111 further added with the polymer Y having the ClogP value of the polysiloxane-containing group or the fluorinated alkylene-containing group in a specific range uses the protective film 104 not containing the polymer. It can be seen that the optical unevenness is further suppressed as compared with the display device 304 (comparison between the display device 304 and 311).

On the other hand, it can be seen that the display devices 315 and 327 using the protective films 115 and 120 that do not contain the glue permeation accelerator X all have optical unevenness due to the low adhesiveness. Further, the display device 301 using the protective film 101 having a low presence rate of the glue permeation accelerator X and the display device 307 using the protective film 107 containing the particles R1 having a low adsorbed water content are also caused by the low adhesiveness. It can be seen that optical unevenness occurs.

Further, the display device 306 using the protective film 106 having a high presence rate of the glue permeation accelerator X and the display device 309 using the protective film 109 containing the particles R2 having a high adsorbed water content have high hydrophilicity and therefore absorb moisture. It can be seen that it is easy to do and causes optical unevenness. Further, since the protective film 119 containing TAC has low moisture resistance, it can be seen that the display device 319 using the protective film 119 also causes optical unevenness. It can be seen that the display device 329 using the protective film 122 having the easy-adhesive layer causes optical unevenness due to the coating unevenness of the easy-adhesive layer. In the display device 330 using the protective film 123 containing an excessive amount of the polymer Y, the adhesive permeates too much, so that the moisture brought into the protective film by the adhesive increases under high temperature and high humidity to protect the display device 330. It can be seen that the moisture resistance of the film decreases and optical unevenness occurs.

This application claims priority under Japanese Patent Application No. 2016-183471 filed September 20, 2016. All the contents described in the application specification and drawings are incorporated in the specification of the present application.

According to the present invention, it is possible to provide a polarizing plate having good adhesiveness to a polarizing element even if the protective film is thin, and a liquid crystal display device containing the same and suppressing optical unevenness.

10 Polarizer 11 Polarizer 13A Protective film (specific protective film)
13B protective film (other protective film)
15A, 15B Adhesive layer 20 Liquid crystal display device 30 Liquid crystal cell 40 First polarizing plate 41 First polarizing element 43A Protective film (F2)
43B protective film (F1)
45A, 45B, 55A, 55B Adhesive layer 50 Second polarizing plate 51 Second polarizing element 53A Protective film (F3)
53B protective film (F4)
60 backlight

Claims (11)

A polarizing element containing a polyvinyl alcohol-based film and a dichroic dye oriented by adsorption thereof,
A protective film provided on at least one surface of the polarizing element, and
A polarizing plate including an adhesive layer provided between the polarizing element and the protective film.
The protective film contains a cycloolefin resin, a glue permeation accelerator X having an adsorbed water content of 1% by mass or more and less than 2% by mass, and a polymer Y.
The abundance of the glue permeation accelerator X in the region 0.5 to 3 μm from the surface of the protective film provided with the adhesive layer is 0 with respect to the total number of atoms of all the atoms constituting the protective film. a .1～10Atom%, and has an adhesive constituting the adhesive layer to penetrate into the interior of the protective film, and the penetration depth D of the adhesive, Ri 0.5~3μm der,
The polymer Y is a polymer having a polysiloxane-containing group or a polymer having a fluorinated alkylene-containing group.
The polymer having a polysiloxane-containing group is a modified polysiloxane compound having a polyether group.
Polarizer. The LogP value of the polysiloxane-containing group or the fluorinated alkylene-containing group is 0.5 or more and 6.0 or less.
The polarizing plate according to claim 1. The modified polysiloxane compound is
One general formula side chain or terminal of the polysiloxane compound represented by the general formula (I) is either a compound is replaced by polyether groups, or the general formula (II) or (III) in represented Ru of compound Is,
The polarizing plate according to claim 1 or 2.

(N in the general formula (I) is an integer of 1 or more)

(In general formula (II),
R ¹ represents an alkyl group
R ² represents a polyether group and represents
m, x and y each represent an integer of 1 or more)

(In general formula (III),
R ³ represents a polyether group and represents
m represents an integer of 1 or more) The polymer Y is a polymer having a fluorinated alkylene-containing group.
The polarizing plate according to any one of claims 1 to 3 . The glue permeation accelerator X is an inorganic particle.
The polarizing plate according to any one of claims 1 to 4. The content of the glue permeation accelerator X is 0.1 to 2.5% by mass with respect to the total mass of the cycloolefin resin.
The polarizing plate according to any one of claims 1 to 5. The content mass ratio of the glue permeation accelerator X and the polymer Y is the polymer Y / the glue permeation accelerator X = 0.1 to 2.
The polarizing plate according to any one of claims 1 to 6. The moisture permeability of the cycloolefin resin at 40 ° C. and 90% RH is 10 to 350 g / m ² · day.
The polarizing plate according to any one of claims 1 to 7. The thickness of the protective film is 10 to 30 μm.
The polarizing plate according to any one of claims 1 to 8. A liquid crystal cell and a pair of polarizing plates sandwiching the liquid crystal cell are included.
At least one of the pair of polarizing plates is the polarizing plate according to any one of claims 1 to 9.
Liquid crystal display device. The protective film contained in the polarizing plate according to any one of claims 1 to 9 is in contact with the liquid crystal cell.
The liquid crystal display device according to claim 10.

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