Process for dyeing textile materials of polyacrylonitrile: quaternized piperazine copolymer as basic dye retarder

This invention relates to dyeing textile materials of polyacrylonitrile or copolymers containing acrylonitrile in polymerized form with basic dyestuffs in aqueous dyeing liquors using the exhaust method employing retarders. The retarders are obtained by condensing (a) piperazine and piperazine derivatives with (b) ethylene chloride, epihalohydrin, propylene chloride, 1,3-dichloro-2-hydroxypropane, bis-epoxybutane, 1,4-dichlorobutene or their mixtures in mole ratios of 1:0.9 to 1:1.1. The condensation products are then quaternized with benzyl chloride using 0.8 to 1.5 moles of benzyl chloride per mole of component (a) for the quaternization. The aqueous solutions of the retarders either do not foam or show a very low foaming tendency.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to dyeing textile materials of 
polyacrylonitrile or copolymers containing acrylonitrile using basic dyes 
in aqueous liquors. 
2. Prior Art 
It is known that an unevenly dyed product results when basic dyes are used 
in a concentrated dyeing liquor for polymer fibers containing anionic 
polyacrylonitrile or acrylonitrile containing copolymer fibers as soon as 
there are even slight temperature and concentration differences in the 
dyeing equipment. The penetration rate of cationic dyes used for 
anionically modified polyacrylonitrile fibers is particularly dependent 
upon temperature. In order to be able to uniformly dye polyacrylonitrile 
fibers with cationic dyes, retarders are used. These are compounds which 
reduce the penetration rates of the dyes in the penetration phase. 
Quaternary ammonium salts of 1,3,5-trisaminoalkylhexahydro-s-triazines 
according to German Pat. No. 23 16 725 and quaternized polyamines 
described in German application No. 25 0/8 242 are known as suitable 
examples for this purpose. However, when used with the most commonly 
applied cationic dyes for dyeing polyacrylonitrile fibers, the known 
retarders do not show uniform retardation effects in the temperature range 
in which the dyeing processes are carried out. 
It is a purpose of this invention to make available retarders for dyeing 
textile materials of polyacrylonitrile or copolymers containing 
acrylonitrile in polymerized form using basic dyes in aqueous liquors and 
employing the exhaust method. These retarders must be compatible with the 
most commonly used cationic dyes, must have a uniform retardation effect, 
if possible, in the entire temperature range used for the dyeing process 
and must not develop any foam or inhibit the development of foams in 
aqueous liquors. 
SUMMARY OF THE INVENTION 
The above requirements are met by this invention by the use of 
water-soluble reaction products as retarders which are obtained by the 
condensation of 
(a) piperazine, bis-(1,4-aminopropyl)piperazine, 1-aminoethylpiperazine, 
1-methylpiperazine or their mixtures with 
(b) ethylene chloride, epihalohydrin, propylene chloride, 
1,3-dichloro-2-hydroxy propane, bisepoxybutane, 1,4-dichlorobutane or 
their mixtures 
in a mole ratio of (a):(b) of 1:0.9 to 1:1.1 and quaternization of the 
condensation products with benzylchloride. The amount of benzylchloride 
used for the quarternization is about 0.8 to 1.5 moles per mole of 
component (a). 
DESCRIPTION OF THE PREFERRED EMBODIMENTS 
The textile materials may be woven or knitted fabric, yarn or flock. They 
consist of polyacrylonitrile and/or copolymers containing acrylonitrile in 
polymerized form. The acrylonitrile share of the copolymers is at least 50 
percent by weight, preferably 80 to 98 percent by weight. The copolymers 
of acrylonitrile may, for example, contain acrylamide, acrylate, 
methacrylate, vinyl ester or vinyl chloride in polymerized form as 
comonomers. In order to improve the tintability of the polyacrylonitrile 
fibers, the copolymers usually contain anionic groups such as carboxyl or 
sulfonic acid groups. An anionic modification of the polyacrylonitrile 
and/or the copolymers of acrylonitrile is obtained by also using 
ethylenically unsaturated carboxylic acids such as acrylic acid, 
methacrylic acid, or maleic acid and/or ethylenically unsaturated sulfonic 
acids such as vinyl sulfonic acids during the copolymerization. A 
sufficient tintability of the fibers is also facilitated by part of the 
nitrile groups of the polyacrylonitrile being hydrolyzed into carboxyl 
groups. 
Basic dyes include, for example, dyes of the di- and triarylmethane series, 
the indolyl- and diindolylaryl methane series, oxazine, thiazine, diazine, 
thiazol, xanthene, acridine, quinoline, quinophthalone, indolin and 
cyanine dyes as well as the basic azo and azomethine dyes. Dyes of this 
type are described, for example, in American Dyestuff Reporter, (1954), 
pages 432-433. 
The textile materials based on polyacrylonitrile are dyed in an aqueous 
liquor according to the exhaust method using temperatures from 70.degree. 
C. to 110.degree. C. The liquor ratio is 1:5 to 1:100. 
In order to achieve uniform wet and lightfast dyeing results, water-soluble 
polymeric reaction products of the above-described type are used are 
retarders. They are prepared by condensing (a) compounds selected from the 
group consisting of piperazine, bis(1,4-aminopropyl)piperazine, 
1-aminoethylpiperazine, 1-methylpiperazine with (b) compounds selected 
from the group consisting of ethylene chloride, epihalohydrin (for 
example, epichlorohydrin and epibromohydrin), propylene chloride such as 
propylene dichloride and 1,3-propylene chloride, 
1,3-dichloro-2-hydroxypropane, bis-epoxybutane or 1,4-dichlorobutane in a 
mole ratio of about 1:0.9 to 1:1.1 with pH values from about 6.5 to 12, 
preferably about 7 to 10, and subsequent quaternization of the 
condensation products with benzylchloride. For adjusting the pH value 
during the condensation, optionally used products include bases such as 
sodium hydroxide solution, potassium hydroxide solution, sodium carbonate, 
calcium oxide, calcium hydroxide, barium oxide or barium hydroxide. If an 
excess of the compounds of group (a) are used for the condensation, a pH 
value in the alkaline range will result based on the bascisity of these 
compounds. 
The condensation takes place in aqueous solution with a solids content in 
the solution of 20 to 60 weight percent and temperatures of 60.degree. C. 
to 100.degree. C. The water-soluble, nonquaternized condensation products 
have a viscosity of at least 3000 mPas in 45 percent aqueous solution at a 
temperature of 20.degree. C. Particularly effective retarders are obtained 
if piperazine is condensed with epichlorohydrin or ethylene oxide and if 
the resultant product is subsequently quaternized with benzylchloride. 
In order to quaternize the condensation products of components (a) and (b), 
0.8 to 1.5, preferably 0.9 to 1.3, moles of benzylchloride are used per 
mole of component (a). The quaternization is preferably carried out in an 
aqueous medium at temperatures from 60.degree. C. to 100.degree. C. The 
condensation reaction as well a the quaternization of the condensation 
products may be carried out at temperatures above 100.degree. C. under 
pressure. This results in shorter reaction times. The aqueous solutions of 
the quaternized condensation products can be used directly as retarders. 
Compared with known retarders for dyeing textile materials of copolymers 
containing polyacrylonitrile or acrylonitrile, the compounds to be used in 
accordance with this invention have the advantage that they are more 
effective and that significantly lower quantities are required in order to 
obtain the same uniformity achieved with previously used retarders. 
Another advantage lies in the fact that the quaternized condensation 
products to be used in accordance with this invention do not tend to fiber 
blocking even with high application concentrations. This means that the 
dye subsequently used for shading the material penetrates within the 
normal dyeing period. This is not the case, for example, as far as the 
prior art retarder lauryl-dimethylbenzyl ammonium chloride is concerned 
even if relatively small quantities are used. A particular advantage in 
the use of quaternized condensation products of components (a) and (b) in 
accordance with this invention must be seen in the fact that the aqueous 
liquors either do not foam at all or foam only very slightly. The dyeing 
liquors contain the retarder in an amount of 0.003 to 2, preferably 0.02 
to 0.5 weight percent. 
As used herein, unless otherwise indicated, all parts and percentages are 
by weight and all temperatures are in .degree. C.

PREATION OF THE RETARDERS 
Retarder 1 
An amount of 47.7 parts of distilled water were added to 95.5 parts by 
weight of a 67.2 percent aqueous piperazine solution and this solution was 
heated to a temperature of 75.degree. C. As soon as this temperature was 
reached, 69 parts of epichlorohydrin were added within a period of one 
hour and a temperature range of 70.degree. C. to 80.degree. C. and the 
mixture was subsequently heated for three hours at a temperature of 
80.degree. C. During this period, the viscosity of the reaction mixture 
increased to approximately 5000 mPas whereas the pH value dropped to 7.0. 
Following this process, 134.3 parts of water and 59.7 parts of a 50 
percent sodium hydroxide solution were added followed by 95 parts of 
benzylchloride at a temperature of 80.degree. C. within a period of 40 to 
60 minutes. The benzylation was completed by heating the mixtures for two 
hours at a temperature of 80.degree. C. The reaction mixture was cooled to 
30.degree. C. and 343.1 parts of an 85 percent formic acid and 156.7 parts 
of water were added. A total of 1000 parts of retarder 1 were obtained. 
Retarder 2 
Three hundred forty-six parts (3.5 moles) of ethylene chloride were added 
to 717 parts (3.7 moles) of piperazine hexahydrate and 200 parts of water 
at a temperature in the range of 70.degree. to 80.degree. C. within a 
period of 3 to 4 hours. After completing the ethylene chloride addition, 
the reaction mixture was heated to boiling under reflux within a period of 
two hours. Following this process, 812 parts of a 50 percent aqueous 
potassium hydroxide solution and 2500 parts of water (pH 11.3) were added, 
and the mixture heated to a temperature of 80.degree. C. to 90.degree. C. 
for three hours. The resulting suspension was diluted with water. The 
finely crystalline polyethylene piperazine was subsequently removed by 
centrifuging and dried. 
At a temperature of 70.degree. C. to 80.degree. C., 63.5 parts of benzyl 
chloride were added to a suspension of 56 parts of the polyethylene 
piperazine in 80 parts of water within a period of ten minutes. The 
reaction mixture was then heated to a temperature of 80.degree. C. for two 
hours. The mixture was subsequently cooled to 25.degree. C. and was 
diluted with 40 parts of water. A 50 percent aqueous solution of retarder 
2 was obtained. 
EXAMPLE 1 
One hundred parts of a commercially available anionically modified 
polyacrylonitrile highly texturized yarn were dyed in 6000 parts of a 
dyeing liquor which contained 0.2 part of the cationic dye having formula 
##STR1## 
1 part of glacial acetic acid, 0.5 part sodium acetate and 0.02 part of 
retarder 1 based on the yarn. 
The temperature of the dyeing bath initially was 85.degree. C. and was 
increased to 100.degree. C. within a period of six minutes. Following this 
process, the yarn was dyed at 100.degree. C. for 30 minutes. The amount of 
retarder was selected in such a manner that approximately 98 percent of 
the dye had penetrated the polyacrylonitrile fiber after this period. A 
uniform, light and wetfast red coloration was obtained. 
EXAMPLE 2 
One hundred parts of a yarn of an anionically modified polyacrylonitrile 
were dyed in 5000 parts of a dyeing liquor which contains 0.5 part sodium 
acetate, 2 parts acetic acid, 0.1 part retarder 2 and 0.1 part of the dye 
having formula 
##STR2## 
After heating the dyeing liquor to a temperature of 75.degree. C., the 
fiber material was introduced into the liquor which was heated to 
100.degree. C. within 50 minutes and the material was dyed at this 
temperature for 40 minutes. A uniform light and wetfast blue coloration 
was obtained. 
EXAMPLE 3 
One hundred parts of a mixed yarn consisting of 55 percent 
polyacrylonitrile fibers (anionically modified) and 45 percent wool were 
introduced in 4000 parts of a dyeing liquor which was heated to 40.degree. 
C. and was subsequently adjusted to a pH of 4.5 with acetic acid. An 
amount of 0.51 parts of the red acid dye C.I. 17070 and 0.2 parts of an 
oleylamine condensed with 12 moles of ethylene oxide were added and the 
dyeing liquor was heated from 40.degree. C. to 80.degree. C. within 60 
minutes. At this temperature the following substances were added: 0.1 part 
of the yellow basic dye C.I. 48055, 0.01 part of the green basic dye C.I. 
4200, 0.1 part of the red basic dye, C.I. 48013, and 0.02 part of retarder 
1. 
The temperature of the dyeing bath was increased to 100.degree. C. within 
40 minutes. Subsequently the dyeing process was continued at this 
temperature for 30 minutes. A uniform red coloration with good fastness 
was obtained. 
EXAMPLE 4 
One hundred parts of a mixed yarn consisting of 45 percent 
polyacrylonitrile fibers (anionically modified) and 45 percent wool were 
introduced into 4000 parts of a dyeing liquor which was heated to 
40.degree. C. and was subsequently adjusted to a pH of 4.5 with acetic 
acid. 
Subsequently 0.5 part of the green acid dye C.I. 61570 and 0.2 part of a 
reaction product of C.sub.18 -fatty alcohol with 30 moles of ethylene 
oxide were added. The dyeing liquor was then heated from 40.degree. C. to 
80.degree. C. within a period of 60 minutes. 
At this temperature, 0.32 part of the green basic dye C.I. 42,000; 0.06 
parts of the yellow basic dye C.I. 48,054; 0.01 part of the red basic dye 
C.I. 48,013 and 0.2 part of retarder 2 were added. 
The temperature of the dyeing bath was increased to 100.degree. C. for 40 
minutes. The fabric was then dyed at this temperature for another 30 
mintues. A uniform, wetfast green coloration was obtained.