TWI578033B - A polarizing film, a circularly polarizing plate, and an organic EL image display device using the same - Google Patents

Description

Polarizing film, circular polarizing plate, and organic EL image display device using the same

The present invention relates to a polarizing film, a circularly polarizing plate, and an organic EL image display device using the same.

In the organic EL image display device, a circularly polarizing plate is used to reflect external light reflection at a bright place. As such a circularly polarizing plate, for example, a polarizing film (iodine-PVA polarizing film) obtained by dyeing PVA (polyvinyl alcohol) with iodine is known (for example, see Patent Document 1).

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. Hei 7- 14170

However, in the organic EL image display device having the circular polarizing plate including the polarizing film, there is a problem that the polarizing film absorbs light from the organic EL light-emitting element by half of the light amount. Therefore, it is necessary to increase the light-emitting intensity of the organic EL light-emitting element, and the life of the organic EL image display device is shortened. In particular, blue light having a short lifetime (a light-emitting element having a wavelength of around 450 nm) is more likely to deteriorate over time. However, circular polarizing plates and polarizing films which can eliminate the above problems have not been realized so far.

The invention includes the following invention.

[1] A polarizing film (hereinafter sometimes referred to as "the present polarizing film"), which is composed of A composition containing two or more types of dichroic dyes having a maximum absorption wavelength (hereinafter, referred to as "a composition for forming a polarizing film" as the case), and having a direction in one direction, and satisfying all of the following formulas ( Absorption spectrum of the relationship expressed by I)~(V): 0.3≦A450/A550<0.8 (I)

0.3≦A450/A650<1.0 (II)

0.5≦A450≦2 (III)

1≦A550≦3 (IV)

1≦A650≦3 (V) (wherein A450 represents the absorbance of polarized light parallel to the above-mentioned alignment direction at a wavelength of 450 nm, A550 represents the absorbance of polarized light parallel to the above-mentioned alignment direction at a wavelength of 550 nm, and A650 represents a wavelength of 650 nm. The absorbance of the polarized light parallel to the above alignment direction).

[2] The polarizing film according to the above [1], wherein the composition further contains a polymerizable smectic liquid crystal compound.

[3] The polarizing film according to the above [1] or [2], wherein the two or more dichroic dyes are polyazo dyes represented by the following formula (1): [In the formula (1), n is 1 or 2, and Ar ₁ and Ar ₃ each independently represent any of the following groups,

Ar ₂ represents any of the following groups,

A ₁ and A ₂ each independently represent any of the following groups,

m is an integer of 0 to 10, and when there are 2 m in the same base, the two m are the same or different from each other].

[4] The polarizing film according to any one of [1] to [3] wherein the visibility correction monomer transmittance Ty is 43% or more, and the visibility correction monomer polarization degree Py is 90% or more.

[5] A circularly polarizing plate (hereinafter sometimes referred to as "the present circular polarizing plate") having the polarizing film and the λ/4 layer according to any one of the above [1] to [4], and satisfying the following ( The conditions of A1) and (A2): (A1) the angle formed by the absorption axis of the polarizing film and the late phase axis of the λ/4 layer is substantially 45°; (A2) the above λ measured by light having a wavelength of 550 nm The positive retardation of the /4 layer is in the range of 100 to 150 nm.

[6] The circularly polarizing plate according to [5] above, wherein the value of the front side retardation of the λ/4 layer with respect to visible light has a characteristic that becomes smaller as the wavelength becomes shorter.

[7] A circularly polarizing plate having the polarizing film, the λ/2 layer, and the λ/4 layer according to any one of the above [1] to [4], and satisfying the following (B1) to (B4) (B1) The angle formed by the absorption axis of the polarizing film and the retardation axis of the λ/2 layer is approximately 15°; (B2) the retardation axis of the λ/2 layer and the λ/4 layer The angle formed by the slow phase axis is approximately 60°; (B3) in the above λ/2 layer, the front side retardation value of the λ/4 layer measured by light having a wavelength of 550 nm is in the range of 200 to 300 nm; (B4) In the λ/4 layer, the value of the front side retardation of the above λ/4 layer measured by light having a wavelength of 550 nm is in the range of 100 to 150 nm.

[8] An organic EL display device (hereinafter referred to as "the present organic EL display device"), comprising the circularly polarizing plate according to any one of the above [5] to [7], and an organic EL device.

[9] The organic EL display device according to the above [8], wherein the intensity of light having a wavelength of 450 nm in the light emitted from the light-emitting layer is set to be I450, and the intensity of light having a wavelength of 550 nm is set to be I550 and the intensity of light having a wavelength of 650 nm. When set to I650, it has an emission spectrum that satisfies the relationship expressed by all the following formulas: 1≦I450/I550<2 (X)

1≦A450/A650<2 (XI).

According to the polarizing film, an organic EL image display device can be provided A circular polarizing plate (the present circular polarizing plate) for reducing the absorption of light from the organic EL light-emitting element, in particular, the absorption of light having a wavelength of around 450 nm.

The present polarizing film can realize a high-life organic EL display device by forming the present circular polarizing plate including the present polarizing film described below.

The A450/A550 in the formula (I) is further preferably in a relationship of 0.5 ≦ A450 / A550 < 0.8.

The A450/A650 in the formula (II) is further preferably in a relationship of 0.5 ≦ A450 / A650 < 0.8.

The A450 in the formula (III) further preferably satisfies the relationship of 0.5 ≦ A450 ≦ 1.6, and the A 550 in the formula (IV) further preferably satisfies the relationship of 1.0 ≦ A 550 ≦ 2.0, and the A 650 in the formula (V) is further preferably To meet the relationship of 1.0≦A650≦2.0.

For ease of observation, the drawings included in this manual are of any size.

<dichroic pigment>

The composition for forming a polarizing film contains two or more kinds of dichroic dyes having different maximum absorption wavelengths. The dichroic dye refers to a dye having a property in which the absorbance in the long axis direction of the molecule is different from the absorbance in the short axis direction. The dichroic dye may be a dye or a pigment. A plurality of the dyes may be used, and a plurality of pigments may be used, or a dye may be used in combination with a pigment.

The dichroic dye is preferably one having a maximum absorption wavelength (λMAX) in the range of 300 to 700 nm. Examples of such a dichroic dye include acridine dyes. Pigments, cyanine pigments, naphthalene pigments, azo dyes, and anthraquinone pigments. Among them, the dichroic dye is preferably an azo dye. Examples of the azo dye include a monoazo dye, a disazo dye, a trisazo dye, a tetrazo pigment, and a quinone azo dye, and a disazo dye and a trisazo dye are preferable.

The dichroic dye is particularly preferably represented by the formula (1) (hereinafter, referred to as "azo dye (1)"). The azo dye (1) is further preferably one which exhibits a maximum absorption wavelength (λMAX) in a wavelength range of 300 to 700 nm.

The positional isomerism of the azobenzene moiety of the azo dye (1) is preferably trans.

Examples of the azo dye (1) include compounds represented by the formulae (1-1) to (1-27), and the like.

In the specific example of the azo dye (1), the formula (1-2), the formula (1-5), the formula (1-6), the formula (1-8), the formula (1-10), and the formula are more preferable. (1-12), Formula (1-13), Formula (1-15), Formula (1-16), Formula (1-19), Formula (1-20), Formula (1-21), Formula ( 1-22), the formula (1-23), the formula (1-24), and the formula (1-26) are respectively represented, and particularly preferably the formula (1-2), the formula (1-5), and the formula (1) -8), the formula (1-10), the formula (1-15), the formula (1-21), the formula (1-22), and the formula (1-26) are respectively indicated.

As the anthraquinone dye, a compound represented by the formula (1-28) is preferred.

In the formula (1-28), R ¹ to R ⁸ each independently represent a hydrogen atom, -R ^x , -NH ₂ , -NHR ^x , -NR ^x ₂ , -SR ^x or a halogen atom.

R ^x represents an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 12 carbon atoms]

As the acridine dye, a compound represented by the formula (1-29) is preferred.

In the formula (1-29), R ⁹ to R ¹⁵ each independently represent a hydrogen atom, -R ^x , -NH ₂ , -NHR ^x , -NR ^x ₂ , -SR ^x or a halogen atom.

R ^x represents an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 12 carbon atoms]

As The pigment is preferably a compound represented by the formula (1-30).

In the formula (1-30), R ¹⁶ to R ²³ independently of each other represent a hydrogen atom, -R ^x , -NH ₂ , -NHR ^x , -NR ^x ₂ , -SR ^x or a halogen atom.

R ^x represents an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 12 carbon atoms]

In the above formula (1-28), formula (1-29) and formula (1-30), the alkyl group having 1 to 6 carbon atoms of R ^x is a methyl group, an ethyl group, a propyl group, a butyl group or a pentyl group. Examples of the aryl group having a carbon number of 6 to 12, such as a phenyl group, a tolylmethyl group, a xylyl group, and a naphthyl group.

The cyanine dye is preferably a compound represented by the formula (1-31) and a compound represented by the formula (1-32).

In the formula (1-31), D ¹ and D ² each independently represent a group represented by any one of the formulae (1-31a) to (1-31d).

N5 represents an integer from 1 to 3]

In the formula (1-32), D ³ and D ⁴ each independently represent a group represented by any one of the formulae (1-32a) to (1-32h).

N6 represents an integer from 1 to 3]

The dichroic dye contained in the composition for forming a polarizing film is preferably two or more kinds, and further preferably contains two to three kinds of dichroic dyes, and more preferably contains two to three kinds of azo dyes (1). A preferred combination of the combination of the two types of azo dyes (1) [indicated by the names of "first pigment", "second pigment" and "third pigment" is shown.

According to the method for producing a polarizing film described below, the polarizing film-forming composition containing the combination of the azo dyes (1) shown in the above table is easily obtained by satisfying all the formulas (I) to (V). The relationship between the absorption spectrum of the present polarizing film.

In addition, the notation in the table corresponds to the specific example of the azo dye (1), and for example, "1-5" means "the azo dye (1) represented by the formula (1-5)".

The content of the dichroic dye in the composition for forming a polarizing film is, for example, preferably 1 part by mass or more and 90 parts by mass or less, more preferably 1 part by mass based on 100 parts by mass of the total of the composition for forming a polarizing film. It is more than 50 parts by mass, more preferably 3 parts by mass or more and 10 parts by mass or less.

The content of the dichroic dye in the composition for forming a polarizing film is, for example, preferably 0.1 parts by mass or more and 50 parts by mass or less, more preferably 0.1% by mass based on 100 parts by mass of the total of the polymerizable liquid crystal compound described below. It is more than 20 parts by mass, and more preferably 0.1 part by mass or more and 10 parts by mass or less. When the content of the dichroic dye is within this range, the polymerizable liquid crystal compound can be polymerized without disturbing the alignment of the polymerizable liquid crystal compound.

<Polymeric liquid crystal compound>

In terms of obtaining a polarizing film of practical strength, the composition for forming a polarizing film preferably contains a polymerizable liquid crystal compound. The polymerizable liquid crystal compound is a compound having a polymerizable group and exhibiting a liquid crystal state. The term "polymerizable group" means a group which participates in a polymerization reaction of a polymerizable liquid crystal compound.

The polymerizable liquid crystal compound and the polymerizable smectic liquid crystal compound are preferable, and a polymerizable smectic liquid crystal compound is preferable from the viewpoint of polarizing performance.

The polymerizable smectic liquid crystal compound exhibits a liquid crystal state which is preferably a higher order smectic phase. Here, the high-order smectic phase, the stratified column B phase, the smectic D phase, the smectic E phase, the smectic F phase, the smectic G phase, the smectic H phase, the smectic I phase, and the smectic column J The phase, the smectic K phase, and the smectic L phase, and more preferably the smectic B phase, the smectic F phase, and the smectic phase I phase.

Obtained by the liquid crystal state of the polymerizable smectic liquid crystal compound The polarizing film with a higher degree of alignment. Further, the present polarizing film having such a high degree of alignment can obtain a Bragg peak in the X-ray reflection measurement.

The Bragg peak is a peak derived from the periodic structure of the molecular alignment, and the polarizing film having a periodic interval of 3.0 to 5.0 Å can be obtained from the composition for forming a polarizing film.

As a preferable polymerizable smectic liquid crystal compound, a compound represented by the formula (2) (hereinafter sometimes referred to as "compound (2)") may be mentioned.

U ¹ -V ¹ -W ¹ -X ¹ -Y ¹ -X ² -Y ² -X ³ -W ² -V ² -U ² (2) [In the formula (2), X ¹ , X ² and X ³ The pendant phenyl group which may have a substituent or the cyclohexane-1,4-diyl group which may have a substituent is represented independently of each other. Wherein at least one of X ¹ , X ² and X ³ is a para-phenyl group which may have a substituent.

Y ¹ and Y ² independently of each other represent -CH ₂ CH ₂ -, -CH ₂ O-, -COO-, -OCOO-, a single bond, -N=N-, -CR ^a =CR ^b -, -C≡ C- or -CR ^a =N-. R ^a and R ^b each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

U ¹ represents a hydrogen atom or a polymerizable group.

U ² represents a polymerizable group.

W ¹ and W ² independently of each other represent a single bond, -O-, -S-, -COO- or -OCOO-.

V ¹ and V ² independently of each other represent an alkanediyl group having 1 to 20 carbon atoms which may have a substituent, and -CH ₂ - constituting the alkanediyl group may be substituted by -O-, -S- or -NH-]

Preferably, at least one of X ¹ , X ² and X ³ is a 1,4-phenylene group which may have a substituent, and at least two of these are a para-phenyl group which may have a substituent.

The phenylene group is preferably unsubstituted. The cyclohexane-1,4-diyl group is preferably a trans-cyclohexane-1,4-diyl group, and the trans-cyclohexane-1,4-diyl group is also more preferably unsubstituted.

Examples of the substituent which the phenylene group or the cyclohexane-1,4-diyl group has may be an alkyl group having 1 to 4 carbon atoms such as a methyl group, an ethyl group or a butyl group; a cyano group; a halogen atom; Further, -CH ₂ - constituting the cyclohexane-1,4-diyl group may be substituted with -O-, -S- or -NR-. R is an alkyl group having 1 to 6 carbon atoms or a phenyl group.

Y ¹ is preferably -CH ₂ CH ₂ -, -COO- or a single bond, and Y ² is preferably -CH ₂ CH ₂ - or -CH ₂ O-.

U ² is a polymerizable group. U ¹ is a hydrogen atom or a polymerizable group, and is preferably a polymerizable group. That is, both U ¹ and U ^{2 are} preferably all polymerizable groups, and are preferably all photopolymerizable groups. The photopolymerizable group refers to a group which can participate in a polymerization reaction by an active radical or an acid generated by the following photopolymerization initiator. When a polymerizable smectic liquid crystal compound having a photopolymerizable group is used, it is also advantageous in that the polymerizable smectic liquid crystal compound can be polymerized under lower temperature conditions.

The polymerizable groups of U ¹ and U ² may be different from each other, but are preferably the same kind of groups. Examples of the polymerizable group include a vinyl group, a vinyloxy group, a 1-chlorovinyl group, an isopropenyl group, a 4-vinylphenyl group, an acryloxy group, a methacryloxy group, and an oxiran group. An oxypropylene group or the like. Among them, an acryloxy group, a methacryloxy group, a vinyloxy group, an oxiranyl group, and an propylene oxide group are preferred, and an acryloxy group is more preferred. U ¹ and U ² are the same type of polymerizable group means, for example, when both U ¹ and U ² are acryloxy groups.

Examples of the alkanediyl group of V ¹ and V ² include a methylene group, an ethylidene group, a propane-1,3-diyl group, a butane-1,3-diyl group, and a butane-1,4-diyl group. Pentane-1,5-diyl, hexane-1,6-diyl, heptane-1,7-diyl, octane-1,8-diyl, decane-1,10-diyl , tetradecane-1,14-diyl and eicosane-1,20-diyl and the like. V ¹ and V ^{2 are} preferably an alkanediyl group having 2 to 12 carbon atoms, more preferably an alkanediyl group having 6 to 12 carbon atoms.

Examples of the substituent which the alkanediyl group has may include a cyano group and a halogen atom. However, the alkanediyl group is preferably unsubstituted, and more preferably an unsubstituted and linear alkanediyl group.

W ¹ and W ² are preferably each a single bond or -O- independently of each other.

The compound (2) includes a compound represented by the formula (2-1) to the formula (2-24), and the like. In the case where the specific example of the compound (2) has a cyclohexane-1,4-diyl group, the cyclohexane-1,4-diyl group is preferably a trans form.

The polymerizable smectic liquid crystal compound may be used alone or in combination of two or more kinds for the composition for forming a polarizing film. Further, two or more kinds of polymerizable smectic liquid crystal compounds may be used, and at least one of the two or more polymerizable smectic liquid crystal compounds is the compound (2).

When the polymerizable smectic liquid crystal compound is used in the composition for forming a polarizing film, the phase transition temperature of the polymerizable smectic liquid crystal compound is determined in advance, and the polymerizable smectic liquid crystal of the composition for forming a polarizing film is adjusted. A component other than the compound is polymerized at a temperature lower than the phase transition temperature by the polymerizable smectic liquid crystal compound. Examples of such a component capable of controlling the polymerization temperature include the following photopolymerization initiators, photosensitizers, and polymerization inhibitors. The polymerization temperature of the polymerizable smectic liquid crystal compound can be controlled by appropriately adjusting the kind and amount of the liquid crystal compound. In the case where a mixture of two or more kinds of polymerizable smectic liquid crystal compounds is used in the composition for forming a polarizing film, a mixture of two or more kinds of polymerizable smectic liquid crystal compounds is also obtained. After the phase transfer temperature, the polymerization temperature was controlled in the same manner as described above.

The compound (2) is preferably selected from the group consisting of the formula (2-2), the formula (2-3), the formula (2-4), the formula (2-6), the formula (2-7), and the formula (2). 8) At least one of the groups consisting of the formula (2-13), the formula (2-14), the formula (2-15), and the formula (2-24).

The polymerizable smectic liquid crystal compound can be easily mixed at a temperature lower than the phase transition temperature by mixing two or more kinds or by a polymerization initiator which is used together, that is, a layer which is sufficiently maintained at a high level The liquid crystal state of the columns is polymerized. More specifically, the polymerizable smectic liquid crystal compound is preferably one which can be sufficiently maintained at a temperature of 70 ° C or lower, preferably 60 ° C or lower, by interaction with a polymerization initiator. The liquid crystal state of the smectic phase is polymerized.

The polymerizable smectic liquid crystal compound to be contained in the composition for forming a polarizing film may be a single species or a plurality of (two or more), and preferably plural.

In the case of using a composition for forming a polarizing film containing a polymerizable smectic liquid crystal compound, the content ratio of the polymerizable smectic liquid crystal compound is preferably 70% with respect to the solid content of the composition for forming a polarizing film. 99.9 mass%, more preferably 90-99.9 mass%. When the content ratio of the polymerizable smectic liquid crystal compound is within the above range, the alignment property of the polymerizable smectic liquid crystal compound tends to be high. Here, the solid content component refers to a total amount of components obtained by removing a volatile component such as a solvent from the composition for forming a polarizing film. In the case where a plurality of polymerizable smectic liquid crystal compounds are contained in the composition for forming a polarizing film, the total content ratio may be within the above range.

<solvent>

The composition for forming a polarizing film may also contain a solvent. In general, a polymerizable smectic liquid crystal compound has a high viscosity, and therefore it is easy to apply by containing a solvent, and as a result, a polarizing film is easily formed in many cases. As the solvent, those which can dissolve the polymerizable smectic liquid crystal compound and the dichroic dye are preferable. Further, a solvent which is inert to the polymerization reaction of the composition for forming a polarizing film is preferred.

Examples of the solvent include alcohol solvents such as methanol, ethanol, ethylene glycol, isopropanol, propylene glycol, ethylene glycol methyl ether, ethylene glycol butyl ether, and propylene glycol monomethyl ether; ethyl acetate, butyl acetate, and ethylene Ester solvent such as alcohol methyl ether acetate, γ-butyrolactone or propylene glycol methyl ether acetate and ethyl lactate; acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, 2-heptanone and methyl a ketone solvent such as isobutyl ketone; an aliphatic hydrocarbon solvent such as pentane, hexane or heptane; toluene and xylene (xylene may be any of an ortho, a meta and a para or a An aromatic hydrocarbon solvent such as a mixture of two or more kinds thereof; a nitrile solvent such as acetonitrile; an ether solvent such as tetrahydrofuran or dimethoxyethane; a chlorine-containing solvent such as chloroform or chlorobenzene; and the like. These solvents may be used singly or in combination of plural kinds.

The content of the solvent is preferably from 50 to 98% by mass based on the total amount of the composition for forming a polarizing film. In other words, the solid content in the composition for forming a polarizing film is preferably from 2 to 50% by mass. When the solid content component is 2% by mass or more, the thin polarizing film tends to be easily obtained. On the other hand, when the content of the solid content is 50% by mass or less, the viscosity of the composition for forming a polarizing film is lowered, so that the thickness of the polarizing film is substantially uniform, and thus it is difficult to cause unevenness in the polarizing film. Further, the solid content component can be determined in such a manner as to form a desired thickness of the polarizing film described below.

<Polymerization Aid>

The composition for forming a polarizing film preferably contains a polymerization initiator. The polymerization initiator is a compound which can start the polymerization reaction of the polymerizable layer-type liquid crystal compound, and is preferably a photopolymerization initiator in terms of starting a polymerization reaction under a lower temperature condition. Specifically, a compound which can generate an active radical or an acid by the action of light is used as a photopolymerization initiator. Among the photopolymerization initiators, those which generate radicals by the action of light are more preferred.

Examples of the polymerization initiator include a benzoin compound, a diphenyl ketone compound, a phenylalkyl ketone compound, a decyl phosphine oxide compound, and the like. Compounds, strontium salts and strontium salts.

Examples of the benzoin compound include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzoin isobutyl ether.

Examples of the diphenyl ketone compound include diphenyl ketone, methyl phthalic acid benzoate, 4-phenyl diphenyl ketone, and 4-benzylidene-4'-methyl diphenyl sulfide. 3,3',4,4'-tetrakis(t-butylperoxycarbonyl)diphenyl ketone and 2,4,6-trimethyldiphenyl ketone.

Examples of the phenylalkyl ketone compound include diethoxyacetophenone and 2-methyl-2- Lolinyl-1-(4-methylthienyl)propan-1-one, 2-benzyl-2-dimethylamino-1-(4- Polinylphenyl)butan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1,2-diphenyl-2,2-dimethoxyethane-1 -ketone, 2-hydroxy-2-methyl-1-[4-(2-hydroxyethoxy)phenyl]propan-1-one, 1-hydroxycyclohexyl phenyl ketone and 2-hydroxy-2-methyl An oligomer of keto-1-[4-(1-methylvinyl)phenyl]propan-1-one or the like.

As the fluorenylphosphine oxide compound, 2,4,6-trimethylbenzimidazole is exemplified. Diphenylphosphine oxide and bis(2,4,6-trimethylbenzylidene)phenylphosphine oxide.

As three The compound may, for example, be 2,4-bis(trichloromethyl)-6-(4-methoxyphenyl)-1,3,5-tri , 2,4-bis(trichloromethyl)-6-(4-methoxynaphthyl)-1,3,5-three 2,4-bis(trichloromethyl)-6-(4-methoxystyryl)-1,3,5-three , 2,4-bis(trichloromethyl)-6-[2-(5-methylfuran-2-yl)vinyl]-1,3,5-three , 2,4-bis(trichloromethyl)-6-[2-(furan-2-yl)vinyl]-1,3,5-three , 2,4-bis(trichloromethyl)-6-[2-(4-diethylamino-2-methylphenyl)vinyl]-1,3,5-three And 2,4-bis(trichloromethyl)-6-[2-(3,4-dimethoxyphenyl)vinyl]-1,3,5-tri Wait.

The polymerization initiator can also be used as readily available from the market. As a commercially available photopolymerization initiator, "Irgacure 907", "Irgacure 184", "Irgacure 651", "Irgacure 819", "Irgacure 250", "Irgacure 369" (Ciba Japan), "Seikuol BZ", " Seikuol Z", "Seikuol BEE" (Seiko Chemicals Co., Ltd.); "kayacureBP100" (Nippon Chemical Co., Ltd.); "kayacure UVI-6992" (manufactured by Dow); "Adeka Optomer SP-152", "Adeka Optomer SP-170" (ADEKA (share)); "TAZ-A", "TAZ-PP" (Nihon Siber Hegner); and "TAZ-104" (Sanwa Chemical).

When the composition for forming a polarizing film contains a polymerization initiator, the content thereof can be appropriately adjusted depending on the type and amount of the polymerizable liquid crystal compound (polymerizable smectic liquid crystal compound) contained in the composition for forming a polarizing film. For example, the content of the polymerization initiator is preferably 0.1 to 30 based on 100 parts by mass of the total of the polymerizable liquid crystal compound (polymerizable smectic liquid crystal compound). The amount is more preferably 0.5 to 20 parts by mass, still more preferably 0.5 to 10 parts by mass. When the content of the polymerizable initiator is within this range, the polymerization can be carried out without disturbing the alignment of the polymerizable smectic liquid crystal compound. Therefore, the polymerizable smectic liquid crystal compound can be polymerized while maintaining the liquid crystal state of the higher order smectic phase.

When the composition for forming a polarizing film contains a polymerization initiator, the sensitizer may be contained in the composition for forming a polarizing film. As the sensitizer, a photosensitizer is preferred. As a sensitizer, for example, Ketone and 9-oxosulfur Wait Ketone compounds (for example, 2,4-diethyl 9-oxosulfur [ 2-isopropyl 9-oxosulfur [ And other compounds such as anthracene and alkoxy-containing anthracene (eg, dibutoxyanthracene, etc.); And red fluorene and the like.

When the composition for forming a polarizing film contains a polymerization initiator and a sensitizer, the polymerization reaction of the polymerizable liquid crystal compound (polymerizable smectic liquid crystal compound) contained in the composition for forming a polarizing film can be further promoted. The amount of the sensitizer to be used may be appropriately adjusted depending on the type and amount of the polymerization initiator and the polymerizable smectic liquid crystal compound, and is preferably, for example, 100 parts by mass based on the total of the polymerizable smectic liquid crystal compound. It is 0.1 to 30 parts by mass, more preferably 0.5 to 10 parts by mass, still more preferably 0.5 to 8 parts by mass.

The case where the polymerization reaction of the polymerizable liquid crystal compound (polymerizable smectic liquid crystal compound) is promoted by including the sensitizer in the composition for forming a polarizing film, but the polymerization reaction may be stably performed. The composition for forming a polarizing film is appropriately contained in a polymerization inhibitor. By containing a polymerization inhibitor, the degree of progress of the polymerization reaction of the polymerizable liquid crystal compound (polymerizable smectic liquid crystal compound) can be controlled.

Examples of the polymerization inhibitor include hydroquinone and alkoxy group-containing. Hydroquinone, alkoxy-containing catechol (eg, butyl catechol, etc.), pyrogallol, 2,2,6,6-tetramethyl-1-piperidinyl free Radical scavengers such as radicals; thiophenols; β-naphthylamines and β-naphthols.

When the polymerization inhibitor is contained in the composition for forming a polarizing film, the content thereof can be appropriately adjusted depending on the type and amount of the polymerizable smectic liquid crystal compound to be used, the amount of the sensitizer used, and the like, for example, relative The content of the polymerization inhibitor is preferably 0.1 to 30 parts by mass, more preferably 0.5 to 10 parts by mass, even more preferably 0.5 to 8 parts by mass per 100 parts by mass of the polymerizable liquid crystal compound (polymerizable smectic liquid crystal compound). . When the content of the polymerization inhibitor is within the above range, the polymerizable liquid crystal compound (polymerizable liquid crystal compound) can be polymerized without disturbing the alignment of the polymerizable liquid crystal compound (polymerizable smectic liquid crystal compound) contained in the composition for forming a polarizing film, so that the polymerizable liquid crystal compound (polymerizable layer) The smectic liquid crystal compound can be further polymerized by maintaining the liquid crystal state of the higher order smectic phase.

<leveling agent>

The composition for forming a polarizing film preferably contains a leveling agent. The leveling agent is a function of adjusting the fluidity of the composition for forming a polarizing film and further flattening the coating film obtained by applying the composition for forming a polarizing film, and examples thereof include a surfactant. Further, the leveling agent is preferably at least one selected from the group consisting of a leveling agent containing a polyacrylate compound as a main component and a leveling agent containing a fluorine atom-containing compound as a main component.

As a leveling agent containing a polyacrylate compound as a main component, "BYK-350", "BYK-352", "BYK-353", "BYK-354", "BYK-355", "BYK-" 358N", "BYK-361N", "BYK-380", "BYK-381" and "BYK-392" [BYK Chemie].

Examples of the leveling agent containing a fluorine atom-containing compound as a main component include "Megafac R-08", "Megafac R-30", "Megafac R-90", "Megafac F-410", and "Megafac F- 411", "Megafac F-443", "Megafac F-445", "Megafac F-470", "Megafac F-471", "Megafac F-477", "Megafac F-479", "Megafac F-482" And "Megafac F-483" [DIC (share)]; "Surflon S-381", "Surflon S-382", "Surflon S-383", "Surflon S-393", "Surflon SC-101", "Surflon SC-105", "KH-40" and "SA-100" [AGC Seimi Chemical (share)]; "E1830", "E5844" [Dakin Precision Chemical Research Institute (share)]; "Eftop EF301" , "Eftop EF303", "Eftop EF351" and "Eftop EF352" [Mitsubishi Materials Electronic Chemicals (share)].

When the leveling agent is contained in the composition for forming a polarizing film, the content thereof is preferably 0.3 parts by mass or more and 5 parts by mass or less based on 100 parts by mass of the polymerizable liquid crystal compound (polymerizable smectic liquid crystal compound). Further, it is preferably 0.5 parts by mass or more and 3 parts by mass or less. When the content of the leveling agent is within the above range, the polymerizable liquid crystal compound (polymerizable smectic liquid crystal compound) tends to be aligned horizontally, and the obtained polarizing film tends to be smoother. When the content of the leveling agent for the polymerizable layer-type liquid crystal compound exceeds the above range, unevenness tends to occur in the obtained polarizing film. Further, the composition for forming a polarizing film may contain two or more kinds of leveling agents.

<Method of Forming the Polarizing Film>

Then, the method of forming the present polarizing film from the composition for forming a polarizing film is further Line description. In this method, it is preferred to form the present polarizing film by applying a composition for forming a polarizing film on a substrate, preferably a transparent substrate.

<Transparent substrate>

The transparent substrate is a substrate having transparency to the extent that light, particularly visible light, is permeable. The term "transparency" refers to a property in which the transmittance of light passing through a wavelength of 380 to 780 nm is 80% or more. Specifically, examples of the transparent substrate include a glass substrate, a translucent sheet made of plastic, and a translucent film. In addition, examples of the plastic constituting the light-transmitting sheet or the light-transmitting film include polyethylene, polypropylene, and Polyolefin such as olefin polymer; cyclic olefin resin; polyvinyl alcohol; polyethylene terephthalate; polymethacrylate; polyacrylate; cellulose triacetate, cellulose diacetate and propionic acid acetate Cellulose esters such as cellulose; polyethylene naphthalate; polycarbonate; polyfluorene; polyether oxime; polyether ketone; polyphenylene sulfide and polyphenylene ether. In a specific example of the transparent substrate, a light transmissive film made of plastic, that is, a polymer film is preferable in view of a preferred translucent sheet made of plastic and a translucent film. In the polymer film, it is easy to obtain from the market or the transparency is excellent, and it is particularly preferable to include cellulose ester, cyclic olefin resin, polyethylene terephthalate or polymethacrylate. Molecular membrane. When the polarizing film is produced by using a transparent substrate, the transparent substrate can be transported or stored without causing breakage such as cracking, and the support substrate or the like can be attached to the transparent substrate. Further, in the case where a circularly polarizing plate is produced from the present polarizing film, there is a case where phase difference is imparted to the transparent substrate. In this case, the polymer film is prepared as a transparent substrate, and the polymer film is subjected to elongation treatment or the like to impart phase difference to the polymer film, and after the phase difference film is formed, the phase difference film is used as a transparent substrate. Material can be. Further, a method of imparting phase difference to a transparent substrate (polymer film) will be described later.

In the polymer film, when the phase difference is imparted, it is preferable to control the phase difference, and it is preferably a film containing a cellulose ester, a polycarbonate or a cyclic olefin resin (cellulose ester film, Polycarbonate film or cyclic olefin resin film). Hereinafter, the three types of polymer films will be described in detail.

The cellulose ester constituting the cellulose ester film is one in which at least a part of the hydroxyl groups contained in the cellulose are acetated. Cellulose ester films comprising such cellulose esters are readily available on the market. As a commercially available cellulose triacetate film, for example, "Fujitac Film" (Fuji Film Co., Ltd.); "KC8UX2M", "KC8UY", and "KC4UY" (Konica Minolta Opto) are available. Such a commercially available cellulose triacetate film can be used as a transparent substrate directly or as needed to impart phase difference. Further, the surface of the prepared transparent substrate may be used as a transparent substrate after surface treatment such as antiglare treatment, hard coating treatment, antistatic treatment or antireflection treatment.

When the phase difference is imparted to the polymer film, a method of stretching the polymer film or the like is used as described above. The polymer film containing a plastic, that is, a thermoplastic resin, can be subjected to stretching treatment, but a cyclic olefin resin film is preferred in terms of easily controlling phase difference. The cyclic olefin resin constituting the cyclic olefin resin film is, for example, included Alkene or polycyclic drop In the case of a polymer or a copolymer (cyclic olefin resin) of a cyclic olefin such as an olefinic monomer, the cyclic olefin resin may partially contain a ring-opening portion. Further, it may be a hydrogenated cyclic olefin resin containing an open ring portion. Further, the cyclic olefin-based resin may be, for example, a cyclic olefin, a chain olefin or an ethylated aromatic compound (styrene, etc.) in terms of not impairing transparency or not significantly increasing hygroscopicity. Copolymer. Further, the cyclic olefin resin may have a polar group introduced into the molecule.

When the cyclic olefin resin is a copolymer of a cyclic olefin and a chain olefin or an aromatic compound having a vinyl group, the chain olefin is ethylene or propylene, and the vinylated aromatic compound is styrene or α. -methylstyrene and alkyl substituted styrene. In such a copolymer, the content ratio of the structural unit derived from the cyclic olefin is 50 mol% or less, and is, for example, about 15 to 50 mol%, based on the total structural unit of the cyclic olefin resin. When the cyclic olefin resin is a terpolymer obtained from a cyclic olefin, a chain olefin, or an ethylenic aromatic compound, for example, the content ratio of the structural unit derived from the chain olefin is relative to the cyclic olefin system. The total structural unit of the resin is about 5 to 80 mol%, and the content of the structural unit derived from the vinylated aromatic compound is about 5 to 80 mol%. The cyclic olefin resin of such a terpolymer has an advantage that the amount of the cyclic olefin which is expensive can be relatively reduced when the cyclic olefin resin is produced.

A cyclic olefin-based resin which can produce a cyclic olefin-based resin film can be easily obtained from the market. Examples of the commercially available cyclic olefin resin include "Topas" [Ticona Co., Ltd.]; "Arton" [JSR (share)]; "Zeonor (ZEONOR)" and "Zeonex (ZEONEX)" [Japan Zeon] (shares)]; "Apel" [Mitsui Chemicals Co., Ltd.] and so on. The cyclic olefin-based resin can be formed into a film (cyclic olefin-based resin film) by a known film forming method such as a solvent casting method or a melt extrusion method. Also, you can also use the film already A commercially available cyclic olefin resin film. Examples of the commercially available cyclic olefin-based resin film include "S-SINA" and "SCA40" [Sekisui Chemical Industry Co., Ltd.]; "Zeonor Film" [Optronics (share)]; "Arton Film" [JSR (shares)] and so on.

Further, in the case of a polycarbonate film, it is also possible to easily obtain a film having phase difference from the market. As the polycarbonate film, there are a uniaxially stretched film WRF-S [(modified polycarbonate resin) manufactured by Teijin Chemical Co., Ltd.].

Next, a method of imparting phase difference to the polymer film will be briefly described. The polymer film can be imparted with phase difference by a known stretching method. For example, a roll (a coiled body) in which a polymer film is wound up is prepared, and a film is continuously taken up from the take-up body, and the wound film is conveyed to a heating furnace. The set temperature of the heating furnace is set to the range of the glass transition temperature (°C) to the [glass transition temperature +100] (°C) of the polymer film, preferably near the glass transition temperature (°C) to [glass transition temperature +50]. (°C) range. In the heating furnace, when extending in the direction in which the film travels or in the direction orthogonal to the traveling direction, the conveying direction or the tension is adjusted to be inclined at an arbitrary angle, and the uniaxial or biaxial heat stretching treatment is performed. The magnification of the stretching is usually in the range of about 1.1 to 6 times, preferably in the range of about 1.1 to 3.5 times. Further, the method of extending in the oblique direction is not particularly limited as long as the alignment axis can be continuously inclined to a desired angle, and a known extension method can be employed. For example, the method described in Japanese Laid-Open Patent Publication No. Hei. No. Hei. No. Hei.

In terms of the thickness of the polymer film, the thickness of the polymer film is such that it can be handled practically, and sufficient transparency can be ensured. On the other hand, the thinner the better, but if it is too thin, the strength is lowered, and the workability tends to be poor. Therefore, the appropriate thickness of the films is, for example, about 5 to 300 μm, preferably 20 to 200 μm. When the polarizing film is used as the circular polarizing plate described below, it is assumed that the display device using the circular polarizing plate is used for mobile phones, and therefore the thickness of the film is preferably about 20 to 100 μm. Further, in the case where phase difference is imparted to the film by stretching, the thickness after stretching is determined by the thickness or stretching ratio of the film before stretching.

<Alignment film>

Preferably, an alignment film is formed on the substrate used in the production of the polarizing film. In this case, the composition for forming a polarizing film is applied onto the alignment film. Therefore, the alignment film preferably has solvent resistance to such an extent that it is not dissolved by coating or the like of the composition for forming a polarizing film. Further, it is preferable to have heat resistance at the time of heat treatment for removal of a solvent or alignment of liquid crystals. As the alignment film, an alignment polymer can be used.

Examples of the orienting polymer include polyamine or gelatin having a guanamine bond in the molecule, polyimine having a quinone bond in the molecule, and polyglycine, polyethylene which is a hydrolyzate thereof. Alcohol, alkyl modified polyvinyl alcohol, polypropylene decylamine, poly A polymer such as azole, polyethyleneimine, polystyrene, polyvinylpyrrolidone, polyacrylic acid or polyacrylate. Among these, polyvinyl alcohol is preferred. These alignment polymers which form an alignment film may be used alone or in combination of two or more.

The alignment polymer can be formed on the substrate by coating it on the substrate in the form of an alignment polymer composition (solution containing the alignment polymer) dissolved in a solvent. Solvent for the alignment polymer composition Specific limitations include, in particular, water; alcohol solvents such as methanol, ethanol, ethylene glycol, isopropanol, propylene glycol, methyl stilbene, butyl sarbuta and propylene glycol monomethyl ether; ethyl acetate, Ester solvent such as butyl acetate, ethylene glycol methyl ether acetate, γ-butyrolactone, propylene glycol methyl ether acetate and ethyl lactate; acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, Ketone solvents such as pentyl ketone and methyl isobutyl ketone; aliphatic hydrocarbon solvents such as pentane, hexane and heptane; aromatic hydrocarbon solvents such as toluene and xylene; nitrile solvents such as acetonitrile; tetrahydrofuran and dimethoxy An ether solvent such as ethane; a chlorine-substituted hydrocarbon solvent such as chloroform or chlorobenzene; These organic solvents may be used singly or in combination of plural kinds.

Further, as the alignment polymer composition for forming the alignment film, a commercially available alignment film material can be used as it is. The commercially available alignment film material may, for example, be Sunever (registered trademark, manufactured by Nissan Chemical Industries Co., Ltd.) or Optomer (registered trademark, manufactured by JSR Co., Ltd.).

As a method of forming an alignment film on a substrate, for example, an alignment polymer composition or a commercially available alignment film material may be applied onto a substrate, followed by annealing to form an alignment film on the substrate. The thickness of the alignment film obtained in this manner is, for example, in the range of 10 nm to 10000 nm, preferably in the range of 10 nm to 1000 nm.

In order to impart an alignment restricting force to the alignment film, it is preferred to perform rubbing (friction method) as needed. By imparting an alignment restricting force, the polymerizable smectic liquid crystal compound can be aligned in a desired single direction (orientation direction).

As a method of imparting an alignment restricting force by a rubbing method, for example, a method of preparing a rubbing roller that is wound with a rubbing cloth and rotating is prepared on a substrate The layered body on which the coating film for forming an alignment film is formed is placed on the stage and conveyed toward the rotating rubbing roll, whereby the coating film for forming an alignment film is brought into contact with the rotating rubbing roll.

Further, a so-called light alignment film can also be used. The photo-alignment film also has a case where a photo-alignment-inducing layer is formed and an alignment regulating force is imparted by irradiation of polarized light (preferably, polarized light UV). When the photo-alignment-inducing layer is formed, first, a polymer or a monomer having a photoreactive group and a solvent (hereinafter sometimes referred to as "photo-alignment film-forming composition") are prepared. The photoreactive group refers to a group which generates a liquid crystal alignment ability by irradiation of light (light irradiation). Specifically, a photoreactor which is an origin of liquid crystal alignment ability which generates an alignment induction or isomerization reaction, a dimerization reaction, a photocrosslinking reaction, or a photodecomposition reaction, which are generated by irradiation of light, is generated. Among the photoreactive groups, those having excellent alignment properties and maintaining the smectic liquid crystal state at the time of forming the polarizing film are preferably those which utilize a dimerization reaction or a photocrosslinking reaction. As the photoreactive group which can cause the reaction as described above, it is preferably one having an unsaturated bond, especially a double bond, and particularly preferably having a carbon-carbon double bond (C=C bond) and a carbon-nitrogen double bond. A group of at least one of a group consisting of a bond (C=N bond), a nitrogen-nitrogen double bond (N=N bond), and a carbon-oxygen double bond (C=O bond).

Examples of the photoreactive group having a C=C bond include a vinyl group, a polyalkenyl group, a decyl group, a carbazolyl group, a heterofluorenyl group, a chalcone group, and a cinnamyl group. Examples of the photoreactive group having a C=N bond include a group having a structure such as an aromatic Schiff base and an aromatic fluorene. Examples of the photoreactive group having an N=N bond include an azophenyl group, an azonaphthyl group, an aromatic heterocyclic azo group, a bisazo group, a formazan group, or the like, or an oxyazobenzene group. Basic structure. As Examples of the photoreactive group having a C=O bond include a diphenylketone group, a coumarin group, a mercapto group, and a maleimine group. These groups may also have a substituent such as an alkyl group, an alkoxy group, an aryl group, an allyloxy group, a cyano group, an alkoxycarbonyl group, a hydroxyl group, a sulfonic acid group or a halogenated alkyl group.

Among them, a photoreactive group capable of generating a photodimerization reaction, a light having a relatively small amount of polarized light necessary for obtaining a photo-alignment, and having excellent thermal stability or stability over time, is preferred. The alignment film is preferred. Further, as the polymer having a photoreactive group, it is particularly preferred that the terminal portion of the side chain of the polymer has a cassia base which forms a cinnamic acid structure.

The photoreactive group-forming polymer or monomer is applied to the transparent substrate in the form of a photo-alignment film-forming composition dissolved in a solvent to form a photo-alignment-inducing layer on the transparent substrate. The solvent to be used in the composition is not particularly limited, and a solvent such as a user in the above-mentioned alignment polymer composition can be used depending on the solubility of the polymer or monomer having a photoreactive group.

The concentration of the photoreactive group-containing polymer or monomer relative to the photo-alignment film-forming composition can be appropriately adjusted depending on the kind of the photoreactive group-containing polymer or monomer or the thickness of the photo-alignment film to be produced. The solid content concentration is preferably at least 0.2% by mass, and more preferably 0.3 to 10% by mass. Further, the composition for forming an alignment film may contain a polymer material such as polyvinyl alcohol or polyimine or a photosensitizer in a range in which the characteristics of the photo-alignment film are not significantly impaired.

As a method of applying an alignment polymer or a polymer or monomer having a photoreactive group to a transparent substrate, a spin coating method, an extrusion method, A known method such as a gravure coating method, a die coating method, a bar coating method, or an applicator method, or a printing method such as a soft plate printing method. Further, in the case where the polarizing film is produced by the continuous production method in the form of Roll to Roll described below, the coating method is usually a printing method such as a gravure coating method, a die coating method or a soft plate printing method.

<Method of Manufacturing the Polarizing Film>

A coating film forming composition is applied onto an alignment film formed on a substrate to obtain a coating film. A method (coating method) of applying a composition for forming a polarizing film on an alignment film, for example, coating a polymer (monomer) as an alignment polymer or a photoreactive group on a transparent substrate The method of the above is exemplified by the same method.

Then, the solvent is dried and removed under the condition that the polymerizable smectic liquid crystal compound contained in the coating film is not polymerized to form a dried film. Examples of the drying method include a natural drying method, a ventilation drying method, a heat drying method, and a vacuum drying method. In this case, it is preferred to temporarily transfer the nematic phase to a smectic phase after the liquid crystal state of the polymerizable smectic liquid crystal compound contained in the dried film is a nematic phase (nematic liquid crystal state). In order to form the smectic phase through the nematic phase, for example, the method is as follows: heating to a temperature at which the polymerizable smectic liquid crystalline compound phase contained in the dried film is transferred to a liquid crystal state of the nematic phase, and then cooled to a polymerizable layer The liquid crystal compound shows the temperature of the liquid crystal state of the layer phase.

When the polymerizable smectic liquid crystal compound in the dried film is in a smectic liquid crystal state or the polymerizable smectic liquid crystal compound is in a smectic liquid crystal state via a nematic liquid crystal state, it is used for measurement. polymerization The phase transition temperature of the smectic liquid crystal compound can easily determine the conditions (heating conditions) for controlling the liquid crystal state. The measurement conditions of the phase transition temperature measurement are described in the examples of the present invention.

When the polymerizable layer-type liquid crystal compound is polymerized, it is preferable to use a composition for forming a polarizing film containing two or more kinds of polymerizable smectic liquid crystal compounds as a polymerizable layer in order to maintain the liquid crystal state of the smectic phase. Column type liquid crystal compound. When a composition for forming a polarizing film in which a content ratio of two or more kinds of polymerizable smectic liquid crystal compounds is adjusted, a liquid crystal state of a smectic phase is formed through a nematic phase, and a supercooled state can be temporarily formed. It is easy to maintain the advantages of the liquid crystal state of the higher order layer phase.

Next, the polymerization step of the polymerizable smectic liquid crystal compound will be described. Here, the photo-polymerization initiator is contained in the composition for forming a polarizing film, and the liquid crystal state of the polymerizable smectic liquid crystal compound in the dried film is made into a smectic phase, and the stratified column is held. The polymerizable smectic liquid crystal compound is photopolymerized in a liquid crystal state. In the photopolymerization, the light to be irradiated to the dried film may be based on the type of the photopolymerization initiator contained in the dried film or the type of the polymerizable smectic liquid crystal compound (especially, the polymerizable smectic liquid crystal compound) The type of the photopolymerizable group and the amount thereof are suitably carried out using light or an active electron beam selected from the group consisting of visible light, ultraviolet light, and laser light. Among these, ultraviolet light is preferred in terms of the ease of controlling the progress of the polymerization reaction or the use of a wide range of users in the field as a device for photopolymerization. Therefore, when the type of the polymerizable smectic liquid crystal compound or the photopolymerization initiator contained in the composition for forming a polarizing film is selected by photopolymerization using ultraviolet light, It is better. Further, at the time of polymerization, while irradiating with ultraviolet light, the polymerization temperature can be controlled by cooling the dried film by an appropriate cooling method. If the polymerization of the polymerizable smectic liquid crystal compound can be carried out at a lower temperature by using such a cooling method, there is also an advantage that even if the transparent substrate is used in a relatively low heat resistance, the cost of polarized light can be appropriately formed. membrane.

By carrying out the photopolymerization as described above, the polymerizable smectic liquid crystal compound is polymerized while maintaining the smectic phase, preferably in a liquid crystal state of a stratified phase as high as exemplified, to form the present polarizing film. The polymerizable smectic liquid crystal compound maintains the liquid crystal state of the smectic phase and the obtained polarizing film has the following advantages: with the action of the azo dye (1), the polarizing performance is much higher than that of the previous guest-type polarizing film, That is, a polarizing film obtained by polymerizing a polymerizable liquid crystal compound or the like while maintaining the liquid crystal state of the nematic phase.

The thickness of the polarizing film is preferably in the range of 0.5 μm or more and 10 μm or less, and more preferably 1 μm or more and 5 μm or less. Therefore, the thickness of the coating film for forming the polarizing film can be determined in consideration of the thickness of the obtained polarizing film. Furthermore, the thickness of the polarizing film can be determined by interference with a film thickness meter, a laser microscope, or a stylus film thickness meter.

The present polarizing film is formed by using at least two kinds of dichroic dyes having mutually different maximum absorption wavelengths, preferably at least two kinds of azo dyes (1), and particularly preferably the azo shown in Table 1. The composition for forming a polarizing film of the combination of the dyes (1) has an absorption spectrum satisfying the relationship of the formulae (I) to (V). In particular, when a combination of the azo dyes (1) shown in Table 1 is used as the composition for forming a polarizing film, an absorption spectrum having a relationship satisfying the formula (I) to the formula (V) can be more easily obtained. The present polarizing film.

Further, it is preferable that the present polarizing film thus formed is a Bragg peak which can be obtained by X-ray reflection measurement. As the present polarizing film in which the Bragg peak is obtained, for example, a diffraction peak derived from a hexatic phase or a crystal phase can be cited.

Further, it is preferable that the polarizing film has a visibility correction monomer transmittance Ty of 43% or more and a visibility correction monomer polarization degree Py of 90% or more. Here, the visibility correction monomer transmittance Ty and the visibility correction monomer polarization degree Py are values for measuring the transmittance (T ¹ ) and absorption in the transmission axis direction of the polarizing film in the wavelength range of 300 to 800 nm. The transmittance (T ² ) in the axial direction was calculated by using the following formula (VI) and formula (VII) to calculate the monomer transmittance and the degree of polarization, and the visibility was corrected by a 2 degree field of view (C light source) of JIS Z8701.

Ty(%)=(T ¹ +T ² )/2 (VI)

Py(%)={(T1-T2)/(T1+T2)}×100 Formula (VII)

<Continuous manufacturing method of the present polarizing film (this circular polarizing plate)>

As described above, the outline of the method for producing the polarizing film has been described. When the present polarizing film is commercially produced, a method of continuously producing the polarizing film can be achieved. Such a continuous manufacturing method is a method using the Roll to Roll form, and is sometimes referred to as "this manufacturing method". In the present manufacturing method, a description will be given focusing on a case where a transparent substrate to which phase difference is applied is used as a substrate.

The manufacturing method includes, for example, a step of preparing a first roll in which a transparent substrate is wound on a first core, continuously feeding a transparent substrate from the first roll, and applying a polymer and a solvent containing a photoreactive group. Composition, The first coating film is continuously formed on the transparent substrate; the solvent is dried from the first coating film, the first dried film is formed on the transparent substrate, and the first laminate is continuously obtained; and the first dried film is irradiated Polarizing UV, forming a photo-alignment film, continuously obtaining a second layered body, and applying a composition containing a polymerizable smectic liquid crystal compound, a dichroic dye, and a solvent to the photo-alignment film, and continuously forming on the photo-alignment film The second coating film is formed by drying the second coating film under the condition that the polymerizable smectic liquid crystal compound contained in the second coating film is not polymerized, thereby continuously forming a second dry film on the photo-alignment film. After the third layered product is obtained, the polymerizable smectic liquid crystal compound contained in the second dried film is in a smectic liquid crystal state, and the polymerized smectic liquid crystal compound is maintained in a smectic liquid crystal state, thereby continuously A polarizing film was obtained; and a continuously obtained polarizing film was wound up on the second core to obtain a second roll.

An essential part of the manufacturing method will be described here with reference to FIG. 1.

The first roll 210 on which the transparent substrate is wound on the first core 210A can be easily obtained, for example, from the market. As a transparent substrate which can be obtained from the market in such a rollable form, examples of the transparent substrate which is exemplified include cellulose ester, cyclic olefin resin, polyethylene terephthalate, polycarbonate or poly. Methacrylate film and the like. Further, a transparent substrate which can be used in the case of obtaining a polarizing film in the form of a circularly polarizing film can be easily obtained from the market, and examples thereof include cellulose ester, polycarbonate or cyclic olefin. A retardation film of a resin or the like.

Then, the transparent substrate is taken up from the first volume 210. The method of winding out the transparent substrate can be performed by providing an appropriate rotating mechanism to the winding core 210A of the first roll 210 and rotating the first roll 210 by the rotating mechanism. Moreover, it is also possible to provide a suitable auxiliary roll 300 in the direction in which the transparent substrate is conveyed from the first roll 210, and to wind up the transparent substrate by the rotating mechanism of the auxiliary roll 300. Further, a configuration may be adopted in which a rotation mechanism is provided to each of the first core 210A and the auxiliary roll 300 to apply an appropriate tension to the transparent substrate and to wind up the transparent substrate.

When the transparent substrate rolled out from the first roll 210 passes through the coating device 211A, the coating film forming composition is applied onto the surface of the coating device 211A. In order to continuously apply the composition for forming an alignment film in this manner, the coating device 211A is a printing method such as a gravure coating method, a die coating method, or a soft-plate printing method as described above.

The film that has passed through the coating device 211A corresponds to a laminate of the transparent substrate and the first coating film thereon. The transparent substrate in which the first coating film is formed (laminated) is conveyed to the drying furnace 212A, heated by the drying furnace 212A, and converted into the first layered body including the transparent substrate and the first dried film. As the drying furnace 212A, for example, a hot air drying oven or the like can be used. The set temperature of the drying furnace 212A can be determined according to the type of the solvent contained in the composition for forming an alignment film to be applied by the coating device 211A. Further, the drying furnace 212A may be in a form divided into appropriate regions, and each of the divided plurality of regions may have a different set temperature, or a plurality of drying ovens may be arranged in series, and each of the plurality of drying furnaces may be operated at different set temperatures. The drying furnace sequentially transports the film to the form of the plurality of drying furnaces.

Regarding the first layered body continuously formed by the heating furnace 212A, Then, the surface of the first dry film side or the surface of the transparent substrate side of the laminate is irradiated with polarized light UV by the polarized UV irradiation device 213A to convert the first dry film into a light polarizing film. At this time, the angle formed by the film transport direction D1 and the alignment direction D2 of the formed light alignment film was substantially 45°. Fig. 2 is a view schematically showing the relationship between the alignment direction D2 of the photo-alignment film formed after the polarized UV irradiation and the film transport direction D1. In other words, when the film transport direction D1 and the alignment direction D2 of the photo-alignment film are observed on the surface of the first layered body after passing through the polarized UV irradiation device 213A, the angle formed by the film is approximately 45°.

The first layered body thus formed is coated with the composition for forming a polarizing film on the photo-alignment film of the first layered product by the coating device 211B, and then passes through the drying furnace 212B to form the second layer. The polymerizable smectic liquid crystal compound contained in the second dry film of the second or second layered product forms a smectic liquid crystal state. The drying furnace 212B functions to dry and remove the solvent from the composition for forming a polarizing film formed on the photo-alignment film, and to form a liquid crystal state of the stratified phase in the polymerizable smectic liquid crystal compound contained in the second dried film. The heat energy is applied to the second dry film. In addition, as described above, in order to make the polymerizable smectic liquid crystal compound into a liquid crystal state of a smectic phase, and to temporarily make the polymerizable smectic liquid crystal compound into a liquid crystal state of a nematic phase, it is necessary to borrow the first laminate. The first laminate is subjected to a plurality of stages of heat treatment under different heating conditions. Therefore, as described in the drying furnace 212A, the drying furnace 212B preferably includes a plurality of regions having different set temperatures from each other, or a plurality of drying furnaces having different set temperatures different from each other, and arranged in series.

The film contained in the composition for forming a polarizing film is sufficiently removed by the film of the drying furnace 212B, and the polymerizable smectic liquid crystal compound in the second dried film retains the liquid crystal state of the layer phase and is transported to the light irradiation device 213B. By the light irradiation of the light irradiation device 213B, the polymerizable smectic liquid crystal compound is subjected to photopolymerization while maintaining a liquid crystal state, and the polarizing film is continuously formed on the alignment film.

The present polarizing film thus formed is wound around the second core 220A in a form of a laminate including a transparent substrate and an alignment film, and the second roll 220 is obtained. When the second polarized film is obtained by winding up the second polarizing film, it is also possible to carry out the feeding using a suitable separator.

Thus, the transparent substrate sequentially passes through the first roll/coating device 211A/drying furnace 212A/polarized UV irradiation device 213A/coating device 211B/drying furnace 212A/light irradiation device 213A, thereby being on the transparent substrate. The present polarizing film is continuously produced on the photoalignment film.

Further, in the present production method shown in Fig. 1, a method of continuously producing the transparent substrate to the present polarizing film has been exemplified, but for example, the transparent substrate may be sequentially passed through the first roll/coating device 211A/ The drying furnace 212A/polarized UV irradiation device 213A winds the continuously formed first laminated body on the winding core, and manufactures the first laminated body in the form of a roll, and winds up the first laminated body to wind up the first laminated body. The laminated body was sequentially passed through the coating device 211B/drying furnace 212A/light irradiation device 213A to produce the present polarizing film.

In the above, the configuration of the polarizing film and the manufacturing method thereof have been described focusing on the form of the laminated body of the transparent substrate/light alignment film/the present polarizing film. As described above, the polarizing film can be peeled off from the laminated body. The film or the transparent substrate may also be used as a laminated layer transparent substrate/photoalignment film/this polarizing film. The shape of the outer layer or membrane. As the layers and films, as described above, the polarizing film may further include a retardation film, and may further include an antireflection layer or a brightness enhancement film.

Further, by using the transparent substrate itself as a retardation film, a circularly polarizing plate or a circularly polarizing plate in the form of a retardation film/optical alignment film/the present polarizing film can be formed. For example, when a uniaxially extending quarter-wavelength plate is used as the retardation film, the irradiation direction of the polarized light UV is set to be approximately 45° with respect to the conveyance direction of the transparent substrate, whereby Roll- can be used. To-Roll makes a circular polarizer. The quarter-wavelength plate used in the production of the circularly polarizing plate in this manner preferably has a characteristic that the in-plane retardation value with respect to visible light becomes shorter as the wavelength becomes shorter.

Further, a 1⁄2 wavelength plate can be used as the retardation film, and a linear polarizing plate roll which is set at an angle deviating from the absorption axis of the retardation axis and the polarizing film can be formed, and formed on the side opposite to the surface on which the polarizing film is formed. A quarter-wave plate is used to form a wide-band circular polarizing plate.

In the above production method described above, the transparent substrate may be replaced with a substrate having no phase difference. In this case, when manufacturing the circular polarizing plate, first, the substrate obtained by the present manufacturing method (having no phase difference) / the photo-alignment film / the polarizing film is peeled off to form a winding film. Body 225. On the other hand, the take-up body 230 having the retardation film is prepared to be taken up. Then, the polarizing film is continuously wound from the take-up body 225, and the retardation film is continuously wound from the take-up body 230, and the polarizing film is produced by bonding them in an appropriate manner. A necessary part of the method is shown in FIG. In this case, the retardation film may be bonded to the retardation film so as to be substantially 45° with respect to the alignment direction of the polarizing film. Furthermore, when the polarizing film is bonded to the retardation film, The polarizing film may be bonded to the retardation film via an adhesive layer formed of an adhesive by using an appropriate adhesive.

In the case where the present polarizing film manufactured by the present production method has an absorption spectrum satisfying the relationship of the formula (I) to the formula (V), the polarizing film is obtained in a single film state by peeling off a transparent substrate or the like. The absorption spectrum of the polarizing film of the single film may be measured by a conventional method. For example, the absorption spectrum of a transparent substrate or the like may be measured in advance, and the absorption spectrum of the transparent substrate or the like may be used as a baseline to measure the formation. An absorption spectrum of the present polarizing film in a state of being on a transparent substrate or the like; or a method of measuring an absorption spectrum of a transparent substrate or the like in advance, and then measuring an absorption spectrum of the polarizing film formed on a transparent substrate or the like, Further, the difference between the absorption spectrum of the present polarizing film formed on a transparent substrate or the like and the absorption spectrum of a transparent substrate or the like is determined. By using such a method of measuring the absorption spectrum of a transparent substrate or the like in advance, the absorption spectrum of the present polarizing film can be easily obtained without peeling off the transparent substrate or the like.

<Use of the polarizing film>

The polarizing film can produce a circular polarizing plate which is extremely useful for an organic EL (electroluminescence) display device. Furthermore, the display device may also be an inorganic electroluminescence (EL) display device.

FIG. 4 and FIG. 6 are schematic diagrams showing a cross-sectional configuration of an EL display device (hereinafter sometimes referred to as "the present organic EL display device") using the polarizing film.

The present organic EL display device 30 using the present polarizing film will be described with reference to Fig. 4 . When the present polarizing film is used in the organic EL display device, it is preferable to use the polarizing film as a circular polarizing plate (hereinafter, sometimes referred to as "the circular polarizing light" Use after the board"). There are two embodiments of the present circular polarizing plate. Therefore, two embodiments of the present circular polarizing plate will be described with reference to FIG. 5 before explaining the configuration of the organic EL display device 30 and the like.

Fig. 5(A) is a cross-sectional view schematically showing the first embodiment of the circular polarizing plate 110. In the first embodiment, the present polarizing film 3 is further provided with a circular polarizing plate 110 of a retardation layer (retardation film) 4. Fig. 5(B) is a cross-sectional view schematically showing a second embodiment of the circular polarizing plate 110. In the second embodiment, the transparent polarizing substrate 110 is provided by using a transparent substrate (retardation film) having a phase difference in advance as a transparent substrate 1 used for producing a polarizing element, and the transparent substrate 1 itself is used. It has the function as the phase difference layer 4.

In the organic EL display device 30, the organic functional layer 36, which is a light source, and the cathode electrode 37 are laminated on the substrate 33 on which the pixel electrode 35 is formed. The circular polarizing plate 31 is disposed on the side opposite to the organic functional layer 36, and the circular polarizing plate 110 is used as the circular polarizing plate 31. A positive voltage is applied to the pixel electrode 35, a negative voltage is applied to the cathode electrode 37, and a direct current is applied between the pixel electrode 35 and the cathode electrode 37, whereby the organic functional layer 36 emits light. The light source, that is, the organic functional layer 36, includes an electron transport layer, a light emitting layer, a hole transport layer, and the like. The light emitted from the organic functional layer 36 passes through the pixel electrode 35, the interlayer insulating film 34, the substrate 33, and the circularly polarizing plate 31 (the present circular polarizing plate 110). The organic EL display device having the organic functional layer 36 will be described, and it can also be applied to an inorganic EL display device having an inorganic functional layer.

When the organic EL display device 30 is manufactured, first, the thin film transistor 40 is formed into a desired shape on the substrate 33. Then, the interlayer insulating film 34 is formed into a film, and then the pixel electrode 35 is formed into a film by sputtering to be patterned. Thereafter, the layer Organic functional layer 36.

Then, a circular polarizing plate 31 (the present circular polarizing plate 110) is provided on the opposite surface of the surface of the substrate 33 on which the thin film transistor 40 is provided.

In the case where the circular polarizing plate 110 is used as the circular polarizing plate 31, the order of lamination will be described with reference to an enlarged view of the C portion of the broken circle shown in FIG. When the circular polarizing plate 110 is used as the circular polarizing plate 31, the phase difference layer 4 in the circular polarizing plate 110 is disposed on the substrate 33 side. Fig. 5(A) is an enlarged view showing the first embodiment of the circular polarizing plate 110 as the circular polarizing plate 31, and Fig. 5(B) showing the second embodiment of the circular polarizing plate 110 as circularly polarized light. An enlarged view of the board 31.

Then, members other than the present polarizing film 31 (circular polarizing plate 110) of the organic EL display device 30 will be briefly described.

Examples of the substrate 33 include a sapphire glass substrate, a quartz glass substrate, a soda glass substrate, a ceramic substrate such as alumina, a metal substrate such as copper, and a plastic substrate. Although not shown, a thermally conductive film may be formed on the substrate 33. Examples of the thermally conductive film include a diamond thin film (such as DLC (Diamond-like carbon)). When the pixel electrode 35 is of a reflective type, light is emitted in a direction opposite to the substrate 33. Therefore, not only a transparent material but also a non-transmissive material such as stainless steel can be used. The substrate may be formed singly or in the form of a laminated substrate by bonding a plurality of substrates with an adhesive. Moreover, these substrates are not limited to a plate shape, and may be a film.

As the thin film transistor 40, for example, a polycrystalline germanium transistor or the like may be used. The thin film transistor 40 is provided at the end of the pixel electrode 35 and has a size of about 10 to 30 μm. Furthermore, the size of the pixel electrode 35 is 20 μm × 20 μm to 300 Μm × 300 μm or so.

A wiring electrode of the thin film transistor 40 is provided on the substrate 33. The wiring electrode has a low resistance and has a function of electrically connecting to the pixel electrode 35 and suppressing a low resistance value. Generally, the wiring electrode is made of Al, Al, and a transition metal (other than Ti), Ti or titanium nitride (TiN). Any one or two or more of them.

An interlayer insulating film 34 is provided between the thin film transistor 40 and the pixel electrode 35. The interlayer insulating film 34 is formed by sputtering or vacuum deposition to form an inorganic material such as cerium oxide or tantalum nitride such as SiO _{2 ,} and a cerium oxide layer formed by SOG (spin-coated glass), a photoresist, and a polymer. Any one of the coating film of a resin material such as a quinone imine or an acrylic resin may have insulation properties.

A barrier wall 41 is formed on the interlayer insulating film 34. The barrier 41 is disposed at a peripheral portion of the pixel electrode 35 (between adjacent pixels). Examples of the material of the barrier rib 41 include an acrylic resin and a polyimide resin. The thickness of the barrier rib 41 is preferably 1.0 μm or more and 3.5 μm or less, and more preferably 1.5 μm or more and 2.5 μm or less.

Next, an EL element including a pixel electrode 35 as a transparent electrode, an organic functional layer 36 as a light-emitting source, and a cathode electrode 37 will be described. The organic functional layer 36 has at least one layer of a hole transport layer and a light-emitting layer, and has, for example, an electron injection transport layer, a light-emitting layer, a hole transport layer, and a hole injection layer in this order.

Examples of the pixel electrode 35 include ITO (tin-doped indium oxide), IZO (zinc-doped indium oxide), IGZO (Indium Gallium Zinc Oxide), ZnO, SnO _{2 ,} and In ₂ O _{3 ,} and the like. For ITO or IZO. The thickness of the pixel electrode 35 may have a thickness sufficient to sufficiently fill the hole, and is preferably about 10 to 500 nm.

The pixel electrode 35 can be formed by an evaporation method (preferably, a sputtering method). The sputtering gas is not particularly limited, and an inert gas such as Ar, He, Ne, Kr or Xe or a mixed gas thereof may be used.

As a constituent material of the cathode electrode 37, for example, a metal element such as K, Li, Na, Mg, La, Ce, Ca, Sr, Ba, Al, Ag, In, Sn, Zn, or Zr may be used, but the electrode is improved. For the activation stability, it is preferred to use an alloy system selected from two or three of the metal elements exemplified. As the alloy system, for example, Ag‧Mg (Ag: 1 to 20 at%), Al‧Li (Li: 0.3 to 14 at%), In‧Mg (Mg: 50 to 80 at%), and Al‧Ca (Ca: 5~20at%) and so on.

The cathode electrode 37 is formed by a vapor deposition method, a sputtering method, or the like. The thickness of the cathode electrode 37 is preferably 0.1 nm or more, preferably 1 to 500 nm or more.

The hole injection layer has a function of facilitating the injection of holes from the pixel electrode 35. The hole transport layer has a function of transmitting holes and a function of blocking electrons, and is also called a charge injection layer or a charge transport layer.

The thickness of the light-emitting layer, the thickness of the hole injection layer and the hole transport layer, and the thickness of the electron injecting and transporting layer are not particularly limited, and are preferably about 5 to 100 nm depending on the method of formation. Various organic compounds can be used for the hole injection layer or the hole transport layer. When a hole is injected into the transport layer, the light-emitting layer, and the electron injecting and transporting layer, a vacuum thin film method can be used in terms of forming a homogeneous film.

As the light-emitting source, that is, the organic functional layer 36, it is possible to use light-emitting (phosphorescence) from triplet excitons using light (fluorescence) from singlet excitons. The layer including the light-emitting (fluorescent) from the singlet exciton and the layer using the light-emitting (phosphorescence) from the triplet exciton, the layer formed by the organic substance, the layer formed by the organic substance, and the layer formed by the inorganic substance, Polymer materials, low molecular materials, materials containing polymers and low molecular materials. However, the present invention is not limited thereto, and an organic functional layer 36 using various known materials can be used for the organic EL display device 30 as an EL element.

A desiccant 38 is disposed in the space between the cathode electrode 37 and the sealing cover 39. The reason for this is that the organic functional layer 36 cannot withstand moisture. The desiccant 38 absorbs moisture to prevent deterioration of the organic functional layer 36.

Fig. 6 is a schematic view showing a cross-sectional structure of another aspect of the organic EL display device 30. The organic EL display device 30 has a sealing structure using a film sealing film 41, and light can be obtained from the opposite surface of the array substrate.

As the film sealing film 41, a DLC film in which DLC (Diamond-Like Carbon) is vapor-deposited on a film using an electrolytic capacitor is preferable. The DLC film has a characteristic of poor moisture permeability and high moisture resistance. Further, a DLC film or the like may be formed by directly vapor-depositing the surface of the cathode electrode 37. Further, a multilayer resin film and a metal thin film may be laminated to form a film sealing film 41.

In the above manner, a novel organic EL display device comprising the novel polarizing film (the present polarizing film) of the present invention and a circular polarizing plate comprising the present polarizing film is provided.

In the organic EL display device, the intensity of light having a wavelength of 450 nm is referred to as I450, and the intensity of light having a wavelength of 550 nm is referred to as I550, and the intensity of light having a wavelength of 650 nm is recorded as I650 by providing a circular polarizing plate including the present polarizing film. , having an illuminance spectrum that satisfies all of the relationships shown below: 1≦I450/I550<2 (X)

1≦A450/A650<2 (XI).

In the organic EL display device, the polarizing film hardly absorbs light from the organic EL light-emitting element, particularly blue light having a short lifetime (a light-emitting element having a wavelength of around 450 nm), so that it is not necessary to increase the light-emitting intensity of the organic EL light-emitting element. The organic EL image display device has a long life. Therefore, the polarizing film and the present polarizing plate are extremely valuable in the industry.

[Examples]

Hereinafter, the present invention will be described in further detail by way of examples. In the examples, "%" and "parts" are % by mass and parts by mass unless otherwise specified.

In the present embodiment, the following polymerizable smectic liquid crystal compound was used.

Compound (2-6) (a compound represented by the following formula (2-6))

The compound (2-6) was synthesized by the method described in Lub et al. Recl. Trav. Chim. Pays-Bas, 115, 321-328 (1996).

[Measurement of phase transition temperature]

The phase transition temperature of the compound (2-6) was confirmed by determining the phase transition temperature of the film containing the compound (2-6). Its operation is as follows.

A film containing the compound (2-6) was formed on the glass substrate on which the alignment film was formed, and the phase transition temperature was confirmed by observation of the texture of a polarizing microscope (BX-51, manufactured by Olympus Co., Ltd.) while heating. It was confirmed that when the film containing the compound (2-6) was cooled to 120 ° C and then cooled, the phase was transferred to a nematic phase at 112 ° C, and the phase was transferred to a layer A phase at 110 ° C, and the phase was transferred at 94 ° C. Move to the layer B phase.

Compound (2-8) (compound represented by the following formula (2-8))

The compound (2-8) is synthesized by the synthesis of the above compound (2-6) as a reference.

[Measurement of phase transition temperature]

The phase transition temperature of the compound (2-8) was confirmed in the same manner as the phase transition temperature measurement of the compound (2-6). After confirming that the compound (2-8) was cooled to 140 ° C and then cooled, the phase was transferred to a nematic phase at 131 ° C, phase-transformed into a layer A phase at 80 ° C, and phase-transformed into a layer B phase at 68 ° C.

Example 1 [Preparation of Composition for Forming Polarizing Film]

The components shown in Table 3 were mixed and stirred at 80 ° C for 1 hour to obtain a composition for forming a polarizing film. In addition, the structure and the composition of each component (refer to Table 3 of the composition of the dichroic dye) are as follows.

Polymeric smectic liquid crystal compound: compound (2-6) 90 parts of compound (2-8) 10 parts

Dichroic pigment:

Compound (1-5) 2.5 parts

Compound (1-8) 2.5 parts

Compound (1-21) 2.5 parts

Polymerization initiator:

2-dimethylamino-2-benzyl-1-(4- Polinylphenyl)butan-1-one (Irgacure 369; manufactured by Ciba Specialty Chemicals Co., Ltd.) 6 parts

Leveling agent:

Polyacrylate compound (BYK-361N; manufactured by BYK-Chemie) 1.2 parts

Solvent: xylene 250 parts

[Measurement of phase transition temperature]

In the same manner as in the case of the compound (2-6) and the compound (2-8), a mixture of the compound (2-6) and the compound (2-8) contained in the composition for forming a polarizing film prepared in the above manner was obtained. (The mixing ratio of the compound (2-6) and the compound (2-8) is 90 parts: 10 parts). When the temperature was raised to 140 ° C and the temperature was lowered, the polymerizable liquid crystal compound was phase-transferred to a nematic phase at 116 ° C, phase-transformed into a layer A phase at 107 ° C, and phase-transformed into a layer B phase at 76 ° C.

[Manufacture and evaluation of this polarizing film] 1. Formation of alignment film

A glass substrate was used as the transparent substrate.

A 2% by mass aqueous solution (orthogonal polymer composition) of polyvinyl alcohol (polyvinyl alcohol 1000 completely saponified, manufactured by Wako Pure Chemical Industries, Ltd.) was applied to the glass substrate by spin coating to form a dry mass. A film having a thickness of 100 nm. Then, by performing rubbing treatment on the surface of the obtained film An alignment film is formed. In the case of the friction treatment, a semi-automatic friction device (trade name: LQ-008 type, manufactured by Changyang Engineering Co., Ltd.) was used, and the cloth was used (trade name: YA-20-RW, manufactured by Yoshikawa Chemical Co., Ltd.) at a press-in amount of 0.15. It was carried out under the conditions of mm, rotation speed of 500 rpm, and 16.7 mm/s. By this rubbing treatment, the laminated body 1 in which the alignment film was formed on the glass substrate was obtained.

2. Formation of polarizing film

The composition for forming a polarizing film was applied onto the alignment film of the laminate 1 by a spin coating method, and dried by heating on a hot plate at 120 ° C for 1 minute, and then rapidly cooled to room temperature to form a dried film on the alignment film. The liquid crystalline state of the polymerizable smectic liquid crystal compound contained in the dried film is a smectic B phase. Then, using a UV irradiation apparatus (SPOT CURE SP-7; manufactured by Ushio Electric Co., Ltd.) under a nitrogen atmosphere, the dried film was irradiated with ultraviolet rays at an exposure amount of 2000 mJ/cm ² (365 nm basis), thereby allowing the dried film to be contained. The polymerizable liquid crystal compound is polymerized while maintaining the liquid crystal state of the polymerizable liquid crystal compound, and a polarizing film is formed from the dried film. The thickness of the polarizing film at this time was measured by a laser microscope (OLS3000, manufactured by Olympus Co., Ltd.), and it was 1.8 μm.

4. Absorbance and transmittance measurement

In order to confirm the usefulness of the polarizing element, the absorbance was measured in the following manner. Absorbance with a polarizing element mounted on a spectrophotometer (UV-3150 manufactured by Shimadzu Corporation) was used to absorb the absorbance in the direction of the transmission axis in the range of 300 to 800 nm by the double beam method (A ^{1 )} And the absorbance (A ² ) in the direction of the absorption axis was measured by spectrometry. Regarding the holder, the reference side is provided with a mesh that cuts off the light amount by 50%. The absorbances A450, A550, A650, absorbance ratios A450/A550 and A450/A650 in the absorption axis direction at wavelengths of 450 nm, 550 nm, and 650 nm were determined. In the spectrum measurement, the absorption spectrum of the layered body 1 for forming the present polarizing film is measured in advance, and the absorption spectrum is used as a baseline to obtain a correction.

Further, the visibility corrected polarization (Py) and the visibility corrected transmittance (Ty) calculated based on the spectral results were obtained. The measurement results of these are shown in Table 2. Further, the visibility correction polarization (Py) and the visibility correction transmittance (Ty) are values for measuring the transmittance (T ¹ ) in the transmission axis direction and the transmittance in the absorption axis direction in the wavelength range of 300 to 800 nm ( T ² ), the monomer transmittance and the degree of polarization were calculated using the following formula (VI) and formula (VII), and were obtained by performing visibility correction by a 2 degree field of view (C light source) of JIS Z8701.

Ty(%)=(T ¹ +T ² )/2 (VI)

Py(%)={(T ¹ -T ² )/(T ¹ +T ² )}×100 Formula (VII)

In Examples 2 to 8, a polarizing film was produced in the same manner as in Example 1 except that the type of the dichroic dye was changed. Table 1 shows the results of the amount of the dichroic dye added and the film thickness of the produced polarizing film. Further, the absorption spectrum was measured in the same manner. The absorbances A450, A550, and A650 in the absorption axis direction at the wavelengths of 450 nm, 550 nm, and 650 nm were measured, and the absorbance ratios were A450/A550 and A450/A650. Further, the measurement results of the visibility correction polarization (Py) and the visibility correction transmittance (Ty) are shown in Table 4 in the same manner.

Reference example 1 [Production of iodine PVA polarizing plate]

The average degree of polymerization is about 2400, the degree of saponification is 99.9 mol% or more, and the thickness is 75. The μm polyvinyl alcohol film is uniaxially stretched to about 5.5 times in a dry state, and further immersed in pure water at 60 ° C for 60 seconds in a stretched state, and an aqueous solution having a weight ratio of iodine/potassium iodide/water of 0.05/5/100. Immerse at 28 ° C for 20 seconds. Thereafter, it was immersed in an aqueous solution of potassium iodide/boric acid/water in a weight ratio of 8.5/8.5/100 at 72 ° C for 300 seconds. Then, it was washed with pure water at 26 ° C for 20 seconds, and then dried at 65 ° C to obtain a polarizing film in which an iodine was adsorbed and aligned in a polyvinyl alcohol resin.

On both sides of the polarizing element obtained in the above manner, 3 parts of polyvinyl alcohol [Kuraray Poval KL318 manufactured by Kuraray Co., Ltd.] was modified with a carboxyl group, and water-soluble polyamine epoxy resin [Sumika Chemtex Co., Ltd. Sumirez Resin 650 (aqueous solution having a solid content of 30%)] 1.5 parts of a polyvinyl alcohol-based adhesive, which is protected by a saponified cellulose triacetate film [KC8UX2MW manufactured by Konica Minolta Opto Co., Ltd.] And make a polarizing film.

Reference example 2

A polarizing film was produced in the same manner as in Reference Example 1 except that the mixture was immersed in an aqueous solution of iodine/potassium iodide/water in a weight ratio of 0.05/5/100 at 28 ° C for 35 seconds.

The spectroscopic film thus produced was subjected to spectrometry in the same manner as in Example 1. The measurement results of absorbance A450, A550, A650, absorbance ratio A450/A550, A450/A650, and visibility correction polarization (Py) and visibility correction transmittance (Ty) at wavelengths of 450 nm, 550 nm, and 650 nm are shown. In Table 4.

Example 9 [Production of a light alignment film on a retardation film]

Using a retardation film (uniaxially stretched film WRF-S (modified polycarbonate resin), phase difference of 137.5 nm, thickness of 50 μm, manufactured by Teijin Chemical Co., Ltd.) as a transparent substrate, coating by a bar coating method A solution obtained by dissolving light of the following formula (3) in a polymer of 5% in xylene was dried at 120 ° C to obtain a dried film. The polarized film was irradiated on the dried film in a direction of 45° with respect to the retardation axis of the retardation film to obtain a photoalignment film. Polarized UV treatment The UV irradiation apparatus (SPOT CURE SP-7; manufactured by Ushio Electric Co., Ltd.) was used under the conditions of an intensity of 100 mJ measured at a wavelength of 365 nm.

[Production of circular polarizer]

The composition for forming a polarizing film prepared in Example 1 was applied onto the photo-alignment film by a bar coating method, and dried by heating in a drying oven at 120 ° C for 1 minute, and then cooled to room temperature. In the dried film, the liquid crystal state of the polymerizable liquid crystal compound contained is a smectic B phase. Then, using a UV irradiation apparatus (SPOT CURE SP-7; manufactured by Ushio Electric Co., Ltd.), the layer formed of the composition for forming a polarizing film was irradiated with ultraviolet rays having an exposure amount of 2000 mJ/cm ² (base of 365 nm). The polymerizable liquid crystal compound contained in the dried film is polymerized while maintaining the liquid crystal state of the polymerizable liquid crystal compound, and a polarizing film is formed from the dried film.

The film thickness of the polarizing film at this time was measured by a laser microscope (OLS 3000 manufactured by Olympus Co., Ltd.), and it was 1.8 μm.

Example 10

A circular polarizing plate was produced by the same experiment as in Example 9 except that the composition for forming a polarizing film formed by adjusting the liquid in Example 2 was used instead of the composition for forming a polarizing film prepared in Example 1.

Example 11

The composition for forming a polarizing film formed by adjusting the liquid in Example 8 was used instead of the composition for forming a polarizing film prepared in Example 1, and A circular polarizing plate was produced in the same experiment as in Example 9.

Reference example 3

The absorption axis of the polarizing film prepared in Reference Example 1 and the retardation film (uniaxially stretched film WRF-S (modified polycarbonate resin) have a phase difference of 137.5 nm and a thickness of 50 μm. In the manufacturing method, the angle at which the retardation axis is formed is 45°, and the bonding is performed via an adhesive to produce a circularly polarizing plate.

Reference example 4

A circular polarizing plate was produced by performing the same experiment as in Reference Example 3 except that the polarizing film produced in Reference Example 2 was used instead of the polarizing film prepared in Reference Example 1.

<Measurement of optical characteristics>

The retardation film of the circularly polarizing plate obtained in each of Examples 9 to 10 and Reference Examples 3 to 4 was bonded to the aluminum metal plate by an adhesive, and the wavelengths of 450 nm and 550 nm were measured in the same manner as in the previous transmittance measurement. Reflectance at 650 nm. Further, the visibility correction was performed by the 2 degree field of view (C light source) of JIS Z8701, and the visibility corrected reflectance was calculated. The results are shown in Table 4.

It can be seen that the circular polarizing plate made of the polarizing film has good anti-reflection characteristics for human visibility.

[Industrial availability]

The polarizing film is extremely useful for producing a liquid crystal display device, an (organic) EL display device, and a projection type liquid crystal display device.

1‧‧‧Transparent substrate

2‧‧‧Light alignment film

3‧‧‧This polarizing film

30‧‧‧EL display device

31‧‧‧ polarizing film

32‧‧‧ phase difference film

33‧‧‧Substrate

34‧‧‧Interlayer insulating film

35‧‧‧pixel electrode

36‧‧‧Lighting layer

37‧‧‧Cathode electrode

38‧‧‧Drying agent

39‧‧‧ Sealing cover

40‧‧‧film transistor

41‧‧‧ blocking wall

42‧‧‧film sealing film

44‧‧‧EL display device

100‧‧‧Polarized elements

101‧‧‧1st laminate

102‧‧‧2nd layered body

103‧‧‧3rd layer body

210‧‧‧ Volume 1

210A‧‧‧core

211A‧‧‧ Coating device

211B‧‧‧ Coating device

212A‧‧‧ drying oven

212B‧‧‧ drying oven

213A‧‧‧Polarized UV irradiation device

213B‧‧‧Lighting device

220‧‧‧ Volume 2

220A‧‧‧core

300‧‧‧Auxiliary volume

Fig. 1 is a cross-sectional view schematically showing an embodiment of a continuous production method of the polarizing film.

Fig. 2 is a plan view schematically showing an angle formed by an absorption axis of the polarizing film and a retardation axis of the λ/4 layer in an embodiment of the present circular polarizing plate.

Fig. 3 is a cross-sectional view schematically showing an embodiment of a continuous production method of the polarizing film.

Fig. 4 is a cross-sectional view schematically showing the configuration of the organic EL display device.

5(A) and 5(B) are cross-sectional views schematically showing the layer sequence of the C portion of the organic EL display device 30.

Fig. 6 is a cross-sectional view schematically showing the configuration of the organic EL display device.

Claims (9)

A polarizing film which is formed of a composition containing two or more kinds of dichroic dyes having different maximum absorption wavelengths and a polymerizable liquid crystal compound, and the composition of the composition is the same as the solid content of the composition The content ratio of the polymerizable liquid crystal compound is 70 to 99.9% by mass, and the polarizing film has an alignment direction in one direction and has an absorption spectrum satisfying the relationship expressed by all the following formulas (I) to (V): 0.3 ≦ A450 /A550<0.8 (I) 0.3≦A450/A650<1.0 (II) 0.5≦A450≦2 (III) 1≦A550≦3 (IV) 1≦A650≦3 (V) (wherein A450 represents the wavelength at 450nm The absorbance of the polarized light parallel to the alignment direction, A550 represents the absorbance of the polarized light parallel to the alignment direction at a wavelength of 550 nm, and A650 represents the absorbance of the polarized light parallel to the alignment direction at a wavelength of 650 nm). The polarizing film of claim 1, wherein the composition is further composed of a polymerizable smectic liquid crystal compound. The polarizing film of claim 1 or 2, wherein the two or more dichroic dyes are polyazo dyes represented by the following formula (1): [In the formula (1), n is 1 or 2, and Ar ₁ and Ar ₃ each independently represent any of the following groups, Ar ₂ represents any of the following groups, A ₁ and A ₂ each independently represent any of the following groups, m is an integer of 0 to 10, and when there are 2 m in the same base, the two m are the same or different from each other]. The polarizing film according to any one of claims 1 to 3, wherein the visibility correction monomer transmittance Ty is 43% or more, and the visibility correction monomer polarization degree Py is 90% or more. A circularly polarizing plate having the polarizing film and the λ/4 layer according to any one of claims 1 to 4, and The following conditions (A1) and (A2) are satisfied: (A1) an angle formed by the absorption axis of the polarizing film and the late phase axis of the λ/4 layer is substantially 45°; (A2) is measured by light having a wavelength of 550 nm. The positive retardation value of the above λ/4 layer is in the range of 100 to 150 nm. The circularly polarizing plate of claim 5, wherein the value of the front side retardation of the λ/4 layer with respect to visible light has a characteristic that becomes smaller as the wavelength becomes shorter. A circularly polarizing plate having the polarizing film, the λ/2 layer, and the λ/4 layer according to any one of claims 1 to 4 in sequence, and satisfying the following (B1) to (B4): (B1) An angle formed by the absorption axis of the polarizing film and the late phase axis of the λ/2 layer is substantially 15°; (B2) an angle formed by the late phase axis of the λ/2 layer and the late phase axis of the λ/4 layer (B3) in the above λ/2 layer, the front side retardation value of the λ/4 layer measured by light having a wavelength of 550 nm is in the range of 200 to 300 nm; (B4) in the above λ/4 layer, The value of the front side retardation of the above λ/4 layer measured by light having a wavelength of 550 nm is in the range of 100 to 150 nm. An organic EL display device comprising the circularly polarizing plate according to any one of claims 5 to 7 and an organic EL element. The organic EL display device according to claim 8, wherein the intensity of light having a wavelength of 450 nm in the light emitted from the light-emitting layer is referred to as I450, and the intensity of light having a wavelength of 550 nm is recorded as I550, and the intensity of light having a wavelength of 650 nm is recorded as I650. , having an emission spectrum that satisfies all of the relationships expressed as follows: 1≦I450/I550<2 (X) 1≦A450/A650<2 (XI).