Softener composition containing cis- and trans- isomers of ethylenically unsaturated quaternary ammonium salts

A softener composition comprising a quaternary ammonium salt having two hydrocarbon radicals having 12-22 carbon atoms and one unsaturated bond; the stereoisomeric structure of the above salt includes both the cis-isomer and the trans-isomer with the cis-isomer/trans-isomer ratio being in the range of from 25/75-90/10.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to a softener composition which provides 
excellent water absorbency to treated clothing. 
2. Description of the Prior Art 
Most of the presently commercially available softener compositions for 
ordinary household use are compositions comprising; as a main ingredient, 
Di-(hydrogenated beef tallow alkyl) dimethyl ammonium chloride. 
This quaternary ammonium salt exerts good softening and antistatic effects 
to various fibers, even when used in small amounts. 
It is believed that a softener molecule needs to impart a lipophilic 
property in order to exert excellent softening effects, since the 
softening effect by the softener is the result of a lowering of the 
friction coefficient on a fabric surface which is caused by a lubricating 
effect based upon the lipophilic parts of softener molecule adsorbed on 
the fabric surface. 
However, this lipophilic property is defective in making the treated 
clothing water-repellant and reduces the water-absorbency of the treated 
clothing, especially causing a remarkable reduction in water-absorbency 
when the concentration of the softening agent is high. 
From this point of view, many investigations on the softener compound have 
been conducted in order to improve the water-absorbency. 
It is known that dioleyl dimethyl quaternary ammonium salt is a softener 
compound which exerts excellent water-absorbency (JAOCS, Vol. 60, No. 6, 
1166-1169). 
However, the softener compound comprising the above compound exerts more 
water-absorbency than Di-(hydrogenated beef tallow alkyl) dimethyl 
quaternary ammonium salt, yet it exerts less softening properties than the 
others. 
On the other hand, even though the above compound is used with other 
softening agents, for example, Di-(hydrogenated beef tallow alkyl) 
dimethyl quaternary ammonium salt in order to improve the softening 
property, a reduction in water-absorbency occurs. 
Under the situation described above, the present inventors have conducted 
research and studies eagerly in order to find the quaternary ammonium salt 
which exerts greater water-absorbency and a greater softening property 
than the usual dioleyl type quaternary ammonium salt. Consequently, the 
inventors have found that unsaturated quaternary ammonium salt having 
specific stereoisomeric structure exerts good softening effects as well as 
remarkably increased water-absorbency. 
SUMMARY OF THE INVENTION 
The present invention provides a softener composition comprising at least 
one quaternary ammonium salt having the following formula (I)-(III): 
##STR1## 
wherein R.sup.1 and R.sup.2 each represent a hydrocarbon radical having 
12-22 carbon atoms, preferably 16-22 carbon atoms and one unsaturated 
bond. Moreover, the stereoisomeric structure of the above salts having the 
formula (I) include both the cis-isomer and the trans-isomer with the 
cis-isomer/trans-isomer ratio being in the range of from 25/75-90/10; 
R.sup.3 and R.sup.4 each represent a methyl, ethyl or 
##STR2## 
in which n is an integer from 1 to 5, and Y represents H or methyl; 
R.sup.5 and R.sup.6 each represent a hydrocarbon radical having 11-21 
carbon atoms, preferably 15-21 carbon atoms and one unsaturated bond. 
Moreover, the stereoisomeric structure of the above salts having the 
formula (II)-(III) include both the cis-isomer and the trans-isomer with 
the cis-isomer/trans-isomer ratio being in the range of from 25/75-90/10; 
and X represents a halogen, CH.sub.3 SO.sub.4 or C.sub.2 H.sub.5 SO.sub.4.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
With regard to the properties of the softener composition of the present 
invention, the stereoisomeric ratio of R.sup.1 and R.sup.2 in formula (I) 
and R.sup.5 and R.sup.6 in formulas (II) and (III) is particularly 
important in order to satisfy the requirements of both the softening 
property and water-absorbency. 
Namely, it is necessary that the stereoisomeric structure of the quaternary 
ammonium salt having the formula (I)-(III) includes both the cis-isomer 
and trans-isomer, and moreover, it is necessary that the 
cis-isomer/trans-isomer ratio is in the range of from 25/75-90/10, 
preferably from 50/50-80/20. 
The ratio of the cis-isomer to the trans-isomer in the present invention 
means, for example, with respect to the compound salt of formula (I), the 
total ratio of both R.sup.1 and R.sup.2. 
As an example, with respect to the compound salt of formula (I), R.sup.1 
can be the cis-isomer, and R.sup.2 can be the trans-isomer. 
The present ratio can also be obtained by mixing a salt wherein both 
R.sup.1 and R.sup.2 are the cis-isomer with a salt wherein both R.sup.1 
and R.sup.2 are the trans-isomer, such that the total ratio of the 
cis-isomer to the trans-isomer is within the required range as described 
above. 
In the same manner, the ratio with regard to R.sup.5 and R.sup.6 in the 
compound salt of formulas (II) and (III) can also be obtained. 
There are several methods to preferably adjust the ratio of the cis-isomer 
to the trans-isomer to arrive at the distinctive feature of the present 
invention. 
One method to adjust the cis- and trans-isomer ratio is by mixing the 
cis-isomeric and the trans-isomeric quaternary ammonium salt after 
producing them separately. 
Another method is to produce the quaternary ammonium salt from a mixture of 
the cis-isomeric and the trans-isomeric fatty acid or ester thereof after 
mixing them according to the desired ratio. 
Another method is to produce the quaternary ammonium salt from the mixture 
after adjusting the ratio thereof by isomerizing a portion of the 
cis-isomeric fatty acid or ester thereof into the trans-isomer in the 
presence of, e.g., a metallic catalyst, etc. 
Still a further method utilized to adjust the ratio is by isomerizing 
between the cis-isomer and the trans-isomer during the process for 
producing the quaternary ammonium salt using the fatty acid or ester 
thereof as a precursor. 
Examples of fatty acids used as precursors of the compound salt having the 
above formula (I)-(III) are cis-6-octadecenoic acid, cis-9-octadecenoic 
acid (oleic acid), cis- 13-docosenoic acid, trans-6-octadecenoic acid, 
trans-7-octadecenoic acid, trans-13-docosenoic acid. 
In case of manufacturing the softener composition of the present invention, 
the unsaturated quaternary ammonium salt, having the formula (I)-(III) 
described above, is commonly used in the range of 3-20% by weight, based 
on the total weight of the composition. 
In order to exert both the softening property and water-absorbency, it is 
necessary that both the cis-isomer and the trans-isomer exist together 
and, furthermore, that the ratio is within a certain range as discussed 
above. While not being bound to any theory on the reason why this is so, 
the present inventors believe that when the quaternary ammonium salt of 
the present invention is adsorbed onto clothing, the orientation of the 
salts are disturbed due to this mixture of the cis-isomer and the 
trans-isomer, and it is this disturbed orientation which results in a 
decrease in water-repellency while increasing the water absorbency. 
If the ratio of the cis-isomer to the trans-isomer is less than 25/75, 
water-absorbency decreases remarkably. 
If the ratio of the cis-isomer to the trans-isomer is greater than 90/10, 
both water-absorbency and the softening property decrease. 
In practicing the present invention, dimethylpolysiloxane (silicone) or 
modified silicone can be added to the composition, in the range of from 
0.5-10% by weight, based on the weight of compound in formula (I)-(III) in 
order to enhance the softening property and water-absorbency of the 
unsaturated quaternary ammonium salt of formula (I)-(III). 
Up to now, silicone is known an ingredient which enhances the softening 
effect and ironing characteristics of a fabric (see Japanese patent 
laid-open No. 52-53094). 
In conjunction with these above characteristics, it is known that silicone 
itself has water-repellency and adversely affects water-absorbency. 
The fact that silicone enhances water-absorbency when it is used in 
conjunction with the specific unsaturated quaternary ammonium salt of the 
present invention is surprising since it is contrary to what would be 
expected to one skilled in the art. 
More specifically, dimethylpolysiloxane or a modified silicone, having a 
viscosity of 20-10000 cps at 25.degree. C. is preferred. 
Modified silicones useful in the present invention include, for example, 
polyoxyethylene modified silicone and amino-modified silicone. 
It is preferable that the amount of the modification is less than 10%. 
It is preferable that dimethylpolysiloxane or modified silicones are 
emulsified with a polyoxyethylene-type nonionic surfactant or a 
monoalkylcationic-type or dialkylcationic-type cationic surfactant prior 
to their use. 
In addition to the quaternary ammonium salts of formula (I)-(III), the 
following substances may be incorporated in any amount which will not 
impede the effects of the softener composition of the present invention; 
other known quaternary ammonium salts; polyoxyethylene alkyl or alkenyl 
ether, polyoxyethylene alkylphenyl ether, polyoxyethylene oxypropylene 
polyalkylenepolyamine, nonionic surfactants such as glycerine or 
pentaerythritol which has been partially esterified with higher fatty 
acids such as stearic acid or oleic acid, or 2-ethylhexanoic acid; 
water-soluble salts such as sodium chloride, ammonium chloride and calcium 
chloride; solvents such as ethyl alcohol, isopropyl alcohol, propylene 
glycol and ethylene glycol; urea; germicides; antioxidants; pigments, 
dyes, perfumes, etc. 
The present invention will now be further described by reference to the 
following illustrative Examples. Of course, the present invention is to be 
in no way construed as being limited by these Examples. 
EXAMPLE 
The softening effects and water-absorbency of the compositions set forth in 
Table 2 on various fibers were examined. 
As the unsaturated quaternary ammonium salt of the present invention, those 
having the formula set forth in Table 1 were used. 
TABLE 1 
__________________________________________________________________________ 
FORMULA OF QUATERNARY AMMONIUM SALT 
COMPOUND R.sup.1, R.sup.2 or R.sup.5, R.sup.6 
NO. FORMULA 
CARBON NO. 
CIS-ISOMER/TRANS-ISOMER 
R.sup.3 
R.sup.4 
X 
__________________________________________________________________________ 
1 - 1* 1 18 95/5 CH.sub.3 
CH.sub.3 
C1 
1 - 2 1 18 65/35 " " " 
1 - 3 1 18 50/50 " " " 
1 - 4 1 22 70/30 " " " 
1 - 5* 1 18 20/80 " " " 
2 - 1 2 17 70/30 " -- CH.sub.3 SO.sub.4 
2 - 2 2 17 50/50 " -- " 
3 - 1 3 17 80/20 " -- " 
__________________________________________________________________________ 
*Comparative Example. 
The ratio of the cis-isomer to the trans-isomer was calculated by comparing 
the integration of the cis-olefinic proton with the integration of the 
trans-olefinic proton measured by using 400 MH.sub.z NMR (Nihon Electron 
Co. Ltd.) for example, as seen in FIG. 1. 
(1) Softening Treatment 
A commercially available cotton towel and cotton knitwork underwear were 
washed repeatedly 5 times with a commercially available detergent, Zab (a 
registered trademark for a product of Kao Corporation), and fiber treating 
agents were removed from the thus-washed fiber products. Then, the fiber 
products were treated in a 0.1% aqueous solution of the softener 
composition (water having a hardness of 3.5.degree. DH being used) at a 
temperature of 25.degree. C. and a bath ratio of 1/30 for 5 minutes under 
agitation. 
(2) Evaluation 
The clothes treated according to the above-mentioned method were air-dried 
in a room and were allowed to stand still in a thermostat chamber 
maintained at a temperature of 25.degree. C. and a relative humidity of 
65% for 24 hours. 
The softness and water-absorbency of each cloth was evaluated in the 
following manner: 
(a) softness 
The softness was evaluated according to the paired comparison testing 
method using, as a control, a cloth treated with a comparative softener 
composition (which contains 5% of Di-(hydrogenated beef tallow alkyl) 
dimethyl ammonium chloride). 
______________________________________ 
+2 soft 
+1 relatively soft 
0 same as control 
-1 relatively hard 
-2 hard 
______________________________________ 
(b) water-absorbency 
The cotton towel and the cotton knitwork underwear were cut into 3 
cm.times.20 cm rectangular strips. 
One end of the cloth was dipped into water to a depth of 2 cm. 
After 15 minutes, the rise in water, on each strip was measured in 
centimeters. 
(3) Results 
The results obtained are shown in Table 2. As will be apparent from the 
results shown in Table 2, in the case of the softener of the present 
invention, water-absorbency was remarkably enhanced while sufficient 
softness was retained. 
TABLE 2 
__________________________________________________________________________ 
COMPOSITION 
OF COTTON KNITWORK 
COMPO- 
QUATERNARY COTTON TOWEL UNDERWEAR 
SITION 
AMMONIUM SILICON SOFT- WATER- WATER- 
NO. SALT (WEIGHT %) 
(WEIGHT %) 
NESS ABSORPTIVITY 
SOFTNESS 
ABSORPTIVITY 
__________________________________________________________________________ 
1* Di-(hydrogenated 
(5) -- Standard 
6.1 Standard 
4.3 
beef tallow 
alkyl) dimethyl 
ammonium chloride 
2* dioleyl dimethyl 
(5) -- -1 9.0 -1 7.0 
ammonium chloride 
3* Di-(hydrogenated 
(2.5) -- -0.5 6.5 -0.5 4.5 
beef tallow 
alkyl) dimethyl 
ammonium chloride 
Dioleyl dimethyl 
(2.5) 
ammonium chloride 
4* 1 - 1 (5) 0.4 0 6.3 0 5.8 
5 1 - 2 (5) -- 0 10.8 0 8.2 
6 1 - 2 (5) 0.4 0 12.3 0 9.0 
7 1 - 3 (5) 0.2 0 12.0 0 9.2 
8 1 - 4 (5) 0.4 0 11.8 0 9.2 
9* 1 - 5 (5) -- 0 6.2 -1 5.9 
10 2 - 1 (5) -- 0 11.0 0 8.3 
11 2 - 2 (5) 0.2 0 12.0 0 9.2 
12 3 - 1 (5) 0.4 0 12.0 0 9.4 
__________________________________________________________________________ 
*Comparative Example. 
Having thus described the invention, it is to be understood that the above 
embodiment can be modified or changed without departing from the spirit 
and scope of the invention, for which applicants request protection, and 
as set forth in the claims hereinbelow.