CA1043777A - Monoazo-dye for equalized dyeing of synthetic polyamides and method of preparing same - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE:

Dye for synthetic fibers such as polyamide fibers.
Dye is of the formula

Description

7~
The present inventio.n .relates to a.new valuable monoazo dye, to a process for the preparation of this dye, and to the application of the dye i.n equalized dyeing of sy.nthetic pol~a~ide fibers. .
rrhis inve.ntio.n relates to a novel dye havi.ng the following structural formula:

CN

~ ~ ~ N=N ~ ~ / 2H5 ~I) =/ C2H5 ~his dye may be used i.n the dyei.ng of various kinds of synthetic fibers, for example, fibers made of po:Lyester, cellulose esters or ethers, polyacrylonitrile, acrylo.ni-trile copolymers, etc.
However, the preferred use of the dye ls in the dyeing of sy.nthe-tic polyamide fibers such as, e.g., fibers made from hexamethylene-di.amine adipate, poly- ~-caprolactams, polyco~ndensates of omega-amino-undecanoic acid, and the like, as well as from polyurethanes. -As regards sy.nthetic polyamide fibers, dye (I) is suitable for dyeing all articles made of co.ntinuous filaments 9 e.gv, stockings, knitwear, conti~uous thread fabrics, etc. : ~-As is known, synthetic polyamide fibers are freque.ntly irregular or ~on-~niform i.n their chemical structure (e.g., due to non-homogenuity in the distribu-tio.n of the basic e.nd groups). In additio.n, polyamide fibers often exhibit variatio.ns in their . -chemical-physical and physical state, e.g. 9 differe~ces in their morphological states, variations in crystallinity, diflere~nces i.n surface struc-ture and in the microporosity of the fibers.
All of the above differe~ces giYe rise to differences in-.the ..

3~ 7r;~7 distributio:n of the dye in the fi.beris, 30 that there are di.ffere.nces i.n their behavior under li~ht as a result of diffusion and absorption phenome.na.
'~he tintorial characteristics of dye (I) are unusually good.
It is known that in the dyeing of synthetic polyi~mide fibers, which are i.nvariably more or less "streaked", the fibers exhibit differing requirements as reg~rds the various dyes.
As a matter of fact, the dlspersed dyes such as, e.g., the "Microsetile" clyes (registered trademark of Montedison), may co.nveniently be used for the productio.n of light colors inas~uch as they ha~e a high co~ering power for irregularities of the fibers (streaks). ~ s I.n the productio.n of medium or full colors, one must keep in mind, apart from the virtual impossibili-ty of obtaining very i.ntense dyei.n~s with dispersed dyec, their poor fast.ness to wet treatments.
0.~ the other hand, most of the anio.nic dyes, such as, e.~., "Nailammide" dyes (trademark of Montedison) offer good poissibili-ties for the production of dark colors, moderate possibilities ~or medium shades, and in general they are not suitable fox the productio.n of light shades because of their . .
i.nsufficie.nt leveling power. .:.~
.
~he dyeings of sy.nthetic polyiamide fibers resulting ~ :
from the application of dye (I) are particularly valuable because : . ..
of their fastness and resistance to light and to perspiration, . :
i as well as because of the brightness of the color shade~ j :
This result was altogether unexpected inasmuch as the i isomer of dye (I), which isomer is of the formula (II) below . : .

' ~ .
.

- 2 - -.
, .. . . . .. .
.,.:. ~ . . . .. . . . . .
, . : ~ . . ~ : . .. . . . .
:,. . . , :. . .

7~7r7 Cl NC ~ N N~ N \ (II) imparts to polyamide fiber~ a fastmess to light, perspiration, and an equalization, that are distinctly inferior to those of dye (I).
Dye (I) may be applied to synthe-tic fibers9 and partic~larly to synthetic polyamide fibers, by conventional dyeing methods utilizing aqueous dispersions.
}lowever, for best applicational results as regards equalization, a method is utilized which involves a firs-t stage using a slightly alkaline medium. For this purpose it is desirable to employ a system buffered with borates and phosphates that permit the dyeing to start at a pH of about 8.5-9, which pH
is gradually reduced to a final slightly acid pH (5-5.5) by the gradual addition of an organic acid according to known techniqueæ.
~or light shades it is preferable to complete the dyei~g at a pH of about 6-6.5.
Dye ~I) is prepared by diaæotizing 2 cyano-5-chloro-aniline with sodium nitrite and hydrochloric acid, followed by coupling the resulting diazo compound in an acid medium with N,N-diethyl meta~amino~succinyl-anilide~
The following examples will fur-ther illustrate the invention. All parts and percentages are by weight, unless otherwise indicated, and the relationship between parts by weight and parts in volume corresponds to kg/liter.
~XAMP~E 1 ` ~ ~-15.25 parts of 2-cyano-5-chloro-anili~e were treated 37r~7 ~ith 220 par-ts of CM3COOH at 50~C for 15 minutes. This mass was then cooled down to 0C with ice, and 30 r~ of HCl(d=1.18) were added. Then under agitation, diazotization was effected by slowly adding over a 30 minuteSperiod a solution of 6.9 parts of NaN02 dissolved in 50 partsof H20. The diaæo suspension was then poured o~er a period of one hour at O~G into a solution of 30 parts of the sodium salt of N~N-diethyl-m-amino-succinyl-anilide, ~2 parts of sodium acetate crystals, and 500 parts of H20.
After about two hours of stirring at 0C, there were added 30 parts by volume of (HCl d=1.18), then stirring was effected for 30 minutes. The mass was then filtered and the resulting precipitate was washed with H20 and then dried.
~ here was thus obtained 32~5 parts of a dye having the following structure:
.. ~, .
CN

Cl NHCOCH2CH2-COOH

' ~ :'':
This dye was in the form of a red powder which, when applied `~ -to polyamide fibers 7 resulted in a fast dyeing of a bright red-scarlet color9 having an excellent equali~ation.
~XAMPLæ 2 0.5 part of the dye obtained in Example 1 was micron- -ized in a ball mill and then dispersed in water. ~his dispersion was added to a dyeing bath containing 1 g/l of a nonionic surfactant ~oxyethylated castor oil, "E~ulson ~L", trademark of Montedison) and a small amount o~ amonia and ammonium salt (ammonium s~lfate) 90 as to obtain a pH of 8-~.5.
Dyeing was commenced on 100 parts of polyamide fabric . . .
:~ .- : : . . . . . .
.
., ,.. . ,, . .:

'777 at 70C, and the temperature was gradually raised to the boiling point. The fabric was then dyed for 30-~0 minutes at the boiling temperature, and -then acetic acid was gradually added until a final pll of 5.5-5 was obtained.
The dyed material was thoroughly rinsed in water and then dried in hot air.
There was thus obtain a brilliant scarlet shade of excellent equalization, endowed with good fastess to light and stability to wet treatments.
Variations can, of course, be made without departing from the spirit and scope of the invention.
Having thus described the invention, what is desired to be secured by Letters Patent a~d hereby claimed is:

:., ., -..
,.
"' ' .. : ' ,

Claims (4)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A monazo-dye of the formula

2. A method of making the dye of claim 1 comprising coupling in an acid medium the diazo derivative of 2-cyano-5-chloro-aniline with N,N-diethyl-meta-amino-succinyl-anilide.

3. Synthetic polyamide or polyurethane fibers dyed with the dye of claim 1.

4. The dyed product of claim 3 wherein said fibers are polyamide fibers.