JPH08225750A - Disazo compound and dye-based polarizing film containing the same - Google Patents

Abstract

PURPOSE: To obtain the subject compound having a specific group as a substituting group of an amino group in a J-acid skeleton and having an excellent polarizing property and also durability at a high temperature and a high humidity in using as a dye for a polarizing film. CONSTITUTION: The objective disazo compound is composed of formula I in a form of free acid [Q1 is a (substituted) phenyl or a naphthyl substituted by more than one sulfo group; R1 and R2 are independently H, hydroxy or a lower alkyl, etc.; R is hydroxy and may form a complex condensation: O-Cu-0 together with R2 ]. The Q1 is preferably a phenyl of formula II (R3 and R4 ) are each independently H, nitro or sulfo group, etc.) or a naphthyl of formula III (R5 and R6 are each independently H, hydroxy or sulfo group). At least one kind of the compound of the formula I and at least one kind of the other organic dye are contained in a polarizing film substrate composed of polyvinyl alcohol or its derivative to obtain the objective dye-based polarizing film.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dye, especially a disazo compound useful as a dye for a polarizing film, and a dye-based polarizing film containing the same.

[0002]

2. Description of the Related Art A polarizing film is made of a stretched and oriented film of polyvinyl alcohol or a derivative thereof, or a polyene-based film in which polyene is produced and oriented by dehydrochlorination of a polyvinyl chloride film or dehydration of a polyvinyl alcohol-based film. It is manufactured by adding iodine or a dichroic dye as a polarizing element to a polarizing film substrate. Among these, the iodine-based polarizing film has excellent initial polarization performance, but has poor durability against heat and water, and therefore has a problem that its performance deteriorates at high temperature and high humidity. In order to improve durability, a method of treating with an aqueous solution containing formalin or boric acid, a method of using a polymer film having a low moisture permeability as a protective film, and the like have been considered, but it is still not sufficient. In addition, recently, liquid crystal display materials are increasingly used for indoor applications such as office automation equipment such as offices, as well as outdoor applications, especially for vehicles. Therefore, it is necessary for the polarizing film to have excellent durability under more severe conditions, that is, high temperature and high humidity conditions. On the other hand, a dye-based polarizing film using a dichroic dye as a polarizing element is more excellent in durability against heat and water than an iodine-based polarizing film, but generally has an insufficient initial polarizing performance. Difficult to cause discoloration even in a high temperature state, and as a dye-based polarizing film having high-performance polarization performance, for example, JP-A-2-96102 discloses a dye obtained by adsorbing a metal-containing disazo dye on a polymer film. System polarizing films are described.

[0003]

However, the dye-based polarizing film has not yet fully met the needs of consumers.

[0004]

DISCLOSURE OF THE INVENTION The inventors of the present invention provide a compound having excellent polarization performance and excellent durability under high temperature and high humidity conditions, especially when used as a dye for a polarizing film. Therefore, as a result of intensive studies, they found that a disazo compound having a specific group as a substituent of an amino group in the J acid skeleton was effective, and completed the present invention. That is, the present invention provides the following formula (I) in the form of free acid.

[0005]

[Chemical 4]

(In the formula, Q ₁ represents a phenyl group, a substituted phenyl group or a naphthyl group substituted by at least one sulfo, and R ₁ and R ₂ are each independently a hydrogen atom, a hydroxy group or a lower alkyl group. , A lower alkoxy group or a substituted amino group, R represents a hydroxy group, and R ₂ and R may be taken together to form a complex bond O—Cu—O.), And The present invention provides a dye-based polarizing film containing the disazo compound in a polarizing film substrate.

In the formula (I), the disazo compound in which R ₂ and R together form a complex bond O-Cu-O is represented by the following formula (II) in the form of a free acid.

[0008]

Embedded image

(In the formula, Q ₁ and R ₁ have the same meanings as described above).

In formulas (I) and (II), Q₁Nothing
Substituted phenyl group, substituted phenyl group, or less
A naphthyl group substituted by at least one sulfo group
It Examples of the substituent of the phenyl group include a nitro group and a sulfur group.
Rufo group, sulfamoyl group, alkyl group, alkoxy
Group, hydroxy group, substituted amino group, carboxy group
And a halogen atom, where the position of the amino group is
Examples of the substituent include a methyl group, an ethyl group, an acetyl group
And β-hydroxyethyl group and the like. Also,
The naphthyl substituent does not include hydroxy or sulfo groups.
Which can be mentioned. Q₁Preferred as a phenyl group represented by
In addition to unsubstituted phenyl groups, new ones include nitro groups and
Ruho group, sulfamoyl group, C₁~ C_FourAn alkyl group of
C₁~ C _FourAlkoxy, hydroxy, substituted
Selected from amino group, carboxy group and halogen atom
A phenyl group substituted with one or two substituents
is there. Such preferred phenyl groups have the formula

[0011]

[Chemical 6]

(Wherein R ₃ and R ₄ are each independently a hydrogen atom, a nitro group, a sulfo group, a sulfamoyl group,
A C ₁ -C ₄ alkyl group, a C ₁ -C ₄ alkoxy group,
It represents a hydroxy group, a substituted amino group, a carboxy group or a halogen atom. ). Of these, a nitro group, a sulfo group, a sulfamoyl group, a methyl group, an ethyl group, a methoxy group, an ethoxy group, a carboxy group or a phenyl group substituted with a chlorine atom is preferable. Further, the naphthyl group represented by Q ₁ is preferably a 2-naphthyl group, and the 2-naphthyl group is a 2-naphthyl group substituted with at least one sulfo group, or at least one sulfo group. A 2-naphthyl group which is substituted and further substituted with 1 to 2 substituents selected from a hydroxy group and a sulfo group can be mentioned. Such preferred naphthyl groups have the formula:

[0013]

[Chemical 7]

(In the formula, R ₅ and R ₆ each independently represent a hydrogen atom, a hydroxy group or a sulfo group). The lower alkyl group and lower alkoxy group represented by R ₁ and R ₂ in formula (I), and the lower alkyl group and lower alkoxy group represented by R ₁ in formula (II) each have 1 to 4 carbon atoms. Can be about
Further, examples of the substituent of the amino group include a methyl group, an ethyl group, an acetyl group, a carbamoyl group and a methylsulfonyl group. Preferred R ₁ and R ₂ are each independently a hydrogen atom, a hydroxy group, a methyl group, an ethyl group, a methoxy group, an ethoxy group, an acetylamino group, a methylsulfonylamino group, a ureido group or a methylamino group. Among them, preferred R ₂ is a hydroxy group.

The disazo compound represented by the formula (I) can be produced, for example, by the method described below. That is, the aromatic amine represented by the formula Q ₁ —NH ₂ (III) (wherein Q ₁ has the above-mentioned meaning) is diazotized, and the obtained diazo compound is converted into the following formula (IV)

[0016]

Embedded image

An aniline compound represented by the formula (wherein R ₁ and R ₂ have the above meanings) or a ω-methanesulfonate compound thereof is coupled. Then, after hydrolyzing the obtained coupling product as needed,
It is diazotized by a conventional method, and the resulting diazotized product is represented by the following formula (V)

[0018]

[Chemical 9]

The disazo compound represented by the formula (I) can be obtained by coupling with the compound represented by or a salt thereof. During the above process, the formula (V)
The compound of formula (VI)

[0020]

[Chemical 10]

A compound represented by the following formula (VII)

[0022]

[Chemical 11]

3-amino-8-naphthol represented by
Reacting with 6-sulfonic acid or a salt thereof in an aqueous medium,
It can be produced by hydrolyzing the obtained reaction product. The disazo compound of formula (II) is the compound of formula (I), wherein R ₂ is a hydroxy group,
The hydroxy group and 1-hydroxy-3-sulfo-
A copper complex is formed with a hydroxy group of 2,6-naphthylene, and the disazo compound represented by the formula (II) is, for example, in place of the aniline compound represented by the formula (IV), Below formula (IVa)

[0024]

[Chemical 12]

Using an aniline compound represented by the formula (wherein X ₀ represents a hydrogen atom or a methyl group and R ₁ represents the above meaning) or its ω-methanesulfonate compound, the same procedure as described above is carried out. After the disazo compound is obtained, it can be produced by forming a complex copper by a known method. Further, the disazo compound (copper complex) represented by the formula (II) is subjected to a demetallation reaction by a conventional method, for example, treatment in a strongly acidic aqueous medium, or a chelating agent such as ethylenediaminetetraacetic acid is used. By subjecting it to the demetallation reaction used, it is possible to obtain a disazo compound represented by the formula (I) in which both R and R ₂ are hydroxy groups.

Examples of the aromatic amine represented by the formula (III) include the followings. Aniline, 2-, 3- or 4-nitroaniline, 2
-, 3- or 4-aminobenzenesulfonic acid, 5-aminobenzene-1,3-disulfonic acid, 2-aminobenzene-1,4-disulfonic acid, 4-aminobenzene-
1,2-disulfonic acid, 2-, 3- or 4-sulfamoylaniline, 2-, 3- or 4-aminobenzoic acid, 2-, 3- or 4-chloroaniline, 2,5-dichloroaniline, 2-, 3- or 4-bromoaniline, 2-, 3- or 4-methylaniline, 2-, 3-
Or 4-ethylaniline, 2-, 3- or 4-methoxyaniline, 2-, 3- or 4-ethoxyaniline, 2-, 3- or 4-hydroxyaniline, 4-di (β-hydroxyethyl) aminoaniline , 1-aminonaphthalene-4-, 5-, 6-, 7- or 8-sulfonic acid, 2-aminonaphthalene-1-, 5-, 6-, 7-
Or 8-sulfonic acid, 1-aminonaphthalene-4,7
-, 4,6-, 3,7-, 3,8- or 3,6-disulfonic acid, 2-aminonaphthalene-4,8-, 6,8
-, 3,6-, 1,5- or 5,7-disulfonic acid,
1-aminonaphthalene-3,6,8-trisulfonic acid,
2-aminonaphthalene-3,6,8- or 4,6,8
-Trisulfonic acid, 2-amino-5-hydroxynaphthalene-7-sulfonic acid, 2-amino-8-hydroxynaphthalene-6-sulfonic acid and the like.

Examples of the aniline compound represented by the formula (IV) include the followings. Aniline, 2- or 3-methylaniline, 2- or 3-ethylaniline, 2- or 3-methoxyaniline, 2- or 3-ethoxyaniline, 2- or 3-
Hydroxyaniline, 3-acetylaminoaniline, 3
-Carbamoylaminoaniline, 2-methoxy-5-methylaniline, 2-methoxy-5-ethoxyaniline,
2,5-dimethoxyaniline, 2,5-diethoxyaniline, 2-methoxy-5-carbamoylaminoaniline, 2-methoxy-5- (methylsulfonylamino) aniline and the like.

The aniline compound represented by the formula (IVa) is
Among the compounds exemplified above as the compound of the formula (IV), those having a hydroxy group or a methoxy group at the 2-position of aniline can be used.

Formula (I) or formula thus obtained
The disazo compound represented by (II) may be in the form of a free acid, but it is usually preferably used in the form of a sodium salt, and other salts such as a lithium salt, a potassium salt, an ammonium salt, an ethanolamine salt and an alkylamine. It can also be used in the form of salt or the like.

When used as a dye for a polarizing film, the disazo compound represented by the formula (I) or the formula (II) exhibits excellent polarization performance and excellent durability under high temperature and high humidity conditions. , And by using with other organic dyes,
It is possible to correct the hue and improve the polarization performance. As the other organic dye used in this case, any dye may be used as long as it is a dye having absorption characteristics in a wavelength region different from the absorption wavelength region of the disazo compound used in the present invention and having high dichroism, Specifically, the following items described in the color index (CI) are exemplified.

Sea Eye Direct Yellow 12,
C-I Direct Yellow 28, C-I
Direct Yellow 44, C-I Direct
Orange 26, C-I Direct Orange 39
, C-I Direct Orange 107, C-I Direct Red 2, C-I Direct
Red 31, Sea Eye Direct Red 79, Sea Eye Direct Red 81 and Sea Eye
Direct Red 247 etc.

The dye-based polarizing film of the present invention comprises a dichroic dye comprising the disazo compound represented by the formula (I) and / or the formula (II), or a dichroic dye comprising the disazo compound and another organic dye. It can be produced by incorporating a dye into a polymer film as a polarizing film substrate by a known method.

As the polymer film, for example, polyvinyl alcohol or a derivative thereof, an olefin such as ethylene or propylene, or an unsaturated carboxylic acid such as crotonic acid, acrylic acid, methacrylic acid or maleic acid may be used. A modified product, EVA (ethylene / vinyl acetate) resin, saponified EVA resin, nylon resin, polyester resin, or the like is used. Among them, a film made of polyvinyl alcohol or a derivative thereof is preferably used from the viewpoint of dye adsorption and orientation. In order to incorporate a dichroic dye into such a polymer film, a method of dyeing the polymer film is usually adopted. Dyeing can be performed as follows, for example. First, a dichroic dye is dissolved in water to prepare a dye bath. The dye concentration in the dye bath is not particularly limited, but is usually selected from the range of about 0.0001 to 10% by weight. If necessary, a dyeing aid may be used, and for example, Glauber's salt is preferably used at a concentration of about 1 to 10% by weight. The polymer film is immersed in the dyeing bath thus prepared for dyeing. The dyeing temperature is preferably about 40 to 80 ° C. The orientation of the dichroic dye is
It is performed by stretching a polymer film. As the stretching method, any known method such as a wet method or a dry method may be adopted. The stretching of the polymer film may be performed before dyeing. The polymer film containing and orienting the dichroic dye is subjected to post-treatment such as boric acid treatment by a known method, if necessary. Such post-treatment is carried out for the purpose of improving the light transmittance, the degree of polarization and the durability of the polarizing film. The conditions of the boric acid treatment differ depending on the type of polymer film used and the type of dye used, but generally, the boric acid concentration of the boric acid aqueous solution is in the range of 1 to 15% by weight, preferably 5 to 10% by weight. , Processing is 3
It is carried out in a temperature range of 0 to 80 ° C, preferably 50 to 75 ° C. Furthermore, if necessary, a fixing treatment may be performed together with an aqueous solution containing a cationic polymer compound. The dye-based polarizing film thus obtained can be used as a polarizing plate by laminating a protective film having excellent optical transparency and mechanical strength on one side or both sides thereof. The material for forming the protective film may be one that has been conventionally used. For example, in addition to cellulose acetate films and acrylic films, fluorine-based films such as tetrafluoroethylene / hexafluoropropylene-based copolymers. A film made of polyester resin, polyolefin resin, or polyamide resin is used.

[0034]

The disazo compound of the present invention is useful as a dye, especially as a dye for a polarizing film. And since the dye-based polarizing film containing this compound has a high polarizing performance comparable to that of a polarizing film using iodine, and is also excellent in durability,
It is suitable for various liquid crystal displays, especially for outdoor applications requiring high polarization performance and durability (especially when mounted on a car), industrial industrial instruments used in various environments, and the like.

[0035]

The present invention will be described in more detail with reference to the following examples, which are merely illustrative and do not limit the present invention. The% and parts in the examples are
Unless stated otherwise, it is based on weight.

Example 1 3-Amino-8-naphthol-6-sulfonic acid 24.0
Part is dispersed in 250 parts of water, sodium hydroxide is added, and
Prepare to H6-7 and heat to 40 ° C. Then O-
Acetylsalicyloyl chloride (19.9 parts) was added little by little, and sodium hydroxide was appropriately added during this period to keep the pH around 6 to 7. After reacting for a further 2 hours, sodium hydroxide is added to adjust the pH to 8-9 and the temperature is raised to 80 ° C. to react for 5 hours. Then, after cooling, 35% hydrochloric acid is added to adjust the pH to 4, sodium chloride is added to salt out, and the precipitated crystals are filtered to obtain an intermediate (1) having the following structure.

[0037]

[Chemical 13]

Separately, 17.3 parts of sulfanilic acid was added to 20 parts of water.
After being dispersed in 0 part, 20.9 parts of 35% hydrochloric acid and then 6.9 parts of sodium nitrite are added, and the mixture is reacted at 5 ° C. for 1 hour. After adding 15.3 parts of 2,5-dimethoxyaniline thereto and stirring at 5 to 10 ° C for 1 hour, sodium carbonate was added to adjust the pH to 3, and the mixture was further stirred to complete the coupling reaction and filtered to obtain the monoazo compound. To get After dispersing the obtained monoazo compound in 300 parts of water, 35
% Hydrochloric acid 20.9 parts and then sodium nitrite 6.9 parts are added to diazotize to obtain a reaction solution of a monoazodiazodide. Then, 36.0 parts of the intermediate (1) is dispersed in 400 parts of water, and sodium hydroxide is added to adjust the pH to 8,
While maintaining this pH by appropriately adding sodium hydroxide, the reaction solution of the monoazodiazo compound obtained above was injected and stirred to complete the coupling reaction. Salting out was performed with sodium chloride, and the precipitated crystals were filtered to obtain a disazo compound having the following structure.

[0039]

Embedded image

This compound has a λmax 565 in an aqueous medium.
nm is shown.

Example 2 75 parts of the disazo compound obtained in Example 1 was added to 1500 parts of water, and 24 parts of anhydrous copper sulfate and monoethanolamine 3 were added.
Add 0 parts and heat to 95 ° C. and react for 16 hours. Sodium chloride was added to the reaction solution for salting out, followed by filtration to obtain a disazo compound having the following structure.

[0042]

[Chemical 15]

This compound has a λmax 617 in an aqueous medium.
nm is shown.

Example 3 40 parts of the disazo compound obtained in Example 2 was added to 750 parts of water, 29 parts of ethylenediaminetetraacetic acid was added, and then sodium hydroxide was added to adjust the pH to 5 and stirred at 30 to 40 ° C. for 3 hours. To do. Next, sodium chloride was added for salting out, and the precipitated crystals were filtered to obtain a disazo compound having the following structure.

[0045]

Embedded image

This compound has a λmax of 567 in an aqueous medium.
nm is shown.

Example 4 18.0 parts of 4-acetoxybenzoic acid was dissolved in 200 parts of O-dichlorobenzene, 15.5 parts of thionyl chloride was added, the temperature was raised to 70 to 80 ° C., and the reaction was carried out for 6 hours. After cooling to room temperature, it is poured into ice water to obtain a reaction solution. Separately, 3-
Amino-8-naphthol-6-sulfonic acid (24.0 parts) is dispersed in water (250 parts), sodium hydroxide is added to adjust the pH to 6
Adjust to ~ 7 and heat to 40 ° C. Next, the reaction solution obtained above is poured little by little, and during this period, pH of about 6 to 7 is maintained by appropriately adding sodium hydroxide. React for an additional 2 hours. Then, the O-dichlorobenzene layer is separated and removed, and sodium hydroxide is added to the aqueous layer to adjust the pH to 8 to 9 and the temperature is raised to 80 ° C. to react for 5 hours.
Then, after cooling, 35% hydrochloric acid is added to adjust the pH to 4, sodium chloride is added to salt out, and the precipitated crystals are filtered to obtain an intermediate (2) having the following structure.

[0048]

[Chemical 17]

Then, instead of the intermediate (1) used in Example 1, 36 parts of the above intermediate (2) was used to obtain the following disazo compound by the same method as in Example 1.

[0050]

Embedded image

This compound has a λmax 565 in an aqueous medium.
nm is shown.

Example 5 The following disazo compound was obtained in the same manner as in Example 1 except that 13.7 parts of 2-methoxy-5-methylaniline was used instead of 2,5-dimethoxyaniline used in Example 1. It was

[0053]

[Chemical 19]

This compound has a λmax of 555 in an aqueous medium.
nm is shown.

Example 6 The following disazo compound was obtained in the same manner as in Example 1 except that 30.3 parts of 2-aminonaphthalene-6,8-disulfonic acid was used in place of the sulfanilic acid used in Example 1. .

[0056]

Embedded image

This compound has a λmax 573 in an aqueous medium.
nm is shown.

Example 7 A polyvinyl alcohol film (Kuraray vinylon # 7500, manufactured by Kuraray Co., Ltd.) having a thickness of 75 μm is vertically and uniaxially set to 5
Double stretching was carried out to obtain a polarizing film substrate. With the polyvinyl alcohol film kept under tension, Example 3
The disazo compound obtained in 1. was immersed in an aqueous solution of 65 ° C. with a concentration of 0.025% and a salting aid, Glauber's salt, of 2.0%.
Further, after immersing in a 65 ° C. aqueous solution having a boric acid concentration of 7.5% for 5 minutes, it was taken out, washed with water at 20 ° C. for 20 seconds, and dried at 50 ° C. to obtain a polarizing film. Λmax of the obtained polarizing film was 580 nm. This dye-based polarizing film had a high degree of polarization, and did not show discoloration of the dye for a long time even in a high temperature and high humidity state, and showed good durability.

Example 8 In the same manner as in Example 7, except that the disazo compounds obtained in Examples 1, 2 and 4 to 6 were used instead of the disazo compound used in Example 7. A polarizing film was obtained. Table 1 shows the λ max of the obtained polarizing film.

[0060]

[Table 1]

Example 9 Example 1 was used instead of the disazo compound used in Example 7.
A polarizing film was obtained in the same manner as in Example 7 by using the disazo compounds shown in the second column of the following table obtained in the same manner as in Examples 1 to 6. Λmax in the table is λma of the obtained polarizing film.
x. The obtained polarizing film exhibited a high degree of polarization and was excellent in durability under wet heat conditions.

[0062]

[Table 2]

[0063]

[Table 3]

[0064]

[Table 4]

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Satoshi Hayashi 2-10-1 Tsukahara, Takatsuki City, Osaka Prefecture Sumitomo Chemical Co., Ltd. No. 1 98 Sumitomo Chemical Co., Ltd.

Claims (8)

[Claims] 1. The following formula (I): ## STR1 ## in the form of the free acid. (In the formula, Q ₁ represents a phenyl group, a substituted phenyl group or a naphthyl group substituted by at least one sulfo, and R ₁ and R ₂ are each independently a hydrogen atom, a hydroxy group, a lower alkyl group, a lower alkoxy group. Represents a group or a substituted amino group, R represents a hydroxy group, and R ₂ and R
May together form a complex bond O—Cu—O. ) Disazo compound represented by. 2. Q ₁ is represented by the following formula: (In the formula, R ₃ and R ₄ are each independently a hydrogen atom, a nitro group, a sulfo group, a sulfamoyl group, a C _{1 to} C ₄ alkyl group, a C _{1 to} C ₄ alkoxy group, a hydroxy group,
It represents a substituted amino group, a carboxy group or a halogen atom. ] The disazo compound of Claim 1 which is a phenyl group shown by these. 3. Q _{1 in} the form of the free acid is represented by the following formula: The disazo compound according to claim 1, which is a naphthyl group represented by the formula: wherein R ₅ and R ₆ each independently represent a hydrogen atom, a hydroxy group or a sulfo group. 4. R ₁ and R ₂ are each independently a hydrogen atom, a hydroxy group, a methyl group, an ethyl group, a methoxy group,
The disazo compound according to claim 1, which is an ethoxy group, an acetylamino group, a methylsulfonylamino group, a ureido group or a methylamino group. 5. The method according to any one of claims 1 to 4, wherein R ₂ is a hydroxy group.
The disazo compound according to any one of 1. 6. A dye-based polarizing film comprising a polarizing film substrate containing the disazo compound according to any one of claims 1 to 5. 7. A dye-based polarizing film comprising a polarizing film substrate containing at least one disazo compound according to any one of claims 1 to 5 and at least one other organic dye. 8. The polarizing film substrate is a film made of polyvinyl alcohol or its derivative,
The dye-based polarizing film as described in 1.