JPS59145255A - Water-soluble disazo compound - Google Patents

Abstract

PURPOSE:To provide a water-soluble disazo compd. which gives a polarizing film having excellent dichroism and fastness and makes it possible to greatly increase the range of its use which has been limited hitherto, consisting of a free acid having a specified structural formula, and to provide a copper complex salt thereof. CONSTITUTION:The titled water-soluble disazo compd. is obtd. from a free acid of formula I (wherein X is H, methyl, methoxy, ethoxy; Y is methoxy, ethoxy; R1 is H, methyl, -C2H4OH, benzene, phthalic acid, benzenesulfonic acid). The compd. of formula II is diazotized and coupled with a coumpd. of formula III. The resulting monoazo compd. of formula IV is diazotized and coupled with a compd. of formula V to obtain the water-soluble disazo compd. of formula I . If desired, the compd. is treated with copper sulfate to obtain a copper complex salt.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to water-soluble disazo compounds. More specifically, the free acid is represented by the general formula (Formula (I), where X is a hydrogen atom, a methyl group, a methoxy group, or an ethoxy group, Y is a methoxy group or an ethoxy group, and Ro is a hydrogen atom or a methyl group. or 803-, and the position of the -N group 2 is the 6th or 7th position).

Although the compounds of the present invention can also be used to dye cellulose fibers, their primary use is for the production of polarizing films. Conventionally, iodine has been used as a coloring agent for polarizing films, but its poor sublimation resistance and low thermal stability have limited the fields in which it can be used. An object of the present invention is to provide a compound for coloring a polarizing film that has excellent durability.

The water-soluble disazo compound of the present invention is generally produced as follows.

That is, a compound represented by the formula % (formula %) is diazotized by a conventional method, and then camped with a compound represented by the formula (where X and Y have the same meanings as above), (formula (1, In V), X and Y have the same meanings as above.) A monoazo compound represented by the formula is produced, and this compound is further diazotized to form the formula (in M, R,, Et, and 2 have the same meanings as above). A water-soluble disazo compound of the formula (I) is produced by coupling with the compound represented by the formula (I).If necessary, the compound is further treated with copper sulfate or the like to produce a copper complex salt compound of the compound represented by the formula (I). I can do it.

Compounds of formula (IJ) are usually prepared as IJ salts, but they can be prepared as the free acid or as potassium, lithium, ammonium, alkylamine, and ethanolamine salts.

Specific examples of compounds corresponding to formula (m) include J.
acid, N-methyl J acid, N-2-hydroxyethyl J acid,
Phenyl J acid, N-methyl-phenyl J acid, (3 or 4-carbo-'l'so) phenyl J acid, N-methyl-(3 or 4-carboxy) phenyl J acid, (3
or 4-sulfo)phenyl J acid, N-methyl-(3 or 4-sulfo)phenyl J acid, γ acid, N-methyl γ acid, N-2-hydroxyethyl γ acid, phenyl r acid, N
-Methylphenyl gamma, (3 or 4-carboxy) phenyl gamma acid, N-methyl-(3 or 4-carboxy)
Phenyl γ acid, (3 or 4-sulfo) phenyl γ acid, N-may-ru(3 or 4-sulfo) phenyl γ
Examples include acids.

The compounds of the present invention are useful for dyeing cellulose substrates such as cotton, cotton, viscose, rayon, paper, and pulp, as they dye well using ordinary dyeing methods.
It is particularly valuable as a dichroic colorant for polarizing films.

Conventionally, polarizing films using iodine as a polarizing element have been widely used because of their high polarization rate and their ability to absorb light in the entire visible light range, but they lack robustness and are susceptible to heat or light. The disadvantage is that when exposed, the color fades or sublimes, resulting in a significant decrease in effectiveness.

When the disazo compound of formula (I) or the copper complex salt compound with the formula (I) is used as a polarizing element, these drawbacks can be overcome, and a polarizing film with excellent dichroism and fastness can be obtained, allowing applications that were previously limited. can be expanded significantly.

Polyvinyl alcohol is used as a material for manufacturing polarizing films.
A membrane obtained from a synthetic or natural polymer having a hydroxyl group such as cellophane, a polyamide resin such as nylon, or a copolymer of polyvinyl alcohol and vinyl acetate is used.

Next, the present invention will be explained in more detail with reference to Examples. In these examples, parts are by weight and percentages are by weight.

Example 1 4-nitro-4'-aminostilbene-2,2'-di2
18. 57.7 parts of sodium sulfonate was diazotized by a conventional method, and sodium acetate was used as a neutralizing agent to form 2-methoxy-5-methyl ayu9. Coupling the flap part to a solution of aqueous hydrochloric acid. When the reaction is complete, acidify with hydrochloric acid and filter.
After drying, 67.9 parts of a monoazo compound (the following formula) is obtained.

67.9 parts of this monoazo compound are dissolved in 1700 parts of water along with 11.7 parts of caustic soda, and 10.3 parts of sodium nitrite are dissolved in this solution. Separately 160 parts water, 35% salt m7
Make an aqueous solution of hydrochloric acid with 3 parts, and add a mixed solution of the monoazo compound, caustic soda, and sodium nitrite to this f! : Add dropwise and diazotize at 105-10°C. After diazotization is completed, sulfamic acid is added to eliminate nitrite ions.

403 parts of phenyl J acid to 100 parts of a 10% soda ash aqueous solution
0 parts, add the above diazonium salt, and couple at 5 to 10°C. - If the precipitate formed after stirring at night is separated and dried, 753 parts of a water-soluble disazo compound of the following formula is obtained. When this disazo compound was dissolved in a buffer solution of pH 9.5, λrnax was 553 nm.

Example 2゜In place of 40.3 parts of phenyl J acid in Example 1, γ
692 parts of a water-soluble disazo compound (the following formula) was obtained in the same manner as in Example 1 except that 305 parts of acid was used.

λmax when this substance is dissolved in a buffer solution of pH 9.5
was 562 nm.

Example 3 75.3 parts of the disazo compound of Example 1 was dissolved in 1200 parts of water, and 110 parts of a 20% aqueous solution of CuSO4.5H20, 60 parts of N,N-jetanolamine, and 15 parts of 25% aqueous ammonia were added. It was treated at 95°C for 8 hours. The reaction solution was adjusted to pH 9.0 with a small amount of hydrochloric acid, and 12% common salt was added to the solution volume, and the resulting precipitate was dried using P to obtain a powder of a copper complex compound represented by the following formula. When this dye was dissolved in a pH 9.5 buffer, λInaX was 598 nm.

Manufacture of polarizing film: A polyvinyl alcohol film formed using a coating device equipped with a doctor coater and a blow dryer was prepared.Compound 101 obtained in Example x, 2 or 3 was dissolved in 10.13 of water. After immersing the membrane in the solution at 40° C. for 1.5 minutes and washing with running water, a membrane dyed blue is obtained. This film was stretched 35 times in the longitudinal direction using a roll-type stretching machine to obtain a polarizing film. The results of measuring the light transmittance of the polarizing film obtained in this way are shown in the table below. Note: The values in the table are the luminous transmittances determined in the wavelength range of 380 to 740 nm, where Yl is a single plate and Yl is a single plate. When two sheets are stacked parallel to each other in the stretching direction, Yl is the stretching strength. The larger the value of ρ, the better the polarizing film.

Examples 4 to 11゜ Disazo compounds produced in the same manner as in Examples 1 to 3 using the compounds shown in the table as compounds of formula (m) and M, or compounds obtained by converting them into copper complex salts were added to a pH of 9.5. The table below shows the λmax when dissolved in a buffer solution and the value of ρ when a polarizing film was prepared in the same manner as in Example 3 using these compounds.

X The same absorbance was shown at two points.

Examples 12 to 18 The formula shown in the table (■
) and (v) to produce a disazo compound and adjust the pH.
, 9, and 5, and its λmax was measured.

Claims (1)

[Claims] (In formula (Il, X is a hydrogen atom, a methyl group, a methoxy group, or an ethoxy group, Y is a methoxy group or an ethoxy group, and R1 is a hydrogen atom or a methoxy group, or a water-soluble disazo compound or a copper complex salt compound with the same.