 |
Description  |
|
|
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to novel improved cationic surfactants based on
quaternary ammonium compounds and the use of such cationic surfactants in
industrial cleaner solutions.
2. Discussion of Related Art
For cleaning semi-finished products or finished products in industrial
production, for example, automotive parts made of iron or steel, there are
used aqueous solutions which contain tensides in addition to further
auxiliary materials such as builder substances, complexing agents, organic
or inorganic anticorrosive agents and optionally further substances. Thus,
processes have been proposed in German Patent Application Nos. 27 12 900
and 32 47 431 wherein quaternary ammonium compounds are used in the
alkaline pH range as cationic surfactants besides further cleaner
components in which organic residues, more specifically alkyl residues of
varying chain lengths, have been bonded to the ammonium nitrogen atom.
Counter-ions of the used ammonium cations include, for example, anions such
as chloride, sulfate or methylsulfate which are known as anions that cause
corrosion to occur. The necessary content of such anions undesirably
promotes the corrosion of equipment parts and treated metal surfaces. This
is an extraordinary disadvantage, more specifically in the treatment of
metal surfaces with aqueous products, and particularly when the use of
higher concentrations of cationics is desired. In fact, corrosion occurs
not only over extended periods of time during intermediate storage of
treated parts, but also immediately upon treatment of the respective
surfaces with the aqueous application solutions.
In German Patent Application No. 30 48 642 there have also been disclosed
tenside mixtures for cleaning bottles and other articles having hard
surfaces, for example porcelain, china, synthetics, and metal wherein the
mixtures contain cationic tensides based on ammonium compounds. However,
it is also one disadvantage of these tensides that they contain chloride,
bromide or methylsulfate as anions. In this case also, the anions
adversely affect the corrosion resistance of parts of the apparatus such
as dishwashers and of the treated surfaces as a consequence of the
treatment.
Processes for preparing quaternary ammonium compounds which contain at
least one long-chain hydroxyalkyl residue by reacting the salt of a
tertiary amine and an organic acid in water with a terminal epoxide
compound introducing a hydroxyalkyl residue at normal pressure, at a
temperature between 40.degree. C. and 100.degree. C. and a pH value of at
least 7 are known from German Patent Application No. 33 21 608. However,
the resulting quaternary ammonium compounds are also not usable to meet
the high requirements set for commercial cationic surfactants with respect
to practical servicability and anticorrosive properties. Thus, the anions
of numerous organic acids are not suitable as the counter-ions of cationic
surfactants, since the resulting quaternary ammonium compounds are poorly
soluble in water. Following their preparation, they are obtained in pasty
form and, due to their poor solubility in water, cannot be blended in
industrial cleansers. It has also been shown that ammonium cations
containing numerous hydroxyalkyl groups cause interfering precipitations
to occur in water which has not been fully deionized, which fact also
renders the use of such cationics impossible. Furthermore, cationic
surfactants are often expected to provide a demulsifying and/or defoaming
action to emulsions and/or anionic surfactants or emulsifiers,
respectively. However, the quaternary ammonium compounds disclosed in said
afore-mentioned application have not shown any demulsifying action with
respect to emulsions and/or anionic emulsifiers. These disadvantages have
also not been compensated for by distinctly improved anticorrosive
properties of the produced cationics, as only approximately the same
corrosion resistance was obtained as compared with commercially available
cationic tensides.
Thus, it is an object of the present invention to provide new improved
cationic surfactants based on quaternary ammonium compounds which do not
have the disadvantages of the prior art. More specifically, it is an
object of this invention to provide cationic tensides useful for
industrially applicable cleaning agents the components of which inhibit
corrosion, cause a sufficient demulsifying effect to be accomplished with
respect to anionic contamination, can be well blended in aqueous
industrial cleaners, i.e. are readily water-soluble, do not cause the
occurrence of any interfering precipitations, and are compatible with the
components conventionally used in industrial cleaners.
DESCRIPTION OF THE INVENTION
Other than in the operating examples, or where otherwise indicated, all
numbers expressing quantities of ingrdients or reaction conditions used
herein are to be understood as modified in all instances by the term
"about".
The above-mentioned objects are attained by providing new improved cationic
tensides based on quaternary ammonium compounds wherein the ammonium
nitrogen atom contains at last two alkyl radicals, one 2-hydroxyalkyl
radical originating from the reaction with a terminal epoxide having from
10 to 24 carbon atoms and, optionally, one arylalkyl group and the anion
of which is the anion of an organic carboxylic acid selected from the
group consisting of benzoic acid, monosubstituted benzoic acid, aliphatic
dicarboxylic acid, fumaric acid, maleic acid, and sulfosuccinic acid. It
has surprisingly been found that such cationic tensides not only have good
demulsifying properties relative to anionic tensides or emulsifiers,
respectively, but also when present in industrial cleaners render the
treated surfaces hydrophobic and thereby contribute to prevent corrosion
by allowing the application liquids to run off smoothly and without drip
from the treated surfaces and even create an antistatic effect on surfaces
of synthetics.
Accordingly, the present invention provides new improved cationic tensides
based on quaternary ammonium compounds which are characterized by the
general formula
##STR2##
wherein R.sup.1 may be a linear or branched alkyl residue having from 1 to
22 carbon atoms;
R.sup.2 may be hydrogen or a linear or branched alkyl residue having from 1
to 21 carbon atoms, the total number of carbon atoms of the substituents
R.sup.1 and R.sup.2 being in the range of from 8 to 22;
R.sup.3 and R.sup.4 represent methyl, ethyl, 2-hydroxyethyl or
2-hydroxypropyl;
R.sup.5 represents an alkyl residue having from 4 to 6 carbon atoms or a
phenalkyl residue having from 1 to 3 carbon atoms in the alkyl residue;
and
X.sup.- represents the anion of benzoic acid, of benzoic acid
monosubstituted with CH.sub.3, NH.sub.3, NO.sub.2, COOH, OH or SO.sub.3 H,
of an aliphatic dicarboxylic acid having the general formula
HOOC--(CH.sub.2).sub.n --COOH wherein n is a number from 2 to 8, of
fumaric acid, of maleic acid or of sulfosuccinic acid.
Examples of the linear or branched alkyl residue as represented by R.sup.1
and R.sup.2 include methyl, ethyl, propyl, isopropyl, n-butyl, tert-butyl,
pentyl, hexyl, heptyl, octyl, nonyl, decyl, dodecyl, tetradecyl and
hexadecyl. Preferred are those quaternary ammonium compounds wherein
R.sup.2 is hydrogen and R.sup.1 is a linear or branched alkyl residue
having from 8 to 22 carbon atoms, e.g. n-octyl, n-decyl, n-dodecyl,
n-tetradecyl or n-hexadecyl. In any event, the total number of carbon
atoms of the two substituents R.sup.1 and R.sup.2 must be in the range
from 8 to 22 carbon atoms.
The residue R.sup.5 bonded to the ammonium nitrogen atom represents alkyl
residues such as, for example, n-butyl, i-butyl, tert-butyl, n-pentyl,
tert-butyl-methyl, n-hexyl, or phenalkyl residues such as benzyl,
phenylethyl or phenylpropyl.
The corresponding anion in the cationic surfactants according to the
invention is the anion of an organic carboxylic acid, i.e. the residue
X.sup.- in general formula I represents the anion of benzoic acid, of
benzoic acid monosubstituted with CH.sub.3, NH.sub.3, COOH, OH or SO.sub.3
H, of an aliphatic dicarboxylic acid having the general formula
HOOC--(CH.sub.2).sub.n --COOH wherein n is from 2 to 8, i.e. of succinic
acid, of glutaric acid, of adipic acid, of pimelic acid, of suberic acid,
of azelaic acid, of sebacic acid, of fumaric acid, of maleic acid or of
sulfosuccinic acid. Particularly preferred are the anions of benzoic acid
and of fumaric acid.
Depending on the valency of the anion, i.e., the basicity of the respective
organic carboxylic acid, the cation of general formula (I) may be
contained several times in the quaternary ammonium compounds according to
the invention. Thus, general formula (I) includes the neutral as well as
the respective acidic salts.
In industrial cleaning agents, it is preferred to use the following
individual compounds, namely, benzyldimethyl-2-hydroxydodecylammonium
benzoate, and bis-(benzyldimethyl-2-hydroxydodecylammonium)fumarate. Of
these, benzyldimethyl-2-hydroxydodecylammonium benzoate is particularly
preferred.
The compounds having the structure of general formula (I) according to the
present invention can be prepared by per se known methods by reacting the
salt of a tertiary amine having the general formula
NR.sup.3 R.sup.4 R.sup.5 (II)
wherein R.sup.3, R.sup.4 and R.sup.5 are as defined above, and of an
organic acid having the general formula
X.sup.- H.sup.+ (III)
wherein X.sup.- is as defined above, in water with an epoxide compound
having the general formula
##STR3##
wherein R.sup.1 and R.sup.2 are as defined above and taken together have a
total number of 8 to 22 carbon atoms in a stoichiometric ratio at normal
pressure and at a temperature between 40.degree. C. and 100.degree. C.,
the reaction mixture having a pH of at least 7 before the reaction begins.
The epoxides of general formula (IV) used for the preparation of the
quaternary ammonium compounds according to the invention may be epoxides
having from 10 to 24 carbon atoms, wherein the oxirane ring may be in any
position of the molecule. However, those quaternary ammonium compounds
prepared by reaction of the amine salt with an 1,2-epoxide, i.e. the
compounds having general formula (I) wherein R.sup.1 is an alkyl residue
having from 8 to 22 carbon atoms and R.sup.2 is a hydrogen atom are
preferred.
The amines used for the preparation of the quaternary ammonium compounds of
general formula (I) preferably are tertiary alkyl-, hydroxyalkyl- or
alkyl-arylamines; dimethylbutylamine and dimethylbenzylamine being
particularly preferred.
The quaternary ammonium compounds according to the invention are used as
cationic surfactants in industrial cleaner solutions. In said use, they
have the advantage over other cationics such as quaternary ammonium
compounds already known from the prior art that they do not contain any
counter-anions which are corrosive or cause undesirable precipitations to
occur. In contrast thereto, the anions of the organic acid employed in the
preparation of the ammonium compounds according to the invention are even
capable of inhibiting the corrosion process on cleaned metal surfaces.
Thus, due to the absence of an accumulation of corrosive anions in the
bath and the inhibiting effect of the carboxylic acid anions, an
improvement of the anticorrosive properties in aqueous media is
accomplished. This is applicable to parts which have to be subjected to an
intermediate storage period prior to further processing as well as to
parts which are immediately subjected to further processing. The improved
corrosion resistance will be apparent in those parts, having been treated
with industrial cleaners containing quaternary ammonium compounds, which
due to their geometrical shape act like a ladle. In the case of use of
conventional cleaners the danger of corrosion occurring on such parts was
particularly high, since upon vaporization of the solvent, usually water,
a high accumulation of the ingredients and, hence, of the corrosive
components as well, was to be feared. This is prevented by the use of
industrial cleaner solutions containing the quaternary ammonium compounds
according to the invention as cationic tensides.
As the cationic tensides according to the invention are readily
water-soluble, they are easily blendable and do not gel in the use
solution. Corresponding use solutions also show a favorable run-off
property.
The cationic tensides according to the invention provide another advantage
in that a beneficial hydrophobization of the purified surfaces, more
particularly of purified metal surfaces, is observed. Furthermore,
corrosion of the treated articles is prevented by a good run-off property
of the use solution.
It has further been observed that aqueous solutions of industrial cleaners
which contain the quaternary ammonium compounds according to the invention
as cationics, can also be beneficially used for cleaning synthetic
materials since they provide an antistatic effect. It is just this
property which opens a wide field of future applications to such products,
since surfaces of synthetic materials increasingly tend to be cleaned by
spray processes.
The quaternary ammonium compounds according to the present invention are
suitable for use in all cleaners that are important for industrial
cleaning operations. Thus, they can be included in sprayable cleaners,
e.g. neutral to weakly alkaline cleaners or acidic cleaners, more
specifically in such cleaner solutions which are sprayed under high
pressure onto the articles to be cleaned. However, in the same manner they
may be advantageously used in immersion cleaners based on nonionic
surfactants.
The quaternary ammonium compounds according to the present invention may
also be used as cationic tensides to act as demulsifiers or anti-foaming
agents in industrial cleaner solutions for spray cleaning or immersion
cleaning.
The new improved cationic surfactants based on quaternary ammonium
compounds may be blended with further conventional components for
industrial cleaner solutions in accordance with per se known procedures.
In addition to the quaternary ammonium compounds and further conventional
ingredients, said solutions may optionally contain further additives, e.g.
alkanolamines, phosphates, borates or nitrites. If desired, inhibitors,
more specifically those for nonferrous metals, or biocides such as, for
example, hexahydrotriazine derivatives and/or phenols and/or
chlorophenols, may be added to the solutions in order to inhibit the
occurrence of bacteria and/or fungi in the spraying or immersing
equipment.
The present invention is further illustrated by means of the following
examples.
EXAMPLE I
This example describes the preparation of benzyl-2-hydroxydodecyldimethyl
ammonium benzoate.
A three-necked flask equipped with stirrer, contact temperature control,
and reflux condenser was charged, in sequence, with
106.7 g of water,
135.2 g (1.0 mol) of dimethylbenzylamine,
97.7 g (0.8 mol) benzoic acid, and
188.0 g (1.0 mol) of 1,2-epoxydodecane (EpOV 8.551, therefrom calculated MW
188.0)
while stirring, and the mixture was heated to 95.degree. C.
After a few minutes a clear solution has been formed to which after 15
minutes the residual amount of 24.4 g (0.2 mol) of benzoic acid was added;
and the mixture was stirred at 95.degree. C. for 6 hours. The solution was
about 80% solids and had the following characteristic values:
______________________________________
AcV EpOV AV
(acid (epoxide (amine
value)
value) value) Epton value
Barr value
______________________________________
3.6 0.002 104.1 132.2 mval/100 g
128 mval/100 g
______________________________________
EXAMPLE II
This example describes the preparation of
Bis-(benzyl-2-hydroxydodecyl-di-methyl-ammonium)-fumarate.
In a stirrer-equipped apparatus consisting of a three-necked flask, contact
temperature control and reflux condenser
81.25 g (0.7 mol) of fumaric acid were dissolved in 126.98 g of water and,
184.30 g (1.4 mol) of dimethylbenzylamine, and then
263.20 g (1.4 mol) of 1,2-epoxydodecane were added.
With continuous stirring the mixture was heated at 95.degree. C. and
maintained at this temperature for 4.5 hours.
The resulting yellowish about 80% solids solution was viscous upon cooling
and had the following characteristic values:
______________________________________
AcV EpOV AV
(acid (epoxide (amine
value)
value) value) Epton value
Barr value
______________________________________
14.4 0.07 112 138 mval/100 g
112 mval/100 g
______________________________________
EXAMPLE III
This example describes the preparation of
Benzyldimethyl-2-hydroxydodecyl-ammoniumsuccinate.
The apparatus described in Example II was charged, in this sequence, with
109.4 g of water, 135.2 g (1.0 mol) of dimethylbenzylamine, 118.1 g (1.0
mol) of succinic acid (acid value 950.2) and 190.9 g (1.0 mol) of
1,2-epoxydodecane (EpOV 8.38, therefrom calc, MW 190.0). After stirring
for 4.5 hours at 95.degree. C. a solution having a single phase had been
formed. Upon cooling the product became turbid; had an epoxide value of
0.10; and an acid value of 118.6.
EXAMPLE IV
This example describes the preparation of
n-butyldimethyl-2-hydroxydodecylammoniummaleate.
In the same apparatus and under the same conditions as in Example II the
following reactants were reacted: 93.8 g of water, 101.2 g (1.0 mol) of
dimethylbutylamine, 116.1 g (1.0 mol) of maleic acid (acid value 966.8)
and 190.0 g (1.0 mol) of 1,2-epoxy-dodecane (EpOV 8.38). A yellow 80%
solids solution of the product was formed which solution was clear when
hot and turbid after cooling; had an epoxide value of 0.01; an acid value
of 118.8; and an Epton value of 125.1 mval/100 g.
EXAMPLE V
Thie example describes the preparation of
Benzyldimethyl-2-hydroxyhexadecylammonium-sulfosuccinate.
In the same apparatus and under the same conditions as in Example II the
following reactants were reacted: 68.1 g of water, 67.6 g (0.5 mol) of
dimethylbenzylamine, 99.1 g (0.5 mol) of sulfosuccinic acid (acid value
849.5) and 123.8 g (0.5 mol) of 1,2-epoxyhexadecane (epoxide value 6.46).
Upon cooling to room temperature the yellow solution which was clear when
hot solidified to form a semi-solid mass containing the product in a
concentration of 81%; had an epoxide value of 0.06; an acid value of
161.3; and an Epton value of 132.7 mval/100 g.
EXAMPLE VI
Cleaner solutions intended for use as cleaners to be applied by spraying
and having concentrations of use in the range of from 0.5 to 5% were
prepared. The compositions of these cleaner solutions were as follows (the
percent is % by weight):
(a) Neutral Cleaners
Composition I
30% of triethanolamine;
10% of caprylic acid;
5% of hexahydrotriazine derivative;
0.5% of tolyl triazole;
4% of an addition product of 2 moles ethylene oxide (EO) and 4 moles
propylene oxide (PO) to an alcohol having 18 carbon atoms;
1% of an addition product of 5 moles EO and 30 moles PO to 1,2-propylene
glycol;
1.5% of benzyldimethyl-2-hydroxydodecylammonium benzoate; and
48.0% of fully deionized water.
Composition II
10% of sodium caprylate;
10% of triethanolamine;
5% of borax
10% of sodium triphosphate
4% of an addition product of 9 moles EO and 10 moles PO to nonylphenol;
2% of bis(benzyldimethyl-2-hydroxydodecyl-ammonium)fumarate; and
59.0% of fully deionized water.
(b) Alkaline Industrial Cleaner
15% of potassium triphosphate;
6% of triethanolamine;
5% of potassium hydroxide;
2% of an addition product of 3 moles EO and 6 moles PO to an alcohol having
12 to 18 carbon atoms;
4% of isononaoic acid;
2% of bis(benzyldimethyl-2-hydroxydodecylammonium)succinate; and
66% of fully deionized water.
(c) Acidic Cleaners
Composition 1
25% of sodium dihydrogenphosphate;
1% of benzoic acid;
0.2% of sodium molybdate;
1% of butyldimethyl-2-hydroxydodecylammonium benzoate;
3% of the nonionic tenside Triton DF16.RTM.; and
69.8% of fully deionized water.
Composition 2
12% of diethanolamine;
15% of 2-phosphonobutane-1,2,4-tricarboxylic acid;
5% of gluconic acid;
3% of the nonionic tenside Triton DF16.RTM.;
8% of fatty alcohol sulfate in the form of the sodium salt;
3% of phosphoric acid;
2% of bis(benzyldimethyl-2-hydroxydodecyl-ammonium)fumarate; and
52% of fully deionized water.
The cleaning agents formulated as described above were well aaplicable by
spraying. They only showed low tendency, or no tendency at all, to
foaming. The cleaning baths were stable over an extended period of time
and did not lose any cleaning power during that period. Due to the use of
the quaternary ammonium compounds according to the present invention, the
metal surfaces treated by being sprayed with the cleaners did not corrode,
but had an increased corrosion resistance as compared to surfaces treated
with conventional cleaners.
EXAMPLE VII
This example describes the preparation and use of alkaline industrial
immersion cleaners; concentration of application in the range of from 1 to
7%.
Composition 1
15% of potassium triphosphate;
6% of triethanolamine;
6% of isononaoic acid;
1.5% of benzyldimethyl-2-hydroxyhexadecylammonium benzoate;
10% of diethanolamine;
5% of an addition product of 10 moles EO to nonylphenol, and
56.5% fully deionized water.
Composition 2
40% of sodium diphosphate;
30% of sodium orthophosphate;
10% of sodium triphosphate;
10% of sodium metasilicate;
1% of bis(benzyldimethyl-2-hydroxydodecyl-ammonium)fumarate; and
9% of an addition product of 10 moles EO to nonylphenol.
The cleaning agents formulated as described above had a high cleaning power
on treated metal surfaces over an extended period of time, and their baths
had a high stability. Metal surfaces subjected to an immersion treatment
using the above-described cleaners had an increased corrosion resistance
as compared to surfaces treated with conventional cleaners.
EXAMPLE VIII
This example illustrates the demulsifying effect of various cleaner
compositions.
A. Neutral Cleaner
Described is the demulsifying activity of a neutral cleaner having the
composition as follows:
35% of alkanolamine C.sub.8 -C.sub.12 -carboxylate;
2% of 1-hydroxyethane-1,1-diphosphonic acid;
0.5% of mercaptobenzthiazole;
3% of a block polymer of ethylenediamine with 30 moles of ethylene oxide
and 60 moles of propylene oxide;
1% of an addition product of 10 moles of ethylene oxide to a C.sub.12
-C.sub.16 -fatty amine; and
58.5% of water.
a. Segregation of an Emulsion
The ability of segregating an emulsion was determined according to the
following test:
10 g of drilling oil were emulsified with 40 g of a 2% aqueous neutral
cleaner solution in a 270 ml oil-separating flask at room temperature. An
equivalent amount of BDHA benzoate (BDHA=benzyl
dimethyl-2-hydroxydodecylammoniumion) was added. The flask was filled up
while shaken by adding a hot 2% neutral cleaner solution. Demulgation
spontaneously began to take place. The liquid mixture was maintained at a
temperature of 80.degree. C. for 2 hours to effect complete separation of
the oil from the "emulsion-like phase". It was found the the oil was
substantially quantitatively separated.
b. Addition of an Anti-Foaming Agent
10 g of drilling oil were emulsified with 40 g of a 2% aqueous neutral
cleaner solution in a 270 ml oil-separating flask at room temperature.
BDHA benzoate was added to this emulsion in an excess over the
stoichiometric amount (ratio of demulsifier to anionic emulsifier to be
1.2:1). There was further added the addition product of 30 moles of
ethylene oxide and 60 moles of propylene oxide to ethylene diamine as an
anti-foaming agent (ratio of demulsifier to anti-foaming agent to be 1:1)
The flask was filled up while shaken by adding a hot 2% neutral cleaner
solution. Separation spontaneously began to take place. The recycled
cleaner solution could be sprayed without foam-formation.
B. Alkaline Cleaners
Illustrated in the following is the demulgation in the presence of alkaline
cleaners having the compositions as set forth hereinbelow:
Composition a
63% of sodium metasilicate;
14% of sodium hydroxide;
15% of soda;
2% of fatty alcohol containing 14 moles of ethylene oxide; and;
3% of alkylbenzenesulfonate.
A 4% cleaner solution in tap water was emulsified at room temperature with
a 2% drilling oil concentrate. Then more than an equivalent amount (1:1.1)
of BDHA benzoate was added, and the mixture was well stirred for about 3
minutes. Then the mixture was allowed to sit. Separation of the oil began
immediately.
Composition b
60% of sodium metasilicate;
10% of sodium hydroxide;
15% of soda;
10% of sodium diphosphate;
2.5% of fatty alcohol containing 14 of moles ethylene oxide; and
2.5% of cocoamine containing 12 moles of ethylene oxide.
To a 3% cleaner solution loaded as described under composition a, double
the equivalent amount of BDHA benzoate was added to effect the segregation
of the emulsion. Separation of the oil began immediately, the aqueous
phase being nearly clear.
Composition c
50% of sodium diphosphate;
15% of sodium triphosphate;
15% of trisodium phosphate;
10% of soda;
7.7% of nonylphenol containing 14 moles of ethylene oxide; and
2.3% of coconut fatty acid monoethanolamide containing 4 moles of ethylene
oxide.
To a 2% clear solution loaded as described under compositions a and b,
double the equivalent amount of BDHA benzoate was added. Separation of the
oil began spontaneously, the aqueous phase becoming nearly clear.
The presence of pyro-or polyphosphates and/or anionic tensides required the
addition of a higher amount of demulsifier to effect a complete and rapid
demulsification.
EXAMPLE IX
This example illustrates the use of general cleaners, e.g. cleaners for
cars, cleaners for walls and floors of industrial plants and products for
use in steam jet cleaning; application concentration in the range of from
2 to 30%.
Composition 1
8% of an addition product of 14 moles of EO to an alcohol having 12 to 14
carbon atoms;
7% of a fatty alcohol sulfate;
3% of butyldimethyl-2-hydroxydodecylammonium benzoate;
5% of potassium hydroxide;
10% of diethanolamine;
6% of phosphoric acid and
61% of fully deionized water.
Composition 2
8% of sodium triphosphate;
5% of isononaic acid;
5% of boric acid;
8% of monoethanolamine;
1% of potassium hydroxide;
5% of an addition product of 12 moles of EO to an amine having 12 carbon
atoms;
3% of bis(benzyldimethyl-2-hydroxydodecylammonium)fumarate; and
65% of fully deionized water.
The cleaning agents having the above-described compositions showed good
cleaning effects and at the same time a uniform sag-free run-off behavior
on the treated surfaces.
Due to the use of the quaternary ammonium compounds according to the
invention, the corrosion resistance of metal surfaces and articles treated
with the cleaner solutions was significantly improved over that of metal
surfaces and articles treated with conventional cleaners.
EXAMPLE X
This example illustrates a comparative corrosion test.
In the following test, the corrosion-inhibiting properties of two solutions
were tested by comparison, one of which contained Dehyquart.RTM.LDB
(Henkel) as a quaternary ammonium compound known from the prior art, and
the other one contained BDHA benzoate as the quaternary ammonium compound
according to the present invention.
The test was carried out in accordance with the chips test of DIN 51360/2
using solutions having concentrations of from 1% to 3% in fully deionized
(f.d.) and 20.degree.d-water of concentrates of the formulations I and II
as follows:
Formulation I
12.5% of Dehyquart.RTM.LDB (content of active ingredient: 35%);
37.5% of diethanolamine; and
remainder, water.
Formulation II
5.5% of BDHA benzoate (content of active inghredient; 80%);
37.5% of diethanolamine; and
remainder, water.
The results are summarized in the following Table.
______________________________________
Degree of Corrosion according to
DIN 51360/2 using:
Formulation I
Formulation II
Concentration
f.d. 20.degree. d-
f.d. 20.degree. d-
of solution water water water water
______________________________________
1% 2 4 0.5 3
2% 0 3 0 2
3% 0 2 0 0.5
______________________________________
From columns 4 and 5, it will be apparent that Formulation II (BDHA
benzoate) provides a significantly improved anticorrosive property.
* * * * *
|
|
 |
|
 |
Description |
|
