Betaine-amine oxides, a process for their preparation and their use as surfactants

Betaine-amine oxides of the formula ##STR1## in which R denotes alkyl, alkenyl or hydroxyalkyl, each of which has 8-22 carbon atoms, R.sup.1 denotes hydrogen or methyl, R.sup.2 denotes ethylene, propylene or 2-hydroxypropylene, R.sup.3, R.sup.4 and R.sup.5 can be identical or different and denote C.sub.1 -C.sub.3 -alkyl or a group of the formula ##STR2## or R.sup.3 denotes a group of the formula --R.sup.2 --BR.sup.4 R.sup.5, X denotes a direct bond or a group of the formula EQU --CO--, PA0 A and B denote a group of the formulae ##STR3## it being necessary for at least one amine oxide group and at least one betaine group to be present, a denotes 0 or 1, b denotes 1, 2 or 3, n denotes a number from 0 to 10 and m denotes 1, 2 or 3. These compounds are obtained by partially quaternizing the parent polyamines with the alkali metal salt of an .omega.-halogenocarboxylic acid and then oxidizing the non-quaternized nitrogen atoms. These betaine-amine oxides are suitable for use as surfactants in cleansing agents.

It is already known to employ amphoteric surfactants having a betaine group 
in the molecule, or amine oxides having an amine oxide group in the 
molecule, on their own or in combination with anionic surfactants in 
cleansing agents. For example, the use of alkylbetaines in cleansing 
agents is known from German Auslegeschrift No. 1,249,433, while 
amidoalkylbetaines are recommended in German Auslegeschrift No. 1,172,802 
as bath additives which are tolerated by the skin and in German 
Auslegeschrift No. 1,537,218 as microbicidal hair-washing agents which do 
not irritate the eyes. Surfactant mixtures composed of monobetaines and 
monoamine oxides are also mentioned in German Offenlegungsschrift No. 
2,063,422 as advantageous surfactants which are kind to the skin. 
Known difunctional amine oxides are the diamine-diamine oxides disclosed in 
U.S. Pat. Nos. 3,197,509 and 3,234,139. In the way of difunctional 
dibetaines, polyaminepolybetaines are described, inter alia, in German 
Auslegeschrift No. 2,139,074 as amphoteric, surface-active cleansing 
agents in a washing agent composition. 
It has been found, however, that neither diamine-diamine oxides nor 
diaminedibetaines can satisfy the increasing demands made on components of 
cleansing agents. 
It has now been found, surprisingly, that amphoteric surfactants containing 
one or more amine oxide groups and, at the same time, one or more betaine 
groups in one molecule have better technical properties in use than the 
pure amine oxides or betaines or mixtures of the latter with one another. 
The invention relates, therefore, to mixed betaine-amine oxides of the 
formula 
##STR4## 
in which R denotes alkyl, alkenyl or hydroxyalkyl, each of which has 8-22, 
preferably 12-18, carbon atoms, R.sup.1 denotes hydrogen or methyl, 
R.sup.2 denotes ethylene, propylene or 2-hydroxypropylene, R.sup.3, 
R.sup.4 and R.sup.5 can be identical or different and denote C.sub.1 
-C.sub.3 -alkyl or a group of the formula 
##STR5## 
and R.sup.3 also denotes the group 
##STR6## 
X denotes a direct bond or a group of the formula 
EQU --CO--, 
A and B denote a group of the formulae 
##STR7## 
it being necessary for at least one amine oxide group and at least one 
betaine group to be present, a denotes 0 or 1, b denotes 1, 2 or 3, n 
denotes a number from 0 to 10 and m denotes 1, 2 or 3. 
Preferred compounds are those of the above formula in which R.sup.1 denotes 
hydrogen, R.sup.2 denotes propylene or 2-hydroxypropylene, R.sup.3, 
R.sup.4 and R.sup.5 are identical and denote methyl or hydroxyethyl, a is 
zero and m is 1 or 2. 
These compounds are prepared by quaternizing one mole of a polyamine of the 
formula 
##STR8## 
with 1 to 3 moles of an alkali metal salt of an .omega.-halogenocarboxylic 
acid of the formula 
EQU Hal--(CH.sub.2).sub.b --COOH 
and then oxidizing the resulting betaine with hydrogen peroxide. 
The betaine-amine oxides according to the invention are prepared from 
polyamines containing tertiary nitrogen atoms. These polyamines have 
already been known for a long time. They are obtained, for example, by 
reactions carried out on alkylamines or alkylpolyoxethylamines which still 
contain at least one reactive hydrogen atom on the basic nitrogen atom. 
Such reactions can be cyanoalkylations with acrylonitrile followed by 
hydrogenation, which can be repeated several times; aminoalkylations with 
cyclic amine compounds, such as, for example, aziridine; reaction with 
.omega.-halogenoalkyl nitriles or .omega.-halogenoamines, such as, for 
example, chloroacetonitrile, chloroethyldimethylamine or 
chloroethyldiethanolamine; epoxidization reactions with compounds such as 
ethylene oxide, propylene oxide, glycidol or epichlorohydrin, followed by 
ammonolysis or aminolysis. The polyamines thus obtained are reacted with 
customary alkylating agents, such as alkyl halides, formaldehyde, ethylene 
oxide, propylene oxide or mixtures thereof, to give the tertiary 
polyamines (see Houben-Weyl, Volume 11/1 et seq. or S. J. Gutcho, 
Surfactants and Sequestrants, Chem. Techn. Rev. 89). Examples of starting 
amines which can be employed are the following amines, some of which are 
also available as commercial products: 
##STR9## 
The radical R in these starting compounds and correspondingly also in the 
end products represents longchain alkyl, alkenyl or hydroxyalkyl groups, 
preferably those which are derived from naturally occurring fatty acids 
composed of linear or branched alkyl chains originating from the Ziegler 
process (ethylene synthesis alcohols) or from the oxo synthesis. 
Accordingly, the starting materials and the end products can be mixtures 
in which the radical R has various meanings, depending on the composition 
of the particular fatty alkyl mixture. Examples of such mixtures, derived 
from naturally occurring fatty acids, are tallow fatty alkyl or coconut 
fatty alkyl. 
The compounds according to the invention are obtained from the tertiary 
polyamines by quaternization with an alkali metal salt of an 
.omega.-halogenocarboxylic acid, preferably with the sodium salts of 
chloroacetic acid, chloropropionic acid, bromoacetic acid or 
chloro-n-butyric acid. Instead of these alkali metal salts, the reaction 
can also be carried out by means of the corresponding free acids if an 
alkali metal hydroxide is added. The quaternization takes place in an 
aqueous solution at temperatures of approx. 70.degree.-100.degree. C. The 
ratio between the polyamine and the halogenocarboxylic acid salt is 
selected in such a way that at least one nitrogen atom in the molecule is 
quaternized. However, at least one nitrogen atom in the molecule must not 
be quaternized, but must remain free for the introduction of the amine 
oxide group. Accordingly, the molar ratio of halogenocarboxylic acid salt 
to polyamine is 1:1 to 3:1. 
It is known that the rate of the quaternization reaction between tertiary 
amines and--halogenocarboxylic acids or alkali metal salts thereof depends 
on the basicity, reactivity and steric environment of the tertiary 
nitrogen atoms, the reaction rate and the degree of reaction of, for 
example, sodium chloroacetate with a tertiary amine decreasing in the 
following sequence: 
EQU R--N(CH.sub.3).sub.2 &gt;R--N(C.sub.2 H.sub.4 OH).sub.2 &gt;&gt;R.sub.2 
--N--CH.sub.3 &gt;R.sub.2 N(C.sub.2 H.sub.4 OH)&gt;&gt;R.sub.3 N. 
In accordance with this series, terminal tertiary amino groups are 
quaternized preferentially by the alkali metal salt of an 
.omega.-halogenocarboxylic acid, inner tertiary amino groups are only 
quaternized to a minor extent, since they correspond to an R.sub.2 
N(CH.sub.3) or R.sub.2 N(C.sub.2 H.sub.4 OH) group. 
An alkylpolyaminoalkylbetaine or alkylpolyoxalkylpolyaminoalkylbetaine is 
thus obtained as an intermediate stage, preferably in the form of a 30 to 
40% strength solution in water. The remaining, non-quaternized tertiary 
nitrogen of the aminobetaine formed as an intermediate stage is then 
oxidized at a temperature of 60.degree.-90.degree. C. to give the 
polyfunctional betaine/amine oxides according to the invention, using 35% 
strength or 70% strength hydrogen peroxide, which is used in a 5 to 10% 
molar excess, relative to free tertiary amino groups. It is advantageous 
to prepare the betaine/amine oxides according to the invention in the form 
of 30-40% strength aqueous formulations by choosing a suitable water 
content in the last reaction stage. In addition to the betaine-amine 
oxides according to the invention, the reaction product can also contain, 
additionally, varying quantities of polyamines which carry only betaine 
groups or only amine oxide groups. However, the proportion of these 
compounds is not critical for practical use. 
The betaine-amine oxides according to the invention are used as surfactants 
in the known and customary cleansing agents, such as, for example, washing 
agents of all kinds for the hair and the body, household cleansing agents, 
washing agents for textiles, washing-up liquids, automobile cleansing 
agents and other industrial cleansing agents. The content of betaine-amine 
oxide in these cleansing agents is within the limits customary in this 
respect, that is to say, for instance, between 1 and 50, preferably 5 and 
15, % by weight. The nature and amount of other components in these 
cleansing agents is customary and known and therefore needs no further 
explanation. 
The advantage of the products according to the invention compared with the 
single-substance polyaminepolybetaines and polyaminepolyoxides is that the 
foaming behavior, the foam stability, the viscosity, the possibility of 
thickening by means of electrolytes and alkylsulfates or ether-sulfates, 
the behavior under cold conditions, the wetting power and the 
hair-conditioning effects when used in shampoos are improved.

EXAMPLE 1 
170.4 g (0.4 mole) of laurylpropylenediaminetrisoxethylate of the formula 
##STR10## 
and 318.9 g of water are initially placed in a flask equipped with a 
reflux condenser, a thermometer, a stirrer and a metering vessel, and are 
warmed to 90.degree. C., while stirring. 46.6 g (0.4 mole) of sodium 
chloroacetate in 108.7 g of water are then added at this temperature in 
the course of one hour, and stirring is continued for 12 hours at 
95.degree. C. 23.3 g (0.48 mole) of 70% strength hydrogen peroxide are 
then added and the mixture is stirred for a further 8 hours at 70.degree. 
C. The betaine-amine oxide according to the invention is obtained in the 
form of a 30% strength aqueous solution. 
The conversion is checked by determining the amine number and the content 
of amine oxide and by comparing the content of organically linked chlorine 
with the total chlorine content, in accordance with customary analytical 
methods. 
EXAMPLE 2 
81.6 g of sodium chloroacetate in 190.3 g of water are added to 286.3 g 
(0.7 mole) of coconut fatty aminopropylaminetrisoxethylate of the formula 
##STR11## 
R=6% C.sub.8 ; 6% C.sub.10 ; 54% C.sub.12 ; 18% C.sub.14 ; 8% C.sub.16 and 
8% C.sub.18) and 530 g of water, and the mixture is stirred for 12 hours 
at 95.degree. C. It is then oxidized with 40.7 g of 70% strength hydrogen 
peroxide for 8 hours at 70.degree. C. The betaine-amine oxide is obtained 
in the form of a 30% strength solution in water. 
EXAMPLE 3 
619.0 g (1 mole) of coconut alkylpentaoxethylaminopropylaminetrisoxethylate 
of the formula 
##STR12## 
(composition of R as in Example 2) and 1,519.4 g of water are reacted with 
116.5 g (1 mole) of sodium chloroacetate for 12 hours at 95.degree. C., 
and the mixture is then oxidized with 58.3 g of 70% strength hydrogen 
peroxide to give the corresponding betaine-amine oxide. 
EXAMPLE 4 
550.0 g (1 mole) of tallow fatty alkyldipropylenetriaminetetrakisoxethylate 
of the formula 
##STR13## 
(R=C.sub.16 H.sub.33 -alkyl and C.sub.18 H.sub.37 -alkyl) and 1,329.9 g of 
water are reacted with 233.0 g (2 moles) of sodium chloroacetate for 12 
hours at 95.degree. C., and the mixture is then reacted with 116.6 g (2 
moles) of 70% strength hydrogen peroxide for 8 hours at 70.degree. C. 
A statistical mixture of bisbetaine-amine oxide and betaine-bisamine oxide 
is obtained in the form of a 30% strength emulsion in water. 
EXAMPLE 5 
366 g (1 mole) of coconut alkylamino-2-hydroxypropylaminotrisoxethylate of 
the formula 
##STR14## 
(composition of R as in Example 2) and 929.1 g of water are reacted with 
122.3 g (1.05 moles) of sodium chloroacetate for 12 hours at 95.degree. 
C., and the mixture is then reacted with 68.0 g (1.4 moles) of 70% 
strength hydrogen peroxide to give the betaine-amine oxide (30% strength 
in water). 
EXAMPLE 6 
308.0 g (1 mole) of coconut alkylmethylamino-2-hydroxypropyldimethylamine 
of the formula 
##STR15## 
(composition of R as in Example 2) and 793.7 g of water are reacted with 
128.2 g (1.1 moles) of ClCH.sub.2 COONa for 8 hours at 95.degree. C., and 
the mixture is then reacted with 53.4 g (1.1 moles) of 70% strength 
H.sub.2 O.sub.2 at 70.degree. C. The betaine-amine oxide is obtained in 
the form of a 30% strength solution in water. 
The use examples listed below show the possible ways in which the 
betaine-amine oxides may be employed in cleansing agents for the hair and 
the body. Unless otherwise specified, the quantity and percentage figures 
in the examples relate in each case to weight. 
______________________________________ 
Hair shampoo with a highlighting effect 
Betaine-amine oxide prepared 
15.00% 
in accordance with Example 2 
Polyethylene glycol 6000 distearate 
5.20% 
Perfume oil 0.30% 
Formaldehyde 0.05% 
Water up to 100.00% 
Hair shampoo 
Betaine-amine oxide prepared 
12.00% 
in accordance with Example 2 
Hydroxyethylcellulose ether 
1.40% 
Perfume oil 0.30% 
Formaldehyde 0.05% 
Water up to 100.00% 
Acid shampoo 
Betaine-amine oxide prepared 
15.00% 
in accordance with Example 1 
Citric acid 0.30% 
Perfume oil 0.10% 
Preservatives, dyestuffs and water up to 
100.00% 
Anti-dandruff shampoo 
Betaine-amine oxide prepared 
5.00% 
in accordance with Example 3 
Sodium salt of palm kernel fatty 
6.00% 
acid methyltauride 
Sodium salt of stearic acid methyltauride 
4.00% 
Sodium salt of lauroylsarcoside 
2.00% 
Zinc salt of 2-mercaptopyridine N--oxide 
0.50% 
Perfume oil 0.20% 
Water and dyestuffs up to 100.00% 
Shampoo for greasy hair 
Betaine-amine oxide prepared 
7.00% 
in accordance with Example 3 
Sodium salt of a secondary alkane- 
5.00% 
sulfate (alkane radical C.sub.13 -C.sub.17) 
Sodium salt of an .alpha.-olefin sulfonate 
2.00% 
(C.sub.14 -C.sub.16) 
Sodium laurylsulfate 2.00% 
Water, preservatives and 100.00% 
dyestuffs up to 
Shower lotion 
Betaine-amine oxide prepared 
12.00% 
in accordance with Example 4 
Disodium lauryltetraglycol-ether- 
3.00% 
sulfosuccinate 
Hydroxyethylcellulose ether 
1.20% 
Perfume oil 0.10% 
Coconut fatty acid monoethanolamide 
0.80% 
Water, preservatives and 100.00% 
dyestuffs up to 
Bubble bath 
Betaine-amine oxide prepared 
5.00% 
in accordance with Example 5 
Sodium lauryldiglycol-ether-sulfate 
20.00% 
Sodium salt of a secondary alkanesulfonate 
5.00% 
(alkane radical C.sub.13 -C.sub.17) 
Coconut fatty acid diethanolamide 
2.00% 
Perfume oil 0.40% 
Sodium chloride 3.00% 
Water, preservatives and 100.00% 
dyestuffs up to 
______________________________________ 
FOAM BEHAVIOR 
In order to demonstrate the improved foam behavior of the mixed 
betaine-amine oxides according to the invention, comparison tests were 
made with the analogous bisbetaines and bisamine oxides according to U.S. 
Pat. No. 3,197,509 and German Auslegeschrift No. 2,139,074. Since 
combinations of two or more surfactants are frequently used in practice 
for commercial reasons, a mixture composed of 7 parts of sodium 
alkyldiglycol-ether-sulfate (R=75-70% C.sub.12 and 25-30% C.sub.14) and 3 
parts in each case of the betaine-amine oxide according to Example 2 or 3 
parts of the analogous bisbetaine and bisamine oxide was taken here. 
Measuring the foam height in mm by the Ross-Miles method at 20.degree. of 
German hardness of water gave the following values for these mixtures: 
______________________________________ 
Surfactant 
Betaine-amine 
concentration, 
oxide according Bisamine- 
% to Example 2 Bisbetaine 
oxide 
______________________________________ 
1.0 270 260 245 
0.3 255 240 235 
0.1 245 230 215 
0.07 225 210 195 
0.03 180 165 145 
0.01 -- 105 -- 
0.006 95 60 25 
0.002 30 25 15 
______________________________________ 
The figures demonstrate the improved effect of the mixed betaine-amine 
oxides.