Concentrated acid dye solutions: storage stable aqueous dye concentrate with di-ethyl-amino-propylamine

Concentrated dye solutions of dyes of the formula (1) shown in claim are described. The dye solutions are distinguished by a good storage stability and are suitable, in particular, for dyeing paper.

The present invention relates to concentrated aqueous dye solutions, 
comprising 
a) 7 to 30% by weight of a dye of the formula 
##STR1## 
in which K is a coupling component of the acetoacetanilide, pyridone, 
pyrazolone or pyrimidine series, 
b) at least 0.1 but less than 1 mol of 3-diethylamino-1-propylamine, per 
mol of dye of the formula (1), 
c) a quantity of a hydroxyalkylamine such that altogether 1.5 to 5 mol of 
the components b) and c) are present per mol of dye, and 
d) if desired, other additives. 
Preferred dye solutions according to the invention contain 0.1 to 0.9, in 
particular 0.2 to 0.6 mol, of 3-diethylamino-1-propylamine per mol of dye 
of the formula (1) and 2 to 4, in particular 2.5 to 4 mol, of 
hydroxyalkylamine. 
The dye solutions according to the invention preferably comprise 10 to 25% 
by weight of a dye of the formula (1). 
In the above formula (1), K is a coupling component of the 
acetoacetanilide, pyridone, pyrazolone or pyrimidine series. It is, in 
particular, the coupling components customary in azo dyes, in particular 
in paper dyes. 
K is preferably a coupling component of the formula 
##STR2## 
in which Y.sub.1 and Y.sub.2 independently of one another are .dbd.O, 
.dbd.NH or .dbd.N--C.sub.1 -C.sub.4 alkyl, Y.sub.3 is .dbd.O, .dbd.S, 
.dbd.NR or .dbd.N--CN, where R is hydrogen or C.sub.1 -C.sub.4 alkyl, and 
R.sub.1 and R.sub.2 independently of one another are each hydrogen, 
substituted or unsubstituted alkyl or substituted or unsubstituted phenyl. 
In the above formula (2), only one tautomeric form is indicated for the 
coupling component, the other tautomeric forms, however, are also intended 
to be included by this formula. 
A substituted or unsubstituted alkyl group R.sub.1 and/or R.sub.2 is, for 
example, a methyl, ethyl, n-or iso-propyl, n-, sec- or tert-butyl radical, 
a straight-chain or branched pentyl or hexyl radical or a cyclohexyl 
radical, which can be monosubstituted or polysubstituted, for example, by 
--OH, C.sub.1 -C.sub.4 alkoxy or C.sub.1 -C.sub.4 hydroxyalkoxy. 
Examples of suitable substituted alkyl radicals are: methoxymethyl, 
ethoxymethyl, ethoxyethyl, ethoxypropyl, n-propoxymethyl, 
isopropoxymethyl, butoxymethyl, butoxyethyl, butoxypropyl, methoxybutyl, 
ethoxypentyl and 2-hydroxyethoxypentyl. 
Substituted or unsubstituted phenyl radicals R.sub.1 and/or R.sub.2 are 
phenyl radicals which are unsubstituted or monosubstituted or 
polysubstituted by identical or different radicals. 
Examples of suitable radicals of this type are: C.sub.1 -C.sub.4 alkyl, 
which in this application is generally to be understood as meaning methyl, 
ethyl, n- or iso-propyl or n-, sec- or tert-butyl, C.sub.1 -C.sub.4 
alkoxy, which in this application or generally includes methoxy, ethoxy, 
n-or iso-propoxy or n-, sec- or tert-butoxy, halogen such as fluorine, 
chlorine or bromine, or nitro. 
Preferably, R.sub.1 and/or R.sub.2 as phenyl are phenyl which is 
unsubstituted or substituted by 1 to 3 C.sub.1 -C.sub.4 alkyl, chlorine or 
methoxy groups, the meaning unsubstituted phenyl being particularly 
preferred. 
R.sub.1 and R.sub.2 are preferably hydrogen or C.sub.1 -C.sub.4 alkyl and 
particularly preferably hydrogen or methyl. 
Y.sub.1 and/or Y.sub.2 are preferably the functional group .dbd.O or 
.dbd.NH, it additionally being preferred that Y.sub.1 and Y.sub.2 are 
identical. Y.sub.1 and Y.sub.2 are particularly preferably identical and 
are in each case .dbd.NH. 
Y.sub.3 is preferably the group .dbd.O, .dbd.S, .dbd.NH or .dbd.N--CN and 
particularly preferably the group .dbd.NH. 
In a particularly preferred embodiment, the dye solutions according to the 
invention contain azo dyes of the formula (1) in which R.sub.1 and R.sub.2 
independently of one another are each hydrogen or C.sub.1 -C.sub.4 alkyl, 
Y.sub.1 and Y.sub.2 independently of one another are each .dbd.O or 
.dbd.NH and Y.sub.3 is .dbd.O, .dbd.S, .dbd.NH or .dbd.N--CN. 
The dyes of the formula (1) are known or are obtained in a known manner. 
The aqueous dye solutions according to the invention contain at least 0.1 
but less than 1 mol of 3-diethylamino-1-propylamine per mol of dye of the 
formula (1) and a hydroxyalkylamine, for example ethanolamine, 
diethanolamine, triethanolamine, 2-dimethylaminoethanol, 
2-methylaminoethanol, N,N-bis(2-hydroxyethyl)-1,3-diaminopropane, 
N-(2-hydroxyethyl)ethylenediamine or 2-hydroxypropylamine. Mixtures 
comprising 2 or more of these hydroxyalkylamines can also be employed. 
The dye solutions according to the invention can additionally contain 
water-soluble organic solubilisers. Suitable examples are: urea, 
formamide, .epsilon.-caprolactam, dimethylformamide, 1,2-diaminopropane, 
or polyhydric alcohols, for example ethylene glycol, propylene glycol or 
glycerol. 
The amount of organic solubiliser depends, inter alia, on how much 
3-diethylamino-1-propylamine and hydroxyalkylamine is present in the dye 
solutions. If the content of the amines mentioned is about 2 to 4 mol per 
mol of dye, in general no organic solubiliser or only about 5 to 10% by 
weight thereof, based on the total weight of the dye solution, is 
necessary. On the other hand, it is often advantageous for economic 
reasons to set the content of the amines mentioned at about 1.5 to 2.5 mol 
per mol of dye and additionally to employ about 10 to 25% by weight of 
organic solubiliser. 
Preferred aqueous dye solutions according to the invention comprise 
a) 10 to 30% by weight of a dye of the formula (1), 
b) 0.1 to 0.9 mol of 3-diethylamino-1-propylamine per mol of dye of the 
formula (1), 
c) 2-4 mol of hydroxyalkylamine per mol of dye of the formula (1) and 
d) 0 to 25% by weight of an organic solubiliser. 
Of these, those are particularly preferred which comprise 
a) 10 to 30% by weight of a dye of the formula (1), 
b) 0.2 to 0.6 mol of 3-diethylamino-1-propylamine per mol of dye of the 
formula (1), 
c) 2.5 to 4 mol of hydroxyalkylamine per mol of dye of the formula (1) and 
d) 0 to 25% by weight of an organic solubiliser. 
The concentrated aqueous dye solutions according to the invention are in 
general prepared by stirring the free dye acids with a mixture of water, 
3-diethylamino-1-propylamine, hydroxyalkylamine and, if appropriate, an 
organic solubiliser, until a homogeneous solution is formed. If necessary, 
the mixture can be warmed, for example to 40.degree. to 80.degree. C., 
and, if necessary, can be filtered. 
The concentrated aqueous dye solutions obtained are distinguished, in 
particular, by a good storage stability. 
The concentrated dye solutions according to the invention are used, if 
desired after dilution with water, in particular for dyeing and printing 
paper, including semi-cardboard and cardboard, it being possible to dye 
these materials, for example, in the mass by coating or by dipping. 
Otherwise, a liquid formulation of this type can also be employed for a 
continuous or batchwise dyeing process for textile materials, in 
particular cellulosic or cellulose-containing textile materials.

The following examples illustrate the invention. Parts are parts by weight. 
EXAMPLE 1 
1522 parts of the aqueous press cake, comprising 456.5 parts of the dye of 
the formula 
##STR3## 
as the free dye acid, are treated with 41.3 parts of 
3-diethylamino-1-propylamine, 42 parts of diethanolamine and 246 parts of 
2-methylaminoethanol and the mixture is adjusted to a total weight of 4348 
parts with water. The suspension obtained is warmed to 50.degree. C. with 
stirring and stirred at this temperature until the dye has completely gone 
into solution. The dye solution is then additionally subjected to 
clarifying filtration. 
A commercial liquid dye form is obtained, which contains no residue at all 
even after one month's storage at 3.degree.-5.degree. C. 
EXAMPLE 2 
920 parts of the aqueous press cake, comprising 260 parts of the dye of the 
formula shown in Example 1, are treated with 23.5 parts of 
3-diethylamino-1-propylamine and 167 parts of 2-methylaminoethanol and the 
mixture is adjusted to a total weight of 2600 parts with water. The 
suspension obtained is warmed to 50.degree. C. with stirring and stirred 
at this temperature until the dye has completely gone into solution. The 
dye solution is then additionally subjected to clarifying filtration. 
A liquid storage-stable commercial dye form is obtained. 
EXAMPLE 3 
920 parts of the same aqueous press cake as in Example 2 are treated with 
14.8 parts of 3-diethylamino-1-propylamine and 193 parts of 
dimethylaminoethanol, the mixture is adjusted to a total weight of 2600 
parts with water and otherwise additionally processed as explained in 
Example 2 to give a liquid storage-stable commercial form. 
EXAMPLE 4 
920 parts of the same aqueous press cake as in Example 2 are treated with 
11.7 parts of 3-diethylamino-1-propylamine, 12.6 parts of diethanolamine 
and 165.5 parts of 2-methylaminoethanol, the mixture is adjusted to a 
total weight of 2600 parts with water and otherwise additionally processed 
as explained in Example 2 to give a liquid commercial form. 
EXAMPLE 5 
920 parts of the same aqueous press cake as in Example 2 are treated with 
18.5 parts of 3-diethylamino-1-propylamine, 15 parts of diethanolamine and 
107 parts of 2-methylaminoethanol, the mixture is adjusted to a total 
weight of 2600 parts with water and otherwise additionally processed as 
explained in Example 2 to give a liquid commercial form. 
EXAMPLES 6-10 
The procedure described in Example 1 is repeated, except that equivalent 
amounts of the dyes which are obtained by diazotisation of 
dehydrothiotoluidine-7-sulfonic acid and coupling with the coupling 
components shown in the following table are used instead of the dyes 
employed therein, in this manner affording concentrated solutions of the 
dyes, which are distinguished by good storage stability. 
______________________________________ 
Example Coupling components 
______________________________________ 
6 Barbituric acid 
7 Cyanoiminobarbituric acid 
8 3-Methyl-5-pyrazolone 
9 1,3-Dimethylbarbituric acid 
10 4-Amino-2,6-dihydroxypyrimidine 
______________________________________ 
EXAMPLE 11 
70 parts of chemically bleached sulfite cellulose from conifers and 30 
parts of chemically bleached sulfite cellulose from birchwood are ground 
in 2000 parts of water in a hollander. 0.3 part of the commercial dye form 
described in Example 1 are added to this pulp. After a mixing time of 20 
minutes, paper is manufactured from this pulp. The absorbent paper 
obtained in this manner is coloured yellow. The waste water is virtually 
colourless.