Alkali metal salts of hydroxyalkyl sulfonates of aminoalkyl alkanol amines and aminoalkyl alkanol ethers and method of making same

The subject invention relates to a novel class of compounds, known as alkali metal salts of hydroxyalkyl sulfonates of aminoalkyl alkanol amines and/or aminoalkyl alkanol ethers, the methods of making such compounds, the alkali-stable solutions containing such compounds, and the use of said solutions as strong detergent compositions. Those alkali-stable solutions are temperature-stable, exhibit superior wetting characteristics, and can be made into low or high foam formulations useful for hard surface cleaning, oven and grill cleaning, metal cleaning, bottle washing, steam cleaning and wax stripping formulations.

I. BACKGROUND OF THE INVENTION 
The prior art predominantly describes amphoteric surface compounds that 
show no particular alkali stability. For example, sulfonic acid salts are 
the most common types of synthetic detergents described in the literature. 
Despite the fact that various synthetic surfactants exist for detergent 
applications, the need for acid- and alkali-stable surfactants remains. 
The necessity for surface active agents that are stable in moderately 
strong alkali is discussed in U.S. Pat. No. 4,214,102. This patent teaches 
that many materials with amide linkages are destabilized in strong acids 
and alkalis, because that linkage readily breaks down in such media 
resulting in turbid solutions. The object of that invention is to develop 
amphoteric surface-active compounds that give a greater hydrophilic effect 
to the molecule and exhibit wide pH range stability from acidic to 
alkaline over long time periods. Those products are obtained by reaction 
of a glycidal ether with an excess of an N-hydroxy-C.sub.2-4 
-alkyl-C.sub.2-6 -alkylene diamine and then N-alkylating the product with 
an excess of halo C.sub.2-4 alkanoic acid or halo C.sub.2-4 hydroxyalkane 
sulfonic acid. 
Among the compounds produced are ones that have "the probable formulae": 
##STR1## 
The products formed are shown to be good foamers and stable in both 20% 
sodium hydroxide and 20% sulfuric acid. However, the surface tension of 
20% NaOH containing either 1% or 5% of the subject product was only 
reduced to 66.4 dyne/cm, indicating very poor surface activity in such a 
solution. 
U.S. Pat. No. 3,839,318 describes the only commercial product that is 
stable in concentrated alkali solutions; it is sold under the trademark 
Triton BG-10 and comprises higher alkyl monosaccharides and higher 
oligosaccharides. Triton BG-10 is characterized by some deficiencies; 
namely, it is quite dark and viscous, has a burnt odor, only dissolves 
slowly in 50% NaOH, does not reduce the surface tension of 50% NaOH to any 
great extent, and produces foam. 
U.S. Pat. No. 4,978,781 describes low-foam alkali-stable amphoteric surface 
active agents, including products of the formula: 
##STR2## 
wherein R is selected from alkyl, aryl or alkylaryl groups of 4-18 carbon 
atoms or alkoxymethylene; wherein the alkoxy group contains 4-18 carbon 
atoms; R.sub.2 and R.sub.3 are individually selected from the group 
consisting of methyl, alkyl of 5-6 carbons, where said alkyl group is 
substituted by an electron-donating group on the beta carbon thereof, 
polyoxyethylene and polyoxypropylene; alternatively, R.sub.2 and R.sub.3 
may together be --CH.sub.2 CH.sub.2 OCH.sub.2 CH.sub.2 -- or --CH.sub.2 
CH.sub.2 SCH.sub.2 CH.sub.2 -- (i.e., together with nitrogen constitute a 
morpholine or thiomorpholine ring); M is hydrogen or an alkali metal 
cation; and X is hydrogen or an electron-donating group such as OH, SH, 
CH.sub.3 O or CH.sub.3 S. Those products are said to be compatible with 
aqueous solutions containing up to 50% NaOH, appreciably reduce the 
surface tension of such solutions, remain dissolved when the concentrate 
is diluted with water to use concentrations of 5-20%, generate little or 
no foam in solutions containing 50% or less NaOH, and remain unchanged 
upon extended boiling of such solutions containing 5-20% NaOH. 
II. SUMMARY OF THE INVENTION 
The present invention is directed to a class of alkali metal salts of 
hydroxyalkyl sulfonates of aminoalkyl alkanol amines and/or aminoalkyl 
alkanol ethers (herein "sulfonates") useful as alkali-stable amphoteric 
surfactant wetting agents. These sulfonates may be prepared by the 
addition of a substituted aminoalkyl amine or aminoalkyl alkanol ether 
compound to an alkali metal salt of a halohydroxy alkyl sulfonic acid, an 
alkylating agent, at elevated temperatures between 50.degree. C. and 
100.degree. C. in an aqueous environment. 
Another aspect of the present invention is the discovery that the sulfonate 
surfactant compounds are fully soluble and stable in aqueous caustic 
solutions, such as those containing up to 50 wt. % NaOH. However, these 
solutions offered no performance advantages such as improved wetting. 
Solutions of this type have wetting times in excess of 10 minutes. 
It has been discovered that these sulfonates and amine oxides form unique 
wetting agents (herein "wetting agent admixtures") which are also fully 
soluble and stable in aqueous 50% caustic solutions. Interestingly, the 
solubility of the amine oxides in caustic are enhanced by the addition of 
the sulfonate. Without the sulfonate, amine oxides are not soluble in 
highly concentrated caustic solutions. 
In general, the wetting agent admixtures are clear light amber solutions, 
which maintain performance and color stability at 25.degree. C. and after 
heating at 50.degree. C. The wetting agent admixtures readily dissolve in 
concentrated caustic solutions and appreciably reduce the surface tension 
of the resultant solutions. Significantly, prolonging wetting time length 
allows those admixtures to more effectively penetrate surfaces to be 
cleaned. Typical wetting times of caustic admixtures of the present 
invention were found to be 32 sec. at 25.degree. C. and the performance 
advantages remained after heating to 50.degree. C. 
A further improvement of the present invention is that low or high foaming 
compositions or formulations may be produced depending on the amine oxide 
used. In such cases, the sulfonate/amine oxide weight ratio is from 80:20 
to 90:10, preferably 85:15. 
The wetting agent admixtures in concentrated alkaline solutions remain 
dissolved when those solutions are further diluted with water to normal 
use concentrations. Dilutions of those caustic solutions is generally from 
1:10 to 1:50 ratio, preferably about 1:20 ratio. 
The caustic solutions of the invention, alone or in combination with an 
amine oxide, in aqueous form may also contain conventional additives. 
These include lower alcohols of 1-6 carbons, glycols, glycol ethers, 
chelating agents, and thickeners such as amides, cellulose derivatives and 
polyacrylates. In some cases, additional anionic, nonionic or amphoteric 
surface agents may also be present. 
The caustic solutions of the present invention may be used as heavy duty 
cleaning agents. Such compositions typically include formulations for 
heavy duty cleaning agents for hard surface cleaners, oven and grill 
cleaning, metal cleaning, bottle washing, steam cleaning and wax stripping 
applications. 
III. DETAILED DESCRIPTION OF THE INVENTION 
All patents, patent applications, and literature references cited in the 
specification are hereby incorporated by reference in their entirety. 
The Sulfonates of the Invention 
The sulfonate surfactants of the present invention may be represented by 
two general formulas. Formula (I) is as follows: 
##STR3## 
wherein A and B may be hydrogen, a straight or branched hydroxy aliphatic, 
amino aliphatic, hydroxylated amino aliphatic, or alkoxylated amino 
aliphatic group; wherein any one of the amino hydrogens of the amino 
aliphatic, hydroxylated or alkoxylated amino aliphatic groups may be 
substituted with --(CH.sub.2).sub.o --CH(OH)--CH.sub.2 SO.sub.3 M wherein 
o is 1 to 10; M is an alkali metal; and n is 1 to 3. 
General Formula (II) is as follows: 
##STR4## 
wherein R and N form a heterocyclic radical substituted with one or two 
ring nitrogen atoms; or a heterocyclic radical having up to one ring 
oxygen atom; M is hydrogen or an alkali metal; and n is 1 to 3. 
Examples of straight or branched hydroxy aliphatic groups include, but are 
not limited to, methylol, ethylol and isopropylol. 
Examples of straight or branched amino aliphatic groups include, but are 
not limited to: 
--CH.sub.2 NH.sub.2 
--CH.sub.2 CH.sub.2 NH.sub.2 
--CH.sub.2 CH.sub.2 NHCH.sub.2 CH.sub.2 NH.sub.2 
--(CH.sub.2 CH.sub.2 NH).sub.m CH.sub.2 CH.sub.2 NH.sub.2 
wherein any one of the underlined amino hydrogens may be substituted with 
--(CH.sub.2).sub.o --CH(OH)--CH.sub.2 SO.sub.3 M; and wherein M is 
hydrogen or an alkali metal, m is 1 to 4, and o is 1 to 10. 
Examples of straight or branched hydroxylated amino aliphatic groups 
include, but are not limited to: 
--CH.sub.2 NH(CH.sub.2).sub.p OH 
--CH.sub.2 CH.sub.2 NH(CH.sub.2).sub.p OH 
--CH.sub.2 CH.sub.2 NHCH.sub.2 CH.sub.2 NH(CH.sub.2).sub.p OH 
--(CH.sub.2 CH.sub.2 NH).sub.m CH.sub.2 CH.sub.2 NH(CH.sub.2).sub.p OH 
--CH.sub.2 CH.sub.2 N[(CH.sub.2).sub.p OH].sub.2 
--CH.sub.2 CH.sub.2 N[(CH.sub.2).sub.p OH].sub.3.sup.+ X.sup.- 
--CH.sub.2 CH.sub.2 N[(CH.sub.2).sub.p CH(OH)CH.sub.3 ].sub.2 --CH.sub.2 
CH.sub.2 N[(CH.sub.2).sub.p CH(OH)CH.sub.3 ].sub.3.sup.+ X.sup.- 
wherein X is chlorine, bromine or iodide and any one of the 
above-underlined amino hydrogens may be substituted with 
--(CH.sub.2).sub.o --CH(OH)--CH.sub.2 SO.sub.3 M; and wherein M is 
hydrogen or an alkali metal, m is 1 to 4, o is 1 to 10, and p is 1 to 10. 
Examples of straight or branched alkoxylated amino aliphatic groups 
include, but are not limited to: 
--CH.sub.2 CH.sub.2 NH(CH.sub.2).sub.q --O-alkoxy; 
--CH.sub.2 CH.sub.2 N[(CH.sub.2).sub.q --O-alkoxy].sub.2 ; and 
--CH.sub.2 CH.sub.2 N[(CH.sub.2).sub.q --O-alkoxy].sub.3.sup.+ X.sup.-; ; 
wherein X is chlorine, bromine or iodide; and q is 1 to 4. 
Examples of O-alkoxy radicals include, but are not limited to, methoxy, 
ethoxy, n-propoxy, iso-propoxy, n-butoxy, isobutoxy and sec-butoxy. 
Examples of some of the preferred compounds of Formula (I) are: 
__________________________________________________________________________ 
##STR5## 
Amino Sulfonate based on: 
__________________________________________________________________________ 
##STR6## Ethylenediamine 
##STR7## Di-ethanol 
##STR8## Tri-ethanol 
##STR9## n-Propanol 
##STR10## Di-propanol 
##STR11## Tri-propanol 
##STR12## Mono isopropanol 
##STR13## Di-isopropanol 
##STR14## Tri-isopropanol 
##STR15## Alkoxy ethoxylated 
__________________________________________________________________________ 
According to one preferred embodiment of this invention, A and B of Formula 
(I) may be hydrogen, --CH.sub.2 CH.sub.2 --OH, --CH.sub.2 
CH(OH)--CH.sub.3, --CH.sub.2 CH.sub.2 --NH.sub.2, --CH.sub.2 CH.sub.2 
--NH--CH.sub.2 CH.sub.2 --OH or --CH.sub.2 CH.sub.2 --OCH.sub.2 CH.sub.3. 
The most preferred compounds of Formula (1) of this invention are wherein: 
A is HO--CH.sub.2 CH.sub.2 --NH--CH.sub.2 CH.sub.2 ; B is hydrogen; M is 
an alkali metal cation, most desirably sodium; and n is 1. 
Examples of the preferred compounds of Formula (II) are piperazinyl, 
morpholine, and N and C substituted derivatives thereof wherein the 
substitutions are lower alkyl, hydroxyalkyl, or hydroxyaminoalkyl. 
The most preferred compounds of Formula (II) of this invention are the 
salts of N-hydroxyethyl piperazine-N'-2-hydroxypropyl sulfonic acid, 
piperazine-N,N'-2-hydroxypropyl sulfonic acid (dihydrate), 
3-(N-morpholino)-2-hydroxypropyl sulfonic acid, and 
3-[N-(bis-cyclohexyl)-amino]-2-hydroxypropyl sulfonic acid. The 
preparation of the acids of these compounds is shown in Examples 3, 4, 6, 
and 8 of U.S. Pat. No. 4,246,194. 
Preparation of the Sulfonates 
The sulfonate surfactants of the invention may be prepared by first 
combining epichlorohydrin with sodium metabisulfite in water at elevated 
temperatures between 50.degree. C. to 100.degree. C. in an aqueous 
environment by methods well-known in the art. 
##STR16## 
wherein n is 1. 
The second step involves the addition of the substituted aminoalkylamine 
compound to the sodium salt of halohydroxyalkyl sulfonic acid: 
##STR17## 
Preferably, the reaction is carried out at a temperature of from 60.degree. 
to 100.degree. C., at atmospheric pressure, in a solvent such as water and 
at a pH of from 8 to 10, most desirably 9.5. For making the 
mono-substituted compounds, the preferred molar ratio is from 1.04 to 2.5 
moles of the sulfonate for each mole of the amine. 
After the complete addition of the substituted amine, an alkaline pH within 
the range of 9-9.5 is maintained by the incremental addition of a 
concentrated NaOH solution, which may range from about 20% to 50%. 
When chlorohydroxypropyl sulfonate is added to aminoethyl ethanol amine 
(AEEA) in a mole ratio of 1.2 to 1.0, the resulting product is a mixture 
of unreacted AEEA, mono-substituted, di-substituted, and tri-substituted 
AEEA. The approximate mole ratio of the first three components is 
0.3:0.3:0.5. Some tri-substituted AEEA is also present. The ratio was 
calculated from elemental analysis after accounting for the free AEEA (by 
GC). The high content of di-substituted AEEA was confirmed in 
electroscopy-MS and 13C NMR spectra. There is also evidence of the 
tri-substituted AEEA. There was no evidence of substitution on the 
hydroxyl group. Therefore, these products (those with more than one 
nitrogen) are and will always be (given the synthetic process) mixtures of 
free amine, mono-, di-, tri-, etc. sulfonates. 
The compounds of the present invention may also be in the form of a di-salt 
by combining the resultant substituted hydroxyalkyl sulfonates with a 
halohydroxypropyl sulfonate. For example, the reaction of the 
hydroxypropyl sulfonate of aminoethylethanol amine and 1-chloro-2-hydroxy 
propyl sulfonate forms a di-salt having the following formula: 
EQU HO--CH.sub.2 CH.sub.2 --NH--CH.sub.2 CH.sub.2 --N(CH.sub.2 CH(OH)CH.sub.2 
--SO.sub.3 Na).sub.2. 
The compounds of the invention also include quaternized compounds of 
Formula (I) and Formula (II). The basic nitrogen in each of those Formulas 
can be quaternized with lower alkyl halides, such as methyl, ethyl, propyl 
and butyl chloride, bromides and iodides. Water or oil soluble or 
dispersible products may be obtained by such quaternization. 
Sulfonate Surfactant Compatibility with Aqueous Alkaline Solutions 
The sulfonate surfactants of the present invention are soluble in up to 50 
wt. % aqueous alkaline solutions, such as caustic solutions. In addition, 
the resultant caustic solutions remain phase-stable at 25.degree. C. and 
upon heating to 50.degree. C. for 24 hours. Upon dilution of a 50% 
caustic/sulphonate solution with ten parts of water (1:10), it was found 
to have a wetting time of greater than 10 minutes. 
As discussed below, novel wetting agent admixtures were developed, wherein 
the unique ability of the sulfonate surfactants to solubilize amine oxide 
wetting agents in highly concentrated caustic solutions resulted in 
cleaning agents with enhanced wetting times. 
Sulfonate Surfactant-Amine Oxide Admixture: Wetting Agent Compatibility 
with Aqueous Alkaline Solutions 
An admixture of these sulfonate surfactants with amine oxides were also 
found to be soluble in aqueous solutions of 40% to 50% caustic or 
equivalent. These admixtures were found to possess good wetting 
properties, while maintaining phase and performance stability. The 
sulfonate to amine oxide ratio in those solutions should be from a range 
of 95:5 to 80:20, with an optimal ratio being 85:15. 
As noted above, the solubility of the amine oxides is enhanced by the 
addition of the sulfonate surfactants. Not all wetting agents can be 
successfully mixed with these sulfonates to form blends soluble in 
alkaline solutions. For example, other wetting agents, such as 
Lonzaine.RTM. CO or Aerosol.RTM. OTB, do not blend well with the 
sulfonates and mixtures thereof lack solubility, i.e., are unstable in 50% 
NaOH or highly caustic solutions. 
The surface tension of the concentrated alkaline solutions containing the 
solubilized admixture of the present invention is appreciably reduced. 
This results in reducing wetting time length, which allows the admixture 
solutions to more effectively penetrate the surfaces to be cleaned. 
Dilutions of the Concentrated Admixture-Caustic Solutions 
The concentrated caustic containing the wetting agent admixture, i.e., the 
sulphonate and the amine oxide, is diluted with water to the desired use 
concentrations. Importantly, the components remain dissolved when these 
concentrated alkaline solutions are diluted. Dilutions are in a 1:10 to 
1:50 ratio range, preferably in a 1:20 ratio. 
Low or High Foaming Compositions 
Compositions of the present invention may be produced that are low or high 
foaming depending on the amine oxide used. In such cases, the 
sulfonate/amine oxide ratio is from 80:20 to 90:10, preferably 85:15 
ratio. 
The low foaming surfactant is an amine oxide having the following 
structure: 
##STR18## 
wherein the R.sub.1 groups are independently selected from C.sub.1 
-C.sub.4 alkyl or alkoxy groups, and R.sub.2 is a branched C.sub.11 
-C.sub.16 alkyl chain group. For R.sub.1, methyl, ethyl, and hydroxyethyl 
are preferred and methyl is most preferred. For R.sub.2, the branched 
C.sub.12 and C.sub.13 are preferred. 
Specific examples of the preferred amine oxide surfactants for use in the 
novel formulations of the present invention include isononyldimethylamine 
oxide, isododecyidimethylamine oxide and isotridecyidimethylamine oxide. A 
particularly preferred non-foaming amine oxide is prepared using a 
branched alcohol having two to four branches, e.g., a typical chain length 
distribution of 6% C.sub.10, 18% C.sub.11, 55% C.sub.12, 20% C.sub.13, and 
1% C.sub.14 (the major isomer is trimethyl-1-nonanol.) 
The high foaming surfactant is an amine oxide has the same structure as set 
for immediately above wherein R.sub.2 is a straight chain C.sub.10 
-C.sub.16 alkyl chain group. For R.sub.2, the straight chain C.sub.10 and 
C.sub.12 are preferred. 
Specific examples of the preferred amine oxide surfactants for use in the 
foaming formulations of the present invention include n-decyldimethylamine 
oxide, n-dodecyldimethylamine oxide and isododecyldimethylamine oxide. 
The aim of the above amine oxides can be synthesized by well known methods. 
Components of Compositions of the Invention 
Compositions of the present invention include the sulfonates alone or in 
combination with selected amine oxide, in aqueous NaOH or equivalent 
alkaline solutions, with or without conventional additives such as 
silicates, phosphates, pyrophosphates and polyphosphates for example in 
the form of the sodium salts. Other additives that may be present include 
lower alcohols of 1-6 carbons, glycols, glycol ethers, chelating agents, 
thickeners such as amides, cellulose derivatives and polyacrylates. In 
some cases, additional anionic, nonionic or amphoteric surface agents may 
also be present. 
Uses of the Invention 
The caustic solutions containing the wetting agent additive of the 
invention are useful as heavy duty cleaning agents for hard surface 
cleaners, oven and grill cleaning, metal cleaning, bottle washing, steam 
cleaning and wax stripping applications. 
The present invention is illustrated by the following examples. These 
examples are intended to exemplify this invention, but not to limit its 
scope.

EXAMPLE 1 
1-Chloro-2-Hydroxy Propane Sodium Sulfonate 
580 grams (3.05 moles) of sodium metabisulfite and 1,572 ml of water were 
added to a five liter round bottom flask equipped with a mechanical 
stirrer, a vertical condenser and a temperature control unit. Reaction 
mixture stirred for approximately 30 minutes heated to 70.degree. C. until 
the sodium metabisulfite had dissolved. 542.1 grams (5.86 moles) of 
epichlorohydrin was added dropwise at 70.degree. C. over a 45 minute 
period to sodium metabisulfite-water mixture. The rate of epichlorohydrin 
addition was controlled to prevent an exotherm from rising above 
85.degree. C. This reaction was monitored by gas chromatography, as 
indicated by the disappearance of starting materials. The resulting 
reaction solution was used as is in the subsequent reaction. 
Hydroxy Propane Sodium Sulfonate of AEEA 
509.3 grams (4.89 moles) of AEEA were added dropwise over a one-hour period 
to the reaction solution. Reaction temperature was maintained between 
80.degree. C. to 85.degree. C. at the completion of the AEEA addition and 
the pH of the reaction mixture was raised at 80.degree. C. from 9 to 9.5 
with a 50% solution of aqueous NaOH (240.5 grams, 3.01 moles). These 
conditions were maintained constant until the completion of the reaction. 
Approximately 4 hours after the complete addition of AEEA, the sodium 
chloride levels of the solution were determined to have reached its 
theoretically calculated weight % of 9.9%. This was an indication that the 
reaction had gone to completion. The final product contained 52% solids, 
had a pH at 10% active of 9.3, and had an amber clear liquid appearance. 
EXAMPLE 2 
Physical Properties as Wetting Agents 
To demonstrate the efficacy of the instant invention, the hydroxy propane 
sodium sulfonate of AEEA (prepared as shown in Example 1) and an admixture 
of the sodium sulfonate of Example 1 and dodecyl dimethylamine oxide 
(85:15) were prepared. These were evaluated for solubility in 50% sodium 
hydroxide, temperature stability at 25.degree. C. and 50.degree. C., 
wetting ability and surface tension against Mirataine ASC (Rhone-Poulenc) 
CAS No. 108797-84-8 and 108797-85-9, a mixture of alkylether hydroxypropyl 
sultaines. This compound is a low foaming amphoteric wetting agent that is 
stable in 50% sodium hydroxide and described in U.S. patent Ser. Nos. 
4,891,159 and 4,978,781. 
For the comparison, the compounds were evaluated as wetting agents by 
Draves method SAPM No. 002-1-01; for surface tension by SensaDyne SAPM No. 
010-1-01; and for accelerated oven aging by SAPM No. 012-1-01. 
Results are shown in the following table: 
TABLE 1 
______________________________________ 
Draves Wetting** 
Surface 
sec. Tension** 
Solubility* After 24 
SensaDyne, 
in 50% hrs. @ dynes/cm after 24 
Agent NaOH 25.degree. C. 
50.degree. C. 
hrs. @ 50.degree. C. 
______________________________________ 
Sulfonate of 
10 &gt;600 &gt;600 72 
AEEA 
5436- 10 32 32 41 
191B*** 
Mirataine 
10 240 37 39 
ASC 
______________________________________ 
*Based on active surface active agent 
**At 5000 ppm actives concentration 
***A blend of 85% of 5342147 and 15% of an amine oxide (Barlox .RTM. 12, 
Lonza Inc.) 
The foregoing data show that all compounds are soluble at 10% active 
ingredients in sodium hydroxide and that the Mirataine ASC showed superior 
wetting properties to the sulfonate by itself. However, the 85:15 
admixture of sulfonate to amine oxide of the invention had substantially 
better wetting properties than the Mirataine ASC. 
The superiority of the admixture is particularly significant in light of 
the lower cost for producing the admixture as compared to the Mirataine 
ASC. The cost estimated for the hydroxypropyl sultaine of AEEA would be 
between $0.55 and $0.60 a pound, whereas estimated cost for the Mirataine 
ASC would be approximately $2 a pound. 
EXAMPLE 3 
Comparison of the Physical Properties of Sulfonate/Amine Oxide Admixtures 
and Other Alkali Stable Surface Active Agents 
In order to further show the efficacy of the combination of the sulfonate 
compounds of the invention with amine oxide, tests were performed at 
different ratios using the cocoamine oxide (Barlox.RTM. 12, Lonza Inc.), 
the straight chain amine oxide; isododecylamine oxide (Barlox.RTM. 12i, 
Lonza Inc.), a branched chain amine oxide; and the cocobetaine (Lonzaine 
CO, Lonza Inc.), a straight chain betaine. These admixtures were compared 
with Mirataine ASC, and Mazon 40LF, a proprietary surfactant of PPG 
Industries containing 78% solids. The results are shown in Table 2. 
TABLE 2 
__________________________________________________________________________ 
Experimental Alkali Stable Wetting Agent Phase Stability Results 
1:20 dilution in DI water 
(1 part NaOH mix + 
Solubility in 50% NaOH at 30 days 
19 parts DI water) 
Phase Stability at 30 days 
Ratio of Blend S.T. 
Description 
25.degree. C. 
50.degree. C. 
to 50% Caustic 
25.degree. C. 
50.degree. C. 
Draves, sec 
dynes/cm 
__________________________________________________________________________ 
Sulfonate of AEEA 
Good 
Good 
20/80 -- Good &gt;10 min. 
-- 
Alkali Stable Wetting Agent High Foaming* 
95/5 Good 
Good 
20/80 Good -- 317 54 
85/15 Good 
Good 
20/80 Good Good 30 42 
75/25 Good 
Good 
25/75 Good Good -- -- 
70/30 Good 
-- 11/89 slight haze 
-- 21 42 
Alkali Stable Wetting Agent Low Foaming** 
90/10 Good 
Good 
20/80 Good *** -- -- 
85/15 Good 
Good 
20/80 Good *** 95 46 
70/30 Good 
Good 
20/80 2.phi., 25.degree. C. 
-- -- -- 
10 min. 
Commercial Alkali Wetting Agent 
Mirataine .RTM. ASC 
Good 
-- 20/80 slight ppt. 
Good: 150 44 
day 4 darkness in 24 
39 
hrs. 
Mazon .RTM. 40LF 
Good 
-- 2/98 black soln. 
-- 29 (opaque) 
43 
Mazon .RTM. 40LF 
Good 
-- 4/96 black soln. 
-- 8, 2.phi. 50.degree. C. 
37 
__________________________________________________________________________ 
*Ratio of sulfonate of AEEA to straight chain amine oxide (Barlox 12) 
**Ratio of sulfonate of AEEA to branched chain amine oxide (Barlox 12i) 
***At 50.degree. C. the solution separated into two phases. Upon cooling, 
the solution will return to a single clear phase. 
Table 2 shows the results of phase stability (at 25.degree. C. and 
50.degree. C.), solubility, wetting and surface tension tests of: (1) the 
identified sulfonate/amine oxide admixtures, in different ratios, in 
aqueous 50% NaOH solutions and (2) the dilution of the aforementioned 
samples in a 1:20 ratio with water. Those admixtures contain a sodium 
sulfonate of AEEA of the present invention, and a wetting agent selected 
from Barlox.RTM. 12, Barlox.RTM. 12i, Mirataine.RTM. ASC and Mazon.RTM. 
40LF (PPG Industries Inc.). 
In particular, the 85:15 blend of Barlox.RTM. 12 high foaming admixture and 
the 85:15 blend of Barlox 12i low foaming admixture were found to dissolve 
in a ratio of 20 parts of admixture to 80 parts of 50% NaOH, which can be 
further diluted with water in a 1:20 ratio to show good wetting properties 
of 30-32 sec. Moreover, wetting agents, other than Barlox.RTM. 12 and 
Barlox.RTM. 12i, did not blend well with the sulfonates due to lack of 
solubility or phase stability in 50% NaOH, even with heating at 50.degree. 
C. 
In addition, different types of commercial alkali wetting agents were 
admixed with the sulfonate of AEEA and tested for solubility therein. The 
mixtures were tested for solubility in caustic and their physical 
properties evaluated. The wetting agents are described in Table 3: 
TABLE 3 
______________________________________ 
Chemical Classes Other Than Amine Oxides Blended with 
Sulfonate of AEEA 
Chemical Class 
Trade Name Company 
______________________________________ 
Betaine Lonzaine CO Lonza 
Sodium dioctyl 
Aerosol OTB American Cyanamid 
sulfosuccinate 
Sodium ether sulfate 
Carsonol SES-S 
Lonza 
Sodium lauryl sulfate 
Carsonol SLS-R 
Lonza 
Ethoxylated nonyl 
Carsonon N-9 Lonza 
phenol 
______________________________________ 
None of these admixtures met the criteria of an alkali wetting agent. These 
criteria include solubility in the sulfonate, solubility in 50% caustic, 
low wetting time, and low surface tension. 
EXAMPLE 4 
Performance Study of Alkali Wetting Agents 
Samples containing an admixture of the sulfonate surfactants with 
Barlox.RTM. 12 (high foaming) and Barlox.RTM. 12i (low foaming), 
respectively, in aqueous 50% NaOH solution were studied for performance of 
surface tension, wetting time, blender foam at 25.degree. C. and phase 
stability at 23.degree. C., 40.degree. C. and 50.degree. C. A comparison 
between those samples and Mirataine ASC were made. 
TABLE 4 
______________________________________ 
Alkali-Stable Wetting Agents (ASWA): Low and High Foam Versions 
Lonza 
Performance ASWA-HF ASWA-LF Mirataine .RTM. ASC 
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Surface Tension, 
42 46 44 
dynes/cm 
Wetting Time, sec. 
30 95 150 
Blender Foam, 
52/50 39/7 27/0 
initial/2 min. 
Phase Stability in 50% NaOH @ 30 Days 
23.degree. C. 
Good Good Good 
40.degree. C. 
Good Good Good 
50.degree. C. 
Good Separated Separated 
in &lt;24 on day 7* 
hrs.** 
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*Darkened in 2 hours. 
**Sample became clear upon cooling to 25.degree. C. 
This chart indicates that the compounds of the invention are comparable to 
Mirataine.RTM. ASC with respect to surface tension and blender foaming. 
The ASWA-HF formulation of the invention had outstanding phase stability, 
with appreciably better wetting times. 
EXAMPLE 5 
Alkali Solubility of Sulfonates Based upon Various Amines 
A variety of sulfonates were prepared following the procedure described in 
Example 1 and screened for their solubility (10 wt. %) in 50% caustic and 
solubility as a blend (80:20) with amine oxide in 50% caustic. This test 
is called a screening test because no attempts were made to optimize the 
blend ratio to improve the solubility. 
The samples varied from each other in the type of amine used (i.e., AEEA, 
diethanol amine, ammonia, etc.) and mole ratio of alkylating agent, 
1-chloro-2-hydroxy propane sodium sulfonate, to amine. 
TABLE 5 
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Alkali Solubility of Hydroxyl Propyl Sulfonates 
M/R* Solubility of Blend 
Solubility of 
Amine Sample 
(sulfonate/ 
Solids 
Sodium Chloride 
Color 
of Barlox 12 
Barlox/Sulfonate Blend 
Type Number 
amine) 
Wt. % 
Wt. % (Gardner) 
in Sulfonate at 15% 
in 50% NaOH at 
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20% 
AEEA** 25 1.2 50.7 
9.0 3+ Yes Yes 
Diethanol-amine 
26 1.2 53.4 
9.5 1 Yes Yes 
Monoiso- 21 1.2 55.0 
10.9 1 Yes Yes 
propylamine 
AEEA 13 2.0 55.5 
11.2 1 Yes Yes 
Ammonia 27 1.2 48.8 
10.8 1 Yes No 
Monoethanol- 
17 1.2 53.5 
11.2 1 Yes No 
amine 
Ethylene-diamine 
14 1.2 54.0 
11.6 3+ Yes No 
Ethylene-diamine 
15 2.0 58.0 
12.5 3.5 
Yes No 
Triethanol-amine 
18 1.2 53.4 
9.2 1 No No 
Diethylene triamine 
16 1.2 55.3 
10.1 5 No No 
Diisopropyl 
22 1.2 51.4 
9.0 3+ No No 
amine 
Triisopropylamine 
28 1.2 54.0 
7.3 2 No No 
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*M/R is the molar ratio of sulfoante to amine 
**Sample is a duplicate of sample mentioned in Example 1 
Table 5 shows that the caustic solubility of the sulfonate and the 
admixture of the sulfonate with amine oxide can be influenced by altering 
the amine substitution and the mole ratio of alkylating agent to amine. It 
also shows the claim of alkali solubility is broader than just sulfonates 
based upon AEEA and a mole ratio of 1.2 moles alkylating agent to 1.0 mole 
amine. In the case of the last four sulfonates in Table 5, the blends were 
not optimized for solubility.