KR20220133851A - Polarizing film, circular polarizing plate and method of producing the same - Google Patents

Abstract

The present invention provides a polarizing film characterized in that film-thinning is easy and the neutral hue of the polarizing film is excellent, a polarizing element containing the polarizing film, and a method of producing the same. The present invention provides a polarizing film, a polarizing element containing the polarizing film, and a method of producing the same, wherein the polarized film comprises: a polymer formed of a polymerizable liquid crystal compound; at least one kind of dichroic dye (1) having a maximum absorption value within the wavelength range of 380-550 nm in the case of measuring light absorption by being dispersed in the polymer; and at least two kinds of dichroic dye (2) having the maximum absorption within the wavelength range of 550-700 nm. It is preferable for the dichroic dye (2) to contain: dichroic dyes absorptive within the wavelength range of 550-600 nm; and dichroic dyes absorptive within the wavelength range of 600-700 nm.

Description

Polarizing film, circularly polarizing plate and manufacturing method thereof

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

Since the polarizer used in the liquid crystal display has both high transmittance and polarization degree, a film (polarizing film) made of polyvinyl alcohol (iodine-dyed PVA) dyed with a dichroic dye such as iodine and stretched is used universally. have. For example, Patent Document 1 describes a polarizing film made of iodine dyed PVA.

Patent Document 1: Japanese Patent Laid-Open No. 7-142170

However, a polarizing film made of iodine-dyed PVA tends to have a yellowish aura, and there is a problem that so-called neutral color properties are inferior. In addition, the polarizing film made of iodine-dyed PVA is difficult to thin, and there is a limit to its application to recent display devices that require further thinning. Then, an object of this invention is to provide the polarizing film which is easy to thin film and excellent in neutral color property, the polarizer containing the said polarizing film, its manufacturing method, etc. are provided.

The present invention includes the following inventions.

[1] a polymer formed of a polymerizable liquid crystal compound, and at least one dichroic dye (1) having an absorption maximum in a wavelength range of 380 to 550 nm when the light absorption is measured by dispersing it in the polymer; A polarizing film comprising at least two dichroic dyes (2) having an absorption maximum in a wavelength range of 550 to 700 nm.

[2] The polarized light according to [1], wherein the dichroic dye (1) has an absorption maximum in a wavelength range of 400 to 550 nm when light absorption is measured by dispersing it in a polymer formed of a polymerizable liquid crystal compound. membrane.

[3] At least two dichroic dyes (2) having absorption maxima in the wavelength range of 550 to 700 nm when light absorption is measured by dispersing in the polymer;

When the light absorption is measured 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] Described in any of [1] to [5] in which the color coordinate a* and b* values in the L*a*b* color space satisfy the relationships of the following formulas (1F) and (2F) one polarizer.

-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] The polarizing film according to any one of [1] to [7], wherein the dichroic dye (2) 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 a formula (AR2-1), a formula (AR2-2), or a 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 the number of bonds.

(mc is an integer of 0 to 10, and when there are two mc in the same group, these two mc are the same or different from each other)]

[9] The polarizing film according to any one of [1] to [8], wherein the dichroic dye (1) consists of a compound represented by formula (1).

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

(Wherein, 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 one of formulas (R ^1-1 ) to (R ^1-3 ).

(Wherein, ma is an integer of 0 to 10, and when there are two ma in the same group, these two ma are the same or different from each other. * indicates the number of bonds.)

R ² is a group represented by any of the formulas (R ² -1) to (R ² -6).

(Wherein, mb is an integer from 0 to 10.)]

[10] A polarizer obtained by forming the polarizing film according to any one of [1] to [9] on a transparent substrate.

[11] The method for manufacturing the polarizer according to [10], comprising:

A step of preparing a laminate having an alignment film on a transparent substrate;

When light absorption is measured by dispersing a polymerizable liquid crystal compound and a polymer formed of the polymerizable liquid crystal compound on the alignment layer of the laminate, a dichroic dye having an absorption maximum in a wavelength range of 380 to 550 nm. (1) a step of applying a composition containing one, two dichroic dyes (2) having an absorption maximum in a wavelength range of 550 to 700 nm, and a solvent;

The manufacturing method which has a process of polymerizing the said polymerizable liquid crystal compound contained in the said 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 provided with the polarizing film according to any one of [1] to [9].

[14] A circularly polarizing plate having the polarizing film according to any one of [1] to [9] and a λ/4 layer, and satisfying the requirements of (A1) and (A2) below.

(A1) the angle between 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.

Advantageous Effects of Invention According to the present invention, it is possible to provide a polarizing film that is easy to form a thin film and excellent in neutral color properties, and a polarizer including the polarizing film.

BRIEF DESCRIPTION OF THE DRAWINGS 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 which shows the relationship between the orientation direction D2 of a photo-alignment film, and the conveyance direction D1 of a film.
3 is a schematic diagram showing a cross-sectional configuration of a liquid crystal display device using the polarizing film of the present invention.
FIG. 4 is a schematic diagram showing the order of layers of the present polarizer used in the liquid crystal display device of FIG. 3 .
FIG. 5 is a schematic diagram showing the order of layers of the present polarizer used in the liquid crystal display of FIG. 3 .
6 is a schematic diagram showing a cross-sectional configuration of an EL display device using the polarizing film of the present invention.
7 is a schematic diagram showing a cross-sectional configuration of an embodiment of the present polarizer including the polarizing film of the present invention.
8 is a schematic diagram showing an example of a continuous manufacturing method of a circularly polarizing plate (this circularly polarizing plate) including the polarizing film of the present invention.
Fig. 9 is a schematic diagram showing the order of layers of the present circularly polarizing plate used in the EL display device of Fig. 6;
Fig. 10 is a schematic diagram showing a cross-sectional configuration of an EL display device using the polarizing film of the present invention.
11 is a schematic diagram showing the configuration of a projection type liquid crystal display device using the polarizing film of the present invention.

The polarizing film of the present invention (hereinafter referred to as "the present polarizing film" in some cases) is characterized in that it contains a polymer formed of a polymerizable liquid crystal compound and three or more specific dichroic dyes. The present polarizing film is preferably formed of a polymerizable liquid crystal compound and a composition containing three or more kinds of dichroic dyes (hereinafter, sometimes referred to as “composition for forming a polarizing film”). First, the composition for polarizing film formation is demonstrated.

1. Composition for forming a polarizing film

It is preferable that the composition for forming a polarizing film of the present invention contains a polymerizable liquid crystal compound and three or more specific dichroic dyes as described above, and further contains a solvent. The present polarizing film formed of such a composition for forming a polarizing film can be easily formed into a thin film. First, each of the components contained in the composition for polarizing film formation is demonstrated.

1-1. dichroic pigment

When the dichroic dye contained in the composition for forming a polarizing film is dispersed in a polymer formed of a polymerizable liquid crystal compound and light absorption is measured, at least one dichroic dye having an absorption maximum in a wavelength range of 380 to 550 nm. At least two kinds of dichroic dyes (2) having absorption maxima in the wavelength range of 550 to 700 nm are included in the same measurement as (1).

1-1-1. Dichroic pigments (1)

The dichroic dye (1) has an absorption maximum in a wavelength range of 380 to 550 nm when light absorption is measured by dispersing it in a polymer formed of a polymerizable liquid crystal compound. On the other hand, this measurement prepares the composition for maximal absorption measurement in which the dichroic dye of the composition for polarizing film formation in this invention is replaced with the dichroic dye whose absorption maxima are to be measured, For polarizing film formation mentioned later What is necessary is just to form the film|membrane for absorption maximal measurement by the method similar to the method of forming this polarizing film from a composition, and to measure the light absorption of this absorption maximal measurement film|membrane. The specific method of measuring the absorption maxima is the same as the method described in Examples of the present application.

As the dichroic dye 1, an azo compound is mentioned, for example. Preferably, the compound represented by the said Formula (1) (Hereinafter, it is called "compound (1)" in some cases) is mentioned.

The geometric isomerism of the azobenzene moiety of compound (1) is preferably trans.

Y in Formula (1) is group represented by said Formula (Y1) or Formula (Y2), Preferably it is group represented by Formula (Y1). In formulas (Y1) and (Y2), straight lines at both ends indicate the number of bonds, the number of bonds on the left is bonded to a phenylene group having an azo group, and the number of bonds to the right is bonded to a phenylene group having R ² , have. 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 them, L is preferably an oxygen atom or -NH-, and more preferably an oxygen atom.

R ¹ is a group represented by the above formula (R ^1-1 ), formula (R ^1-2 ) or formula (R ^1-3 ), preferably formula (R ^1-2 ) and formula (R ¹ - 3) is the group represented. The two ma in the group represented by the formula (R ^1-2 ) may be the same or different, but preferably the same. It is more preferable that ma is an integer of 0-5.

R ² is a formula (R ² -1), a formula (R ² -2), a formula (R ² -3), a formula (R ² -4), a formula (R ² -5), or a formula (R ² -6) is a group represented by , more preferably a group represented by a formula (R ² -2), a formula (R ² -5) or a formula (R ² -6), and a group represented by a formula (R ² -6) more preferably. When R ² is a group represented by a formula (R ² -1), a formula (R ² -2), a formula (R ² -3), a formula (R ² -5) or a formula (R ² -6), the group It is preferable that it is an integer of 0-10, and, as for mb contained, it is more preferable in it being an integer of 0-5.

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

Among them, compounds represented by formulas (1-1), (1-2), (1-3), (1-5), (1-7) and (1-8) are preferable. , the compounds represented by the formulas (1-1), (1-2), (1-3) and (1-7) are particularly preferable.

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

Here, the manufacturing method of compound (1) is demonstrated. Compound (1) can be produced, for example, by a reaction shown by the following scheme with a compound represented by formula (1X) [compound (1X)] and a compound represented by formula (1Y) [compound (1Y)].

In the above scheme, R ¹ , R ² and Y have the same meanings as above, and Re ¹ and Re ² are groups that react with each other to become a group represented by Y. Combinations of Re ¹ and Re ² include, for example, 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, a carbonyl halide 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 combination of a carbonyloxyalkyl group and an amino group (the amino group may be substituted with R), and the like. Incidentally, here, the compound (1X) having R ¹ and the compound (1Y) having R ² are explained, but a compound in which R ¹ is protected by an appropriate protecting group and a compound in which R ² is protected by an appropriate protecting group react with each other, and the Then, compound (1) can also be manufactured by performing an appropriate deprotection reaction.

The reaction conditions for reacting the compound (1X) and the compound (1Y) can be appropriately selected and known optimally according to the types of the compound (1X) and the compound (1Y) to be used.

For example, when Re ¹ is a carboxy group, Re ² is a hydroxyl group, and Y is -C(=O)-O-, the reaction conditions include, for example, conditions for condensation in a solvent in the presence of an esterification condensing agent. As a solvent, a solvent soluble in both compound (1X) and compound (1Y), such as chloroform, is mentioned. Examples of the esterification condensing agent include diisopropylcarbodiimide (IPC). Here, it is preferable to further use together bases, such as dimethylamino pyridine (DMAP). The reaction temperature is selected depending on the kind of compound (1X) and compound (1Y), for example, in the range of -15 to 70°C, preferably in the range of 0 to 40°C. The reaction time is, for example, in the range of 15 minutes to 48 hours.

The reaction time is determined by appropriately sampling the reaction mixture during the reaction, and determining the degree of disappearance of compound (1X) and compound (1Y) and the degree of formation of compound (1) by known analytical means such as liquid chromatography or gas chromatography. You can check and fix it.

Compound (1) can be extracted from the reaction mixture after the reaction by known methods such as recrystallization, reprecipitation, extraction and various kinds of chromatography, or by combining these operations.

1-1-2. Dichroic pigments (2)

The dichroic dye (2) has an absorption maximum in a wavelength range of 550 to 700 nm when the above measurement is carried out. The method of measuring the absorption maxima is the same as in the case of the dichroic dye (1).

The dichroic dye (2) contains two or more types in the composition for forming a polarizing film. Among them, the dichroic dye (2-1) having an absorption maximum in a wavelength range of 550 to 600 nm, and a wavelength of 600 to 700 nm It is more preferable to include the dichroic dye (2-2) having an absorption maximum in the range of . Here, the dichroic dye (2-1) more preferably has an absorption maximum in the wavelength range of 570 to 600 nm, and the dichroic dye (2-2) further preferably has an absorption maximum in the wavelength range of 600 to 680 nm. do.

As the dichroic dye 2, an azo compound is mentioned, for example. The dichroic dye (2) is preferably a compound represented by the formula (2) (hereinafter, sometimes referred to as "compound (2)").

The geometric isomerism of the azobenzene moiety of compound (2) is preferably trans.

^In the combination of each group of the compound ( ² ), the ^dichroic dye (2- Compound (2) which can be used as 1) is determined. As a specific dichroic dye (2-1), the compound (2) shown by the combination of each group in Table 1 is mentioned. 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 addition, in Table 1, the group etc. which are represented, for example by Formula (AR-1) are described with "(AR-1)" etc.

Then, in the combination of each group of the compound (2), the dichroic dye (2) 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 measurement. Compound (2) that can be used as -2) is determined. As a specific dichroic dye (2-2), the compound (2) shown by the combination of each group in Table 2 is mentioned. The compound (2-2) which shows the combination of each group in Table 2 shows the case where n in Formula (2) is 1. On the other hand, the notation of the groups in Table 2 is the same as in the case of Table 1.

Here, when compound (2) is specifically shown, the compound etc. which are respectively represented by Formula (2-11) - Formula (2-39) will be mentioned.

Among the specific examples of the compound (2) cited here, as the dichroic dye (2-1), formulas (2-12), formulas (2-13), formulas (2-18), formulas (2-20), Formula (2-21), Formula (2-22), Formula (2-23), Formula (2-24), Formula (2-26), Formula (2-27), Formula (2-28), Formula Those represented by (2-29) and Formula (2-30) correspond, respectively, and as a dichroic dye (2-2), Formula (2-31), Formula (2-32), Formula (2-33), Those represented by the formula (2-34), the formula (2-35) and the formula (2-36) correspond, respectively. On the other hand, the dyes respectively represented by formulas (2-11), (2-15) and (2-16) are not dyes exhibiting absorption at a wavelength of 550 to 700 nm, but supplementary use with the dyes of formula (1) can do.

Among the specific examples of the compound (2), the dichroic dye (2) contained in the composition for forming a polarizing film is a formula (2-15), a formula (2-16), a formula (2-18), a formula (2-20) ), formula (2-21), formula (2-22), formula (2-23), formula (2-27), formula (2-29), formula (2-31), formula (2-32) , Formula (2-33), Formula (2-34), and Formula (2-35) are more preferable, respectively. Among these, when the dichroic dye (2) is represented by the combination of 2 or more types chosen from the specific example of a compound (2), although it changes with a mixing ratio, it is as shown in Table 3, for example. In Table 3, for example, compound (2) represented by formula (2-11) is represented by "(2-11)".

Content of the dichroic dye (1) in the composition for polarizing film formation is represented by content with respect to 100 mass parts of polymeric liquid crystal compounds mentioned later, 50 mass parts or less are preferable, and 0.1 mass parts or more and 10 mass parts or less are more It is preferable, and 0.1 mass part or more and 5 mass parts or less are still more preferable.

Content of the dichroic dye (2) in the composition for polarizing film formation is represented by content with respect to 100 mass parts of polymeric liquid crystal compounds mentioned later, 10 mass parts or less are preferable, and 0.1 mass parts or more and 5 mass parts or less are more It is preferable, and 0.1 mass part or more and 3 mass parts or less are still more preferable.

In addition, the total content of the dichroic dye (1) and the dichroic dye (2) in the composition for polarizing film formation is represented by content with respect to 100 mass parts of polymeric liquid crystal compounds mentioned later, and 30 mass parts or less are preferable, 0.1 mass part or more and 20 mass parts or less are more preferable, and 1 mass part or more and 15 mass parts or less are still more preferable.

If the content of each dichroic dye is within the above range, since the dichroic dye in the composition for forming a polarizing film shows sufficient solubility in a solvent, when the present polarizing film is manufactured using the composition for forming a polarizing film, defects It is possible to obtain the present polarizing film without the occurrence of Meanwhile, as described above, the composition for forming a polarizing film may contain one or more dichroic dyes (1) and two or more dichroic dyes (2). ) Even if 2 or more types are included, 3 or more types of dichroic dyes (2) may be included. When 2 or more types of dichroic dyes (1) are included, content of dichroic dyes (1) shall be the total amount of 2 or more types of dichroic dyes (1), When 3 or more types of dichroic dyes (2) are included , Let content of the dichroic dye (2) 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, Japanese Patent Application Laid-Open Nos. 58-38756, 63-301850, 58-104984, and the like.

Next, structural components other than the dichroic dye in the composition for polarizing film formation are demonstrated.

1-2. polymerizable liquid crystal compound

A polymerizable liquid crystal compound is a liquid crystal compound which can superpose|polymerize with orientation, and has a polymeric group in a molecule|numerator. The composition for forming a polarizing film containing the polymerizable liquid crystal compound forms the present polarizing film by polymerization in a state in which the polymerizable liquid crystal compound is aligned. The polymerizable group is particularly preferably a radically polymerizable group. A radically polymerizable group means the group which participates in a radical polymerization reaction.

The polymerizable liquid crystal compound contained in the composition for forming a polarizing film of the present invention is a smectic liquid crystal phase (hereinafter referred to as a "nematic liquid crystal phase"), even if it exhibits a nematic liquid crystal phase (hereinafter referred to as "nematic liquid crystal phase" in some cases). In some cases, it may exhibit a "smectic liquid crystal phase") or may exhibit both a nematic liquid crystal phase and a smectic liquid crystal phase, but a polymerizable smectic liquid crystal compound exhibiting at least a smectic liquid crystal phase is preferable. The composition for forming a polarizing film containing a polymerizable smectic liquid crystal compound is a polarizing film having very good neutral color properties and more excellent polarization performance due to the interaction of the dichroic dye (1) and the dichroic dye (2). can be obtained

As the smectic liquid crystal phase represented by the polymerizable smectic liquid crystal compound, a higher order smectic liquid crystal phase is more preferable. The higher-order smectic liquid crystal phase as used herein refers to smectic B phase, smectic D phase, smectic E phase, smectic F phase, smectic G phase, smectic H phase, smectic I phase, smectic J phase, and smectic phase. They are metric K phase and smectic L phase, and among these, smectic B phase, smectic F phase, and smectic I phase are more preferable.

If the smectic liquid crystal phases represented by the polymerizable liquid crystal compound are these higher-order smectic liquid crystal phases, the present polarizing film having a higher degree of alignment order can be produced. In addition, the present polarizing film produced from a higher-order smectic liquid crystal phase having a high degree of alignment order in this way has a Bragg peak derived from a higher-order structure such as a hexatic phase or a crystal phase in X-ray diffraction measurement. The said Bragg peak is a peak derived from the in-plane periodic structure of molecular orientation, and according to the composition for forming a polarizing film of the present invention, the present polarizing film having a periodic interval of 3.0 to 5.0 angstroms can be obtained.

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. A suitable substrate is prepared, a composition for forming a polarizing film is applied to the substrate to form a coating film, and then the solvent contained in the coating film is removed by heat treatment or reduced pressure treatment under conditions in which the polymerizable liquid crystal compound does not polymerize. Next, the liquid crystal phase developed by heating the coating film formed on the substrate to an isotropic temperature and cooling it gradually is inspected by texture observation with a polarizing microscope, X-ray diffraction measurement, or differential scanning calorimetry. In this inspection, for example, a polymerizable liquid crystal compound that exhibits a nematic liquid crystal phase by cooling and a smectic liquid crystal phase by further cooling is particularly preferable. In the nematic liquid crystal phase and the smectic liquid crystal phase, it can be confirmed that the polymerizable liquid crystal compound and the dichroic dye are not phase separated by, for example, surface observation with various microscopes or measurement of scattering with a haze meter.

Hereinafter, the specific example of a thing preferable as a polymeric liquid crystal compound used for the composition for polarizing film formation is given.

As a preferable polymeric liquid crystal composition, the compound (Hereinafter, it is called "compound (4)" in some cases) represented by Formula (4) is mentioned, for example.

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 substituted with -O-, -S- or -NR-. R is an alkyl group having 1 to 6 carbon atoms or a phenyl group.

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

U ¹ represents a hydrogen atom or a polymerizable group.

U ² represents a polymerizable group.

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

V ¹ and V ² each independently represent an alkanediyl group having 1 to 20 carbon atoms which may have a substituent, and -CH ₂ - constituting the alkanediyl group is substituted with -O-, -S- or -NH- Even if it is.]

In 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.

It is preferable that the 1,4-phenylene group which may have a substituent is unsubstituted. The optionally substituted cyclohexane-1,4-diyl group is preferably a optionally substituted trans-cyclohexane-1,4-diyl group, and optionally trans-cyclohexane-1,4-diyl group optionally having a substituent. It is more preferable that the diyl group is unsubstituted.

Examples of the substituent optionally included in the 1,4-phenylene group which may have a substituent or the cyclohexane-1,4-diyl group which may have a substituent include an alkyl group having 1 to 4 carbon atoms such as a methyl group, an ethyl group and a butyl group; cyano group; A halogen atom etc. are mentioned.

Y ¹ in 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, preferably a polymerizable group. It is preferable that it is ^a polymerizable group together, and, as for U< ¹ > and U2, if it is a photopolymerizable group together, it is more preferable. The photopolymerizable group refers to a group capable of participating 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 lower temperature conditions.

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

Examples of 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 include a methylene group, an ethylene group, a propane-1,3-diyl group, and a butane-1 group. ,3-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group , a decane-1,10-diyl group, a tetradecane-1,14-diyl group, and an icosane-1,20-diyl group. V ¹ and V ² are preferably an alkanediyl group having 2 to 12 carbon atoms, and more preferably an alkanediyl group having 6 to 12 carbon atoms.

Examples of the substituent optionally included in the alkanediyl group having 1 to 20 carbon atoms which may have a substituent include a cyano group and a halogen atom. The alkanediyl group is preferably unsubstituted, and is more preferably.

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

As compound (4), the compound etc. which are represented by Formula (4-1) - Formula (4-43) are mentioned. When the specific example of this compound (4) has a cyclohexane-1,4-diyl group, it is preferable that this cyclohexane-1,4-diyl group is a trans body.

The polymerizable liquid crystal compound may be used alone or in combination of two or more in the composition for forming a polarizing film. Moreover, when mixing 2 or more types, it is preferable that at least 1 type is a compound (4). The mixing ratio in the case of mixing 2 types of polymerizable liquid crystal compounds is 1:99-50:50 normally, Preferably it is 5:95-50:50, More preferably, it is 10:90-50:50.

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

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 ratio of the polymerizable liquid crystal compound is within the above range, the orientation of the polymerizable liquid crystal compound tends to increase, which is preferable. Here, solid content means the total amount of components excluding volatile components, such as a solvent, in the composition for polarizing film formation.

The polymerizable liquid crystal compound is described, for example, in Lub et al. Recl. Trav. Chim. Pays-Bas, 115, 321-328 (1996) or a known method described in Japanese Patent No. 4719156 is produced.

1-3. solvent

It is preferable that the composition for polarizing film formation 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 an inactive solvent to the polymerization reaction of the polymeric liquid crystal compound contained in the composition for polarizing film formation.

Examples of the solvent 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; ester solvents such as ethyl acetate, butyl acetate, ethylene glycol methyl ether acetate, γ-butyrolactone or 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; aromatic hydrocarbon solvents such as toluene and xylene; nitrile solvents such as acetonitrile; ether solvents such as tetrahydrofuran and dimethoxyethane; and chlorine-containing solvents such as chloroform and chlorobenzene. These solvents may be used independently and may be used combining plurality.

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, as for solid content in the composition for polarizing film formation, 2-50 mass % is preferable. If the solid content is 2 mass% or more, it tends to be easy to obtain the thin present polarizing film which is one of the objects of the present invention, and it is preferable. In addition, when the solid content is 50 mass% or less, since the viscosity of the composition for forming a polarizing film is low, the thickness of the polarizing film becomes substantially uniform, which tends to make it difficult to cause unevenness in the polarizing film, which is preferable. In addition, the solid content may be determined in consideration of the thickness of the polarizing film.

1-4. other additives

The composition for polarizing film formation in this invention contains additives other than a dichroic dye, a polymerizable liquid crystal compound, and a solvent arbitrarily.

1-4-1. polymerization reaction aid

The composition for forming a polarizing film preferably contains a polymerization initiator. The polymerization initiator is a compound capable of initiating a polymerization reaction of the polymerizable liquid crystal compound. As a polymerization initiator, a photoinitiator is preferable at the point which can start a polymerization reaction under low-temperature conditions. Specifically, a compound that generates active radicals or acids by the action of light is used as the 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 a benzoin compound, a benzophenone compound, an alkylphenone compound, an acylphosphine oxide compound, a triazine compound, an iodonium salt, and a sulfonium salt.

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-butylperoxycarp) Bornyl) benzophenone, 2,4,6-trimethylbenzophenone, etc. are mentioned.

Examples of the alkylphenone compound include diethoxyacetophenone, 2-methyl-2-morpholino-1-(4-methylthiophenyl)propan-1-one, 2-benzyl-2-dimethylamino-1-(4-morph Polynophenyl) butan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1,2-diphenyl-2,2-dimethoxyethan-1-one, 2-hydroxy Roxy-2-methyl-1-[4-(2-hydroxyethoxy)phenyl]propan-1-one, 1-hydroxycyclohexylphenylketone and 2-hydroxy-2-methyl-1-[4- The oligomer of (1-methylvinyl)phenyl]propan-1-one, etc. are mentioned.

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). -Methoxynaphthyl)-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-[ To 2-(furan-2-yl)ethenyl]-1,3,5-triazine, 2,4-bis(trichloromethyl)-6-[2-(4-diethylamino-2-methylphenyl) tenyl]-1,3,5-triazine and 2,4-bis(trichloromethyl)-6-[2-(3,4-dimethoxyphenyl)ethenyl]-1,3,5-triazine, etc. can be heard

A commercially available polymerization initiator may be used. Commercially available polymerization initiators include "Irgacure 907", "Irgacure 184", "Irgacure 651", "Irgacure 819", "Irgacure 250", "Irgacure 369" ( Chiba Japan Co., Ltd.); "Seikuol BZ", "Seikuol Z", "Seikuol BEE" (Seiko Chemical Co., Ltd.); "kayacure BP100" (Nippon Kayaku Co., Ltd.); "Kayacure UVI-6992" (manufactured by Dow Corporation); "Adeka Optoma SP-152", "Adeka Optoma SP-170" (ADEKA Co., Ltd.); "TAZ-A", "TAZ-PP" (Nippon Shiiber Hegna Co., Ltd.); and "TAZ-104" (Sanwa Chemical).

When the composition for forming a polarizing film contains a polymerization initiator, its 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 100 masses of the total of the polymerizable liquid crystal compound Content of the polymerization initiator with respect to a part is 0.1-30 mass parts, Preferably it is 0.5-10 mass parts, More preferably, it is 0.5-8 mass parts. When content of a polymerization initiator is in the said range, since it can superpose|polymerize without disturbing the orientation of a polymeric liquid crystal compound, it is preferable.

1-4-2. photosensitizer

When the composition for polarizing film formation contains a photoinitiator, the composition for polarizing film formation may contain a photosensitizer. As a photosensitizer, For example, xanthone compounds, such as xanthone and thioxanthone (For example, 2, 4- diethyl thioxanthone, 2-isopropyl thioxanthone, etc.); anthracene compounds such as anthracene and alkoxy group-containing anthracene (eg, dibutoxyanthracene); phenothiazine, rubrene, and the like.

When the composition for polarizing film formation contains a photoinitiator and a photosensitizer, the polymerization reaction of the polymeric liquid crystal compound contained in the composition for polarizing film formation is accelerated|stimulated more. The content of such a photosensitizer can be appropriately adjusted depending on the type and amount of the photoinitiator and the polymerizable liquid crystal compound to be used together, and is usually 0.1 to 30 parts by mass, preferably 0.1 to 30 parts by mass based on 100 parts by mass of the content of the polymerizable liquid crystal compound. is 0.5 to 10 parts by mass, more preferably 0.5 to 8 parts by mass.

1-4-3. polymerization inhibitor

The composition for forming a polarizing film may contain a polymerization inhibitor in order to stably advance the polymerization reaction of the polymerizable liquid crystal compound. The degree of progress of the polymerization reaction of the polymerizable liquid crystal compound can be controlled by the polymerization inhibitor.

Examples of the polymerization inhibitor include radicals such as hydroquinone, alkoxy group-containing hydroquinone, alkoxy group-containing catechol (eg, butylcatechol, etc.), pyrogallol, and 2,2,6,6-tetramethyl-1-piperidinyloxy radical. supplements; thiophenols; and β-naphthylamines and β-naphthols.

When a polymerization inhibitor is included in the composition for forming a polarizing film, the content thereof is appropriately adjusted depending on the type and amount of the polymerizable liquid crystal compound used, and the content of the photosensitizer, etc., usually with respect to 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.

When content of a polymerization inhibitor is in the said range, since it can superpose|polymerize without disturbing the orientation of the polymeric liquid crystal compound contained in the composition for polarizing film formation, it is preferable.

1-4-4. leveling agent

It is preferable when the composition for polarizing film formation contains a leveling agent. A leveling agent adjusts the fluidity|liquidity of the composition for polarizing film formation, It has a function of making flatter the coating film obtained by apply|coating the composition for polarizing film formation, Surfactant etc. are mentioned. As a preferable leveling agent, the leveling agent which has a polyacrylate compound as a main component, the leveling agent which has a fluorine atom containing compound as a main component, etc. are mentioned.

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

As a leveling agent containing a fluorine atom-containing compound as a main component, "Megapark R-08", the same "R-30", the same "R-90", the same "F-410", the same "F-411", the same "F" -443", East "F-445", East "F-470", East "F-471", East "F-477", East "F-479", East "F-482", and East "F-" 483" [DIC Co., Ltd.]; "Suplon S-381", East "S-382", East "S-383", East "S-393", East "SC-101", East "SC-105", "KH-40" and " SA-100"[AGC Semi Chemical Co., Ltd.]; "E1830", "E5844" [Daikin Fine Chemical Genkyusho Co., Ltd.]; "Ftop EF301", "EF303", "EF351", and "EF352" (Misbishima Terial Denshi Gassei Co., Ltd.) etc. are mentioned.

When making the composition for polarizing film formation contain a leveling agent, the content is 0.3 mass part or more and 5 mass parts or less with respect to content 100 mass parts of a polymeric liquid crystal compound normally, Preferably they are 0.5 mass part or more and 3 mass parts or less . It is easy to horizontally align a polymeric liquid crystal compound as content of a leveling agent is in the above-mentioned range, and since there exists a tendency for the polarizing film obtained to become smoother, it is preferable. When content of the leveling agent with respect to a polymeric liquid crystal compound exceeds an above-mentioned range, there exists a tendency for nonuniformity to arise easily in this polarizing film obtained. In addition, the said composition for polarizing film formation may contain 2 or more types of leveling agents.

2. Method of forming the present polarizing film

Next, the method of forming this polarizing film with the composition for polarizing film formation is demonstrated. In this method, the present polarizing film is formed by applying the composition for forming a polarizing film to a substrate, preferably to a transparent substrate.

2-1. transparent substrate

A transparent base material is a base material which has transparency enough to transmit light, especially visible light. The transparency refers to a characteristic in which the transmittance with respect to light having a wavelength of 380 to 780 nm is 80% or more. Specifically, as a transparent base material, a glass base material, a plastic base material, etc. are mentioned, Preferably it is a plastic base material. Examples of the plastic constituting the plastic substrate include polyolefins such as polyethylene, polypropylene and norbornene-based polymers; Cyclic olefin resin; polyvinyl alcohol; polyethylene terephthalate; polymethacrylic acid ester; polyacrylic acid ester; cellulose esters such as triacetyl cellulose, diacetyl cellulose and cellulose acetate propionate; polyethylene naphthalate; polycarbonate; polysulfone; polyether sulfone; polyether ketone; and plastics such as polyphenylene sulfide and polyphenylene oxide. Especially, from the point that it can obtain easily in a market or it is excellent in transparency, Especially preferably, they are a cellulose ester, a cyclic olefin resin, a polyethylene terephthalate, or polymethacrylic acid ester. In manufacturing the present polarizing film using such a transparent substrate, the transparent substrate can be easily handled without causing damage such as tearing when transporting or storing the transparent substrate. It's okay to let go In addition, although mentioned later, when manufacturing a circularly polarizing plate with this polarizing film, retardation property may be provided to a plastic base material. In this case, retardation may be imparted to the plastic substrate by stretching treatment or the like.

When providing retardation property to a plastic base material, the plastic base material which consists of a cellulose ester or a cyclic olefin resin is preferable at the point of being easy to control the retardation value.

In the cellulose ester, at least a part of the hydroxyl groups contained in the cellulose is acetic acid esterified. The cellulose-ester film which consists of such a cellulose ester can be obtained easily in a market. Commercially available triacetyl cellulose films include, for example, "Fuji Tack Film" (Fuji Shashin Film Co., Ltd.); "KC8UX2M", "KC8UY" and "KC4UY" (Konica Minolta Opt Co., Ltd.) and the like. Such a commercially available triacetyl cellulose film can be used as a transparent substrate as it is or after imparting retardation as needed. In addition, after the surface of the prepared transparent substrate is subjected to a surface treatment such as an anti-glare treatment, a hard coat treatment, an antistatic treatment or an antireflection treatment, it can be used as a transparent substrate.

In order to impart retardation to the plastic substrate, a method such as stretching the plastic substrate as described above is used. Although any of the plastic base materials which consist of a thermoplastic resin can be extended, the plastic base material which consists of a cyclic olefin resin from the point of being easy to control retardation property is more preferable. The cyclic olefin-based resin is constituted of, for example, a polymer or copolymer of a cyclic olefin such as norbornene or a polycyclic norbornene-based monomer, and the cyclic olefin-based resin may partially contain a ring-opening part. Moreover, what hydrogenated the cyclic olefin resin containing a ring-opening part may be sufficient. The cyclic olefin resin may be, for example, a copolymer of a cyclic olefin and a chain olefin or a vinylated aromatic compound (styrene, etc.) from the viewpoint of not significantly impairing transparency or not significantly increasing hygroscopicity. Moreover, in the said cyclic olefin resin, a polar group may be introduce|transduced in the molecule|numerator.

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 or propylene, and the vinylated aromatic compound is styrene, α-methylstyrene and alkyl-substituted styrene. Such a copolymer WHEREIN: The content rate of the structural unit derived from a cyclic olefin is 50 mol% or less with respect to all the structural units of a cyclic olefin resin, For example, it is the range of about 15-50 mol%. When the cyclic olefin resin is a terpolymer obtained from a cyclic olefin, a chain olefin, and a vinylated aromatic compound, for example, the content of the structural unit derived from the chain olefin is about 5 to 80 mol% with respect to the total structural units of the cyclic olefin resin. and the content ratio of the structural unit derived from the vinylated aromatic compound is about 5 to 80 mol%. The cyclic olefin resin of such a terpolymer has the advantage that the usage-amount of an expensive cyclic olefin can be comparatively decreased, when manufacturing the said cyclic olefin resin.

Cyclic olefin resin can be obtained easily in a market. As commercially available cyclic olefin resin, "Topas" [Ticona company (Germany)]; "Aton" [JSR Co., Ltd.]; "ZEONOR" and "ZEONEX" [Nippon Zeon Co., Ltd.]; "Apel" [manufactured by Mitsui Chemicals Co., Ltd.] and the like. Such cyclic olefin resin can be formed into a film (cyclic olefin resin film) by well-known film forming means, such as a solvent casting method and melt extrusion method, for example. Moreover, the cyclic olefin resin film already marketed in the form of a film can also be used. As such a commercially available cyclic olefin resin film, "Esshina" and "SCA40" [Sekisui Chemical Co., Ltd.]; "Zeonor Film" [Optess Co., Ltd.]; "Aton Film" [JSR Co., Ltd.], etc. are mentioned.

Next, a method for imparting retardation to the plastic substrate will be described. The plastic substrate can impart retardation by a known stretching method. For example, a roll (winding body) in which a plastic substrate is wound on the roll is prepared, the plastic substrate is continuously unwound from the winding body, and the unwound plastic substrate is conveyed to a heating furnace. The set temperature of the heating furnace is in the range of around 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). ) within the range. In the above-mentioned heating furnace, when stretching in the traveling direction or in a direction orthogonal to the traveling direction of the plastic substrate, the conveying direction or tension is adjusted and the inclination is applied at an arbitrary angle to perform uniaxial or biaxial hot stretching treatment. A draw ratio is the range of about 1.1 to 6 times normally, Preferably it is the range of about 1.1 to 3.5 times. In addition, as a method of extending|stretching in an oblique direction, if it can incline an orientation axis|shaft to a desired angle continuously, it will not specifically limit, A well-known extending method can be employ|adopted. As such a stretching method, for example, the method described in Japanese Patent Application Laid-Open No. 50-83482 and Japanese Patent Application Laid-Open No. Hei2-113920 is mentioned.

The thickness of the transparent base material is preferably thin in that it is a weight that can be practically handled and that sufficient transparency can be ensured. A suitable thickness of the glass substrate is, for example, about 100 to 3000 µm, preferably about 100 to 1000 µm. A suitable 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 mentioned later, the thickness of the transparent base material in the case of using especially as a circularly polarizing plate for mobile device use is about 20-100 micrometers is preferable. On the other hand, when providing retardation to a film by extending|stretching, the thickness after extending|stretching is determined by the thickness before extending|stretching, or a draw ratio.

2-2. alignment film

It is preferable that the orientation 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 on the alignment film. For this reason, it is preferable that the said alignment film has solvent resistance to the extent that it does not melt|dissolve by application|coating etc. of the composition for polarizing film formation. Moreover, it is preferable to have heat resistance in the heat processing for removal of a solvent or orientation of a liquid crystal. Such an alignment layer may be formed of an alignment polymer.

Examples of the orientation polymer include polyamide or gelatin having an amide bond in the molecule, polyimide having an imide bond in the molecule, and polyamic acid, polyvinyl alcohol, alkyl-modified polyvinyl alcohol, polyacrylamide, and polyoxa, which are hydrolyzates thereof. Polymers, such as sol, polyethyleneimine, polystyrene, polyvinylpyrrolidone, polyacrylic acid, or polyacrylic acid ester, are mentioned. Among these, polyvinyl alcohol is preferable. These orientation polymers which form an orientation film may be used independently and may be used in mixture of 2 or more types.

The alignment polymer may be applied on a substrate as an alignment polymer composition (a solution containing the alignment polymer) dissolved in a solvent to form an alignment layer on the substrate. 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; ester solvents such as ethyl acetate, butyl acetate, ethylene glycol methyl ether acetate, γ-butyrolactone, 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; aromatic hydrocarbon solvents such as toluene and xylene; nitrile solvents such as acetonitrile; ether solvents such as tetrahydrofuran and dimethoxyethane; Chlorine-substituted hydrocarbon solvents, such as chloroform and chlorobenzene, etc. are mentioned. These organic solvents may be used independently and may be used in combination of multiple types.

In addition, as the orientation polymer composition for forming the orientation film, a commercially available orientation film material may be used as it is. Examples of commercially available alignment film materials include Saneva (registered trademark, manufactured by Nissan Chemical Industries, Ltd.) or Optoma (registered trademark, manufactured by JSR Corporation).

As a method of forming an alignment film on a substrate, for example, a method in which the alignment polymer composition or a commercially available alignment film material is applied on the substrate and annealed may be mentioned. The thickness of the alignment film obtained in this way is usually in the range of 10 nm to 10000 nm, preferably in the range of 10 nm to 1000 nm.

In order to provide an orientation regulating force with respect to the said orientation film, it is preferable to rub as needed (rubbing method). By providing an orientation regulating force, a polymeric liquid crystal compound can be orientated in a desired direction.

As a method of imparting an orientation regulating force by the rubbing method, for example, a rubbing cloth is wound and 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 placed on a stage, and directed toward the rotating rubbing roll. By conveying, the method of making the said coating film for orientation film formation and the rotating rubbing roll contact is mentioned.

Moreover, a so-called photo-alignment film can also be used. The photo-alignment film is a polymer or a monomer having a photoreactive group and a composition containing a solvent and a solvent (hereinafter referred to as "composition for photo-alignment layer formation" in some cases) is applied to a substrate and polarized light (preferably, polarized UV) is irradiated By doing so, it refers to an alignment film to which an alignment regulating force is imparted. A photoreactive group refers to the group which produces liquid-crystal orientation ability by irradiating light (light irradiation). Specifically, it causes a photoreaction that is the origin of the liquid crystal alignment ability, such as an orientation induction or isomerization reaction, a dimerization reaction, a photocrosslinking reaction, or a photolysis reaction of molecules generated by irradiation with light. Among the photoreactive groups, those that cause a dimerization reaction or a photocrosslinking reaction are preferable in terms of excellent orientation and maintaining the smectic liquid crystal state at the time of formation of the polarizing film. As the photoreactive group capable of causing the above reaction, it is preferable to have an unsaturated bond, particularly a double bond, carbon-carbon double bond (C=C bond), carbon-nitrogen double bond (C=N bond), nitrogen A group having at least one selected from the group consisting of - a nitrogen double bond (N=N bond) and a carbon-oxygen double bond (C=O bond) is particularly preferred.

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 a group 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 azoxybenzene as a basic structure. 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 are preferable because it is easy to obtain a photo-alignment film having a relatively small amount of polarization irradiation required for photo-alignment, and excellent thermal stability and stability over time. do. In other words, as the polymer having a photoreactive group, one having a cinnamoyl group in which the terminal portion of the polymer side chain has a cinnamic acid structure is particularly preferable.

As a solvent of the composition for photo-alignment layer formation, it is preferable to melt|dissolve the polymer and monomer which have a photoreactive group, As said solvent, the solvent used for the above-mentioned orientation polymer composition is mentioned, for example.

The concentration of the polymer or monomer having a photoreactive group with respect to the composition for forming the photo-alignment layer can be appropriately adjusted according to the type of the polymer or monomer having the photo-reactive group or the thickness of the photo-alignment layer to be prepared. It is preferable to set it as 0.2 mass %, and the range of 0.3-10 mass % is especially preferable. In addition, as long as the characteristics of the photo-alignment layer are not significantly impaired, the composition for forming the alignment layer may contain a polymer material such as polyvinyl alcohol or polyimide, and a photosensitizer.

As a method of applying the orientation polymer composition or the composition for forming a photo-alignment layer on the substrate, a spin coating method, an extrusion method, a gravure coating method, a die coating method, a bar coating method and an applicator method, etc. A well-known method, such as a printing method, is employ|adopted. On the other hand, when the production of the present polarizing film is carried out by a continuous production method of a RolltoRoll type to be described later, a printing method such as a gravure coating method, a die coating method, or a flexographic method is usually employed as the coating method.

On the other hand, if masking is performed when rubbing or polarized light irradiation, a plurality of regions (patterns) having different orientation directions can be formed.

2-3. Method for manufacturing the present polarizing film

A coating film is obtained by applying a composition for forming a polarizing film on the substrate or the alignment film formed on the substrate. As a method of apply|coating the composition for polarizing film formation, the method similar to that illustrated as a method of apply|coating an orientation polymer or the composition for photoreaction layer formation to a base material is mentioned, for example.

Next, a dry film is formed by drying and removing the solvent under conditions in which the polymerizable liquid crystal compound contained in the coating film does not polymerize. Examples of the drying method include a natural drying method, a ventilation drying method, heat drying, and a reduced pressure drying method.

Next, as a preferred embodiment, the liquid crystal state of the polymerizable liquid crystal composition contained in the dry film is once set to a nematic liquid crystal phase, and then the nematic liquid crystal phase is transferred to a smectic liquid crystal phase.

In order to form a smectic liquid crystal phase via the nematic liquid crystal phase as described above, for example, the polymerizable liquid crystal compound contained in the dry film is heated to a temperature higher than the nematic liquid crystal phase, and then the polymerizable liquid crystal compound is smectic. The method of cooling to the temperature which shows a liquid-crystal phase is employ|adopted.

When the polymerizable liquid crystal compound in the dry film is used as a smectic liquid crystal phase or the polymerizable liquid crystal compound is made into a smectic liquid crystal phase via a nematic liquid crystal phase, by measuring the phase transition temperature of the polymerizable liquid crystal compound to be used , conditions (heating conditions) for controlling the liquid crystal state can be obtained. Conditions for measuring such a phase transition temperature are described in Examples herein.

Next, the polymerization process of a polymerizable liquid crystal compound is demonstrated. Here, a photoinitiator is contained in the composition for forming a polarizing film, the liquid crystal state of the polymerizable liquid crystal compound in the dry film is made into a smectic liquid crystal phase, and then the polymerizable liquid crystal compound is maintained while the liquid crystal state of the smectic liquid crystal phase is maintained. A method of photopolymerization will be described in detail.

In the photopolymerization, the light irradiated to the dry film is appropriate depending on the type of photoinitiator or the type of the polymerizable liquid crystal compound (in particular, the type of polymerizable group that the polymerizable liquid crystal compound has) and the amount contained in the dry film. It can be carried out by light or an active electron beam selected from the group consisting of visible light, ultraviolet light and laser light. Among these, ultraviolet light is preferable from the point of being easy to control advancing of a polymerization reaction, and the point that what is widely used in this field|area can be used as an apparatus related to photopolymerization. Therefore, it is preferable to select the kind of a polymerizable liquid crystal compound or a photoinitiator contained in the composition for forming a polarizing film so that it can be photopolymerized by ultraviolet light. In addition, when superposing|polymerizing, superposition|polymerization temperature can also be controlled by cooling a dry film by an appropriate cooling means together with ultraviolet light irradiation. If the polymerization of the polymerizable liquid crystal compound can be performed at a lower temperature by employing such a cooling means, there is also an advantage that the present polarizing film can be appropriately formed even if a substrate having relatively low heat resistance is used for the above-described substrate. On the other hand, during photopolymerization, the patterned present polarizing film may be obtained by masking or developing.

By performing the photopolymerization as described above, the polymerizable liquid crystal compound is polymerized while maintaining a nematic liquid crystal phase, a smectic liquid crystal phase, and preferably a higher-order smectic liquid crystal phase as previously exemplified to form the present polarizing film. This polarizing film obtained by polymerization of a polymerizable liquid crystal compound while maintaining a smectic liquid crystal phase is a conventional host-guest type polarizing film, that is, a polarizing film obtained by polymerizing a polymerizable liquid crystal compound while maintaining the liquid crystal state of a nematic liquid crystal phase. There is an advantage that polarization performance is high compared with . Moreover, there exists an advantage that it is excellent in intensity|strength compared with the thing which apply|coated only the lyotropic dichroic dye.

The thickness of the present polarizing film thus formed is preferably in the range of 0.5 µm or more and 10 µm or less, more preferably 1 µm or more and 5 µm or less. Therefore, the thickness of this coating film for polarizing film formation is determined in consideration of the thickness of this polarizing film obtained. On the other hand, the thickness of the present polarizing film is determined by measuring an interference thickness meter, a laser microscope, or a stylus thickness meter.

In addition, the present polarizing film formed in this way is particularly preferable as long as a Bragg peak is obtained in X-ray diffraction measurement as described above. As the present polarizing film from which such a Bragg peak is obtained, for example, the present polarizing film exhibiting a diffraction peak derived from a hexatic phase or a crystal phase is exemplified.

In addition, the present polarizing film produced in this way is excellent in neutral color properties. Here, the polarizing film having excellent neutral color properties means that the color coordinates a* value and b* value in the L*a*b*(Lab) color space satisfy the relationship of the following formulas (1F) and (2F). will do On the other hand, these color coordinates a* value and b* value are obtained, for example, by the measurement method described in the examples of the present application.

-3≤Chromaticity a*≤3 (1F)

-3≤Chromaticity b*≤3 (2F)

Each of the color coordinates a* value and b* value referred to herein is also referred to as “chromaticity a*” and “chromaticity b*”. When a* and b* are both closer to 0 (zero), it is determined that the polarizing film exhibits a neutral color. In a display device provided with such a polarizing film, good white display without coloring can be obtained.

In addition, in the hue of the polarizing film, when two polarizing films are overlapped so that the absorption axes are orthogonal to each other, the hue at that time is obtained in the same manner as above, and "orthogonal a*" and "orthogonal b*" are calculated. It is more preferable if each of a* and orthogonal b* satisfy|fills the relationship of the following formulas (1F') and (2F'). These orthogonal a* and orthogonal b* are indicators indicating whether the hue of black display is neutral in a display device provided with a polarizing film. When the orthogonal a* and the orthogonal b* are both closer to 0 (zero), a good black display without coloring can be obtained.

-3≤orthogonal a*≤3 (1F')

-3≤orthogonal b*≤3 (2F')

3. Continuous manufacturing method of the present polarizing film

As mentioned above, although the outline|summary of the manufacturing method of this polarizing film was demonstrated, when manufacturing this polarizing film commercially, the method which can manufacture this polarizing film continuously is calculated|required. This continuous manufacturing method is based on the RolltoRoll type, and is sometimes referred to as "the present manufacturing method". In addition, in this manufacturing method, the case where a base material is a transparent base material is demonstrated mainly. When the base material is a transparent base material, what is finally obtained becomes a polarizer (hereinafter, sometimes referred to as "main polarizer") having a transparent base material and this polarizing film.

This manufacturing method is, for example,

A step of preparing a first roll in which the transparent substrate is wound around a first core;

continuously sending out the transparent substrate from the first roll;

A process of continuously forming an alignment film on the transparent substrate;

a step of continuously applying a composition for forming a polarizing film on the alignment layer;

A step of continuously forming a dry film on the alignment film by drying the applied composition for forming a polarizing film under conditions in which the polymerizable liquid crystal compound does not polymerize;

After the polymerizable liquid crystal compound contained in the dry film is set to a nematic liquid crystal phase, preferably a smectic liquid crystal phase, the polymerizable liquid crystal compound is polymerized while maintaining the smectic liquid crystal phase, whereby the polarizing film is continuously The process of obtaining it and making it into a polarizer,

It has the process of winding up the continuously obtained polarizer to a 2nd core, and obtaining a 2nd roll. Here, with reference to FIG. 1, the present manufacturing method will be specifically described with respect to the case where the photo-alignment film is used as the alignment film.

The first roll 210 in which the transparent substrate is wound around the first core 210A can be easily obtained, for example, in the market. As a transparent base material which can be obtained in the market in the form of such a roll, the film etc. which consist of a cellulose ester, a cyclic olefin resin, polyethylene terephthalate, polycarbonate, or polymethacrylic acid ester among the transparent base materials already illustrated are mentioned. Moreover, in using this polarizing film as a circularly polarizing plate, the transparent base material to which retardation property was previously provided can also be obtained easily in the market, For example, the retardation film etc. which consist of a cellulose ester or a cyclic olefin resin are mentioned.

Next, the transparent substrate is released from the first roll 210 . The method of unwinding the transparent base material is performed by providing an appropriate rotation means to the core 210A of the said 1st roll 210, and rotating the 1st roll 210 by the said rotation means. In addition, an auxiliary roll 300 suitable for the direction in which the transparent substrate is conveyed from the first roll 210 may be provided, and the transparent substrate may be unwound by means of rotation of the auxiliary roll 300 . In addition, by providing rotation means for both the 1st winding core 210A and the auxiliary|assistant roll 300, the type|system|group which unwinds a transparent base material while providing appropriate tension|tensile_strength to a transparent base material may be sufficient.

When the transparent substrate unrolled from the first roll 210 passes through the coating device 211A, the composition for forming a photo-alignment layer is applied on the surface thereof by the coating device 211A. As described above, in order to continuously apply the composition for forming a photo-alignment layer in this way, a printing method such as a gravure coating method, a die coating method, or a flexographic method is performed by the coating device 211A.

The transparent base material which passed through the coating device 211A is conveyed to the drying furnace 212A, and it is heated by the said drying furnace 212A, and forms a 1st dry film continuously on the transparent base material. As the drying furnace 212A, a hot air drying furnace or the like is used, for example. The set temperature of the drying furnace 212A is determined according to the kind of solvent contained in the composition for forming a photo-alignment layer applied by the coating device 211A. In addition, the drying furnace 212A may be divided into a plurality of zones, and a type having a different set temperature for each of the divided zones may be used, or a drying furnace of a type having a different set temperature for each drying furnace by arranging a plurality of drying furnaces in series may be used.

The first dried film continuously formed by passing through the heating furnace 212A is then irradiated with polarized UV to the surface on the side of the first dry film or the surface on the side of the transparent substrate by the polarized UV irradiation device 213A, and the first dried film is dried. The film forms a (photo)alignment film. In that case, you may make it the angle which the conveyance direction D1 of a transparent base material and the orientation direction D2 of the photo-alignment film formed make cross|intersect. It is a schematic diagram which shows the relationship between the orientation direction D2 of the photo-alignment film formed after polarization|polarized-light UV irradiation, and the conveyance direction D1 of a transparent base material. 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 orientation direction D2 of the photo-alignment film, the angle they make represents approximately 45°. have.

The transparent substrate (first laminate) on which the photo-alignment film is continuously formed in this way is then passed through the coating device 211B to apply the composition for forming a polarizing film on the photo-alignment film, and then passes through the drying furnace 212B. By passing through the drying furnace 212B, the polymerizable liquid crystal compound contained in the composition for forming a polarizing film forms a nematic liquid crystal phase, preferably a smectic liquid crystal phase, and a second dry film is formed.

The transparent substrate that has passed through the drying furnace 212B is sufficiently removed from the solvent contained in the composition for forming a polarizing film, so that the polymerizable liquid crystal compound in the second dry film is in a liquid crystal state of a nematic liquid crystal phase, preferably a smectic liquid crystal phase. It is conveyed to the light irradiation apparatus 213B with holding|maintaining. By light irradiation by the light irradiation device 213B, the polymerizable liquid crystal compound is photopolymerized while maintaining the liquid crystal state, the polarizing film is continuously formed on the alignment film, and the present polarizer is obtained.

The polarizing film continuously formed in this way is wound around the second winding core 220A in the form of a laminate including a transparent substrate and an alignment film to obtain the form of the second roll 220 . When winding up the formed main polarizing film and obtaining a 2nd roll, you may perform co-winding using an appropriate spacer.

In this way, the transparent substrate is in the order of the first roll/applicator 211A/drying furnace 212A/polarized UV irradiation device 213A/applying device 211B/drying furnace 212B/light irradiation device 213B. By passing through the polarizer, the present polarizing film is continuously formed on the optical alignment film on the transparent substrate, and the present polarizer is manufactured.

In addition, in this manufacturing method shown in FIG. 1, although the method of manufacturing continuously from a transparent base material to this polarizing film was shown, for example, 1st roll / application|coating apparatus 211A / drying furnace 212A / polarization of a transparent base material. The first laminated body continuously formed by passing through the UV irradiation device 213A in this order is wound around the core, the first laminated body is manufactured in the form of a roll, and the first laminated body is unwound from the roll, You may manufacture this polarizer by making a 1st laminated body pass in order of the application|coating apparatus 211B / drying furnace 212B / light irradiation apparatus 213B.

This polarizer obtained by this manufacturing method is the thing of a film form and an elongate shape in the shape. When this present polarizing film is used for the liquid crystal display device mentioned later, etc., it is cut and used so that it may become a desired dimension according to the scale etc. of the liquid crystal display device.

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

Moreover, it can also be set as a circularly polarizing plate or an elliptically polarizing plate in the form of retardation film/optical-alignment film/main polarizing film by making transparent base material itself into retardation film. For example, when a uniaxially stretched 1/4 wave plate is used as the retardation film, it is possible to produce a circularly polarizing plate by RolltoRoll by setting the irradiation direction of polarized UV to be approximately 45° with respect to the transport direction of the transparent substrate. As described above, it is preferable that the quarter-wave plate used in 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.

In addition, using a 1/2 wave plate as a retardation film, a linear polarizing plate roll set by shifting the angle of the slow axis and the absorption axis of the polarizing film was produced, and a 1/4 wave plate was placed on the opposite side to the side on which the polarizing film was formed. It is also possible to set it as a broadband circularly polarizing plate by further forming.

4. Use of this polarizing film

This polarizing film can be used for 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. As the display device, for example, a liquid crystal display device, an organic electroluminescence (EL) display device, an inorganic electroluminescence (EL) display device, an electron emission display device (such as a field emission display device (FED), a surface field emission display device ( SED)), electronic paper (display apparatus using electronic ink or electrophoretic element, plasma display apparatus, projection display apparatus (eg, a grating light valve (GLV) display apparatus, a display apparatus having a digital micromirror device (DMD)) and piezoelectric ceramic displays, etc. The liquid crystal display includes any of a transmissive liquid crystal display, a transflective liquid crystal display, a reflective liquid crystal display, a direct view liquid crystal display, and a projection liquid crystal display. A display device that displays a two-dimensional image may be used, or a three-dimensional display device that displays a three-dimensional image may be used.

This polarizing film can be effectively used especially for the display apparatus of an organic electroluminescent (EL) display apparatus or an inorganic electroluminescent (EL) display apparatus.

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 by two substrates 14a and 14b.

6 and 10 are schematic diagrams showing the cross-sectional configuration of an EL display device using the present polarizing film (hereinafter referred to as “the present EL display device” in some cases).

11 is a schematic diagram showing the configuration of a projection type liquid crystal display device using the present polarizing film.

First, the present 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 arranged at a position facing the pixel electrode 22 with the liquid crystal layer 17 interposed therebetween, and the black matrix 20 is arranged 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 . On the other hand, an overcoat layer (not shown) may be provided between the color filter 15 and the transparent electrode 16 .

On the liquid crystal layer 17 side of the substrate 14b, the thin film transistor 21 and the pixel electrode 22 are regularly arranged. 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 .

As the substrate 14a and the substrate 14b, a glass substrate and a plastic substrate are used. As such a glass substrate or a plastic substrate, those made of the same material as those exemplified as the transparent substrate used for manufacturing the present polarizing film can be employed. In addition, the transparent substrate 1 of this polarizing film may serve also as the board|substrate 14a and the board|substrate 14b. When manufacturing the color filter 15 or the thin film transistor 21 formed on a board|substrate, when the process of heating to high temperature is required, a glass substrate or a quartz board|substrate is preferable.

An optimal thin film transistor can be employed depending on 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 further reduce the size of the 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 . A spacer 23 is disposed in the liquid crystal layer 17 to keep the distance between the substrate 14a and the substrate 14b constant. On the other hand, although illustrated as a columnar spacer in FIG. 3, the spacer is not limited to a columnar spacer, and has any shape as long as the distance between the substrate 14a and the substrate 14b can be kept constant.

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

Among the substrates 14a and 14b with the liquid crystal layer 17 interposed therebetween, polarizers 12a and 12b are provided outside the substrate 14b, and the present polarizer is used for at least one of them. .

Moreover, it is preferable that retardation layers (for example, a quarter wave plate or an optical compensation film) 13a and 13b are laminated|stacked. By disposing the present polarizing film on the polarizer 12b among the polarizers 12a and 12b, the function of converting incident light into linearly polarized light can be imparted to the present liquid crystal display 10 . On the other hand, the retardation films 13a and 13b may not be arranged depending on the structure of the liquid crystal display device or the type of liquid crystal compound contained in the liquid crystal layer 17, and the transparent substrate is a retardation film, and the circle including the present polarizing film When a polarizing plate is used, since the retardation film can be used as a retardation layer, the retardation layers 13a and/or 13b of FIG. 3 can also be abbreviate|omitted. A polarizing film may be further provided on the light emission side (outside) of the present polarizer.

In addition, an antireflection film for preventing reflection of external light may be disposed on the outer side of the present polarizer (when a polarizing film is further provided on the main polarizing film).

As described above, the present polarizer can be used for the polarizer 12a or 12b of the present liquid crystal display 10 of FIG. 3 . By providing this polarizer in the polarizers 12a and/or 12b, there is an effect that the thickness reduction of the present liquid crystal display device 10 can be achieved.

When this polarizer is used for the polarizer 12a or 12b, the lamination|stacking order is not specifically limited. This will be described with reference to enlarged views of portions A and B surrounded by dotted lines in FIG. 3 .

4 is an enlarged schematic cross-sectional view of a portion A of FIG. 3 . 4A1 shows that when the present polarizer 100 is used as the polarizer 12a, the polarizing film 3, the photo-alignment film 2, and the transparent substrate 1 viewed from the retardation layer 13a side are arranged in the above order. It indicates that it is installed to be placed. 4A2 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.

5 is an enlarged schematic diagram of a portion B of FIG. 3 . FIG. 5(B1) shows that when the present polarizer 100 is used as the polarizer 12b, from the retardation film 13b side, the transparent substrate 1, the photo-alignment film 2, and the main polarizing film 3 are arranged in this order. installed to be placed. FIG. 5B2 shows that when the present polarizer 100 is used as the polarizer 12b, the polarizing film 3, the photo-alignment film 2, and the transparent substrate 1 viewed from the retardation film 13b side are in this order. installed to be placed.

A backlight unit 19 serving as a light emitting 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 present polarizing film can be selected according to the characteristics of the light source.

When the present liquid crystal display device 10 is a transmissive liquid crystal display device, the white light generated from the light source in the backlight unit 19 enters the light guide, changes its path by the reflecting plate, and is diffused through the diffusion sheet. The diffused light enters the polarizer 12b from the backlight unit 19 after being adjusted to have a desired directivity by the viewing angle adjustment sheet.

Of the non-polarized incident light, only one linearly polarized light passes through the polarizer 12b of the liquid crystal panel. The 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, the alignment state of liquid crystal molecules included in the liquid crystal layer 17 changes depending on the presence or absence of a potential difference between the pixel electrode 22 and the opposing transparent electrode 16 , and light emitted from the liquid crystal display device 10 . luminance is controlled. When the liquid crystal layer 17 is in an alignment state that converts and transmits polarized light, the polarized light passes through the liquid crystal layer 17 and the transparent electrode 16 , and light in a specific wavelength range passes through the color filter 15 . It reaches the polarizer 12a, and the liquid crystal display displays the color determined by the color filter the 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, the pixel displays black. In the alignment state intermediate between these two states, the luminance of the light emitted from the liquid crystal display device 10 is also intermediate between the above-mentioned two, so this pixel displays an intermediate color.

When this liquid crystal display device 10 is a transflective liquid crystal display device, it is preferable to use what further laminated|stacked the 1/4 wavelength plate (circularly polarizing plate) on the main polarizing film side of this polarizer. At this time, the pixel electrode 22 has a transmissive part made of a transparent material and a reflective part made of a material that reflects light, and an image is displayed on the transmissive part in the same manner as in the above-described transmissive liquid crystal display device. On the other hand, in the reflection unit, external light is incident on the liquid crystal display device, and circularly polarized light passing through the main polarizing film by the action of a quarter wave plate further provided in the main polarizing film passes through the liquid crystal layer 17, and the pixel electrode ( 22) and used for display.

Next, the present EL display device 30 using the present polarizing film will be described with reference to FIG. 6 . When using this polarizing film for this EL display device, it is preferable to use this polarizing film after making it into a circularly-polarizing plate (Hereinafter, it is called "this circularly-polarizing plate" in some cases). There are two embodiments of the present circularly polarizing plate. Therefore, before describing the configuration of the present EL display device 30 and the like, two embodiments of the present circularly polarizing plate will be described with reference to FIG. 7 .

FIG. 7A is a schematic diagram showing the first embodiment of the present circularly polarizing plate 110 . The first embodiment is a circularly polarizing plate 110 in which a retardation layer (retardation film) 4 is further formed on the main polarizing film 3 in the present polarizer 100 . FIG. 7B is a schematic diagram showing a second embodiment of the present circularly polarizing plate 110 . In this 2nd embodiment, by using the transparent base material 1 (retardation film 4) to which retardation property is previously provided for the transparent base material 1 used when manufacturing this polarizer, the transparent base material 1 itself is This circularly polarizing plate 110 is assumed to have both a function as the retardation layer 4 .

As this circularly polarizing plate including this polarizing film, if it is 2nd Embodiment of this circularly-polarizing plate mentioned above, since a structure is simple, it is preferable, and in this case, it is preferable to use a quarter-wave plate as a transparent substrate, Furthermore, it is transparent substrate. It is preferable to use a quarter-wave plate as the circuit and satisfy the requirements of (A1) and (A2) below.

(A1) an angle between the absorption axis of the polarizing film and the slow axis of the 1/4 wave plate is approximately 45°;

(A2) The value of the front retardation of the 1/4 wave plate measured with light having a wavelength of 550 nm is in the range of 100 to 150 nm

Here, the manufacturing method of this circularly polarizing plate 110 is demonstrated. The second embodiment of the circularly polarizing plate 110 is, as already described, in the present manufacturing method for manufacturing the present polarizing film 100, the transparent substrate 1 to which retardation property has been previously provided as the transparent substrate 1, that is, the phase difference It can manufacture by using a film. In the first embodiment of the present circularly polarizing plate 110 , the retardation layer 4 may be formed by bonding the retardation film on the main polarizing film 3 manufactured by the present manufacturing method B. On the other hand, when the present polarizing film 100 is manufactured in the form of the second roll 220 by the present manufacturing method B, the polarizing film 100 is unwound from the second roll 220 and has a predetermined size. After cutting with , the shape of bonding the retardation film to the cut main polarizing film 100 may be sufficient, but by preparing a third roll in which the retardation film is wound on the core, the circularly polarizing plate having a film-like and elongated shape ( 110) may be manufactured continuously.

A method of continuously manufacturing the first embodiment of the present circularly polarizing plate 110 will be described with reference to FIG. 8 . This manufacturing method is

A step of continuously releasing the polarizer 100 seen from the second roll 220 and continuously releasing the retardation film from the third roll 230 on which the retardation film is wound;

A step of continuously bonding the polarizing film formed on the main polarizer 100 unrolled from the second roll 220 and the retardation film unrolled from the third roll to form the main circular polarizing plate 110;

The formed circularly polarizing plate 110 is wound around the fourth winding core 240A to obtain a fourth roll 240 .

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

Next, the present EL display device provided with the present circularly polarizing plate 110 will be described again with reference to FIG. 6 .

In the present EL display device 30, an organic functional layer 36 serving as a light emitting 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 to the organic functional layer 36 with the substrate 33 interposed therebetween, and the circularly polarizing plate 110 is used as this circularly polarizing plate 31 . The organic functional layer 36 emits light 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, which is a light emitting source, includes an electron transport layer, a light emitting layer, and a hole transport layer. 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 electroluminescent display which has the organic functional layer 36 is demonstrated, you may apply also to the inorganic electroluminescent display which has an inorganic functional layer.

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

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

When the present circularly polarizing plate 110 is used as the circularly polarizing plate 31, the lamination procedure will be described with reference to an enlarged view of portion C surrounded by a dotted line in FIG. 6 . When the circularly polarizing plate 110 is used as the circularly polarizing plate 31 , the retardation layer 4 in the circularly polarizing plate 110 is disposed on the substrate 33 side. Fig. 9 (C1) is an enlarged view using the first embodiment of the present circularly polarizing plate 110 as the circularly polarizing plate 31, and Fig. 9 (C2) is an enlarged view of the second embodiment of the present circularly polarizing plate 110 It is an enlarged view used as the polarizing plate 31.

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

Examples of the substrate 33 include ceramic substrates such as sapphire glass substrates, quartz glass substrates, soda glass substrates, and alumina; metal substrates such as copper; A plastic substrate etc. are mentioned. Although not shown, a thermally conductive film may be formed on the substrate 33 . Examples of the thermally conductive film include a diamond thin film (DLC, etc.). When the pixel electrode 35 is of a reflective type, light is emitted in a direction opposite to that of the substrate 33 . Therefore, not only transparent materials, but also non-transmissive materials such as stainless steel can be used. The substrate may be formed singly, or may be formed as a laminated substrate by bonding a plurality of substrates with an adhesive. In addition, these board|substrates are not limited to a plate-shaped thing, A film may be sufficient as them.

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

A wiring electrode of the thin film transistor 40 is provided on the substrate 33 . The wiring electrode has a low resistance and is electrically connected to the pixel electrode 35 and has a function of suppressing the resistance value low. Generally, the wiring electrode is made of Al, Al and transition metals (except Ti), Ti or nitride. Those containing any 1 type or 2 or more types of titanium (TiN) are used.

An interlayer insulating layer 34 is formed 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), photoresist, polyimide, acrylic resin, etc. As long as it has insulation, such as a coating film of the resin-based material of

Ribs 41 are formed on the interlayer insulating film 34 . The rib 41 is disposed at the periphery of the pixel electrode 35 (between adjacent pixels). As a material of the rib 41, an acrylic resin, polyimide resin, etc. are mentioned. 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, the EL element which consists of the pixel electrode 35 which is a transparent electrode, the organic functional layer 36 which is a light emission source, and the cathode electrode 37 is demonstrated. The organic functional layer 36 has at least one hole transport layer and a light emitting layer, respectively, and has, for example, an electron injection transport layer, a light emitting layer, a hole transport layer and a hole injection layer in sequence.

Examples of the pixel electrode 35 include ITO (tin-doped indium oxide), IZO (zinc-doped indium oxide), IGZO, ZnO, SnO ₂ , In ₂ O ₃ , and the like, and ITO and IZO are particularly preferable. The thickness of the pixel electrode 35 may be at least a certain thickness capable of sufficiently performing hole injection, and is preferably set to about 10 to 500 nm.

The pixel electrode 35 can be formed by a vapor deposition 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, 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). -20 at%) and the like.

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

The hole injection layer has a function of facilitating injection of holes from the pixel electrode 35, and the hole transport layer has a function of transporting holes and blocking electrons, and is also called a charge injection layer or a charge 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 and transport layer are not particularly limited and, although depending on the formation method, is preferably set to about 5 to 100 nm. Various organic compounds can be used for the hole injection layer and the hole transport layer. A vacuum deposition method can be used for the formation of the hole injection transport layer, the light emitting layer, and the electron injection transport layer in that a homogeneous thin film can be formed.

As the organic functional layer 36 as a light emission source, light emission from singlet excitons (fluorescence) is used, light emission from triplet excitons (phosphorescence) is used, light emission from singlet excitons (fluorescence) is used, and triplet excitons are used. Including those using light emission (phosphorescence) from, those formed by organic substances, those formed by organic substances and those formed by inorganic substances, including polymeric materials, low-molecular materials, high-molecular materials and low-molecular materials can be used, etc. However, it is not limited to this, The organic functional layer 36 using various well-known things for EL elements can be used for this EL display device 30. As shown in FIG.

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 weak against humidity. The desiccant 38 absorbs moisture to prevent deterioration of the organic functional layer 36 .

10 is a schematic diagram showing a cross-sectional configuration of another embodiment of the present EL display device 30. As shown in FIG. This EL display device 30 has a sealing structure using a thin film sealing film 42, and can obtain emitted light also from the opposite surface of the array substrate.

As the thin film sealing film 42, it is preferable to use a DLC film in which DLC (diamond-like carbon) is vapor-deposited on a film of an electrolytic capacitor. A DLC film|membrane has the characteristic that water permeability is very bad, and moisture-proof performance is high. Alternatively, a DLC film or the like may be formed by directly vapor-depositing on the surface of the cathode electrode 37 . Moreover, the thin film sealing film 42 may be formed by laminating|stacking a resin thin film and a metal thin film in multilayer.

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

Finally, a projection type liquid crystal display device using the present polarizing film will be described.

11 is a schematic diagram 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 this projection type liquid crystal display device.

The light bundle emitted from the light source (eg, a high-pressure mercury lamp) 111 that is the light emitting source is first the first lens array 112 , the second lens array 113 , the polarization conversion element 114 , and the overlapping lens 115 . By passing through, the luminance is uniformed and polarized in the cross-section of the anti-ray bundle.

Specifically, the light bundle emitted from the light source 111 is divided into a plurality of minute light bundles by the first lens array 112 in which the minute lenses 112a are formed in a matrix. The second lens array 113 and the superposition lens 115 are provided so that each of the divided light bundles illuminates the entire three liquid crystal panels 140R, 140G, and 140B to be illuminated, so that each liquid crystal panel incident side The surface becomes almost uniform roughness as a whole.

The polarization conversion element 114 is constituted by a polarization beam splitter array, and is disposed between the second lens array 113 and the superposition lens 115 . Accordingly, random polarization from the light source is converted into polarized light having a specific polarization direction in advance, thereby reducing light loss in the incident-side polarizer, which will be described later, and improving the luminance of the screen.

As described above, the luminance uniformed and polarized light is sequentially red, green, and blue channels by the dichroic mirrors 121, 123, and 132 for separating the three primary colors of RGB through the reflection mirror 122. are separated and incident on the liquid crystal panels 140R, 140G, and 140B, respectively.

A polarizer 142 is disposed on the incident side of the liquid crystal panels 140R, 140G, and 140B, and a polarizer 143 is disposed on the exit side, respectively. The present polarizing film can be used for the polarizers 142 and 143 .

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

The present polarizing film 100 is useful as a polarizing film having excellent durability even in optical paths such as a blue channel, a green channel, and a red channel by selecting a type of a dichroic dye suitable for a corresponding channel.

An optical image created by transmitting incident light at different transmittances for each pixel according to image data of the liquid crystal panels 140R, 140G, and 140B is synthesized by a cross dichroic prism 150, and is then combined by a projection lens 170 on the screen 180. magnified and projected on

As electronic paper, those represented by molecules such as optical anisotropy and dye molecular orientation; those represented by particles such as electrophoresis, particle movement, particle rotation, phase change; Examples include those displayed by color development/phase change, those displayed by light absorption of molecules, and those displayed by self-luminescence by combining electrons and holes. More specifically, microcapsule type electrophoresis, horizontal movement type electrophoresis, vertical movement type electrophoresis, spherical twisted ball, magnetic twisted ball, circumferential twisted ball method, charged toner, electropowder fluid, magnetophoretic type, magnetic thermal type, electrophoresis Wetting, light scattering (transparency/cloudy change), cholesteric liquid crystal/photoconductive layer, cholesteric liquid crystal, bistable nematic liquid crystal, ferroelectric liquid crystal, dichroic dye/liquid crystal dispersion type, movable film, color development by leuco dye, photochromic, electrochromic, electrodeposition, flexible organic EL, etc. are mentioned. The electronic paper may be used not only for personal use of texts and images, but also for use in advertisement signage and the like. According to this polarizing film, the thickness of electronic paper can be made thin.

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

Example

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

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

Preparation of compound (1-1) (compound represented by (1-1) below)

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 4-hydroxybenzoate, 0.23 g of dimethylaminopyridine (DMAP) and 25 g of chloroform are mixed, and under a light-shielding nitrogen atmosphere, 5° C. was stirred for 10 minutes. To the obtained liquid mixture, 2.58 g of diisopropylcarbodiimide (IPC) was added dropwise over 5 minutes, followed by stirring for 4 hours. To the obtained reaction solution, 75 g of methanol was added, crystallized, and 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 compound (1B).

¹ H-NMR (CDCl ₃ ) of 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).

Preparation of compound (1-7) (compound represented by the following (1-7))

Compound (1-7) was synthesized according to the following scheme.

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

¹ H-NMR (CDCl ₃ ) of 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 compound (4-6) was confirmed by determining the phase transition temperature of the film made of compound (4-6). The operation is as follows.

A film made of 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. When the temperature of the film made of compound (4-6) is raised to 120°C, and then when the temperature is lowered, the film undergoes a phase transition to the nematic phase at 112°C, a smectic phase transition at 110°C to the smectic A phase, and a smectic phase at 94°C. phase transitioned to phase B.

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 the measurement of the phase transition temperature of compound (4-6). Compound (4-8) raises the temperature to 140° C. and then, when the temperature is lowered, phase transitions to the nematic phase at 131° C., phase transitions to the smectic A phase at 80° C., and into the smectic B phase at 68° C. phase has been transferred

Compound (4-22) (compound represented by the following formula (4-22))

Compound (4-22) was synthesized with reference to the 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) undergoes a phase transition to a nematic phase at 106°C, a smectic A phase at 103°C, and a smectic B phase at 86°C when the temperature is lowered after raising the temperature to 140°C. phase has been transferred

Compound (4-25) (compound represented by the following formula (4-25))

Compound (4-25) was synthesized with reference to the 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 the measurement of the phase transition temperature of compound (4-6). Compound (4-25) undergoes a phase transition to the nematic phase at 119° C., a smectic A phase at 100° C., and a smectic B phase at 77° C. when the temperature is lowered after raising the temperature to 140° C. phase has been transferred

Example 1 [Preparation of the composition (A) for forming a polarizing film]

The composition (A) for polarizing film formation was obtained by mixing the following components and stirring at 80 degreeC for 1 hour. In addition, the "compound (1-7)" of the dichroic dye used here means the compound represented by said Formula (1-7), and the compound used as another dichroic dye also follows the formula number. Do the same below.

polymerizable liquid crystal compounds; compound (4-6) 75 copies

compound (4-8) 25 copies

dichroic pigment; Compound (1-7) 3.0 copies

compound (2-17) 2.5 copies

compound (2-29) 1.5 copies

compound (2-32) 2.0 copies

polymerization initiator; 2-dimethylamino-2-benzyl-1-(4-morpholinophenyl)butan-1-one (Irgacure 369; manufactured by Chiba Specialty Chemicals) part 6

leveling agent; Polyacrylate compound (BYK-361N; manufactured by BYK-Chemie) Part 1.2

solvent; toluene 250 copies

1. X-ray diffraction measurement

A 2 mass % aqueous solution (composition for alignment layer formation) of polyvinyl alcohol (polyvinyl alcohol 1000 complete saponification type, manufactured by Wako Pure Chemical Industries, Ltd.) is applied on a glass substrate by a spin coating method, dried and then the thickness A 100 nm film was formed. Next, the orientation layer was formed by giving a rubbing process to the surface of the obtained film|membrane. The rubbing treatment was performed using a semi-automatic rubbing device (trade name: LQ-008 type, manufactured by Joyo Kogaku Co., Ltd.), and a press-in amount of 0.15 mm with cloth (brand name: YA-20-RW, manufactured by Yoshikawa Kako Co., Ltd.) , rotation speed of 500 rpm, and 16.7 mm/s conditions. The composition (A) for forming a polarizing film is applied on the alignment film prepared in this way by spin coating, and then dried by heating on a hot plate at 120° C. for 1 minute, then rapidly cooled to room temperature and dried on the alignment layer. A film was formed. Next, using a UV irradiation device (SPOT CURE SP-7; manufactured by Ushio Denki Co., Ltd.), the dried film is irradiated with ultraviolet rays at an exposure amount of 2000 mJ/cm 2 (based on 365 nm), whereby the polymerizable properties contained in the dry film are irradiated. The liquid crystal compound was polymerized while maintaining the liquid crystal state of the polymerizable liquid crystal composition, and a polarizing film was formed from the dried film. It was 1.7 micrometers when the thickness of the polarizing film at this time was measured with the laser microscope (OLS3000 manufactured by Olympus Corporation). As a result of similarly performing X-ray diffraction measurement with respect to the polarizing film using an X-ray diffraction apparatus X'Pert PRO MPD (manufactured by Spectris Co., Ltd.), the peak half maximum width (FWHM) = about 0.17° near 2θ = 20.2° A sharp diffraction peak (Bragg peak) was obtained. In addition, the same result was obtained also in the incidence from the rubbing perpendicular|vertical direction. The order period (d) calculated from the peak position was about 4.4 Å, confirming that a structure reflecting the higher-order smectic phase was formed.

2. Preparation of photo-alignment film on transparent film

Using a triacetyl cellulose film (KC8UX2M, manufactured by Konica Minolta Co., Ltd.) as a transparent substrate, a solution obtained by dissolving 5% of a photo-alignment polymer represented by the following formula (3) in toluene is applied by a bar coating method, 120 It dried at ℃ to obtain a dry film. Polarized UV was irradiated on this dry film to obtain a photo-alignment film. Polarization UV treatment was performed under the condition that the intensity measured at a wavelength of 365 nm was 100 mJ using a UV irradiation device (SPOT CURE SP-7; manufactured by Ushio Denki Co., Ltd.).

3. Fabrication of polarizing film

On the film having the photo-alignment film obtained as described above, the composition (A) for forming a polarizing film was applied by a bar coating method (#5 17 mm/s), and after drying by heating in a drying oven at 120° C. for 1 minute , and cooled to room temperature. Then, using a UV irradiation device (SPOT CURE SP-7; manufactured by Ushio Denki Co., Ltd.), ultraviolet rays with an exposure amount of 2000 mJ/cm 2 (based on 365 nm) are irradiated to the layer formed of the composition for forming a polarizing film, and the drying thereof The polymerizable liquid crystal compound contained in the film was polymerized while maintaining the liquid crystal state of the polymerizable liquid crystal composition, and a polarizing film was formed from the dried film. It was 1.6 micrometers when the film thickness of the polarizing film at this time was measured with the laser microscope (OLS3000 manufactured by Olympus Corporation). What was obtained in this way was a polarizer containing a polarizing film and a transparent base material.

4. Measurement of Polarization, Transmittance, and Color

In order to confirm the usefulness of the polarizer, the visibility corrected polarization degree, the visibility corrected transmittance, the chromaticity a* value, the chromaticity b* value, the orthogonal a* and the orthogonal b* were measured as follows.

In the wavelength range of 380 nm to 780 nm, the transmittance (T ¹ ) in the transmission axis direction and transmittance (T ² ) in the absorption axis direction were measured in a spectrophotometer (UV-3150 manufactured by Shimadzu Corporation) with a folder with a polarizer set. Measurements were made by the double beam method using one device. The folder has a mesh that cuts the amount of light by 50% on the reference side. Using the following formulas (Formula 1) and (Formula 2), the transmittance and polarization degree of a single body at each wavelength are calculated, and the visibility is corrected by the 2 degree field of view (C light source) of JIS Z 8701, and the visibility correction single body Transmittance (Ty) and visibility corrected polarization degree (Py) were calculated. In addition, the chromaticity a* and b* in the L*a*b* (CIE) color system were calculated from the monochromatic transmittance measured in the same way by using the color matching function of the C light source. Moreover, orthogonal a* and orthogonal b* in the L*a*b*(CIE) color system were computed from the orthogonal transmittance|permeability measured similarly using the color matching function of C light source. Chromaticity a*, chromaticity b*, orthogonal a*, and orthogonal b* may be determined to be neutral colors as the values are closer to 0. These results are shown in Table 4.

Monolith transmittance (%)=(T1+T2)/2 (Equation 1)

Polarization degree (%)=(T1-T2)/(T1+T2)×100 (Equation 2)

Example 2

1. Fabrication of polarizing film

A polarizing film was produced in the same manner as in Example 1 except that the wire width of the bar of the bar coater and the coating speed were changed (#7 15 mm/s). It was 1.8 micrometers when the film thickness of the polarizing film at this time was measured with the laser microscope (Olympus Co., Ltd. product OLS3000).

2. Measurement of Polarization, Transmittance, and Color

Table 4 shows the results of measuring the visibility corrected monolithic transmittance (Ty) and the visibility corrected polarization degree (Py) and chromaticity a*, chromaticity b*, orthogonal a* and orthogonal b* of the prepared polarizing film in the same manner as in Example 1. indicates.

Example 3 [Preparation of the composition (B) for forming a polarizing film]

The composition (B) for polarizing film formation was obtained by mixing the following components and stirring at 80 degreeC for 1 hour.

polymerizable liquid crystal compounds; compound (4-22) 75 copies

compound (4-25) 25 copies

dichroic pigment; Compound (1-1) 3.0 copies

compound (2-15) 2.5 copies

compound (2-20) Part 1.2

compound (2-33) 2.5 copies

polymerization initiator; 2-dimethylamino-2-benzyl-1-(4-morpholinophenyl)butan-1-one (Irgacure 369; manufactured by Chiba Specialty Chemicals) part 6

leveling agent; Polyacrylate compound (BYK-361N; manufactured by BYK-Chemie) Part 1.2

solvent; toluene 250 copies

1. Fabrication of polarizing film

In the same manner as in Example 1, except that the composition (A) for forming a polarizing film was changed to the composition (B) for forming a polarizing film, and the wire width and coating speed of the bar of the bar coater were changed (#5 25 mm/s). Thus, a polarizing film was produced. It was 1.7 micrometers when the film thickness of the polarizing film at this time was measured with the laser microscope (Olympus Co., Ltd. product OLS3000).

2. Measurement of Polarization, Transmittance, and Color

Table 4 shows the results of measuring the visibility corrected monolithic transmittance (Ty) and the visibility corrected polarization degree (Py) and chromaticity a*, chromaticity b*, orthogonal a* and orthogonal b* of the prepared polarizing film in the same manner as in Example 1. indicates.

Example 4

1. Fabrication of polarizing film

A polarizing film was produced in the same manner as in Example 3 except that the wire width of the bar of the bar coater and the coating speed were changed (#7 20 mm/s). It was 2.0 micrometers when the film thickness of the polarizing film at this time was measured with the laser microscope (Olympus Co., Ltd. product OLS3000).

2. Measurement of Polarization, Transmittance, and Color

Table 4 shows the results of measuring the visibility corrected monolithic transmittance (Ty) and the visibility corrected polarization degree (Py) and chromaticity a*, chromaticity b*, orthogonal a* and orthogonal b* of the prepared polarizing film in the same manner as in Example 1. indicates.

Example 5

1. Preparation of black polarizing film

A polarizing film was produced in the same manner as in Example 3 except that the wire width of the bar of the bar coater and the coating speed were changed (#5 50 mm/s). It was 2.2 micrometers when the film thickness of the polarizing film at this time was measured with the laser microscope (OLS3000 manufactured by Olympus Corporation).

2. Measurement of Polarization, Transmittance, and Color

Table 4 shows the results of measuring the visibility corrected monolithic transmittance (Ty) and the visibility corrected polarization degree (Py) and chromaticity a*, chromaticity b*, orthogonal a* and orthogonal b* of the prepared polarizing film in the same manner as in Example 1. indicates.

Example 6 [Preparation of the composition (C) for forming a polarizing film]

The composition (C) for polarizing film formation was obtained by mixing the following components and stirring at 80 degreeC for 1 hour.

polymerizable liquid crystal compounds; compound (4-6) 75 copies

compound (4-8) 25 copies

dichroic pigment; Compound (1-1) Part 3.6

compound (2-15) 3.0 copies

compound (2-18) 1.5 copies

compound (2-27) 2.0 copies

compound (2-32) 1.5 copies

polymerization initiator; 2-dimethylamino-2-benzyl-1-(4-morpholinophenyl)butan-1-one (Irgacure 369; manufactured by Chiba Specialty Chemicals) part 6

leveling agent; Polyacrylate compound (BYK-361N; manufactured by BYK-Chemie) Part 1.2

solvent; toluene 250 copies

1. Fabrication of polarizing film

In the same manner as in Example 1, except that the composition (A) for forming a polarizing film was changed to the composition (C) for forming a polarizing film, and the wire width and coating speed of the bar of the bar coater were changed (#7 20 mm/s). Thus, a polarizing film was produced. It was 2.0 micrometers when the film thickness of the polarizing film at this time was measured with the laser microscope (Olympus Co., Ltd. product OLS3000).

2. Measurement of Polarization, Transmittance, and Color

Table 4 shows the results of measuring the visibility corrected monolithic transmittance (Ty) and the visibility corrected polarization degree (Py) and chromaticity a*, chromaticity b*, orthogonal a* and orthogonal b* of the prepared polarizing film in the same manner as in Example 1. indicates.

Example 7

1. Preparation of black polarizing film

A polarizing film was produced in the same manner as in Example 6 except that the wire width of the bar of the bar coater and the coating speed were changed (#5 50 mm/s). It was 2.2 micrometers when the film thickness of the polarizing film at this time was measured with the laser microscope (OLS3000 manufactured by Olympus Corporation).

2. Measurement of Polarization, Transmittance, and Color

Table 4 shows the results of measuring the visibility corrected monolithic transmittance (Ty) and the visibility corrected polarization degree (Py) and chromaticity a*, chromaticity b*, orthogonal a* and orthogonal b* of the prepared polarizing film in the same manner as in Example 1. indicates.

Comparative Example 1

1. Fabrication of iodine-PVA polarizer

A polyvinyl alcohol film having an average degree of polymerization of about 2,400, a degree of saponification of 99.9 mol% or more and a thickness of 75 μm is uniaxially stretched to about 5 times by dry method, and immersed in pure water at 60° C. for 1 minute while maintaining the tension state, It was immersed in the aqueous solution whose mass ratio of /potassium iodide/water is 0.1/5/100 at 28 degreeC for 60 second. Then, it immersed in the aqueous solution whose mass ratio of potassium iodide / boric acid / water is 810.5/7.5/100 at 72 degreeC for 300 second. Subsequently, after washing|cleaning for 5 second with 10 degreeC pure water, it dried at 80 degreeC for 3 minutes, and obtained the polarizer by which the iodine adsorption|suction orientation was carried out to the polyvinyl alcohol resin film.

2. Measurement of Polarization, Transmittance, and Color

Table 4 shows the results of measuring the transmittance (Ty) of the manufactured polarizer and the corrected polarization (Py) and chromaticity a*, chromaticity b*, orthogonal a* and orthogonal b* of the manufactured polarizer in the same manner as in Example 1. indicates.

All of the polarizing films of Examples 1-7 were thinner than the conventional iodine-PVA polarizer so that Table 4 may show. In addition, any of the polarizing films of Examples 1 to 7 showed neutral color properties.

Example 8

1. Preparation of photo-alignment film on retardation film

As a transparent substrate, a retardation film (uniaxially stretched film WRF-S (modified polycarbonate resin)) instead of a triacetylcellulose film (KC8UX2M, manufactured by Konica Minolta Co., Ltd.), retardation value 137.5 nm, thickness 50 μm, Teijin Gassei Co., Ltd. ) production), a solution obtained by dissolving 5% of the photo-alignment polymer represented by the above formula (3) in cyclopentanone was applied by a bar coating method, and dried at 120° C. to obtain a dry film. Polarized UV was irradiated on this dry film to obtain a photo-alignment film. Polarization UV treatment was performed under the condition that the intensity measured at a wavelength of 365 nm was 100 mJ using a UV irradiation device (SPOT CURE SP-7; manufactured by Ushio Denki Co., Ltd.). In addition, it implemented so that the irradiation direction of polarization|polarized-light UV might become 45 degrees with respect to the slow axis of retardation film at this time.

2. Manufacture of circularly polarizing plate

After applying the composition (C) for forming a polarizing film on the photo-alignment film of the retardation film having the produced photo-alignment film by a bar coating method (#7 20 mm/s), and drying by heating in a drying oven at 120 ° C. for 1 minute, cooled to room temperature. Then, using a UV irradiation device (SPOT CURE SP-7; manufactured by Ushio Denki Co., Ltd.), ultraviolet rays with an exposure amount of 2000 mJ/cm 2 (based on 365 nm) are irradiated to the layer formed of the composition for forming a polarizing film, and the drying thereof A circularly polarizing plate was produced by polymerizing the polymerizable liquid crystal compound contained in the film while maintaining the liquid crystal state of the polymerizable liquid crystal composition, and forming a polarizing film from the dried film. It was 2.0 micrometers when the film thickness of the polarizing film at this time was measured with the laser microscope (Olympus Co., Ltd. product OLS3000).

3. Confirmation of anti-reflection performance

When the retardation film side of the obtained circularly polarizing plate and the aluminum metal plate were bonded through an adhesive, the metallic luster observed in the aluminum metal plate single body was lost, and a uniform black display was obtained. Thus, it can be seen that the circularly polarizing plate produced with the present polarizing film has good antireflection properties.

This polarizing film is very useful in manufacturing a liquid crystal display device, an (organic) EL display device, and a projection type liquid crystal display device.

1: Transparent substrate 2: Photo-alignment film
3: Main polarizing film 4: Retardation layer
100: present polarizer 210: first roll
210A: winding core 220: second roll
220A: core 230: third roll
230A: winding core 240: fourth roll
240A: winding core 211A, 211B: applicator
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: retardation 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: circularly polarizing plate
32: retardation film 33: substrate
34: interlayer insulating film 35: pixel electrode
36: organic functional layer 37: cathode electrode
38: 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: superimposed lens
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 of a polymerizable liquid crystal compound, at least one dichroic dye (1) having an absorption maximum in a wavelength range of 380 to 550 nm when light absorption is measured by dispersing it in the polymer, and a wavelength of 550 to A polarizing film comprising at least two dichroic dyes (2) having absorption maxima in a range of 700 nm. The polarizing film according to claim 1, wherein when the dichroic dye (1) is dispersed in a polymer formed of a polymerizable liquid crystal compound and light absorption is measured, the polarizing film has an absorption maximum in a wavelength range of 400 to 550 nm. The at least two dichroic dyes (2) having absorption maxima in the wavelength range of 550 to 700 nm when light absorption is measured by dispersing them in the polymer according to claim 1 or 2,
When the light absorption is measured by dispersing in the polymer,
A dichroic dye (2-1) having an absorption maximum in a wavelength range of 550 to 600 nm;
A polarizing film comprising a dichroic dye (2-2) having an absorption maximum in a wavelength range of 600 to 700 nm. The polarizing film according to any one of claims 1 to 3, wherein the polymerizable liquid crystal compound is a compound exhibiting a smectic liquid crystal phase. The polarizing film according to any one of claims 1 to 4, wherein a Bragg peak is obtained in X-ray diffraction measurement. The color coordinate a* value and b* value in the L*a*b* color space system according to any one of claims 1 to 5, wherein the relationship of the following formulas (1F) and (2F) is satisfied polarizing film.
-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. The polarizing film according to any one of claims 1 to 7, wherein the dichroic dye (2) is composed 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 a formula (AR2-1), a formula (AR2-2), or a 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 the number of bonds.

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

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

(Wherein, 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 one of formulas (R ^1-1 ) to (R ^1-3 ).

(Wherein, ma is an integer of 0 to 10, and when there are two ma in the same group, these two ma are the same or different from each other. * indicates the number of bonds.)
R ² is a group represented by any of the formulas (R ² -1) to (R ² -6).

(Wherein, mb is an integer from 0 to 10.)] A polarizer formed by forming the polarizing film according to any one of claims 1 to 9 on a transparent substrate. As a manufacturing method of the polarizer of Claim 10,
A step of preparing a laminate having an alignment film on a transparent substrate;
When light absorption is measured by dispersing a polymerizable liquid crystal compound and a polymer formed of the polymerizable liquid crystal compound on the alignment layer of the laminate, a dichroic dye having an absorption maximum in a wavelength range of 380 to 550 nm. (1) a step of applying a composition containing one, two dichroic dyes (2) having an absorption maximum in a wavelength range of 550 to 700 nm, and a solvent;
A step of polymerizing the polymerizable liquid crystal compound included in the composition
A manufacturing method having The manufacturing method according to claim 11, wherein the transparent substrate is a plastic substrate, and the alignment film is a photo-alignment film. The liquid crystal display device provided with the polarizing film in any one of Claims 1-9. A circularly polarizing plate having the polarizing film according to any one of claims 1 to 9 and a λ/4 layer, and satisfying the requirements of (A1) and (A2) below.
(A1) the angle between the absorption axis of the polarizing film and the slow axis of the λ/4 layer is 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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