JP2013210624A - Polarization film, circular polarization plate and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polarization film whose thinning is easy, and which is excellent in neutral hue characteristics, a polarizer including the polarization film, and a method for manufacturing them.SOLUTION: There is provided a polarization film which contains: a polymer to be formed of a polymerizable liquid crystal compound; at least one kind of dichroic dye (1) having the absorption maximum within a range of wavelength of 380-550 nm when the dichroic dye (1) is dispersed in the polymer to measure optical absorption; and at least two kinds of dichroic dyes (2) having the absorption maxima within a range of wavelength of 550-700 nm, a polarizer containing the polarization film, and a method for manufacturing them. It is preferable that the dichroic dyes (2) contain a dichroic dye having absorption within a range of wavelength of 550-600 nm, and a dichroic dye having absorption within a range of wavelength of 600-700 nm.

Description

  The present invention relates to a polarizing film, a circularly polarizing plate, a manufacturing method thereof, and the like.

  A polarizer used in a liquid crystal display device has a high transmittance and a degree of polarization. Therefore, a film (polarized light) made of polyvinyl alcohol (iodine-stained PVA) dyed with a dichroic dye such as iodine and stretched. Membrane) is used for general purposes. For example, Patent Document 1 describes a polarizing film made of iodine-stained PVA.

JP-A-7-142170

  However, the polarizing film made of iodine-stained PVA has a problem that it tends to be yellowish and is inferior in so-called neutral hue. In addition, it is difficult to reduce the thickness of a polarizing film made of iodine-stained PVA, and there is a limit in applying it to recent display devices that are required to be thinner. SUMMARY OF THE INVENTION An object of the present invention is to provide a polarizing film that can be easily thinned and has excellent neutral hue, a polarizer including the polarizing film, a method for producing the same, and the like.

［式（２）中、
ｎは１又は２である。
Ａｒ^１及びＡｒ^３はそれぞれ独立に、式（ＡＲ−１）〜式（ＡＲ−４）のいずれかで表される基である。

Ａｒ^２は、式（ＡＲ２−１）、式（ＡＲ２−２）又は式（ＡＲ２−３）で表される基である。

Ａ_１及びＡ_２はそれぞれ独立に、式（Ａ−１）〜式（Ａ−９）のいずれかで表される基であり、＊は結合手を表す。

（ｍｃは０〜１０の整数であり、同一の基中にｍｃが２つある場合、この２つのｍｃは互いに同一又は相異なる。）］
[９] 二色性色素（１）が、
式（１）で表される化合物からなる[１]〜[８]のいずれかに記載の偏光膜。

［式（１）中、
Ｙは、式（Ｙ１）又は式（Ｙ２）で表される基である。

（式中、Ｌは、酸素原子又は−ＮＲ−であり、Ｒは水素原子又は炭素数１〜４のアルキル基である。）
Ｒ^１は、式（Ｒ^１−１）〜式（Ｒ^１−３）のいずれかで表される基である。

（式中、ｍａは０〜１０の整数であり、同一の基中にｍａが２つある場合、この２つのｍａは互いに同一又は相異なる。＊は結合手を表す。）
Ｒ^２は、式（Ｒ^２−１）〜式（Ｒ^２−６）のいずれかで表される基である。

（式中、ｍｂは０〜１０の整数である。）］
[１０] 透明基材上に、[１]〜[９]のいずれか記載の偏光膜を設けてなる偏光子。
[１１] [１０]記載の偏光子の製造方法であり、
透明基材上に配向膜を備えた積層体を準備する工程と、
前記積層体の前記配向膜上に、重合性液晶化合物と、該重合性液晶化合物から形成される重合体中に分散させて光吸収を測定した場合に、波長３８０〜５５０ｎｍの範囲に吸収極大を有する二色性色素（１）を１種と、波長５５０〜７００ｎｍの範囲に吸収極大を有する二色性色素（２）を２種と、溶剤とを含む組成物を塗布する工程と、
前記組成物に含まれる前記重合性液晶化合物を重合させる工程と
を有する製造方法。
[１２] 透明基材がプラスチック基材であり、且つ、前記配向膜が光配向膜である[１１]に記載の製造方法。
[１３] [１]〜[９]のいずれか記載の偏光膜を備えた液晶表示装置。
[１４] [１]〜[９]のいずれか記載の偏光膜と、λ/４層とを有し、以下の（Ａ１）及び（Ａ２）の要件を満たす円偏光板。
（Ａ１）前記偏光膜の吸収軸と、前記λ/４層の遅相軸とのなす角度が、略４５°であること；
（Ａ２）波長５５０ｎｍの光で測定した、前記λ/４層の正面リタデーションの値が１００〜１５０ｎｍの範囲であること
[１５] [１４]記載の円偏光板と、有機ＥＬ素子とを備えた有機ＥＬ表示装置。 The present invention includes the following inventions.
[1] A polymer formed from a polymerizable liquid crystal compound, and at least one dichroic dye having an absorption maximum in the wavelength range of 380 to 550 nm when measured for light absorption after being dispersed in the polymer A polarizing film comprising (1) and at least two dichroic dyes (2) having an absorption maximum in a wavelength range of 550 to 700 nm.
[2] When the dichroic dye (1) is dispersed in a polymer formed from a polymerizable liquid crystal compound and measured for light absorption, it has an absorption maximum in a wavelength range of 400 to 550 nm. [1] A polarizing film according to 1.
[3] When the light absorption is measured by dispersing in the polymer, at least two dichroic dyes (2) having an absorption maximum in the wavelength range of 550 to 700 nm are:
When measuring the light absorption by dispersing in the polymer,
A dichroic dye (2-1) having an absorption maximum in a wavelength range of 550 to 600 nm;
The polarizing film according to [1] or [2], comprising a dichroic dye (2-2) having an absorption maximum in a wavelength range of 600 to 700 nm.
[4] The polarizing film according to any one of [1] to [3], wherein the polymerizable liquid crystal compound is a compound exhibiting a smectic liquid crystal phase.
[5] The polarizing film according to any one of [1] to [4], wherein a Bragg peak is obtained in X-ray diffraction measurement.
[6] Any one of [1] to [5], wherein the color coordinate a * value and b * value in the L * a * b * color system satisfy the relationship of the following formulas (1F) and (2F): Polarizing film.
-3 ≦ chromaticity a * ≦ 3 (1F)
−3 ≦ chromaticity b * ≦ 3 (2F)
[7] The polarizing film according to any one of [1] to [6], wherein the dichroic dye (1) and the dichroic dye (2) are azo compounds.
[8] Dichroic dye (2)
The polarizing film in any one of [1]-[7] which consists of a compound represented by Formula (2).

[In Formula (2),
n is 1 or 2.
Ar ¹ and Ar ³ are each independently a group represented by any one of formulas (AR-1) to (AR-4).

Ar ² is a group represented by formula (AR2-1), formula (AR2-2), or formula (AR2-3).

A ₁ and A ₂ are each independently a group represented by any of formulas (A-1) to (A-9), and * represents a bond.

(Mc is an integer of 0 to 10, and when there are two mcs in the same group, these two mcs are the same or different from each other.)]
[9] Dichroic dye (1)
The polarizing film in any one of [1]-[8] which consists of a compound represented by Formula (1).

[In Formula (1),
Y is a group represented by the formula (Y1) or the formula (Y2).

(In the formula, L is an oxygen atom or —NR—, and R is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.)
R ¹ is a group represented by any of the formulas (R ¹ -1) to (R ¹ -3).

(In the formula, ma is an integer of 0 to 10, and when two ma are present in the same group, the two ma are the same or different from each other. * Represents a bond.)
R ² is a group represented by any one of formulas (R ² -1) to (R ² -6).

(Wherein mb is an integer of 0 to 10)]
[10] A polarizer obtained by providing the polarizing film according to any one of [1] to [9] on a transparent substrate.
[11] A method for producing a polarizer according to [10],
Preparing a laminate having an alignment film on a transparent substrate;
When the light absorption is measured by dispersing in a polymer liquid crystal compound and a polymer formed from the polymerizable liquid crystal compound on the alignment film of the laminate, the absorption maximum is in a wavelength range of 380 to 550 nm. Applying a composition containing one kind of dichroic dye (1) having, two kinds of dichroic dye (2) having an absorption maximum in a wavelength range of 550 to 700 nm, and a solvent;
And a step of polymerizing the polymerizable liquid crystal compound contained in the composition.
[12] The production method according to [11], wherein the transparent substrate is a plastic substrate, and the alignment film is a photo-alignment film.
[13] A liquid crystal display device comprising the polarizing film according to any one of [1] to [9].
[14] A circularly polarizing plate comprising the polarizing film according to any one of [1] to [9] and a λ / 4 layer and satisfying the following requirements (A1) and (A2).
(A1) The angle formed by the absorption axis of the polarizing film and the slow axis of the λ / 4 layer is approximately 45 °;
(A2) The value of the front retardation of the λ / 4 layer measured with light having a wavelength of 550 nm is in the range of 100 to 150 nm.
[15] An organic EL display device comprising the circularly polarizing plate according to [14] and an organic EL element.

  According to the present invention, it is possible to provide a polarizing film that is easily thinned and excellent in neutral hue, and a polarizer including the polarizing film.

It is a schematic diagram of the continuous manufacturing method of the polarizer (this polarizer) containing the polarizing film of this invention. It is a schematic diagram showing the relationship between the orientation direction D2 of a photo-alignment film, and the conveyance direction D1 of a film. It is a schematic diagram showing the cross-sectional structure of the liquid crystal display device using the polarizing film of this invention. It is a schematic diagram showing the layer order of this polarizer used for the liquid crystal display device of FIG. It is a schematic diagram showing the layer order of this polarizer used for the liquid crystal display device of FIG. It is a schematic diagram showing the cross-sectional structure of the EL display device using the polarizing film of this invention. It is a schematic diagram showing the cross-sectional structure of the embodiment of this polarizer containing the polarizing film of this invention. It is a schematic diagram showing an example of the continuous manufacturing method of the circularly-polarizing plate (this circularly-polarizing plate) containing the polarizing film of this invention. It is a schematic diagram showing the layer order of this circularly-polarizing plate used for EL display apparatus of FIG. It is a schematic diagram showing the cross-sectional structure of the EL display device using the polarizing film of this invention. It is the schematic which shows the structure of the projection type liquid crystal display device using the polarizing film of this invention.

  The polarizing film of the present invention (hereinafter sometimes referred to as “the present polarizing film”) includes a polymer formed from a polymerizable liquid crystal compound and three or more specific dichroic dyes. . The polarizing film is preferably formed from a composition containing a polymerizable liquid crystal compound and the three or more dichroic dyes (hereinafter sometimes referred to as “polarizing film forming composition”). First, the composition for forming a polarizing film will be described.

1. Composition for Forming Polarizing Film As described above, the composition for forming a polarizing film of the present invention preferably contains a polymerizable liquid crystal compound, three or more specific dichroic dyes, and further contains a solvent. The present polarizing film formed from such a composition for forming a polarizing film can be easily thinned. First, each component included in the composition for forming a polarizing film will be described.

1-1. Dichroic dye The dichroic dye contained in the composition for forming a polarizing film is an absorption maximum in a wavelength range of 380 to 550 nm when measured for light absorption after being dispersed in a polymer formed from a polymerizable liquid crystal compound. And at least two dichroic dyes (2) having an absorption maximum in the wavelength range of 550 to 700 nm in the same measurement.

1-1-1. Dichroic dye (1)
The dichroic dye (1) has an absorption maximum in the wavelength range of 380 to 550 nm when measured for light absorption by dispersing in a polymer formed from a polymerizable liquid crystal compound. This measurement was carried out by preparing a composition for maximum absorption measurement in which the dichroic dye of the composition for forming a polarizing film in the present invention was replaced with a dichroic dye whose absorption maximum was to be measured. An absorption maximum measurement film may be formed by a method similar to the method of forming the present polarizing film from the film forming composition, and the light absorption of the absorption maximum measurement film may be measured. The specific method for measuring the absorption maximum is the same as the method described in the examples of the present application.

  Examples of the dichroic dye (1) include azo compounds. Preferably, a compound represented by the above formula (1) (hereinafter sometimes referred to as “compound (1)”) may be mentioned.

  Trans is preferable for the geometric isomerism of the azobenzene moiety of the compound (1).

Y in the formula (1) is a group represented by the above formula (Y1) or the formula (Y2), preferably a group represented by the formula (Y1). In formula (Y1) and formula (Y2), the straight lines at both ends represent a bond, the bond on the left is bonded to a phenylene group having an azo group, and the bond on the right is bonded to a phenylene group having R ² doing. L is an oxygen atom or —NR—, and R is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. Examples of the alkyl group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group and t-butyl group. Among these, L is preferably an oxygen atom or —NH—, and more preferably an oxygen atom.

R ¹ is a group represented by the formula (R ¹ -1), the formula (R ¹ -2) or the formula (R ¹ -3), and preferably the formula (R ¹ -2) and the formula (R ¹ -3). Two mas in the group represented by the formula (R ¹ -2) may be the same or different, but are preferably the same. ma is more preferably an integer of 0 to 5.

R ² represents formula (R ² -1), formula (R ² -2), formula (R ² -3), formula (R ² -4), formula (R ² -5) or formula (R ² -6). ) with a group represented by the formula ^(R 2 -2), formula ^(R 2 -5) or formula ^(more preferably a group represented by R 2 -6), formula ^(R 2 -6) And more preferably a group represented by: When R ² is a group represented by the formula (R ² -1), formula (R ² -2), formula (R ² -3), formula (R ² -5) or formula (R ² -6) In addition, mb contained in the group is preferably an integer of 0 to 10, and more preferably an integer of 0 to 5.

Preferred examples of the compound (1) include compounds represented by the following formulas (1-1) to (1-8).

  Among these, compounds represented by formula (1-1), formula (1-2), formula (1-3), formula (1-5), formula (1-7) and formula (1-8) are preferable. The compounds represented by formula (1-1), formula (1-2), formula (1-3) and formula (1-7) are particularly preferred.

  The dichroic dye (1) has an absorption maximum in the wavelength range of 380 to 550 nm when the light absorption is determined by the measurement, and preferably has an absorption maximum in the wavelength range of 400 to 550 nm. It is more preferable to have an absorption maximum in the range of 520 nm, more preferable to have an absorption maximum in the range of wavelengths of 430 to 520 nm, and particularly preferable to have an absorption maximum in the range of wavelengths of 440 to 510 nm. As long as it has an absorption maximum in the above range, a plurality of types of compounds (1) can be used as the dichroic dye (1).

前記図式において、Ｒ^１、Ｒ^２及びＹは前記と同じ意味であり、Ｒｅ^１及びＲｅ^２は、互いに反応してＹで表される基となる基である。Ｒｅ^１及びＲｅ^２の組み合わせとしては例えば、カルボキシ基及び水酸基の組み合わせ、カルボキシ基及びアミノ基（かかるアミノ基はＲで置換されていてもよい）の組み合わせ、カルボニルハライド基及び水酸基の組み合わせ、カルボニルハライド基及びアミノ基（かかるアミノ基はＲで置換されていてもよい）の組み合わせ、カルボニルオキシアルキル基及び水酸基の組み合わせ、カルボニルオキシアルキル基及びアミノ基（かかるアミノ基はＲで置換されていてもよい）の組み合わせなどが挙げられる。また、ここでは、Ｒ^１を有する化合物（１Ｘ）及びＲ^２を有する化合物（１Ｙ）で説明するが、Ｒ^１を適当な保護基で保護した化合物や、Ｒ^２を適当な保護基で保護した化合物互いに反応して、その後、適当な脱保護反応を行うことで化合物（１）を製造することもできる。 Here, the manufacturing method of a compound (1) is demonstrated. Compound (1) is produced, for example, from the compound represented by formula (1X) [compound (1X)] and the compound represented by formula (1Y) [compound (1Y)] by the reaction shown in the following scheme. be able to.

In the above diagram, R ¹ , R ² and Y have the same meaning as described above, and Re ¹ and Re ² are groups that react with each other to form a group represented by Y. Examples of the combination of Re ¹ and Re ² include a combination of a carboxy group and a hydroxyl group, a combination of a carboxy group and an amino group (the amino group may be substituted with R), a combination of a carbonyl halide group and a hydroxyl group, and a carbonyl halide. A combination of a group and an amino group (such an amino group may be substituted with R), a combination of a carbonyloxyalkyl group and a hydroxyl group, a carbonyloxyalkyl group and an amino group (such an amino group may be substituted with R) ) And the like. Further, here, the compound (1X) having R ¹ and the compound (1Y) having R ² will be described, but a compound in which R ¹ is protected with an appropriate protecting group, and R ² is protected with an appropriate protecting group. Compound (1) can also be produced by reacting with each other and then performing an appropriate deprotection reaction.

As the reaction conditions for reacting the compound (1X) and the compound (1Y), optimum known conditions can be appropriately selected according to the types of the compound (1X) and the compound (1Y) to be used.
For example, the reaction conditions when Re ¹ is a carboxy group, Re ² is a hydroxyl group, and Y is —C (═O) —O— are, for example, in a solvent in the presence of an esterification condensing agent. The conditions to condense are mentioned. Examples of the solvent include solvents that can dissolve both the compound (1X) and the compound (1Y), such as chloroform. Examples of the esterification condensing agent include diisopropylcarbodiimide (IPC). Here, a base such as dimethylaminopyridine (DMAP) is preferably used in combination. Although reaction temperature is selected according to the kind of compound (1X) and compound (1Y), the range of -15-70 degreeC is mentioned, for example, Preferably it is the range of 0-40 degreeC. Examples of the reaction time include a range of 15 minutes to 48 hours.

  As for the reaction time, the reaction mixture during the reaction is appropriately sampled, and the degree of disappearance of the compound (1X) and the compound (1Y) and the production of the compound (1) by a known analytical means such as liquid chromatography or gas chromatography. It is also possible to determine by checking the degree.

  From the reaction mixture after the reaction, the compound (1) can be taken out by a known method such as recrystallization, reprecipitation, extraction and various chromatography, or by combining these operations.

1-1-2. Dichroic dye (2)
The dichroic dye (2) has an absorption maximum in a wavelength range of 550 to 700 nm when the measurement is performed. The method for measuring the absorption maximum is the same as in the case of the dichroic dye (1).

  The dichroic dye (2) includes two or more kinds in the composition for forming a polarizing film. Among them, the dichroic dye (2-1) having an absorption maximum in the wavelength range of 550 to 600 nm and And a dichroic dye (2-2) having an absorption maximum in a wavelength range of 600 to 700 nm. Here, it is more preferable that the dichroic dye (2-1) has an absorption maximum in a wavelength range of 570 to 600 nm, and the dichroic dye (2-2) has an absorption maximum in a wavelength range of 600 to 680 nm. Further preferred.

  Examples of the dichroic dye (2) include azo compounds. The dichroic dye (2) is preferably a compound represented by the formula (2) (hereinafter sometimes referred to as “compound (2)”).

  Trans is preferable for the geometric isomerism of the azobenzene moiety of the compound (2).

By combining Ar ¹ , Ar ² and Ar ³ so that the compound (2) has an absorption maximum in the wavelength range of 550 to 600 nm in the above measurement in the combination of each group of the compound (2), two colors The compound (2) that can be used as the sex dye (2-1) is determined. Specific examples of the dichroic dye (2-1) include compounds (2) shown in Table 1 by combinations of groups. The compound (2-1) which shows the combination of each group in Table 1 shows the case where n in Formula (2) is 1. In Table 1, for example, a group represented by the formula (AR-1) is represented as “(AR-1)”.

Subsequently, by combining Ar ¹ , Ar ^2, and Ar ³ so that the compound (2) has absorption in the wavelength range of 600 to 700 nm in the above measurement in the combination of each group of the compound (2), The compound (2) that can be used as the dichroic dye (2-2) is defined. Specific examples of the dichroic dye (2-2) include compounds (2) shown in Table 2 by combinations of groups. The compound (2-2) which shows the combination of each group in Table 2 shows the case where n in Formula (2) is 1. The group notation in Table 2 is the same as in Table 1.

  Here, specific examples of the compound (2) include compounds represented by formulas (2-11) to (2-39).

  Among the specific examples of the compound (2) listed here, as the dichroic dye (2-1), the formula (2-12), the formula (2-13), the formula (2-18), the formula (2), 2-20), Formula (2-21), Formula (2-22), Formula (2-23), Formula (2-24), Formula (2-26), Formula (2-27), Formula (2) -28), formula (2-29), and formula (2-30) respectively, and the dichroic dye (2-2) includes formula (2-31), formula (2- 32), Formula (2-33), Formula (2-34), Formula (2-35), and Formula (2-36), respectively. In addition, although what is each represented by Formula (2-11), Formula (2-15), and Formula (2-16) is not a pigment | dye which absorbs in wavelength 550-700 nm, supplementarily of Formula (1) Can be used in combination with a dye.

  Among the specific examples of the compound (2), as the dichroic dye (2) contained in the composition for forming a polarizing film, the formula (2-15), the formula (2-16), the formula (2-18), Formula (2-20), Formula (2-21), Formula (2-22), Formula (2-23), Formula (2-27), Formula (2-29), Formula (2-31), Formula Those represented by (2-32), formula (2-33), formula (2-34) and formula (2-35) are more preferred. Among these, when the dichroic dye (2) is represented by a combination of two or more selected from the specific examples of the compound (2), depending on the mixing ratio, for example, as shown in Table 3. In Table 3, for example, the compound (2) represented by the formula (2-11) is represented as “(2-11)”.

The content of the dichroic dye (1) in the composition for forming a polarizing film is preferably 50 parts by mass or less, preferably 0.1 parts by mass or more and 10 parts by mass with respect to 100 parts by mass of the polymerizable liquid crystal compound described later. Is more preferably 0.1 parts by mass or more and 5 parts by mass or less.
The content of the dichroic dye (2) in the composition for forming a polarizing film is expressed as a content with respect to 100 parts by mass of the polymerizable liquid crystal compound described later, preferably 10 parts by mass or less, and 0.1 parts by mass to 5 parts by mass. Is more preferably 0.1 parts by mass or more and 3 parts by mass or less.
The total content of the dichroic dye (1) and the dichroic dye (2) in the composition for forming a polarizing film is 30 parts by mass or less, expressed as a content with respect to 100 parts by mass of the polymerizable liquid crystal compound described later. Is preferable, 0.1 to 20 parts by mass is more preferable, and 1 to 15 parts by mass is more preferable.
If the content of each dichroic dye is within the above range, the dichroic dye in the composition for forming a polarizing film exhibits sufficient solubility in a solvent. When the present polarizing film is produced, the present polarizing film free from defects is obtained. In addition, as above-mentioned, although the composition for polarizing film formation should just contain 1 or more types of dichroic dye (1) and 2 or more types of dichroic dyes (2), this composition for polarizing film formation The composition may contain two or more dichroic dyes (1) or may contain three or more dichroic dyes (2). When two or more dichroic dyes (1) are included, the content of the dichroic dye (1) is the total amount of the two or more dichroic dyes (1), and the dichroic dye (2) is three kinds. When it contains above, content of a dichroic dye (2) shall be the total amount of 3 or more types of dichroic dyes (2).

  The dichroic dye (2) is produced by a known method described in, for example, JP-A-58-38756, JP-A-63-301850, JP-A-58-104984.

  Next, components other than the dichroic dye in the composition for forming a polarizing film will be described.

1-2. Polymerizable liquid crystal compound The polymerizable liquid crystal compound is a liquid crystal compound that can be polymerized while being aligned, and has a polymerizable group in the molecule. A composition for forming a polarizing film containing a polymerizable liquid crystal compound forms this polarizing film by polymerizing the polymerizable liquid crystal compound in an aligned state. The polymerizable group is particularly preferably a radical polymerizable group. A radically polymerizable group means a group involved in a radical polymerization reaction.

  Even if the polymerizable liquid crystal compound contained in the composition for forming a polarizing film of the present invention exhibits a nematic liquid crystal phase (hereinafter sometimes referred to as “nematic liquid crystal phase”), a smectic phase liquid crystal phase ( Hereinafter, it may be a “smectic liquid crystal phase” or a nematic liquid crystal phase and a smectic liquid crystal phase, but at least a polymerizable smectic liquid crystal compound exhibiting a smectic liquid crystal phase. Is preferable. The composition for forming a polarizing film containing a polymerizable smectic liquid crystal compound has an extremely good neutral hue due to the interaction with the dichroic dye (1) and the dichroic dye (2), and more polarizing performance. An excellent polarizing film can be obtained.

As the smectic liquid crystal phase exhibited by the polymerizable smectic liquid crystal compound, a higher order smectic liquid crystal phase is more preferable. The high-order smectic liquid crystal phase here means a smectic B phase, a smectic D phase, a smectic E phase, a smectic F phase, a smectic G phase, a smectic H phase, a smectic I phase, a smectic J phase, a smectic K phase, and a smectic L phase. Among them, a smectic B phase, a smectic F phase, and a smectic I phase are more preferable.
When the smectic liquid crystal phase exhibited by the polymerizable liquid crystal compound is a higher-order smectic liquid crystal phase, the polarizing film having a higher degree of alignment order can be produced. In addition, this polarizing film prepared from a high-order smectic liquid crystal phase having a high degree of orientational order can obtain a Bragg peak derived from a high-order structure such as a hexatic phase or a crystal phase in X-ray diffraction measurement. The Bragg peak is a peak derived from the molecular periodic surface periodic structure. According to the polarizing film forming composition of the present invention, the polarizing film having a periodic interval of 3.0 to 5.0 mm is obtained. Can do.

  Whether the polymerizable liquid crystal compound contained in the composition for forming a polarizing film exhibits a nematic liquid crystal phase or a smectic liquid crystal phase can be confirmed, for example, as follows. Prepare a suitable base material, apply the polarizing film-forming composition to the base material to form a coating film, and then heat-treat or decompression treatment under conditions where the polymerizable liquid crystal compound is not polymerized. Remove the solvent. Subsequently, the coating film formed on the substrate is heated to the isotropic phase temperature, and the liquid crystal phase that is expressed by gradually cooling is inspected by texture observation, X-ray diffraction measurement or differential scanning calorimetry using a polarizing microscope. To do. In this inspection, for example, a polymerizable liquid crystal compound that exhibits a nematic liquid crystal phase by cooling and further exhibits a smectic liquid crystal phase by further cooling is particularly preferable. Whether the polymerizable liquid crystal compound and the dichroic dye are not phase-separated in the nematic liquid crystal phase and the smectic liquid crystal phase can be confirmed by, for example, surface observation with various microscopes or scattering degree measurement with a haze meter.

Specific examples of preferred polymerizable liquid crystal compounds used in the composition for forming a polarizing film are given below.
As a preferable polymerizable liquid crystal compound, for example, a compound represented by the formula (4) (hereinafter sometimes referred to as “compound (4)”) 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 (4)
[In Formula (4),
X ¹ , X ² and X ³ each independently represent a 1,4-phenylene group which may have a substituent or a cyclohexane-1,4-diyl group which may have a substituent. However, at least one of X ¹ , X ² and X ³ is a 1,4-phenylene group which may have a substituent. —CH ₂ — constituting the optionally substituted cyclohexane-1,4-diyl group may be replaced by —O—, —S— or —NR—. R is a C1-C6 alkyl group or a phenyl group.

Y ¹ and ^{Y 2,} independently of one _{another, -CH 2 CH 2 -, -} CH 2 O -, - COO -, - OCOO-, a single ^{bond, -N = N -, - CR} a = CR b -, - C≡C— or —CR ^a ═N— is represented. 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 each independently represent a single bond, —O—, —S—, —COO— or —OCOO—.
V ¹ and V ² each independently represent an optionally substituted alkanediyl group having 1 to 20 carbon atoms, and —CH ₂ — constituting the alkanediyl group is —O—, — S- or -NH- may be substituted. ]

In the compound (4), it is preferable that at least ^{two of} X ¹ , X ² and X ³ are 1,4-phenylene groups which may have a substituent.
The 1,4-phenylene group which may have a substituent is preferably unsubstituted. The cyclohexane-1,4-diyl group which may have a substituent is preferably a trans-cyclohexane-1,4-diyl group which may have a substituent. It is more preferable that the trans-cyclohexane-1,4-diyl group which may have a non-substituted group.

  Examples of the substituent that the optionally substituted 1,4-phenylene group or the optionally substituted cyclohexane-1,4-diyl group include a methyl group, an ethyl group, and C1-C4 alkyl groups, such as a butyl group; A cyano group; A halogen atom etc. are mentioned.

Y ¹ of the compound (4) 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 preferably a polymerizable group. U ¹ and U ² are both preferably a polymerizable group, and more preferably a photopolymerizable group. The photopolymerizable group refers to a group that can participate in a polymerization reaction by an active radical or an acid generated from a photopolymerization initiator described later. The polymerizable liquid crystal compound having a photopolymerizable group is advantageous in that it can be polymerized under a lower temperature condition.

In the compound (4), the polymerizable groups of U ¹ and U ² may be different from each other, but are preferably the same type. Examples of the polymerizable group include a vinyl group, vinyloxy group, 1-chlorovinyl group, isopropenyl group, 4-vinylphenyl group, acryloyloxy group, methacryloyloxy group, oxiranyl group, and oxetanyl group. Among them, acryloyloxy group, methacryloyloxy group, vinyloxy group, oxiranyl group and oxetanyl group are preferable, and acryloyloxy group is more preferable.

As the alkanediyl group having 1 to 20 carbon atoms in the alkanediyl group having 1 to 20 carbon atoms which may have a substituent represented by V ¹ and V ² , a methylene group, an ethylene group, propane-1,3- Diyl group, butane-1,3-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, heptane-1,7-diyl group, octane- Examples include 1,8-diyl group, decane-1,10-diyl group, tetradecane-1,14-diyl group, icosane-1,20-diyl group and the like. V ¹ and V ² are preferably alkanediyl groups having 2 to 12 carbon atoms, and more preferably alkanediyl groups having 6 to 12 carbon atoms.
Examples of the substituent optionally contained in the optionally substituted alkanediyl group having 1 to 20 carbon atoms include a cyano group and a halogen atom. The alkanediyl group is unsubstituted. It is preferably an unsubstituted and linear alkanediyl group.

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

  Examples of the compound (4) include compounds represented by formulas (4-1) to (4-43). When a specific example of the compound (4) has a cyclohexane-1,4-diyl group, the cyclohexane-1,4-diyl group is preferably a trans isomer.

  The polymerizable liquid crystal compound can be used alone or in combination of two or more for the polarizing film-forming composition. Moreover, when mixing 2 or more types, it is preferable in at least 1 type being a compound (4). When mixing two kinds of polymerizable liquid crystal compounds, the mixing ratio is usually 1:99 to 50:50, preferably 5:95 to 50:50, more preferably 10:90 to 50:50. It is.

  Among the exemplified compounds (4), Formula (4-5), Formula (4-6), Formula (4-7), Formula (4-8), Formula (4-9), Formula (4-10) , Formula (4-11), Formula (4-12), Formula (4-13), Formula (4-14), Formula (4-15), Formula (4-22), Formula (4-24), The compounds represented by formula (4-25), formula (4-26), formula (4-27), formula (4-28) and formula (4-29) are preferred. These compounds can easily polymerize under the temperature conditions below the crystal phase transition temperature, that is, while maintaining the liquid crystal state of the higher order smectic phase sufficiently by interaction with other polymerizable liquid crystal compounds. Can do. Specifically, these compounds can be polymerized under a temperature condition of 70 ° C. or less, preferably 60 ° C. or less, while sufficiently maintaining a liquid crystal state of a higher order smectic phase.

  50-99.9 mass% is preferable with respect to solid content of the composition for polarizing film formation, and, as for the content rate of the polymeric liquid crystal compound in the composition for polarizing film formation, 80-99.9 mass% is more preferable. If the content rate of a polymeric liquid crystal compound is in the said range, there exists a tendency for the orientation of a polymeric liquid crystal compound to become high, and it is preferable. Here, solid content means the total amount of the component remove | excluding volatile components, such as a solvent, from the composition for polarizing film formation.

  Polymerizable liquid crystal compounds are described in, for example, Lub et al. Recl. Trav. Chim. It is manufactured by a known method described in Pays-Bas, 115, 321-328 (1996) or Japanese Patent No. 4719156.

1-3. Solvent The composition for forming a polarizing film preferably contains a solvent. As the solvent, a solvent capable of completely dissolving the polymerizable liquid crystal compound and the dichroic dye is preferable. Moreover, it is preferable that it is a solvent inactive to the polymerization reaction of the polymeric liquid crystal compound contained in the composition for polarizing film formation.

  Solvents include alcohol solvents such as methanol, ethanol, ethylene glycol, isopropyl alcohol, propylene glycol, ethylene glycol methyl ether, ethylene glycol butyl ether and propylene glycol monomethyl ether; ethyl acetate, butyl acetate, ethylene glycol methyl ether acetate, γ-butyrolactone Or ester solvents such as propylene glycol methyl ether acetate and ethyl lactate; ketone solvents such as acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, 2-heptanone and methyl isobutyl ketone; aliphatic hydrocarbon solvents such as pentane, hexane and heptane; toluene And aromatic hydrocarbon solvents such as xylene; nitrile solvents such as acetonitrile; Hydrofuran and ether solvents such as dimethoxyethane; chlorine-containing solvents such as chloroform and chlorobenzene; and the like. These solvents may be used alone or in combination.

  As for content of a solvent, 50-98 mass% is preferable with respect to the total amount of the said composition for polarizing film formation. In other words, the solid content in the composition for forming a polarizing film is preferably 2 to 50% by mass. It is preferable that the solid content is 2% by mass or more because a thin polarizing film which is one of the objects of the present invention tends to be obtained. In addition, when the solid content is 50% by mass or less, the viscosity of the composition for forming a polarizing film is lowered, and thus the thickness of the polarizing film is substantially uniform, and thus the polarizing film is less likely to be uneven. Is preferable. Further, the solid content can be determined in consideration of the thickness of the polarizing film.

1-4. Other Additives The composition for forming a polarizing film in the present invention optionally contains additives other than the dichroic dye, the polymerizable liquid crystal compound, and the solvent.

1-4-1. Polymerization reaction aid The composition for forming a polarizing film preferably contains a polymerization initiator. The polymerization initiator is a compound that can initiate a polymerization reaction of the polymerizable liquid crystal compound. As the polymerization initiator, a photopolymerization initiator is preferable in that the polymerization reaction can be initiated under low temperature conditions. Specifically, a compound that generates an active radical or an acid by the action of light is used as a photopolymerization initiator. Among the photopolymerization initiators, those that generate active radicals by the action of light are more preferable.

  Examples of the polymerization initiator include benzoin compounds, benzophenone compounds, alkylphenone compounds, acylphosphine oxide compounds, triazine compounds, iodonium salts, and sulfonium salts.

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

  Examples of the benzophenone compound include benzophenone, methyl o-benzoylbenzoate, 4-phenylbenzophenone, 4-benzoyl-4′-methyldiphenyl sulfide, 3,3 ′, 4,4′-tetra (tert-butylperoxycarbonyl). ) Benzophenone and 2,4,6-trimethylbenzophenone.

  Examples of the alkylphenone compound include diethoxyacetophenone, 2-methyl-2-morpholino-1- (4-methylthiophenyl) propan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl). ) Butan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1,2-diphenyl-2,2-dimethoxyethane-1-one, 2-hydroxy-2-methyl-1 -[4- (2-hydroxyethoxy) phenyl] propan-1-one, 1-hydroxycyclohexyl phenyl ketone and 2-hydroxy-2-methyl-1- [4- (1-methylvinyl) phenyl] propane-1- ON oligomers.

  Examples of the acylphosphine oxide compound include 2,4,6-trimethylbenzoyldiphenylphosphine oxide and bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide.

  Examples of the triazine compound include 2,4-bis (trichloromethyl) -6- (4-methoxyphenyl) -1,3,5-triazine, 2,4-bis (trichloromethyl) -6- (4-methoxy Naphthyl) -1,3,5-triazine, 2,4-bis (trichloromethyl) -6- (4-methoxystyryl) -1,3,5-triazine, 2,4-bis (trichloromethyl) -6 [2- (5-Methylfuran-2-yl) ethenyl] -1,3,5-triazine, 2,4-bis (trichloromethyl) -6- [2- (furan-2-yl) ethenyl] -1 , 3,5-triazine, 2,4-bis (trichloromethyl) -6- [2- (4-diethylamino-2-methylphenyl) ethenyl] -1,3,5-triazine and 2,4-bis (trichloro Methyl)- - such as [2- (3,4-dimethoxyphenyl) ethenyl] -1,3,5-triazine.

  A commercially available polymerization initiator can also be used. Commercially available polymerization initiators include “Irgacure 907”, “Irgacure 184”, “Irgacure 651”, “Irgacure 819”, “Irgacure 250”, “Irgacure 369” (Ciba Japan Co., Ltd.); “Sake All BZ”, “Sake All Z”, “Sake All BEE” (Seiko Chemical Co., Ltd.); “Kayacure BP100” (Nippon Kayaku Co., Ltd.); “Kayacure UVI-6992” (manufactured by Dow); "Adekaoptomer SP-152", "Adekaoptomer SP-170" (ADEKA); "TAZ-A", "TAZ-PP" (Nihon Shibel Hegner); and "TAZ-104" (Sanwa Chemical) Companies).

  When the composition for forming a polarizing film contains a polymerization initiator, the content can be appropriately adjusted according to the type and amount of the polymerizable liquid crystal compound contained in the composition for forming a polarizing film, but usually the polymerization is performed. The content of the polymerization initiator with respect to 100 parts by mass of the total liquid crystalline compound is 0.1 to 30 parts by mass, preferably 0.5 to 10 parts by mass, and more preferably 0.5 to 8 parts by mass. is there. If the content of the polymerizable initiator is within this range, it can be polymerized without disturbing the orientation of the polymerizable liquid crystal compound, which is preferable.

1-4-2. Photosensitizer When the composition for forming a polarizing film contains a photopolymerization initiator, the composition for forming a polarizing film may contain a photosensitizer. Examples of the photosensitizer include anthracene such as xanthone compounds such as xanthone and thioxanthone (for example, 2,4-diethylthioxanthone and 2-isopropylthioxanthone); anthracene and anthracene containing an alkoxy group (for example, dibutoxyanthracene). Compounds; phenothiazine, rubrene and the like.

  When the composition for forming a polarizing film contains a photopolymerization initiator and a photosensitizer, the polymerization reaction of the polymerizable liquid crystal compound contained in the composition for forming a polarizing film is further promoted. The content of the photosensitizer can be appropriately adjusted according to the type and amount of the photopolymerization initiator and the polymerizable liquid crystal compound to be used in combination, but is usually 100 parts by mass of the polymerizable liquid crystal compound. It is 0.1-30 mass parts, Preferably it is 0.5-10 mass parts, More preferably, it is 0.5-8 mass parts.

1-4-3. Polymerization inhibitor The composition for forming a polarizing film may contain a polymerization inhibitor in order to allow the polymerization reaction of the polymerizable liquid crystal compound to proceed stably. The progress of the polymerization reaction of the polymerizable liquid crystal compound can be controlled by the polymerization inhibitor.

  Examples of the polymerization inhibitor include radical supplements such as hydroquinone, alkoxy group-containing hydroquinone, alkoxy group-containing catechol (for example, butyl catechol), pyrogallol, 2,2,6,6-tetramethyl-1-piperidinyloxy radical, and the like. Agents; thiophenols; β-naphthylamines, β-naphthols and the like.

When the composition for forming a polarizing film contains a polymerization inhibitor, the content is appropriately adjusted according to the type and amount of the polymerizable liquid crystal compound used, the content of the photosensitizer, etc. It is 0.1-30 mass parts with respect to 100 mass parts of content of a polymeric liquid crystal compound, Preferably it is 0.5-10 mass parts, More preferably, it is 0.5-8 mass parts.
If the content of the polymerization inhibitor is within the above range, it can be polymerized without disturbing the orientation of the polymerizable liquid crystal compound contained in the composition for forming a polarizing film, which is preferable.

1-4-4. Leveling agent The composition for forming a polarizing film preferably contains a leveling agent. The leveling agent has a function of adjusting the fluidity of the polarizing film forming composition and flattening the coating film obtained by applying the polarizing film forming composition, and includes a surfactant and the like. be able to. Preferable leveling agents include a leveling agent having a polyacrylate compound as a main component and a leveling agent having a fluorine atom-containing compound as a main component.

  Leveling agents mainly composed of polyacrylate compounds include “BYK-350”, “BYK-352”, “BYK-353”, “BYK-354”, “BYK-355”, “BYK-358N”, “ BYK-361N ”,“ BYK-380 ”,“ BYK-381 ”,“ BYK-392 ”[BYK Chemie], and the like.

  Leveling agents mainly composed of fluorine atom-containing compounds include "Megafac R-08", "R-30", "R-90", "F-410", "F-411", "F-443", "F-445", "F-470", "F-471", "F-477", "F-479", "F-482" and the same "F-483" [DIC Corporation]; "Surflon S-381", "S-382", "S-383", "S-393", "SC-101", "SC" -105 "," KH-40 "and" SA-100 "[AGC Seimi Chemical Co., Ltd.];" E1830 "," E5844 "[Daikin Fine Chemical Laboratory Co., Ltd.];" F-top EF301 "," EF303 " ", EF351" and "EF352" [Mitsubishi Materials Child Kasei Co., Ltd.] and the like.

  When the leveling agent is included in the composition for forming a polarizing film, the content is usually 0.3 parts by mass or more and 5 parts by mass or less with respect to 100 parts by mass of the polymerizable liquid crystal compound, preferably 0.5 parts by mass or more and 3 parts by mass or less. It is preferable that the content of the leveling agent is within the above range because the polymerizable liquid crystal compound can be easily horizontally aligned and the resulting polarizing film tends to be smoother. If the content of the leveling agent with respect to the polymerizable liquid crystal compound exceeds the above range, unevenness tends to occur in the obtained polarizing film. In addition, this polarizing film formation composition may contain 2 or more types of leveling agents.

2. Next, a method for forming the present polarizing film from the composition for forming a polarizing film will be described. In this method, the polarizing film is formed by applying the composition for forming a polarizing film to a substrate, preferably a transparent substrate.

2-1. Transparent base material A transparent base material is a base material which has the transparency which can permeate | transmit light, especially visible light. The transparency refers to a characteristic that the transmittance with respect to a light beam having a wavelength of 380 to 780 nm is 80% or more. Specifically, examples of the transparent substrate include a glass substrate and a plastic substrate, and a plastic substrate is preferable. Examples of the plastic constituting the plastic substrate include polyolefins such as polyethylene, polypropylene, and norbornene polymers; cyclic olefin resins; polyvinyl alcohol; polyethylene terephthalate; polymethacrylic acid esters; polyacrylic acid esters; And cellulose esters such as cellulose acetate propionate; polyethylene naphthalate; polycarbonate; polysulfone; polyethersulfone; polyetherketone; and plastics such as polyphenylene sulfide and polyphenylene oxide. Among these, cellulose ester, cyclic olefin resin, polyethylene terephthalate, or polymethacrylic acid ester is particularly preferable from the viewpoint that it can be easily obtained from the market or has excellent transparency. In producing the polarizing film using such a transparent substrate, the transparent substrate can be easily handled without causing damage such as tearing when the transparent substrate is transported or stored. A support base material or the like may be pasted. Moreover, although mentioned later, when manufacturing a circularly-polarizing plate from this polarizing film, retardation may be provided to a plastic base material. In this case, the phase difference may be imparted to the plastic substrate by a stretching process or the like.

In the case of imparting retardation to a plastic substrate, a plastic substrate made of cellulose ester or a cyclic olefin resin is preferable because the retardation value can be easily controlled.
The cellulose ester is one in which at least a part of the hydroxyl group contained in cellulose is converted to acetic acid ester. A cellulose ester film comprising such a cellulose ester can be easily obtained from the market. Examples of commercially available triacetyl cellulose films include “Fujitack Film” (Fuji Photo Film Co., Ltd.); “KC8UX2M”, “KC8UY” and “KC4UY” (Konica Minolta Opto Co., Ltd.). Such a commercially available triacetyl cellulose film can be used as a transparent substrate as it is or after imparting retardation as necessary. The surface of the prepared transparent substrate can be used as a transparent substrate after being subjected to surface treatment such as antiglare treatment, hard coat treatment, antistatic treatment or antireflection treatment.

  In order to impart retardation to the plastic substrate, as described above, the plastic substrate is stretched. Any plastic base material made of a thermoplastic resin can be stretched, but a plastic base material made of a cyclic olefin-based resin is more preferable in that the retardation can be easily controlled. The cyclic olefin resin is composed of, for example, a polymer or copolymer of a cyclic olefin such as norbornene or a polycyclic norbornene monomer, and the cyclic olefin resin partially includes a ring opening. May be. Moreover, what hydrogenated the cyclic olefin resin containing a ring opening part may be used. In addition, the cyclic olefin-based resin is, for example, a combination of a cyclic olefin and a chain olefin or a vinylated aromatic compound (such as styrene) in that the transparency is not significantly impaired or the hygroscopicity is not significantly increased. It may be a polymer. The cyclic olefin resin may have a polar group introduced in its molecule.

  When the cyclic olefin resin is a copolymer of a cyclic olefin and an aromatic compound having a chain olefin or a vinyl group, the chain olefin is ethylene, propylene, or the like, and a vinylated aromatic Examples of the compound include styrene, α-methylstyrene, and alkyl-substituted styrene. In such a copolymer, the content ratio of the structural unit derived from the cyclic olefin is in the range of 50 mol% or less, for example, about 15 to 50 mol% with respect to all the structural units of the cyclic olefin resin. When the cyclic olefin-based resin is a terpolymer obtained from a cyclic olefin, a chain olefin, and a vinylated aromatic compound, for example, the content ratio of the structural unit derived from the chain olefin is the cyclic olefin. It is about 5-80 mol% with respect to all the structural units of a resin, and the content rate of the structural unit derived from a vinylated aromatic compound is about 5-80 mol%. Such a terpolymer cyclic olefin resin has the advantage that the amount of expensive cyclic olefin used can be relatively reduced when the cyclic olefin resin is produced.

  Cyclic olefin resin is easily available from the market. Commercially available cyclic olefin-based resins include “Topas” [Ticona (Germany)]; “Arton” [JSR Corporation]; “ZEONOR” and “ZEONEX” [Nippon Zeon Corporation] “Apel” [Mitsui Chemicals, Inc.] and the like. Such a cyclic olefin-based resin can be formed into a film (cyclic olefin-based resin film) by, for example, known film forming means such as a solvent casting method or a melt extrusion method. Moreover, the cyclic olefin resin film already marketed with the form of a film can also be used. Examples of such commercially available cyclic olefin resin films include “Essina” and “SCA40” [Sekisui Chemical Co., Ltd.]; “Zeonor Film” [Optes Co., Ltd.]; “Arton Film” [JSR Co., Ltd.] ] Etc. are mentioned.

  Then, the method to provide phase difference to a plastic base material is demonstrated. The plastic substrate can be provided with retardation by a known stretching method. For example, a roll (winding body) in which a plastic substrate is wound around a roll is prepared, the plastic substrate is continuously unwound from the wound body, and the unrolled plastic substrate is transferred to a heating furnace. And carry. The set temperature of the heating furnace is in the range of near the glass transition temperature of the plastic substrate (° C.) to [glass transition temperature +100] (° C.), preferably near the glass transition temperature (° C.) to [glass transition temperature +50] (° C. ). In the heating furnace, when stretching in the direction of travel of the plastic substrate, or in the direction perpendicular to the direction of travel, the transport direction and tension are adjusted, and an arbitrary angle is added to the uniaxial or biaxial thermal stretching process. I do. The draw ratio is usually in the range of about 1.1 to 6 times, preferably in the range of about 1.1 to 3.5 times. In addition, the method of stretching in an oblique direction is not particularly limited as long as the orientation axis can be continuously inclined to a desired angle, and a known stretching method can be employed. Examples of such a stretching method include the methods described in JP-A-50-83482 and JP-A-2-113920.

  The thickness of the transparent substrate is preferably thin in terms of weight that allows practical handling and sufficient transparency, but if it is too thin, the strength decreases and the processability is poor. Tend. The appropriate thickness of the glass substrate is, for example, about 100 to 3000 μm, and preferably about 100 to 1000 μm. The appropriate thickness of the plastic substrate is, for example, about 5 to 300 μm, preferably about 20 to 200 μm. When this polarizing film is used as a circularly polarizing plate to be described later, or particularly when used as a circularly polarizing plate for mobile devices, the thickness of the transparent substrate is preferably about 20 to 100 μm. In addition, when giving retardation to a film by extending | stretching, the thickness after extending | stretching is determined by the thickness before extending | stretching and a draw ratio.

2-2. Alignment film It is preferable that the alignment film is formed in the base material used for manufacture of this polarizing film. In that case, the composition for forming a polarizing film is applied onto the alignment film. For this reason, it is preferable that the alignment film has a solvent resistance that does not dissolve when the polarizing film-forming composition is applied. Moreover, it is preferable to have heat resistance in the heat treatment for removing the solvent and aligning the liquid crystal. Such an alignment film can be formed of an alignment polymer.

  Examples of the orientation polymer include polyamides and gelatins having an amide bond in the molecule, polyimides having an imide bond in the molecule and polyamic acid, polyvinyl alcohol, alkyl-modified polyvinyl alcohol, polyacrylamide, polyacrylamide which are hydrolysates thereof. Mention may be made of polymers such as oxazole, polyethyleneimine, polystyrene, polyvinylpyrrolidone, polyacrylic acid or polyacrylic acid esters. Among these, polyvinyl alcohol is preferable. These alignment polymers forming the alignment film may be used alone or in combination of two or more.

  The alignment polymer can be formed on the substrate by applying the alignment polymer on the substrate as an alignment polymer composition (solution containing the alignment polymer) dissolved in a solvent. Examples of the solvent include water; alcohol solvents such as methanol, ethanol, ethylene glycol, isopropyl alcohol, propylene glycol, methyl cellosolve, butyl cellosolve and propylene glycol monomethyl ether; ethyl acetate, butyl acetate, ethylene glycol methyl ether acetate, γ-butyrolactone, Ester solvents such as propylene glycol methyl ether acetate and ethyl lactate; ketone solvents such as acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, methyl amyl ketone and methyl isobutyl ketone; aliphatic hydrocarbon solvents such as pentane, hexane and heptane; toluene and Aromatic hydrocarbon solvents such as xylene, nitrile solvents such as acetonitrile; tetrahydrofuran and dimethoxyethane Chlorinated hydrocarbon solvent of chloroform and chlorobenzene; an ether solvent like, and the like. These organic solvents may be used alone or in combination of two or more.

  A commercially available alignment film material may be used as it is as the alignment polymer composition for forming the alignment film. Examples of commercially available alignment film materials include Sunever (registered trademark, manufactured by Nissan Chemical Industries, Ltd.) and Optmer (registered trademark, manufactured by JSR).

  Examples of the method for forming the alignment film on the substrate include a method in which the alignment polymer composition or a commercially available alignment film material is applied on the substrate and annealed. The thickness of the alignment film thus obtained is usually 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 regulating force to the alignment film, it is preferable to perform rubbing as necessary (rubbing method). By providing the alignment regulating force, the polymerizable liquid crystal compound can be aligned in a desired direction.

  As a method of applying an alignment regulating force by a rubbing method, for example, a rubbing cloth is wound, a rotating rubbing roll is prepared, and a laminate in which a coating film for forming an alignment film is formed on a substrate is staged. And a method of bringing the alignment film-forming coating film into contact with the rotating rubbing roll by transporting it toward the rotating rubbing roll.

  A so-called photo-alignment film can also be used. The photo-alignment film is a composition comprising a polymer or monomer having a photoreactive group and a solvent (hereinafter sometimes referred to as “photo-alignment layer forming composition”) on a substrate, and polarized light (preferably , Refers to an alignment film imparted with an alignment regulating force by irradiation with polarized UV light. The photoreactive group refers to a group that generates liquid crystal alignment ability when irradiated with light (light irradiation). Specifically, it causes photoreactions that are the origin of liquid crystal alignment ability, such as molecular orientation induction or isomerization reaction, dimerization reaction, photocrosslinking reaction, or photolysis reaction caused by light irradiation. is there. Among the photoreactive groups, those that cause a dimerization reaction or a photocrosslinking reaction are preferable because they are excellent in orientation and maintain a smectic liquid crystal state when a polarizing film is formed. As the photoreactive group capable of causing the above reaction, those having an unsaturated bond, particularly a double bond are preferable, and a carbon-carbon double bond (C═C bond), a carbon-nitrogen double bond (C = N bond), a group having at least one selected from the group consisting of a nitrogen-nitrogen double bond (N = N bond) and a carbon-oxygen double bond (C = O bond) is particularly preferable.

Examples of the photoreactive group having a C═C bond include a vinyl group, a polyene group, a stilbene group, a stilbazole group, a stilbazolium group, a chalcone group, and a cinnamoyl group. Examples of the photoreactive group having a C═N bond include groups having a structure such as an aromatic Schiff base and an aromatic hydrazone. Examples of the photoreactive group having an N = N bond include an azobenzene group, an azonaphthalene group, an aromatic heterocyclic azo group, a bisazo group and a formazan group, and those having a basic structure of azoxybenzene. Examples of the photoreactive group having a C═O bond include a benzophenone group, a coumarin group, an anthraquinone group, and a maleimide group. These groups may 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, and a halogenated alkyl group.
Among them, a photoreactive group capable of causing a photodimerization reaction is preferable, and a cinnamoyl group and a chalcone group have a relatively small amount of polarized light irradiation necessary for photoalignment, and a photoalignment film having excellent thermal stability and temporal stability. Since it is easy to obtain, it is preferable. Further, as the polymer having a photoreactive group, a polymer having a cinnamoyl group in which the terminal portion of the polymer side chain has a cinnamic acid structure is particularly preferable.

  As the solvent for the composition for forming a photo-alignment layer, a solvent capable of dissolving a polymer and a monomer having a photoreactive group is preferable. Examples of the solvent include the solvents used in the above-described alignment polymer composition.

  The concentration of the polymer or monomer having a photoreactive group with respect to the composition for forming a photoalignment layer can be appropriately adjusted depending on the type of the polymer or monomer having the photoreactive group and the thickness of the photoalignment film to be produced. Expressed in terms of solid content concentration, it is preferably at least 0.2 mass%, particularly preferably in the range of 0.3-10 mass%. In addition, the composition for forming a photo-alignment layer may contain a polymer material such as polyvinyl alcohol and polyimide, and a photosensitizer as long as the characteristics of the photo-alignment film are not significantly impaired.

  Examples of the method for applying the alignment polymer composition or the photo-alignment layer forming composition on the substrate include spin coating method, extrusion method, gravure coating method, die coating method, bar coating method and applicator method. A known method such as a coating method or a printing method such as a flexo method is employed. In addition, when this polarizing film manufacture is implemented by the continuous manufacturing method of RolltoRoll format mentioned later, the printing method, such as the gravure coating method, the die coating method, or the flexo method, is normally employ | adopted.

  Note that a plurality of regions (patterns) having different orientation directions can be formed by performing masking when performing rubbing or polarized light irradiation.

2-3. Manufacturing method of this polarizing film The composition for polarizing film formation is apply | coated on the alignment film formed in the said base material or a base material, and a coating film is obtained. Examples of the method for applying the composition for forming a polarizing film include the same methods as those exemplified as the method for applying the alignment polymer composition or the composition for forming a photo-alignment layer to a substrate.

Next, a dry film is formed by drying and removing the solvent under conditions where the polymerizable liquid crystal compound contained in the coating film is not polymerized. Examples of the drying method include a natural drying method, a ventilation drying method, a heat drying method, and a vacuum drying method.
Subsequently, as a preferred form, once the liquid crystal state of the polymerizable liquid crystal compound contained in the dry film is changed to a nematic liquid crystal, the nematic liquid crystal phase is changed to a smectic liquid crystal phase.
In order to form the smectic liquid crystal phase via the nematic liquid crystal phase in this way, for example, the polymerizable liquid crystal compound contained in the dry film is heated to a temperature at which the nematic liquid crystal phase is exhibited, and then the polymerizable liquid crystal compound is A method of cooling to a temperature showing a smectic liquid crystal phase is employed.

  When the polymerizable liquid crystal compound in the dry film is changed to a smectic liquid crystal phase, or the polymerizable liquid crystal compound is changed to a smectic liquid crystal phase via a nematic liquid crystal phase, the phase transition temperature of the polymerizable liquid crystal compound to be used is measured. Thus, a condition (heating condition) for controlling the liquid crystal state can be obtained. The measurement conditions of such a phase transition temperature will be described in the examples of the present application.

Next, the polymerization process of the polymerizable liquid crystal compound will be described. Here, the composition for forming a polarizing film contains a photopolymerization initiator, and after the liquid crystal state of the polymerizable liquid crystal compound in the dry film is changed to a smectic liquid crystal phase, the liquid crystal state of the smectic liquid crystal phase is maintained. A method for photopolymerizing the polymerizable liquid crystal compound will be described in detail.
In the photopolymerization, as the light irradiated to the dry film, the type of photopolymerization initiator contained in the dry film, or the type of polymerizable liquid crystal compound (particularly, the type of polymerizable group possessed by the polymerizable liquid crystal compound) and Depending on the amount, it can be carried out with light selected from the group consisting of visible light, ultraviolet light and laser light, or an active electron beam. Among these, ultraviolet light is preferable in that it is easy to control the progress of the polymerization reaction and that apparatuses widely used in the field as photopolymerization apparatuses can be used. Therefore, it is preferable to select the type of the polymerizable liquid crystal compound and the photopolymerization initiator contained in the composition for forming a polarizing film so that the photopolymerization can be performed with ultraviolet light. Moreover, when superposing | polymerizing, superposition | polymerization temperature can also be controlled by cooling a dry film with a suitable cooling means with ultraviolet light irradiation. By adopting such a cooling means, if the polymerizable liquid crystal compound can be polymerized at a lower temperature, the present polarizing film can be appropriately formed even if the above-mentioned substrate has a relatively low heat resistance. There is also. In the photopolymerization, the patterned main polarizing film can be obtained by masking or developing.

  By performing photopolymerization as described above, the polymerizable liquid crystal compound is polymerized while maintaining a nematic liquid crystal phase or a smectic liquid crystal phase, preferably a higher-order smectic liquid crystal phase as exemplified above. It is formed. This polarizing film obtained by polymerizing a polymerizable liquid crystal compound while maintaining the smectic liquid crystal phase is a conventional host-guest type polarizing film, that is, polymerizing a polymerizable liquid crystal compound while maintaining the liquid crystal state of the nematic liquid crystal phase. There is an advantage that the polarization performance is high as compared with the polarizing film obtained. Furthermore, there is an advantage that the strength is excellent as compared with the case where only the lyotropic dichroic dye is applied.

  The thickness of the polarizing film thus formed is preferably in the range of 0.5 μm to 10 μm, and more preferably 1 μm to 5 μm. Therefore, the thickness of the coating film for forming the present polarizing film is determined in consideration of the thickness of the obtained present polarizing film. In addition, the thickness of this polarizing film is calculated | required by the measurement of an interference film thickness meter, a laser microscope, or a stylus-type film thickness meter.

  Further, as described above, the polarizing film thus formed is particularly preferably one that can obtain a Bragg peak in X-ray diffraction measurement. As this polarizing film from which such a Bragg peak is obtained, for example, the present polarizing film showing a diffraction peak derived from a hexatic phase or a crystal phase can be mentioned.

Furthermore, the polarizing film produced in this way is excellent in neutral hue. Here, the polarizing film excellent in neutral hue is that the color coordinate a * value and b * value in the L * a * b * (Lab) color system have the following formulas (1F) and (2F): Satisfies the relationship. In addition, these color coordinate a * value and b * value are calculated | required with the measuring method demonstrated in this-application Example, for example.
-3 ≦ chromaticity a * ≦ 3 (1F)
−3 ≦ chromaticity b * ≦ 3 (2F)
The color coordinate a * value and b * value here are also referred to as “chromaticity a *” and “chromaticity b *”. Both a * and b * are determined to be polarizing films exhibiting a neutral hue as they are closer to 0 (zero). In a display device provided with such a polarizing film, good white display without coloring can be obtained.

Further, in the hue of the polarizing film, the two polarizing films were overlapped so that the absorption axes were orthogonal to each other, and the hue at that time was obtained in the same manner as described above, and “orthogonal a *” and “orthogonal b *” were calculated. In this case, it is more preferable that each of the orthogonal a * and the orthogonal b * satisfies the relationship of the following expressions (1F ′) and (2F ′). These orthogonal a * and orthogonal b * are indices indicating whether or not the hue of black display is neutral in a display device including a polarizing film. The closer both the orthogonal a * and the orthogonal b * are to 0 (zero), the better black display without coloring can be obtained.
-3 ≦ orthogonal a * ≦ 3 (1F ′)
-3 ≦ orthogonal b * ≦ 3 (2F ′)

3. Method for Continuously Producing the Polarizing Film The outline of the method for producing the polarizing film has been described above. However, when the polarizing film is produced commercially, a method capable of producing the polarizing film continuously is required. Such a continuous manufacturing method is based on the RolltoRoll format, and is sometimes referred to as “the present manufacturing method”. In addition, in this manufacturing method, it demonstrates centering on the case where a base material is a transparent base material. When the substrate is a transparent substrate, the final product is a polarizer having a transparent substrate and the present polarizing film (hereinafter sometimes referred to as “the present polarizer”).

This manufacturing method is, for example,
Preparing a first roll in which a transparent substrate is wound around a first core;
Continuously feeding the transparent substrate from the first roll;
Continuously forming an alignment film on the transparent substrate;
A step of continuously applying the polarizing film-forming composition on the alignment layer and the applied polarizing film-forming composition are dried on the alignment film so as not to polymerize the polymerizable liquid crystal compound. Continuously forming a dry film;
The polymerizable liquid crystal compound contained in the dry film is converted into a nematic liquid crystal phase, preferably a smectic liquid crystal phase, and then the polymerizable liquid crystal compound is polymerized while maintaining the smectic liquid crystal phase, thereby continuously forming a polarizing film. To obtain a polarizer,
A step of winding the polarizer obtained continuously onto a second core to obtain a second roll. Here, with reference to FIG. 1, this manufacturing method will be described particularly in the case of using a photo-alignment film as the alignment film.

  The first roll 210 in which the transparent base material is wound around the first core 210A can be easily obtained from the market, for example. Examples of the transparent substrate that can be obtained from the market in the form of such a roll include a film made of cellulose ester, cyclic olefin resin, polyethylene terephthalate, polycarbonate, or polymethacrylic acid ester, among the already exemplified transparent substrates. . In addition, when the polarizing film is used as a circularly polarizing plate, a transparent substrate previously imparted with retardation is easily available from the market, for example, a retardation film made of a cellulose ester or a cyclic olefin resin. It is done.

  Subsequently, the transparent substrate is unwound from the first roll 210. The method for unwinding the transparent substrate is performed by installing an appropriate rotating means on the core 210A of the first roll 210 and rotating the first roll 210 by the rotating means. Alternatively, a suitable auxiliary roll 300 may be installed in the direction of transporting the transparent base material from the first roll 210 and the transparent base material may be unwound by the rotating means of the auxiliary roll 300. Further, the first winding core 210A and the auxiliary roll 300 may be provided with a rotating means so that the transparent substrate is unwound while applying an appropriate tension to the transparent substrate.

  When the transparent base material unwound from the first roll 210 passes through the coating apparatus 211A, the composition for forming a photo-alignment layer is applied on the surface of the transparent base material by the coating apparatus 211A. Thus, in order to apply | coat the composition for photo-alignment layer formation continuously, as mentioned above, printing methods, such as a gravure coating method, a die coating method, a flexo method, are implemented with the said coating device 211A.

  The transparent base material that has passed through the coating apparatus 211A is transported to the drying furnace 212A and heated by the drying furnace 212A to continuously form a first dry film on the transparent base material. For example, a hot air drying furnace or the like is used as the drying furnace 212A. The set temperature of the drying furnace 212A is determined according to the type of the solvent contained in the composition for forming a photo-alignment layer applied by the coating apparatus 211A. The drying furnace 212A may be divided into a plurality of zones, and the set temperature may be different for each of the divided zones. A plurality of drying furnaces are arranged in series, and the set temperature is set for each drying furnace. Different types of drying ovens may be used.

  The first dry film continuously formed by passing through the heating furnace 212A is then irradiated with polarized UV on the surface on the first dry film side or the surface on the transparent substrate side by the polarized UV irradiation device 213A. The first dry film forms a (light) alignment film. In that case, the angle which the conveyance direction D1 of a transparent base material and the orientation direction D2 of the photo-alignment film formed form can also be made to cross | intersect. FIG. 2 is a schematic diagram showing the relationship between the alignment direction D2 of the photo-alignment film formed after irradiation with polarized UV light and the transport direction D1 of the transparent substrate. That is, FIG. 2 shows that when the surface of the first laminate after passing through the polarized UV irradiation device 213A is viewed in the transport direction D1 of the transparent substrate and the alignment direction D2 of the photo-alignment film, the angle formed by them is approximately 45. Indicates that °.

  Thus, after the transparent base material (1st laminated body) in which the photo-alignment film was continuously formed passed the coating device 211B, the composition for forming a polarizing film was applied on the photo-alignment film, Passes through the drying furnace 212B. By passing through the drying furnace 212B, the polymerizable liquid crystal compound contained in the polarizing film forming composition forms a nematic liquid crystal phase, preferably a smectic liquid crystal phase, and a second dry film is formed.

  The transparent base material that has passed through the drying oven 212B is sufficiently removed of the solvent contained in the polarizing film forming composition, and the polymerizable liquid crystal compound in the second dry film is a liquid crystal in a nematic liquid crystal phase, preferably a smectic liquid crystal phase. It is conveyed to the light irradiation device 213B while maintaining the state. By the light irradiation by the light irradiation device 213B, the polymerizable liquid crystal compound is photopolymerized while maintaining the liquid crystal state, and the present polarizing film is continuously formed on the alignment film to obtain the present polarizer.

  The polarizing film thus continuously formed is wound around the second core 220A in the form of a laminate including the transparent base material and the alignment film, and the form of the second roll 220 is obtained. When the formed polarizing film is wound up to obtain the second roll, co-winding using an appropriate spacer may be performed.

  In this way, the transparent base material passes through the first roll / coating device 211A / drying furnace 212A / polarized UV irradiation device 213A / coating device 211B / drying furnace 212B / light irradiation device 213B in this order. The present polarizing film is continuously formed on the upper photo-alignment film to produce the present polarizer.

  Further, in the present manufacturing method shown in FIG. 1, a method for continuously manufacturing the transparent base material to the polarizing film has been shown. For example, the transparent base material is made of the first roll / coating device 211A / drying furnace 212A /. By passing the polarized UV irradiation device 213A in this order, the first laminated body formed continuously is wound around the core, and the first laminated body is manufactured in the form of a roll, and the first laminated body is produced from the roll. The polarizer may be manufactured by passing the unwound first laminated body in the order of coating device 211B / drying furnace 212B / light irradiation device 213B.

  The present polarizer obtained by this production method has a film shape and a long shape. When this polarizing film is used for a liquid crystal display device to be described later, the polarizing film is cut into a desired size according to the scale of the liquid crystal display device.

  As mentioned above, the configuration and the manufacturing method of the present polarizer have been described mainly with respect to the case of a laminate of a transparent substrate / photo-alignment film / this polarizing film. The polarizing film can be obtained as a single layer by peeling off the film. Moreover, you may make it the form which laminated | stacked layers or films | membranes other than transparent base material / photo-alignment film / this polarizing film on this polarizer. As these layers and films, as described above, the polarizing film may further include a retardation film, or may further include an antireflection layer or a brightness enhancement film.

  Moreover, it can also be set as the circularly-polarizing plate or elliptical polarizing plate of the form of retardation film / photo-alignment film | membrane / this polarizing film by making transparent base material itself into retardation film. For example, when a uniaxially stretched ¼ wavelength plate is used as the retardation film, by setting the irradiation direction of the polarized UV to be approximately 45 ° with respect to the transport direction of the transparent base material, A polarizing plate can be produced. Thus, it is preferable that the quarter wavelength plate used when manufacturing the circularly polarizing plate has a characteristic that the in-plane retardation value with respect to visible light becomes smaller as the wavelength becomes shorter.

  Further, using a half-wave plate as a retardation film, a linear polarizing plate roll was prepared in which the angle between the slow axis and the absorption axis of the polarizing film was shifted, and the surface on which the polarizing film was formed; It is possible to form a broadband circularly polarizing plate by further forming a quarter wavelength plate on the opposite side.

4). Application of the Polarizing Film The polarizing film can be used in various display devices. A display device is a device having a display element and includes a light-emitting element or a light-emitting device as a light-emitting source. Examples of the display device include a liquid crystal display device, an organic electroluminescence (EL) display device, an inorganic electroluminescence (EL) display device, an electron emission display device (for example, a field emission display device (FED), a surface field emission display device (SED). )), Electronic paper (display device using electronic ink or electrophoretic element, plasma display device, projection display device (eg, display device having a grating light valve (GLV) display device, digital micromirror device (DMD)), and Examples of the liquid crystal display device include a transmissive liquid crystal display device, a transflective liquid crystal display device, a reflective liquid crystal display device, a direct view liquid crystal display device, and a projection liquid crystal display device. These display devices may be display devices that display a two-dimensional image. And it may be a stereoscopic display apparatus for displaying a three-dimensional image.
This polarizing film can be effectively used particularly for a display device of an organic electroluminescence (EL) display device or an inorganic electroluminescence (EL) display device.

FIG. 3 is a schematic diagram showing a cross-sectional configuration of a liquid crystal display device (hereinafter, sometimes referred to as “the present liquid crystal display device”) 10 using the present polarizing film. The liquid crystal layer 17 is sandwiched between two substrates 14a and 14b.
6 and 10 are schematic views showing a cross-sectional configuration of an EL display device using the present polarizing film (hereinafter, sometimes referred to as “the present EL display device”).
FIG. 11 is a schematic diagram showing a configuration of a projection type liquid crystal display device using the polarizing film.

First, the liquid crystal display device 10 shown in FIG. 3 will be described.
A color filter 15 is disposed on the liquid crystal layer 17 side of the substrate 14a. The color filter 15 is disposed at a position facing the pixel electrode 22 across the liquid crystal layer 17, and the black matrix 20 is disposed at a position facing the boundary between the pixel electrodes. The transparent electrode 16 is disposed on the liquid crystal layer 17 side so as to cover the color filter 15 and the black matrix 20.
An overcoat layer (not shown) may be provided between the color filter 15 and the transparent electrode 16.

  Thin film transistors 21 and pixel electrodes 22 are regularly arranged on the liquid crystal layer 17 side of the substrate 14b. The pixel electrode 22 is disposed at a position facing the color filter 15 with the liquid crystal layer 17 interposed therebetween. An interlayer insulating film 18 having a connection hole (not shown) is disposed between the thin film transistor 21 and the pixel electrode 22.

A glass substrate and a plastic substrate are used as the substrate 14a and the substrate 14b.
As the glass substrate and the plastic substrate, those made of the same material as those exemplified as the transparent base material used in the production of the polarizing film can be adopted. Moreover, the transparent substrate 1 of this polarizing film may serve as both the substrate 14a and the substrate 14b. When manufacturing the color filter 15 and the thin film transistor 21 formed on the substrate, a glass substrate or a quartz substrate is preferable when a process of heating to a high temperature is required.

  As the thin film transistor, an optimum one can be adopted according to the material of the substrate 14b. Examples of the thin film transistor 21 include a high-temperature polysilicon transistor formed on a quartz substrate, a low-temperature polysilicon transistor formed on a glass substrate, and an amorphous silicon transistor formed on a glass substrate or a plastic substrate. In order to reduce the size of the present liquid crystal display device, a driver IC may be formed on the substrate 14b.

  A liquid crystal layer 17 is disposed between the transparent electrode 16 and the pixel electrode 22. In the liquid crystal layer 17, spacers 23 are arranged in order to keep the distance between the substrate 14a and the substrate 14b constant. In FIG. 3, columnar spacers are illustrated, but the spacers are not limited to columnar shapes, and the shape is arbitrary as long as the distance between the substrate 14 a and the substrate 14 b can be kept constant.

  Each member is laminated in the order of the substrate 14a, the color filter 15 and the black matrix 20, the transparent electrode 16, the liquid crystal layer 17, the pixel electrode 22, the interlayer insulating film 18 and the thin film transistor 21, and the substrate 14b.

Among the substrates 14a and 14b sandwiching the liquid crystal layer 17, polarizers 12a and 12b are provided outside the substrate 14b, and at least one of these polarizers is used. .
Furthermore, it is preferable that retardation layers (for example, quarter-wave plates and optical compensation films) 13a and 13b are laminated. By disposing the present polarizing film on the polarizer 12b out of the polarizers 12a and 12b, the liquid crystal display device 10 can be provided with a function of converting incident light into linearly polarized light. The retardation films 13a and 13b may not be arranged depending on the structure of the liquid crystal display device and the type of liquid crystal compound contained in the liquid crystal layer 17, and the transparent substrate is a retardation film. When the circularly polarizing plate containing is used, the retardation film can be used as a retardation layer, so that the retardation layers 13a and / or 13b in FIG. 3 can be omitted. A polarizing film may be further provided on the light exit side (outside) of the polarizer.
Further, an antireflection film for preventing reflection of external light may be disposed outside the polarizer (on the outside of the polarizing film when a polarizing film is further provided).

  As described above, the polarizer can be used as the polarizer 12a or 12b of the liquid crystal display device 10 of FIG. By providing the polarizer in the polarizer 12a and / or 12b, there is an effect that the liquid crystal display device 10 can be thinned.

  When this polarizer is used for the polarizer 12a or 12b, the stacking order is not particularly limited. This will be described with reference to an enlarged view of portions A and B surrounded by a dotted line in FIG.

  4 is an enlarged schematic cross-sectional view of a portion A in FIG. (A1) in FIG. 4 is provided so that the polarizing film 3, the photo-alignment film 2, and the transparent substrate 1 are arranged in this order from the retardation layer 13a side when the polarizer 100 is used as the polarizer 12a. It is shown that Moreover, (A2) of FIG. 4 shows that the transparent base material 1, the photo-alignment film 2, and the present polarizing film 3 are provided in this order from the retardation layer 13a side.

  FIG. 5 is an enlarged schematic view of a portion B in FIG. (B1) in FIG. 5 is provided so that the transparent substrate 1, the photo-alignment film 2, and the main polarizing film 3 are arranged in this order from the retardation film 13b side when the main polarizer 100 is used as the polarizer 12b. It is done. (B2) in FIG. 5 is provided such that when the present polarizer 100 is used as the polarizer 12b, the present polarizing film 3, the photo-alignment film 2, and the transparent substrate 1 are arranged in this order from the retardation film 13b side. It is done.

A backlight unit 19 serving as a light source is disposed outside the polarizer 12b.
The backlight unit 19 includes a light source, a light guide, a reflection plate, a diffusion sheet, and a viewing angle adjustment sheet. Examples of the light source include electroluminescence, a cold cathode tube, a hot cathode tube, a light emitting diode (LED), a laser light source, and a mercury lamp. In addition, the type of the polarizing film can be selected in accordance with the characteristics of such a light source.

  When the liquid crystal display device 10 is a transmissive liquid crystal display device, white light emitted from a light source in the backlight unit 19 is incident on the light guide, changed in path by a reflector, and diffused by a diffusion sheet. Yes. The diffused light is adjusted to have a desired directivity by the viewing angle adjusting sheet, and then enters the polarizer 12b from the backlight unit 19.

  Of the incident light that is non-polarized light, only one linearly polarized light passes through the polarizer 12b of the liquid crystal panel. This linearly polarized light is converted into circularly polarized light or elliptically polarized light by the retardation layer 13b, and sequentially passes through the substrate 14b, the pixel electrode 22 and the like to reach the liquid crystal layer 17.

  Here, depending on the presence or absence of a potential difference between the pixel electrode 22 and the transparent electrode 16 facing the pixel electrode 22, the alignment state of the liquid crystal molecules contained in the liquid crystal layer 17 changes, and the luminance of the light emitted from the liquid crystal display device 10 is controlled. Is done. When the liquid crystal layer 17 is in an alignment state in which the polarized light is converted and transmitted, the polarized light is transmitted through the liquid crystal layer 17 and the transparent electrode 16, and light in a specific wavelength range is transmitted through the color filter 15 and the polarizer 12a. Therefore, the liquid crystal display device displays the color determined by the color filter brightest.

  Conversely, when the liquid crystal layer 17 is in an alignment state that transmits polarized light as it is, the light transmitted through the liquid crystal layer 17, the transparent electrode 16, and the color filter 15 is absorbed by the polarizer 12a. As a result, this pixel displays black. In the intermediate alignment state between these two states, the luminance of light emitted from the liquid crystal display device 10 is also intermediate between the two, and this pixel displays an intermediate color.

  When the present liquid crystal display device 10 is a transflective liquid crystal display device, it is preferable to use a laminate in which a quarter wavelength plate is further laminated on the polarizing film side of the polarizer (circular polarizing plate). At this time, the pixel electrode 22 has a transmissive portion formed of a transparent material and a reflective portion formed of a material that reflects light. In the transmissive portion, an image is displayed in the same manner as in the transmissive liquid crystal display device described above. Is displayed. On the other hand, in the reflection portion, external light is incident on the liquid crystal display device, and circularly polarized light that has passed through the polarizing film passes through the liquid crystal layer 17 by the action of the quarter wave plate further provided in the polarizing film, and the pixel electrode. 22 is reflected and used for display.

  Next, the EL display device 30 using the polarizing film will be described with reference to FIG. When the present polarizing film is used in the present EL display device, it is preferable to use the present polarizing film after making it into a circularly polarizing plate (hereinafter sometimes referred to as “this circularly polarizing plate”). There are two embodiments of this circularly polarizing plate. Therefore, before describing the configuration of the EL display device 30 and the like, two embodiments of the circularly polarizing plate will be described with reference to FIG.

  FIG. 7A is a schematic diagram illustrating the first embodiment of the circularly polarizing plate 110. The first embodiment is a circularly polarizing plate 110 in which a retardation layer (retardation film) 4 is further provided on the polarizing film 3 in the polarizer 100. FIG. 7B is a schematic diagram showing a second embodiment of the circularly polarizing plate 110. In the second embodiment, a transparent substrate 1 (retardation film 4) to which a phase difference is imparted in advance is used as the transparent substrate 1 used when producing the polarizer. This circular polarizing plate 110 itself has the function as the retardation layer 4.

The circular polarizing plate including the polarizing film is preferably the second embodiment of the circular polarizing plate described above because the configuration is simple, and in this case, a quarter wavelength plate is used as the transparent substrate. Further, it is preferable that a quarter wavelength plate is used as the transparent substrate and the following requirements (A1) and (A2) are satisfied.
(A1) The angle formed by the absorption axis of the polarizing film and the slow axis of the quarter-wave plate is approximately 45 °;
(A2) The value of the front retardation of the ¼ wavelength plate measured with light having a wavelength of 550 nm is in the range of 100 to 150 nm.

  Here, a manufacturing method of the present circularly polarizing plate 110 will be described. As described above, the second embodiment of the present circularly polarizing plate 110 is a transparent substrate 1 that has been previously provided with retardation as the transparent substrate 1 in the present manufacturing method for manufacturing the polarizer 100, that is, a retardation film. It can manufacture by using. 1st Embodiment of this circularly-polarizing plate 110 should just form the retardation layer 4 by bonding the retardation film on this polarizing film 3 manufactured by this manufacturing method B. FIG. In addition, when the present polarizer 100 is manufactured in the form of the second roll 220 by the present manufacturing method B, the present polarizer 100 is unwound from the second roll 220, cut into a predetermined size, and then cut. Although the form which bonds a retardation film to this made polarizer 100 may be sufficient, a shape is a film form and a long form by preparing the 3rd roll by which retardation film is wound up by the core. The circularly polarizing plate 110 can also be manufactured continuously.

A method for continuously manufacturing the first embodiment of the circularly polarizing plate 110 will be described with reference to FIG. Such a manufacturing method includes:
The step of continuously unwinding the polarizer 100 from the second roll 220 and unwinding the retardation film continuously from the third roll 230 on which the retardation film is wound,
The circularly polarizing plate 110 is formed by continuously laminating the polarizing film provided on the polarizer 100 unwound from the second roll 220 and the retardation film unwound from the third roll. Forming, and
The present circular polarizing plate 110 thus formed is wound around the fourth core 240A to obtain the fourth roll 240.

  As mentioned above, although the manufacturing method of 1st Embodiment of this circularly-polarizing plate 110 was demonstrated, when bonding this polarizing film 3 in the polarizer 100 and retardation film, using an appropriate adhesive, The polarizing film 3 and the retardation film may be bonded via an adhesive layer formed from the adhesive.

Next, the EL display device including the circular polarizing plate 110 will be described with reference to FIG. 6 again.
In the EL display device 30, an organic functional layer 36 that is a light source and a cathode electrode 37 are laminated on a substrate 33 on which a pixel electrode 35 is formed. A circularly polarizing plate 31 is disposed on the opposite side of the organic functional layer 36 across the substrate 33, and the circularly polarizing plate 110 is used as the circularly polarizing plate 31. By applying a positive voltage to the pixel electrode 35 and a negative voltage to the cathode electrode 37 and applying a direct current between the pixel electrode 35 and the cathode electrode 37, the organic functional layer 36 emits light. The organic functional layer 36 that is a light emitting source 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 (this circularly polarizing plate 110). Although the organic EL display device having the organic functional layer 36 will be described, the present invention may be applied to an inorganic EL display device having an inorganic functional layer.

  In order to manufacture the EL display device 30, first, the thin film transistor 40 is formed in a desired shape on the substrate 33. Then, an interlayer insulating film 34 is formed, and then a pixel electrode 35 is formed by sputtering and patterned. Thereafter, the organic functional layer 36 is laminated.

  Next, the circularly polarizing plate 31 (the present circularly polarizing plate 110) is provided on the surface of the substrate 33 opposite to the surface on which the thin film transistor 40 is provided.

  When the circularly polarizing plate 110 is used as the circularly polarizing plate 31, the stacking order will be described with reference to an enlarged view of a portion C surrounded by a dotted line in FIG. When the circular polarizing plate 110 is used as the circular polarizing plate 31, the retardation layer 4 in the circular polarizing plate 110 is disposed on the substrate 33 side. (C1) in FIG. 9 is an enlarged view in which the first embodiment of the circularly polarizing plate 110 is used as the circularly polarizing plate 31, and (C2) in FIG. 9 shows the second embodiment of the circularly polarizing plate 110. 3 is an enlarged view used as a circularly polarizing plate 31. FIG.

  Next, members other than the main circularly polarizing plate 31 (the main circularly polarizing plate 110) of the EL display device 30 will be described.

Examples of the substrate 33 include a sapphire glass substrate, a quartz glass substrate, a soda glass substrate and a ceramic substrate such as alumina; a metal substrate such as copper; a plastic substrate.
Although not shown, a heat conductive film may be formed on the substrate 33. Examples of the thermally conductive film include a diamond thin film (DLC or the like). When the pixel electrode 35 is a reflection type, light is emitted in the opposite direction to the substrate 33. Therefore, not only a transparent material but also a non-permeable material such as stainless steel can be used. A single substrate may be formed, or a plurality of substrates may be bonded together with an adhesive to form a laminated substrate. Further, these substrates are not limited to plate-like ones, and may be films.

  For example, a polycrystalline silicon transistor may be used as the thin film transistor 40. 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. The size of the pixel electrode 35 is about 20 μm × 20 μm to 300 μm × 300 μm.

  On the substrate 33, wiring electrodes of the thin film transistor 40 are provided. The wiring electrode has a low resistance and has a function of suppressing resistance by being electrically connected to the pixel electrode 35. In general, the wiring electrode includes Al, Al and transition metals (except for Ti), Ti or Those containing any one or more of titanium nitride (TiN) are used.

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 of an inorganic material such as silicon oxide such as SiO ₂ or silicon nitride, a silicon oxide layer formed by SOG (spin-on-glass), a photoresist, a polyimide. In addition, any film may be used as long as it has insulating properties, such as a coating film of a resin material such as an acrylic resin.

  A rib 41 is formed on the interlayer insulating film 34. The rib 41 is disposed in the peripheral portion (between adjacent pixels) of the pixel electrode 35. Examples of the material of the rib 41 include acrylic resin and polyimide resin. The thickness of the 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 that is a transparent electrode, an organic functional layer 36 that is a light emission source, and a cathode electrode 37 will be described. Each of the organic functional layers 36 includes at least one hole transport layer and a light emitting layer, and sequentially includes, for example, an electron injection transport layer, a light emitting layer, a hole transport layer, and a hole injection layer.

Examples of the pixel electrode 35 include ITO (tin-doped indium oxide), IZO (zinc-doped indium oxide), IGZO, ZnO, SnO _2, and In ₂ O _3, and ITO and IZO are particularly preferable. The pixel electrode 35 only needs to have a certain thickness or more that can sufficiently inject holes, 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 and Xe, or a mixed gas thereof may be used.

As a constituent material of the cathode electrode 37, for example, metal elements such as K, Li, Na, Mg, La, Ce, Ca, Sr, Ba, Al, Ag, In, Sn, Zn, and Zr may be used. In order to improve the operational stability of the electrode, it is preferable to use a two-component or three-component alloy system selected from the exemplified metal elements. Examples of the alloy system include 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 to 20 at%) is preferable.
The cathode electrode 37 is formed by vapor deposition or sputtering. The thickness of the cathode electrode 37 is 0.1 nm or more, preferably 1 to 500 nm.

The hole injection layer has a function of facilitating the injection of holes from the pixel electrode 35, and the hole transport layer has a function of transporting holes and a function of blocking electrons. Also called transport layer.
The thickness of the light-emitting layer, the combined thickness of the hole injection layer and the hole transport layer, and the thickness of the electron injection / transport layer are not particularly limited and may vary depending on the formation method, but should be about 5 to 100 nm. Is preferred. Various organic compounds can be used for the hole injection layer and the hole transport layer. For the formation of the hole injecting and transporting layer, the light emitting layer and the electron injecting and transporting layer, a vacuum deposition method can be used in that a homogeneous thin film can be formed.

  Examples of the organic functional layer 36 that is a light emission source include those that use light emission (fluorescence) from singlet excitons, those that use light emission (phosphorescence) from triplet excitons, and those from singlet excitons. Including those using luminescence (fluorescence) and those using triplet excitons (phosphorescence), those formed with organic matter, those formed with organic matter and those formed with inorganic matter , A high molecular material, a low molecular material, a high molecular material and a low molecular material, and the like can be used. However, the present invention is not limited thereto, and an organic functional layer 36 using various known materials for EL elements can be used for the EL display device 30.

  A desiccant 38 is disposed in the space between the cathode electrode 37 and the sealing lid 39. This is because the organic functional layer 36 is vulnerable to humidity. Moisture is absorbed by the desiccant 38 to prevent the organic functional layer 36 from deteriorating.

FIG. 10 is a schematic diagram showing a cross-sectional configuration of another aspect of the EL display device 30. This EL display device 30 has a sealing structure using a thin film sealing film 42, and can also obtain emitted light from the opposite surface of the array substrate.
As the thin film sealing film 42, it is preferable to use a DLC film obtained by evaporating DLC (diamond-like carbon) on a film of an electrolytic capacitor. The DLC film has a characteristic that moisture permeability is extremely poor, and has high moisture-proof performance. Further, a DLC film or the like may be directly deposited on the surface of the cathode electrode 37. Further, the thin film sealing film 42 may be formed by laminating a resin thin film and a metal thin film in multiple layers.

  As described above, the novel polarizing film (the present polarizing film) according to the present invention and the novel display device (the present liquid crystal display device and the present EL display device) including the present polarizing film are provided.

Finally, a projection type liquid crystal display device using this polarizing film will be described.
FIG. 11 is a schematic view showing a projection type liquid crystal display device using the present polarizing film.
This polarizing film is used as the polarizer 142 and / or the polarizer 143 of the projection type liquid crystal display device.

  A light bundle emitted from a light source (for example, a high-pressure mercury lamp) 111 that is a light emission source first passes through a first lens array 112, a second lens array 113, a polarization conversion element 114, and a superimposing lens 115. The luminance is uniformed and polarized in the cross section of the anti-beam bundle.

  Specifically, the light bundle emitted from the light source 111 is divided into a number of minute light bundles by the first lens array 112 in which minute lenses 112a are formed in a matrix. The second lens array 113 and the superimposing lens 115 are provided so that each of the divided light bundles irradiates the entire three liquid crystal panels 140R, 140G, and 140B that are illumination targets. The liquid crystal panel incident side surface has almost uniform illuminance as a whole.

  The polarization conversion element 114 is configured by a polarization beam splitter array, and is disposed between the second lens array 113 and the superimposing lens 115. As a result, random polarized light from the light source is converted into polarized light having a specific polarization direction in advance, thereby reducing the amount of light loss in the incident side polarizer described later, thereby improving the screen brightness.

  The light whose brightness is uniformed and polarized as described above is sequentially converted into the red channel, the green channel, and the blue channel by the dichroic mirrors 121, 123, and 132 for separation into the three primary colors of RGB via the reflection mirror 122. These are separated and enter the liquid crystal panels 140R, 140G, and 140B, respectively.

  In the liquid crystal panels 140R, 140G, and 140B, a polarizer 142 is disposed on the incident side, and a polarizer 143 is disposed on the exit side. This polarizing film can be used for the polarizer 142 and the polarizer 143.

  The polarizer 142 and the polarizer 143 arranged in the RGB optical paths are arranged so that the absorption axes thereof are orthogonal to each other. Each of the liquid crystal panels 140R, 140G, and 140B arranged in each optical path has a function of converting a polarization state controlled for each pixel by an image signal into a light amount.

  The polarizer 100 is useful as a polarizer having excellent durability even in an optical path such as a blue channel, a green channel, and a red channel by selecting a type of dichroic dye suitable for the corresponding channel.

  An optical image created by transmitting incident light with different transmittance for each pixel according to the image data of the liquid crystal panels 140R, 140G, and 140B is synthesized by the cross dichroic prism 150, and is projected by the projection lens 170 to the screen 180. Is enlarged and projected.

  Electronic paper is displayed by molecules such as optical anisotropy and dye molecule orientation, displayed by particles such as electrophoresis, particle movement, particle rotation, and phase change, and one end of the film moves And the like, those displayed by molecular color development / phase change, those displayed by light absorption of molecules, and those displayed by self-emission by combining electrons and holes. More specifically, microcapsule type electrophoresis, horizontal movement type electrophoresis, vertical movement type electrophoresis, spherical twist ball, magnetic twist ball, cylindrical twist ball method, charged toner, electronic powder fluid, magnetophoretic type, magnetic thermosensitive Formula, electrowetting, light scattering (transparency / translucency change), cholesteric liquid crystal / photoconductive layer, cholesteric liquid crystal, bistable nematic liquid crystal, ferroelectric liquid crystal, dichroic dye / liquid crystal dispersion type, movable film, leuco dye And color erasing, photochromic, electrochromic, electrodeposition, flexible organic EL, and the like. The electronic paper may be used not only for personal use of text and images but also for advertisement display (signage) or the like. According to this polarizing film, the thickness of the electronic paper can be reduced.

  As a stereoscopic display device, for example, a method of arranging different retardation films alternately like a micropole method has been proposed (Japanese Patent Laid-Open No. 2002-185983). However, when this polarizing film is used, printing, inkjet, Since patterning is easy by photolithography or the like, the manufacturing process of the display device can be shortened, and a retardation film becomes unnecessary.

  Hereinafter, the present invention will be described in more detail with reference to examples. Unless otherwise specified, “%” and “parts” in the examples are% by mass and parts by mass.

  In this example, the following dichroic dye (1) was used.

Production of Compound (1-1) (Compound Represented by (1-1) below)

式（１Ｂ）で表される化合物［化合物（１Ｂ）］５．００ｇ、４−ヒドロキシ安息香酸エチル４．６３ｇ、ジメチルアミノピリジン（ＤＭＡＰ）０．２３ｇ及びクロロホルム２５ｇを混合し、遮光・窒素雰囲気下、５℃で１０分間攪拌した。得られた混合液に、ジイソプロピルカルボジイミド（ＩＰＣ）２．５８ｇを５分間かけて滴下し、さらに４時間攪拌した。得られた反応液にメタノール７５ｇ加えて晶析し結晶を濾取した。結晶をさらに同量のメタノールで洗浄後、真空乾燥することにより、化合物（１−１）を６．７８ｇ得た。収率は、化合物（１Ｂ）基準で８７％であった。 Compound (1-1) was synthesized according to the following scheme.

5.00 g of the compound represented by the formula (1B) [compound (1B)], 4.63 g of ethyl 4-hydroxybenzoate, 0.23 g of dimethylaminopyridine (DMAP), and 25 g of chloroform were mixed, and protected from light and in a nitrogen atmosphere. Stir at 5 ° C. for 10 minutes. To the obtained liquid mixture, 2.58 g of diisopropylcarbodiimide (IPC) was added dropwise over 5 minutes, and the mixture was further stirred for 4 hours. The obtained reaction solution was crystallized by adding 75 g of methanol, and the crystals were collected by filtration. The crystals were further washed with the same amount of methanol and then vacuum-dried to obtain 6.78 g of compound (1-1). The yield was 87% based on the compound (1B).

¹ H-NMR (CDCl ₃ ) of the compound (1-1): δ (ppm) 1.41 (t, 3H), 3.12 (s, 6H), 4.40 (m, 2H), 6.76 (M, 2H), 7.33 (m, 2H), 7.93 (dd, 4H), 8.15 (m, 2H), 8.30 (m, 2H).

Production of compound (1-7) (compound represented by (1-7) below)

化合物（１Ｂ）５．００g、４−ブチルオキシフェノール４．６３ｇ、ＤＭＡＰ０．２３ｇ及びクロロホルム２５ｇを混合し、遮光・窒素雰囲気下、５℃で１０分間攪拌した。
得られた混合液に、ＩＰＣ２．５８ｇを５分間かけて滴下し、さらに４時間攪拌した。得られた反応液にメタノール７５ｇ加えて晶析し結晶を濾取した。結晶を５０ｇのジメチルアセトアミドに溶解させ、不溶物をセライト濾過した。濾液を回収して水で晶析した。得られた結晶をさらに５０ｇのテトラヒドロフランに溶解し不溶物を濾過で除去後、ヘプタンを加えて晶析し、真空乾燥することにより、化合物（１−７）を４．６６ｇ得た。収率は、化合物（１Ｂ）基準で６０％であった。 Compound (1-7) was synthesized according to the following scheme.

Compound (1B) (5.00 g), 4-butyloxyphenol (4.63 g), DMAP (0.23 g), and chloroform (25 g) were mixed, and the mixture was stirred at 5 ° C. for 10 minutes in a light-shielded and nitrogen atmosphere.
To the obtained mixed solution, 2.58 g of IPC was dropped over 5 minutes, and the mixture was further stirred for 4 hours. The obtained reaction solution was crystallized by adding 75 g of methanol, and the crystals were collected by filtration. The crystals were dissolved in 50 g of dimethylacetamide, and the insoluble material was filtered through celite. The filtrate was collected and crystallized with water. The obtained crystals were further dissolved in 50 g of tetrahydrofuran, insoluble matters were removed by filtration, and heptane was added for crystallization, followed by vacuum drying to obtain 4.66 g of compound (1-7). The yield was 60% based on the compound (1B).

¹ H-NMR (CDCl ₃ ) of the compound (1-7): δ (ppm) 0.99 (t, 3H), 1.45 (m, 2H), 1.78 (m, 2H), 3.12 (S, 6H), 3.98 (t, 2H), 6.77 (m, 2H), 6.93 (m, 2H), 7.15 (m, 2H), 7.92 (dd, 4H) 8.29 (dd, 2H).

In this example, the following polymerizable liquid crystal compound was used.
Compound (4-6) (compound represented by the following formula (4-6))
Compound (4-6) was prepared according to Lub et al. Recl. Trav. Chim. It was synthesized by the method described in Pays-Bas, 115, 321-328 (1996).

(Measurement of phase transition temperature)
The phase transition temperature of the compound (4-6) was confirmed by determining the phase transition temperature of the film made of the compound (4-6). The operation is as follows.
A film made of the compound (4-6) was formed on the glass substrate on which the alignment film was formed, and the phase transition temperature was confirmed by texture observation with a polarizing microscope (BX-51, manufactured by Olympus) while heating. The film made of the compound (4-6) is heated to 120 ° C., and when cooled, the film transitions to the nematic phase at 112 ° C., the phase transition to the smectic A phase at 110 ° C., and the smectic B phase at 94 ° C. Phase transition.

Compound (4-8) (compound represented by the following formula (4-8))
Compound (4-8) was synthesized with reference to the synthesis method of Compound (4-6) described above.

(Measurement of phase transition temperature)
The phase transition temperature of compound (4-8) was confirmed in the same manner as in the measurement of the phase transition temperature of compound (4-6). Compound (4-8) was heated to 140 ° C., and at the time of temperature decrease, the phase transitioned to the nematic phase at 131 ° C., the phase transition to the smectic A phase at 80 ° C., and the phase transition to the smectic B phase at 68 ° C.

Compound (4-22) (Compound represented by the following formula (4-22))
Compound (4-22) was synthesized with reference to a synthesis method described in Japanese Patent No. 4719156.

(Measurement of phase transition temperature)
The phase transition temperature of compound (4-22) was confirmed in the same manner as in the measurement of the phase transition temperature of compound (4-6). Compound (4-22) was heated to 140 ° C., and at the time of cooling, the phase transition was made to the nematic phase at 106 ° C., the phase transition to the smectic A phase at 103 ° C., and the phase transition to the smectic B phase at 86 ° C.

Compound (4-25) (compound represented by the following formula (4-25))
Compound (4-25) was synthesized with reference to a synthesis method described in Japanese Patent No. 4719156.

(Measurement of phase transition temperature)
The phase transition temperature of compound (4-25) was confirmed in the same manner as in the measurement of the phase transition temperature of compound (4-6). Compound (4-25) was heated to 140 ° C., and at the time of cooling, the phase transition to a nematic phase at 119 ° C., a phase transition to a smectic A phase at 100 ° C., and a phase transition to a smectic B phase at 77 ° C.

Example 1 [Preparation of Composition for Forming Polarizing Film (A)]
The following components were mixed and stirred at 80 ° C. for 1 hour to obtain a polarizing film forming composition (A). The “compound (1-7)” of the dichroic dye used here means the compound represented by the above formula (1-7), and the compounds used as other dichroic dyes also have the formula number. According to The same applies to the following.
Polymerizable liquid crystal compound; Compound (4-6) 75 parts
Compound (4-8) 25 parts Dichroic dye; Compound (1-7) 3.0 parts
Compound (2-17) 2.5 parts
Compound (2-29) 1.5 parts
Compound (2-32) 2.0 parts polymerization initiator;
2-dimethylamino-2-benzyl-1- (4-morpholinophenyl) butan-1-one (Irgacure 369; manufactured by Ciba Specialty Chemicals) 6 parts Leveling agent;
Polyacrylate compound (BYK-361N; manufactured by BYK-Chemie)
1.2 parts Solvent; Toluene 250 parts

1. X-ray diffraction measurement On a glass substrate, a 2% by weight aqueous solution (composition for forming an alignment layer) of polyvinyl alcohol (polyvinyl alcohol 1000 completely saponified type, manufactured by Wako Pure Chemical Industries, Ltd.) was applied by spin coating and dried. Thereafter, a film having a thickness of 100 nm was formed. Subsequently, an alignment layer was formed by subjecting the surface of the obtained film to a rubbing treatment. The rubbing process uses a semi-automatic rubbing apparatus (trade name: LQ-008, manufactured by Joyo Engineering Co., Ltd.) and a push-in amount of 0.15 mm using a cloth (trade name: YA-20-RW, manufactured by Yoshikawa Chemical Co., Ltd.). , Under the conditions of 500 rpm and 16.7 mm / s. The polarizing film-forming composition (A) is applied onto the alignment film thus prepared by spin coating, heated and dried on a 120 ° C. hot plate for 1 minute, and then quickly cooled to room temperature. A dry film was formed on the alignment layer. Next, by using a UV irradiation apparatus (SPOT CURE SP-7; manufactured by Ushio Electric Co., Ltd.), the ultraviolet ray is irradiated to the dry film at an exposure amount of 2000 mJ / cm ² (365 nm standard), thereby polymerization contained in the dry film. The polymerizable liquid crystal compound was polymerized while maintaining the liquid crystal state of the polymerizable liquid crystal compound, and a polarizing film was formed from the dried film. When the thickness of the polarizing film at this time was measured with a laser microscope (OLS3000 manufactured by Olympus Corporation), it was 1.7 μm.
The X-ray diffraction measurement was similarly performed on this polarizing film using an X-ray diffractometer X'Pert PRO MPD (Spectris Co., Ltd.). As a result, the peak half-width (FWHM) was around 2θ = 20.2 °. ) = A sharp diffraction peak (Bragg peak) of about 0.17 ° was obtained. In addition, the same result was obtained even when incident from the rubbing vertical direction. The order period (d) obtained from the peak position was about 4.4 mm, and it was confirmed that a structure reflecting a high-order smectic phase was formed.

2. Preparation of photo-alignment film on transparent film Using triacetyl cellulose film (KC8UX2M, manufactured by Konica Minolta Co., Ltd.) as a transparent substrate, 5% of photo-alignment polymer represented by the following formula (3) is dissolved in toluene. The solution was applied by a bar coating method and dried at 120 ° C. to obtain a dry film. The dried film was irradiated with polarized UV to obtain a photo-alignment film. The polarized UV treatment was performed using a UV irradiation apparatus (SPOT CURE SP-7; manufactured by USHIO INC.) Under the condition that the intensity measured at a wavelength of 365 nm was 100 mJ.

3. Preparation of Polarizing Film On the film with the photo-alignment film obtained as described above, the polarizing film-forming composition (A) was applied by the bar coating method (# 5 17 mm / s) and then dried in a 120 ° C. drying oven. After heat drying for 1 minute, it was cooled to room temperature. Next, using a UV irradiation apparatus (SPOT CURE SP-7; manufactured by USHIO INC.), The layer formed from the polarizing film forming composition is irradiated with an ultraviolet ray having an exposure amount of 2000 mJ / cm ² (365 nm standard). Thus, the polymerizable liquid crystal compound contained in the dry film was polymerized while maintaining the liquid crystal state of the polymerizable liquid crystal compound, and a polarizing film was formed from the dry film. When the film thickness of the polarizing film at this time was measured with a laser microscope (OLS3000 manufactured by Olympus Corporation), it was 1.6 μm. What was obtained in this way is a polarizer containing a polarizing film and a transparent substrate.

4). Measurement of degree of polarization, transmittance and hue In order to confirm the usefulness of the polarizer, visibility correction polarization degree, visibility correction transmittance, chromaticity a * value, chromaticity b * value, orthogonal a ^{* And} orthogonal b ^* were measured.
Set the transmittance axis direction transmittance (T ¹ ) and absorption axis direction transmittance (T ² ) in the wavelength range of 380 nm to 780 nm, and set a folder with a polarizer on a spectrophotometer (Shimadzu Corporation UV-3150) The measurement was performed by the double beam method using the same apparatus. The folder was provided with a mesh that cuts the light amount by 50% on the reference side. Using the following formulas (Formula 1) and (Formula 2), single transmittance and polarization degree at each wavelength are calculated, and further, visibility correction is performed using a 2 degree field of view (C light source) of JIS Z 8701. Single transmittance (Ty) and visibility correction polarization degree (Py) were calculated. Further, the chromaticity a ^* and b ^* in the L ^* a ^* b ^* (CIE) color system was calculated from the single transmittance measured in the same manner using the color matching function of the C light source. Further, the orthogonal a ^* and orthogonal b ^* in the L ^* a ^* b ^* (CIE) color system were calculated from the orthogonal transmittance measured in the same manner using the color matching function of the C light source. As the chromaticity a ^* , chromaticity b ^* , orthogonal a ^*, and orthogonal b ^* are closer to 0, it can be determined that the hue is a neutral hue. These results are shown in Table 4.
Single transmittance (%) = (T1 + T2) / 2 (Formula 1)
Degree of polarization (%) = (T1−T2) / (T1 + T2) × 100 (Expression 2)

Example 2
1. Production of Polarizing Film A polarizing film was produced in the same manner as in Example 1 except that the wire width and coating speed of the bar coater bar were changed (# 715 mm / s). When the film thickness of the polarizing film at this time was measured with a laser microscope (OLS3000 manufactured by Olympus Corporation), it was 1.8 μm.
2. Measurement of polarization degree, transmittance, and hue Visibility corrected single transmittance (Ty) and visibility corrected polarization degree (Py) and chromaticity a ^* , chromaticity b ^* , orthogonal a ^*, and orthogonal b ^{* of the} produced polarizing film Table 4 shows the results obtained by measuring in the same manner as in Example 1.

Example 3 [Preparation of composition for forming polarizing film (B)]
The following components were mixed and stirred at 80 ° C. for 1 hour to obtain a polarizing film forming composition (B).
Polymerizable liquid crystal compound; Compound (4-22) 75 parts
Compound (4-25) 25 parts Dichroic dye; Compound (1-1) 3.0 parts
Compound (2-15) 2.5 parts
Compound (2-20) 1.2 parts
Compound (2-33) 2.5 parts polymerization initiator;
2-dimethylamino-2-benzyl-1- (4-morpholinophenyl) butan-1-one (Irgacure 369; manufactured by Ciba Specialty Chemicals) 6 parts Leveling agent;
Polyacrylate compound (BYK-361N; manufactured by BYK-Chemie)
1.2 parts Solvent; Toluene 250 parts

1. Production of Polarizing Film The composition for forming a polarizing film (A) was changed to the composition for forming a polarizing film (B), and the wire width and coating speed of the bar coater bar were changed (# 5 25 mm / s). A polarizing film was produced in the same manner as in Example 1. When the film thickness of the polarizing film at this time was measured with a laser microscope (OLS3000 manufactured by Olympus Corporation), it was 1.7 μm.
2. Measurement of polarization degree, transmittance, and hue Visibility corrected single transmittance (Ty) and visibility corrected polarization degree (Py) and chromaticity a ^* , chromaticity b ^* , orthogonal a ^*, and orthogonal b ^{* of the} produced polarizing film Table 4 shows the results obtained by measuring in the same manner as in Example 1.

Example 4
1. Production of Polarizing Film A polarizing film was produced in the same manner as in Example 3, except that the wire width and coating speed of the bar coater bar were changed (# 720 20 mm / s). The thickness of the polarizing film at this time was measured with a laser microscope (OLS3000 manufactured by Olympus Corporation), and was 2.0 μm.
2. Measurement of polarization degree, transmittance, and hue Visibility corrected single transmittance (Ty) and visibility corrected polarization degree (Py) and chromaticity a ^* , chromaticity b ^* , orthogonal a ^*, and orthogonal b ^{* of the} produced polarizing film Table 4 shows the results obtained by measuring in the same manner as in Example 1.

Example 5
1. Production of Black Polarizing Film A polarizing film was produced in the same manner as in Example 3, except that the wire width and coating speed of the bar coater bar were changed (# 5 50 mm / s). When the film thickness of the polarizing film at this time was measured with a laser microscope (OLS3000 manufactured by Olympus Corporation), it was 2.2 μm.
2. Measurement of polarization degree, transmittance, and hue Visibility corrected single transmittance (Ty) and visibility corrected polarization degree (Py) and chromaticity a ^* , chromaticity b ^* , orthogonal a ^*, and orthogonal b ^{* of the} produced polarizing film Table 4 shows the results obtained by measuring in the same manner as in Example 1.

Example 6 [Preparation of composition for forming polarizing film (C)]
The following components were mixed and stirred at 80 ° C. for 1 hour to obtain a polarizing film forming composition (C).
Polymerizable liquid crystal compound; Compound (4-6) 75 parts
Compound (4-8) 25 parts Dichroic dye; Compound (1-1) 3.6 parts
Compound (2-15) 3.0 parts
Compound (2-18) 1.5 parts
Compound (2-27) 2.0 parts
Compound (2-32) 1.5 parts Polymerization initiator;
2-dimethylamino-2-benzyl-1- (4-morpholinophenyl) butan-1-one (Irgacure 369; manufactured by Ciba Specialty Chemicals) 6 parts Leveling agent;
Polyacrylate compound (BYK-361N; manufactured by BYK-Chemie)
1.2 parts Solvent; Toluene 250 parts

1. Production of Polarizing Film The composition for forming a polarizing film (A) was changed to the composition for forming a polarizing film (C), and the wire width and coating speed of the bar coater bar were changed (# 720 20 mm / s). A polarizing film was produced in the same manner as in Example 1. The thickness of the polarizing film at this time was measured with a laser microscope (OLS3000 manufactured by Olympus Corporation), and was 2.0 μm.

2. Measurement of polarization degree, transmittance, and hue Visibility corrected single transmittance (Ty) and visibility corrected polarization degree (Py) and chromaticity a ^* , chromaticity b ^* , orthogonal a ^*, and orthogonal b ^{* of the} produced polarizing film Table 4 shows the results obtained by measuring in the same manner as in Example 1.

Example 7
1. Production of Black Polarizing Film A polarizing film was produced in the same manner as in Example 6 except that the wire width and coating speed of the bar coater bar were changed (# 5 50 mm / s). When the film thickness of the polarizing film at this time was measured with a laser microscope (OLS3000 manufactured by Olympus Corporation), it was 2.2 μm.

2. Measurement of polarization degree, transmittance, and hue Visibility corrected single transmittance (Ty) and visibility corrected polarization degree (Py) and chromaticity a ^* , chromaticity b ^* , orthogonal a ^*, and orthogonal b ^{* of the} produced polarizing film Table 4 shows the results obtained by measuring in the same manner as in Example 1.

Comparative Example 1
1. Production of iodine-PVA polarizing plate A polyvinyl alcohol film having an average degree of polymerization of about 2,400 and a saponification degree of 99.9 mol% or more and a thickness of 75 μm was uniaxially stretched about 5 times in a dry manner, and further maintained a tension state. The sample was immersed in pure water at 60 ° C. for 1 minute, and then immersed in an aqueous solution having a mass ratio of iodine / potassium iodide / water of 0.1 / 5/100 at 28 ° C. for 60 seconds. Then, it was immersed in an aqueous solution having a mass ratio of potassium iodide / boric acid / water of 810.5 / 7.5 / 100 at 72 ° C. for 300 seconds. Subsequently, it was washed with pure water at 10 ° C. for 5 seconds and then dried at 80 ° C. for 3 minutes to obtain a polarizer in which iodine was adsorbed and oriented on a polyvinyl alcohol resin film.

2. Measurement of degree of polarization, transmittance, hue Humidity correction single transmittance (Ty) and visibility correction polarization degree (Py) and chromaticity a ^* , chromaticity b ^* , orthogonal a ^* and orthogonal b ^{* of the} prepared polarizer Table 4 shows the results obtained by measuring in the same manner as in Example 1.

  As can be seen from Table 4, the polarizing films of Examples 1 to 7 were all thinner than the conventional iodine-PVA polarizer. Moreover, all of the polarizing films of Examples 1 to 7 showed neutral hue.

Example 8
1. Preparation of photo-alignment film on retardation film A retardation film (uniaxially stretched film WRF-S (modified polycarbonate resin)) instead of a triacetyl cellulose film (KC8UX2M, manufactured by Konica Minolta Co., Ltd.) as a transparent substrate Using a bar coating method, a solution in which 5% of the photo-alignment polymer represented by the formula (3) is dissolved in cyclopentanone using a phase difference value of 137.5 nm, a thickness of 50 μm, manufactured by Teijin Chemicals Ltd. And dried at 120 ° C. to obtain a dry film. The dried film was irradiated with polarized UV to obtain a photo-alignment film. The polarized UV treatment was performed using a UV irradiation apparatus (SPOT CURE SP-7; manufactured by USHIO INC.) Under the condition that the intensity measured at a wavelength of 365 nm was 100 mJ. At this time, the irradiation direction of the polarized UV was performed so as to be 45 ° with respect to the slow axis of the retardation film.

2. Preparation of Circular Polarizing Plate A polarizing film-forming composition (C) was applied on the photo-alignment film of the produced retardation film with a photo-alignment film by the bar coating method (# 7 20 mm / s), and placed in a 120 ° C. drying oven. For 1 minute and then cooled to room temperature. Next, using a UV irradiation apparatus (SPOT CURE SP-7; manufactured by USHIO INC.), The layer formed from the polarizing film forming composition is irradiated with an ultraviolet ray having an exposure amount of 2000 mJ / cm ² (365 nm standard). Thus, the polymerizable liquid crystal compound contained in the dry film was polymerized while maintaining the liquid crystal state of the polymerizable liquid crystal compound, and a polarizing film was formed from the dry film to produce a circularly polarizing plate. The thickness of the polarizing film at this time was measured with a laser microscope (OLS3000 manufactured by Olympus Corporation), and was 2.0 μm.

3. Confirmation of anti-reflective performance When the retardation film side of the obtained circularly polarizing plate was bonded to the aluminum metal plate via an adhesive, the metallic luster observed with the aluminum metal plate alone disappeared, and a uniform black color was observed. An indication was obtained. Thus, it turns out that the circularly-polarizing plate produced from this polarizing film has a favorable antireflection characteristic.

  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.

DESCRIPTION OF SYMBOLS 1 Transparent base material 2 Photo-alignment film 3 This polarizing film 4 Retardation layer 100 This polarizer 110 This circularly-polarizing plate 210 1st roll 210A Core 220 Second roll 220A Core 230 Third roll 230A Core 240 Fourth roll 240A Core 211A, 211B Coating device 212A, 212B Drying furnace 213A Polarized UV irradiation device 213B Light irradiation device 300 Auxiliary roll 10 Liquid crystal display device 11 Surface protective layer 12a, 12b Polarizer 13a, 13b Phase difference layer 14a, 14b Substrate 15 Color Filter 16 Transparent electrode 17 Liquid crystal layer 18 Interlayer insulating film 19 Backlight unit 20 Black matrix 21 Thin film transistor 22 Pixel electrode 23 Spacer 30 EL display device 31 Circular polarizing plate 32 Phase difference film 33 Substrate 34 Interlayer insulating film 35 Pixel electrode 36 Organic functional layer 37 Cathode 3 Desiccant 39 Sealing lid 40 Thin film transistor 41 Rib 42 Thin film sealing film 44 EL display device 111 Light source 112 First lens array 112a Lens 113 Second lens array 114 Polarization conversion element 115 Superimposing lenses 121, 123, 132 Dichroic mirror 122 Reflection mirror 140R, 140G, 140B Liquid crystal panel 142, 143 Polarizer 150 Cross dichroic prism 170 Projection lens 180 Screen

Claims (15)

  A polymer formed from a polymerizable liquid crystal compound, and at least one dichroic dye (1) having an absorption maximum in the wavelength range of 380 to 550 nm when measured for light absorption after being dispersed in the polymer And at least two dichroic dyes (2) having an absorption maximum in the wavelength range of 550 to 700 nm.   The dichroic dye (1) according to claim 1, wherein the dichroic dye (1) has an absorption maximum in a wavelength range of 400 to 550 nm when measured for light absorption by dispersing in a polymer formed from a polymerizable liquid crystal compound. Polarizing film. When the light absorption is measured by dispersing in the polymer, at least two dichroic dyes (2) having an absorption maximum in the wavelength range of 550 to 700 nm are:
When measuring the light absorption by dispersing in the polymer,
A dichroic dye (2-1) having an absorption maximum in a wavelength range of 550 to 600 nm;
The polarizing film according to claim 1 or 2, comprising a dichroic dye (2-2) having an absorption maximum in a wavelength range of 600 to 700 nm.   The polarizing film according to claim 1, wherein the polymerizable liquid crystal compound is a compound exhibiting a smectic liquid crystal phase.   The polarizing film according to claim 1, wherein a Bragg peak is obtained in X-ray diffraction measurement. The polarizing film according to claim 1, wherein the color coordinate a * value and b * value in the L * a * b * color system satisfy the relationship of the following expressions (1F) and (2F).
-3 ≦ chromaticity a * ≦ 3 (1F)
−3 ≦ chromaticity b * ≦ 3 (2F)   The polarizing film according to any one of claims 1 to 6, wherein the dichroic dye (1) and the dichroic dye (2) are azo compounds. Dichroic dye (2)
The polarizing film according to any one of claims 1 to 7, comprising a compound represented by the formula (2).

[In Formula (2),
n is 1 or 2.
Ar ¹ and Ar ³ are each independently a group represented by any one of formulas (AR-1) to (AR-4).

Ar ² is a group represented by formula (AR2-1), formula (AR2-2), or formula (AR2-3).

A ₁ and A ₂ are each independently a group represented by any of formulas (A-1) to (A-9), and * represents a bond.

(Mc is an integer of 0 to 10, and when there are two mcs in the same group, these two mcs are the same or different from each other.)] The dichroic dye (1) is
The polarizing film according to any one of claims 1 to 8, comprising a compound represented by the formula (1).

[In Formula (1),
Y is a group represented by the formula (Y1) or the formula (Y2).

(In the formula, L is an oxygen atom or —NR—, and R is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.)
R ¹ is a group represented by any of the formulas (R ¹ -1) to (R ¹ -3).

(In the formula, ma is an integer of 0 to 10, and when two ma are present in the same group, the two ma are the same or different from each other. * Represents a bond.)
R ² is a group represented by any one of formulas (R ² -1) to (R ² -6).

(Wherein mb is an integer of 0 to 10)]   The polarizer which provides the polarizing film in any one of Claims 1-9 on a transparent base material. It is a manufacturing method of the polarizer according to claim 10,
Preparing a laminate having an alignment film on a transparent substrate;
When the light absorption is measured by dispersing in a polymer liquid crystal compound and a polymer formed from the polymerizable liquid crystal compound on the alignment film of the laminate, the absorption maximum is in a wavelength range of 380 to 550 nm. Applying a composition containing one kind of dichroic dye (1) having, two kinds of dichroic dye (2) having an absorption maximum in a wavelength range of 550 to 700 nm, and a solvent;
And a step of polymerizing the polymerizable liquid crystal compound contained in the composition.   The manufacturing method according to claim 11, wherein the transparent substrate is a plastic substrate, and the alignment film is a photo-alignment film.   A liquid crystal display device comprising the polarizing film according to claim 1. The circularly-polarizing plate which has the polarizing film in any one of Claims 1-9, and (lambda) / 4 layer, and satisfy | fills the requirements of the following (A1) and (A2).
(A1) The angle formed by the absorption axis of the polarizing film and the slow axis of the λ / 4 layer is approximately 45 °;
(A2) The value of the front retardation of the λ / 4 layer measured with 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 claim 14 and an organic EL element.

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