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Description  |
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This invention relates to a new class of surface active agents. More
particularly, it relates to novel carboxyalkylated derivatives of alkyl
and alkenyl catechol ethoxylates and to their use as surface active
agents, and more especially to their use as dual action surfactants,
hereinafter referred to as self-sequestering surfactants.
Synthetic surface active agents, e.g., detergents, can be characterized as
compounds which incorporate within the molecular structure thereof a
hydrophobic moiety, typically a long-chain alkyl moiety, and also a
hydrophilic moiety which, because of being polar in character or having
ionic charge, is capable of interaction with water molecules. When the
hydrophilic moiety is characterized by a formal ionic charge, the surface
active agent is classified as anionic or cationic, depending upon the
nature of the ionic charge. Alternatively, if the hydrophilic moiety does
not possess a formal ionic charge, the surface active agent is termed a
non-ionic surface active agent. One frequently encountered class of
non-ionic surface active agents comprises alkylene oxide derivatives of
active hydrogen compounds, particularly the alkylene oxide derivatives of
fatty acids or long-chain alcohols. However, since the available supply of
natural fatty acids and alcohols does not always coincide with the demands
of the surface active agent industry, such products are subject to
extremely large price fluctuations and, as a consequence thereof, exhibit
severe economic shortcomings.
As is well known in the art, the detergent properties of conventional
surfactants are considerably reduced when such surfactants are employed in
hard water. The reduction in detersive properties is due to the presence
of multivalent ions, such as calcium and magnesium cations, in the water.
To overcome this problem, it is well known to add a sequestering compound
to the detergent composition, the primary function of which is to form a
complex with the multivalent ions of the water and thereby compensate for
the disadvantage of employing hard water.
Of the known sequestering compounds, some exhibit additional properties
besides that of complexing with multivalent ions in hard water. Thus, some
sequestering compounds, more commonly referred to as "builders", enhance
(a) the stabilization of suspended solids; (b) the emulsification of dirt
particles; (c) the activity of surface active agents; and (d) the
solubilization of water-insoluble materials. Moreover, most of the known
sequestering compounds are compatible with the other conventional
components present in detergent compositions. However, a large number of
sequestering compounds, e.g., sodium tripolyphosphate and nitrilotriacetic
acid, have the serious drawback of causing eutrofication phenomena, and
thereby adversely affect the environment.
Other sequestering compounds, e.g., those based on alkaline carbonates and
polysilicates exhibit rather serious caustic and toxic effects, thereby
diminishing their usefulness appreciably.
A further disadvantage of conventional detergent compositions, i.e., those
containing both a surface active agent and a sequestering compound, is
that a separate synthesis is required for the two different compounds,
which compounds are then mixed in various proportions, depending upon
their ultimate use.
Accordingly, it is an object of the present invention to provide a new
class of surface active agents. It is another object of the present
invention to provide a new class of surface active agents which exhibit a
dual action, thereby making them useful as self-sequestering surfactants.
It is still another object of the present invention to provide a new class
of self sequestering surfactants which are especially useful when employed
in hard water. It is a further object of the present invention to provide
a new class of self-sequestering surfactants which, when employed in hard
water, are surprisingly useful at low concentrations of the multivalent
ions in the water. It is yet still another object of the present invention
to provide a new class of self-sequestering surfactants which, when
employed in hard water, neither contribute to eutrofication, nor exhibit
any serious caustic or toxic effect.
The attainment of the above objects is made possible by certain
carboxyalkylated derivatives of alkyl and alkenyl catechol ethoxylates of
formula I:
##STR1##
wherein, R is C.sub.8 -C.sub.22 straight or branched chain alkyl or
alkenyl;
each R.sub.1, independently, is hydrogen or a group --R.sub.2 COOM, where
R.sub.2 is C.sub.1--3 alkylene and M is hydrogen, an alkali metal cation,
an alkaline earth metal cation or ammonium; and
each of x and y is, independently, an integer 1 to 49; with the provisos
that: (1) at least one of the R.sub.1 's is a group --R.sub.2 COOM; and
(2) the sum of x and y is 3 to 50.
R is preferably straight or branched chain alkyl having from 8 to 22 atoms,
more preferably 8 to 14 carbon atoms, and even more preferably from 8 to
12 carbon atoms.
R.sub.2 is --CH.sub.2 --, --CH.sub.2 CH.sub.2 --, --CH.sub.2 CH.sub.2
CH.sub.2 --,
##STR2##
Preferably, R.sub.2 is --CH.sub.2, --CH.sub.2 CH.sub.2 -- or --CH.sub.2
CH.sub.2 CH.sub.2 --. More preferably, R.sub.2 is --CH.sub.2 --.
The preferred alkali metals as M are sodium, potassium and lithium, more
preferably sodium and potassium. The preferred alkaline earth metals as M
are magnesium, calcium, barium and strontium, more preferably magnesium
and calcium. M is preferably hydrogen, an alkali metal or ammonium, more
preferably hydrogen, sodium, potassium or ammonium, and even more
preferably hydrogen.
The variables x and y are preferably each, independently, an integer 1 to
29, with the proviso that the sum of x and y is 3 to 30. The variables x
and y are more preferably each, independently, an integer 1 to 19, with
the proviso that the sum of x and y is 3 to 20. The variables x and y are
even more preferably each, independently, an integer 1 to 14, with the
proviso that the sum of x and y is 3 to 15.
The preferred compounds of formula I are those of formula Ia:
##STR3##
wherein
R' is C.sub.8 --C.sub.22 straight or branched chain alkyl;
each R.sub.1.sup.', independently, is hydrogen or a group --R.sub.2 COOM,
where R.sub.2 is --CH.sub.2 --, --CH.sub.2 CH.sub.2 -- or --CH.sub.2
CH.sub.2 CH.sub.2 -- and M is hydrogen, an alkali metal or ammonium; and
each of x' and y' is, independently, an integer 1 to 29, with the provisos
that: (1) at least one of the R.sub.13.sup.' 's is a group --.sub.2 COOM;
and (2) the sum of x' and y' is 3 to 30.
The more preferred compounds of formula I are those of formula Ib:
##STR4##
wherein
R" is C.sub.8 -C.sub.14 straight or branched chain alkyl;
each R.sub.1 ", independently, is hydrogen or a group --CH.sub.2 COOM,
where M is hydrogen, sodium, potassium or ammonium; and
each of x" and y" is, independently, an integer 1 to 19, with the provisos
that: (1) at least one of the R.sub.1 "'s is a group -CH2COOM; and (2) the
sum of x" and y" is 3 to 20.
The even more preferred compounds of formula I are those of formula Ic:
##STR5##
wherein
R" is C.sub.8 -C.sub.12 straight or branched chain alkyl;
each R1.sup.", independently, is hydrogen or a group --CH.sub.2 COOH; and
each of x'" and y" is, independently, an integer 1 to 14, with the provisos
that: (1) at least one of the R.sub.1 '"'s is a group --CH.sub.2 COOH; and
(2) the sum of x'", and y'" is 3 to 15.
The compounds of formula I are produced by more or less conventional
methods. Thus, the novel carboxyalkylated derivatives of the alkyl and
alkenyl catechol ethoxylates may be prepared by condensing the appropriate
alkyl or alkenyl catechol compound with ethylene oxide by the well-known
methods of adding alkylene oxide compounds to an alcohol. Suitable results
are obtained by adding to the alkyl or alkenyl catechol compound to be
ethoxylated a catalytic amount, e.g., from about 0.2% to 1%, preferably
0.3% to 0.75%, by weight of the total amount of reactants, including the
respective alkylene oxides, of an alkaline catalyst. Catalysts which may
be employed include alkali metal hydroxides, sodium ethoxide, sodium
methoxide, alkali metal acetates and dimethylamine, and mixtures thereof.
Preferred catalysts are the alkali metal hydroxides, more preferably
sodium hydroxide and potassium hydroxide. Other types of catalysts
commonly used for alkylene oxide condensation reactions may also be
employed.
Optionally, a small amount of a reducing agent may be added to the alkyl or
alkenyl catechol compound to be ethoxylated to minimize discoloration of
the resulting ethoxylated alkyl or alkenyl catechol compound. Suitable
reducing agents which may be employed include sodium borohydride, lithium
aluminum hydride, diborane and the like, preferably sodium borohydride.
An amount of ethylene oxide calculated to provide the desired degree of
ethoxylation is then introduced and the resulting mixture is allowed to
react until all of the ethylene oxide is consumed, as indicated by a drop
in reaction pressure. Customarily, the ethoxylated product is finally
treated with weak acid, e.g., glacial acetic acid, to neutralize any basic
catalyst residues.
It should be understood that the ethoxylation procedure serves to introduce
a desired average number of ethylene oxide units per catechol molecule.
Thus, for example, the treatment of an alkyl or alkenyl catechol compound
with x moles of ethylene oxide per mole of catechol compound serves to
effect the ethoxylation of each alcohol moiety with ethylene oxide to an
average of x ethylene oxide moieties per alcohol moiety, although some
alcohol moieties will have become combined with more than x ethylene oxide
moieties and some will have become combined with less than x. The
variation in the number of ethylene oxide moieties is not critical as long
as the average for the number of units in each block is within the limits
set out for the x and y terms in formula I above, which terms, as average
values, are other than whole numbers in some instances.
The ethoxylation procedure is conducted at an elevated temperature and
pressure. Suitable reaction temperatures are from about 120.degree. C. to
about 220.degree. C., preferably 130.degree. C. to 180.degree. C., and
more preferably 140.degree. C. to 160.degree. C. A suitable reaction
pressure is achieved by introducing to the reaction vessel the required
amount of ethylene oxide which has a high vapor pressure at the desired
reaction temperature. The pressure serves as a measure of the degree of
reaction and the ethoxylation is considered to be complete when the
pressure no longer decreases with time.
For best results, it is desirable to carry out the ethoxylation under
relatively moisture-free conditions and to avoid side reactions which form
water. To dry the reaction vessel and connection, they may be swept out
with a dry, oxygen-free gas, e.g., nitrogen, before introducing the
charge. The catalyst or catalyst mixture should also be dry, or
substantially so. The ethylene oxide should preferably be purified to
remove moisture and any impurities which are capable of entering into side
reactions which yield water.
To prepare the corresponding carboxyalkylated derivatives, the resulting
alkyl and alkenyl catechol ethoxylates are then carboxyalkylated by the
Williamson synthesis, involving reaction with an appropriate chloro- or
bromocarboxylic acid or a salt thereof in the presence of a strong base,
e.g., sodium hydroxide, sodium carbonate, etc., or a mixture thereof,
metallic sodium, or by catalytic oxidation. The carboxyalkylation is
conducted at a temperature of between 20.degree. and 100.degree. C.,
preferably between 50.degree. and 90.degree. C., and at a mole ratio of
between 0.5:1 and 2.5:1 preferably between 1:1 and 2:1 of chloro- or
bromocarboxylic acid or a salt thereof, e.g., sodium monochloroacetate, to
alkyi or alkenyl catechol ethoxylate. Such reactions are ordinarily not
complete; hence, the reaction products often contain minor amounts of
uncarboxylated alkyl or alkenyl catechol ethoxylate. While methods are
available for separating the uncarboxylated material as well as for
assuring essentially complete carboxyalkylation, they are usually tedious
and expensive. Fortunately, it has been found that minor proportions of
such uncarboxyalkylated material are not particularly harmful, and may
even be advantageous. The carboxyalkylation involving reaction with an
appropriate chloro- or bromocarboxylic acid or a salt thereof in the
presence of a strong base is preferred for completeness. Preferably, the
carboxyalkyl group is a carboxymethyl group.
Alternatively, the corresponding carboxyalkylated derivatives of formula I
wherein R.sub.2 is --CH.sub.2 CH 2-- may be prepared via base catalyzed
1,4-addition to an appropriate .alpha., .beta.-unsaturated compound such
as methyl acrylate or acrylamide followed by hydrolysis. Moreover, the
corresponding carboxyalkylated derivatives of formula I wherein R.sub.2 is
--CH.sub.2 CH.sub.2 CH.sub.2 -- may be prepared by a reaction involving
alkoxylate addition to an appropriate lactone which yields the
corresponding carboxylate.
The most conspicuous property of the compounds of formula I is their great
activity at surfaces and interfaces, making them especially useful as
surface active agents. The uses to which surface active agents can be put
are numerous and well known and, as a result, the possible applications of
these new compounds are extremely varied. Thus, the surface active agents
of the present invention are suitable as emulsifiers, dispersing agents,
wetting agents, levelling agents and the like in the textile, leather,
paper, lacquer, personal care, e.g., toiletries, cosmetics, etc., and
rubber industries. For example, they can be used as wetting agents in
spinning, twisting, weaving and dyeing operations in the textile industry,
especially in the presence of hard water. In addition, they can be
utilized for converting liquid or solid substances which, per se, are
insoluble in water (such as hydrocarbons, higher alcohols, oils, fats,
waxes and resins) into creamy emulsions, clear solutions or fine, stable
dispersions.
Moreover, the compounds of formula I are valuable emulsifiers for
insecticide compositions and agricultural sprays such as DDT, 2,4-D and
the like; are valuable for use as additives to petroleum products,
hydraulic fluids, lubricating oils, cutting oils and greases; may be
employed as coating aids for use in coating compositions comprising a
hydrophilic, film-forming colloid; may be employed as tackifiers in the
adhesive layer of adhesive tapes in, e.g., the photographic industry; and
as foaming agents and dispersing agents in a wide variety of mining
applications (i.e., or flotation).
Furthermore, because of their ability to complex metal ions, the compounds
of formula I can be used to remove heavy metal contaminants from waste
water. These materials are especially useful in this context due to their
surface active properties. Therefore, processes such as solvent extraction
can be facilitated by utilizing the compounds of the instant invention.
The carboxyalkylated derivatives of the instant invention are especially
useful as self-sequestering surfactants in detergent compositions. Thus,
in view of their detersive properties, they may be employed as the sole
surfactant component in said detergent compositions and, as a result of
their sequestering capabilities, they may be employed as the sole
sequestering component, i.e., the detergent compositions need not contain
a different and separate sequestering compound. As self-sequestering
surfactants, the carboxyalkylated derivatives of the instant invention
form soluble complexes with calcium and magnesium cations sufficiently
stable to eliminate the negative influences on the detersive properties of
the compositions but not so stable as to cause ecological imbalance
because of an accumulation of ions. Such detergent compositions will
normally contain from at least 5% to about 50% of said alkyl or alkenyl
catechol ethoxylate, preferably from about 10% to about 50%, and more
preferably from about 15% to about 50%.
The carboxyalkylated derivatives of the instant invention, because of their
self-sequestering properties, can advantageously be employed in detergent
compositions which already contain a conventional surfactant, e.g., an
anionic, nonionic, ampholytic or zwitterionic surfactant, or mixtures
thereof, coupled with the additional advantage that, as compared with
other known sequestering compounds under equal conditions, such detergent
compositions exhibit greater detersive capability without concomitant
harmful environmental effects or any other drawbacks and disadvantages of
the known sequestering compounds. Representative anionic surfactants are:
(1) alkylbenzenesulfonates, such as sodium and potassium salts having a
branched or straight chain alkyl portion of about 9 to about 15 carbon
atoms; (2) alkyl sulfates, such as the sodium and triethanolammonium salts
of C.sub.10-20 alkyl sulfuric acids, prepared by sulfating the alcohols
derived from coconut oil or tallow, or prepared synthetically; (3) the
alkali metal and ammonium salts of the sulfated ethoxylates of a
long-chain alcohol and 3 to 5 molar; proportions of ethylene oxide, e.g.,
the ammonium salt of an ethoxylate containing an average of 3.1 molar
proportions of ethylene oxide and 1 mole of an alcohol mixture known
commercially as ALFOL 1412, composed of about 2/3 n-tetradecanol and about
1/3 n-dodecanol; (4) the compounds known as "Medialans" which are amido
carboxylic acids formed by condensing fatty acids of C.sub.8-22 chain
length with sarcosine, CH.sub.3 NHCH.sub.2 COOH; (5) alkanesulfonates,
such as ammonium dodecanesulfonate; (6) alkoxyhydroxypropanesulfonates,
such as the water-soluble salts of
3-dodecyloxy-2-hydroxy-1-propane-sulfonate; (7 ) soaps, the surface-active
substances formed usually by the reaction of caustic alkalies with natural
glyceridic fats and oils, generally prepared in high purity, and having
the generic molecular formula RCOONa, wherein R is a straight-chain
hydrocarbon group having from about 7 to about 21 carbon atoms; and (8)
olefin sulfonates, such as dodecene sulfonate, and the compounds described
in U.S. Pat. No. 3,332,880. As representative of non-ionic surfactants may
be mentioned: (1) the Pluronios, formed by condensing propylene oxide with
propylene glycol to a molecular weight of about 600 to 2500 to form a base
followed by condensing ethylene oxide to this base to the extent of about
10 to about 90 percent, total molecule basis U.S. Pat. Nos. 2,674,619 and
2,677,700 describe operable compounds; (2) compounds formed by the
simultaneous polymerization of propylene oxide and ethylene oxide and
containing randomly positioned oxypropylene and oxyethylene groups. These
and related compounds are described in U.S. Pat. Nos. 2,979,528,
3,036,118, 3,022,335, 3,036,130 and U.S. Pat. No. 3,048,548; (3) alkyl
phenols having 9 to 12 carbon atoms in the alkyl portion (straight or
branched) ethoxylated with 4-10 molar proportions of ethylene oxide; and
(4) ethoxylates of fatty alcohols having 8 to 18 carbon atoms per molecule
and 5-30 molar proportions of oxyethylene groups.
As an example of an ampholytic surfactant may be mentioned the hydroxyalkyl
methyl taurates, while cocodimethyl sulfopropyl betaine is exemplary of a
zwitterionic surfactant.
In detergent compositions which contain a carboxyalkylated derivative of
the instant invention and a conventional surfactant, the latter will
normally comprise between 5% and 40% of the weight of the mixture,
preferably between 10% and 30%.
When the self-sequestering compounds of the instant invention are employed
in detergent compositions which contain a different and separate
sequestering compound having one or more of the above-discussed drawbacks
and disadvantages, the concentration of the different sequestering
compound can be reduced, thereby reducing the toxic and polluting
properties of said different sequestering compound. Representative
inorganic sequestering compounds are, e.g., water soluble salts of
pyrophosphates, orthophosphates, polyphosphates, phosphonates, carbonates,
bicarbonates and silicates. As representative of organic sequestering
compounds may be mentioned the alkali metal, ammonium and substituted
ammonium polyacetates, carboxylates, polycarboxylates and
polyhydroxy-sulfonates.
In detergent compositions which contain a carboxylakylated derivative of
the instant invention and a different and separate sequestering compound,
the latter will normally comprise between 5 and 60% of the weight of the
mixture, preferably between 10% and 40%.
The detergent compositions can optionally contain all manner of additional
materials commonly found in laundering and cleaning compositions. For
example, oxidizing bleaches such as sodium perborate, sodium percarbonate,
etc., optionally with bleach precursors such as phthalic anhydride, may be
incorporated at levels of 1% to 25% of the composition. When these
materials are present, the compounds of formula I can also serve as
peroxide stabilizers. Their ability to sequester certain metal ions will
serve to prevent the undersired decomposition of these oxidizing agents.
Defoamers such as long chain fatty acids, silicone fluids and
microcrystalline waxes may be employed alone or as mixtures at levels of
0.005% to 5%, preferably 0.01% to 3%, and most preferably 0.1% to 1%, of
the composition.
Viscosity modifiers and anticaking agents such as the sodium salts of lower
alkyl aromatic sulfonic acids and the alkali metal salts of sulfosuccinic
acid and benzene sulfonic acid are conveniently employed at levels of 0.5%
to 5%, particularly if other anionic surfactants are employed as part of
the surfactant mixture.
Soil suspending agents such as sodium carboxymethyl cellulose and
hydroxyethyl cellulose may also be used in amounts of 0.25% to 5% by
weight of the composition.
Enzymes such as the proteolytic enzymes may be incorporated at levels of up
to 1% by weight, preferably from 0.25% to 0.75% by weight. Such enzymatic
materials may be coated or pilled to aid their stability and to minimize
the formation of dust during processing and subsequent storage.
The following examples illustrate the preparation of the carboxyalkylated
derivatives of the instant invention.
EXAMPLE 1
Dodecaethoxy nonylcatechol acetic acid
##STR6##
where x+y=12; and the sum of the R.sub.1 's=-CH.sub.2 COOH (66%); -H
(34%).
(a) Preparation of nonylcatechol
Into a 500ml, 3-neck reaction vessel was placed 64.8g (0.3125 moles) of
catechol, after which time it was heated to 104.degree. C. under a
nitrogen flow. After the catechol was completely melted, 3.25g (5% based
on the wt. of the catechol) of borontrifluoride-etherate was added
dropwise, with stirring. After adding all of the catalyst, 63.2 g (0.25
moles) of 1-nonene was added dropwise to the reaction mixture, the rate of
addition being adjusted so as to maintain a temperature of 130.degree. C.
After all of the 1-nonene was added, the resultant mixture was allowed to
react for 3 hours, after which time 100 ml of a 10% sodium chloride
solution was added to the reaction mixture. The resultant mixture was then
stirred for 15 minutes at 95.degree. to 100.degree. C., after which time
the bottom layer was separated. The mixture was again stirred at
95.degree. to 100.degree. C. for 15 minutes, after which time the bottom
layer was again separated. The organic layer was then isolated to obtain a
viscous, brown oil of the formula
##STR7##
(b) Preparation of dodecaethoxy nonylcatechol
Into a reaction vessel containing 62 g of the compound prepared in a) above
was added, with stirring, 0.1 g of sodium hydroxide catalyst. The system
was then purged with nitrogen, evacuated and the temperature raised to
120.degree. C., after which time the system was again purged and
evacuated. The purging and evacuation procedure is then repeated twice
more at 120.degree. C, after which time the temperature of the reaction
mixture was raised to 155.degree. C. 140 g of ethylene oxide was then
added to the reaction mixture at a rate such that a constant pressure was
maintained. When the addition of ethylene oxide is complete, the reaction
mixture is allowed to post-react until the pressure drops to a point where
it remains constant for at least 30 minutes. The system is then cooled to
60.degree. C. and the vacuum broken with nitrogen. The remaining sodium
hydroxide catalyst is then neutralized with acetic acid, after which time
the reaction mixture is cooled and filtered to yield a compound of the
formula
##STR8##
where x+y=12.
Preparation of the title compound
76.5 g of the compound prepared in (b) above was placed into a 3-neck
reaction vessel equipped with a condensor, mechanical stirrer and
thermometer. To the flask was added, sequentially with stirring, 5.3 g of
potassium hydroxide and 3.21 g of sodium hydroxide. The resultant mixture
was then stirred for one hour, while the temperature was maintained
between 50.degree. and 55.degree. C. 18.7 g of sodium monochloroacetate
was then added to the mixture in four equal portions over a two hour
period, while the exotherm was controlled to 65.degree..+-.5.degree. C.
After the addition was complete, the reaction was allowed to proceed for
20 hours, after which time the reaction mixture was diluted with 50ml of
water and 75ml of a 10% sulfuric acid solution. Phase separation yielded
the title compound as an amber oil.
EXAMPLE 2
Following essentially the last step of the procedure in preparing the
compound of Example lb) and utilizing the catechol compound prepared in
la) and the appropriate amounts of ethylene oxide, the following compounds
are obtained:
##STR9##
EXAMPLE 3
Triethoxy nonylcatechol acetic acid
##STR10##
where x+y=3; and the sum of the R.sub.1 's=--CH.sub.2 COOH(47%); --H(53%).
73.7 g of the compound of Example 2a) was placed into a 3-neck reaction
vessel equipped with a condensor, mechanical stirrer and thermometer. To
the flask was added, sequentially with stirring, 10.56 g of potassium
hydroxide and 6.4 g of sodium hydroxide. The resultant mixture was then
stirred for one hour, while the temperature was maintained between
50.degree. and 55.degree. C. 37.4 g of sodium monochloroacetate was then
added to the mixture in four equal portions over a two hour period, while
the exotherm was controlled to 65.degree.+/-5.degree. C. After the
addition was complete, the reaction was allowed to proceed for 20 hours,
after which time the reaction mixture was diluted with 50ml of water and
75ml of a 10% sulfuric acid solution. Phase separation yielded the title
compound as an amber oil.
EXAMPLE 4
Hexaethoxy nonylcatechol acetic acid
##STR11##
where x+y=6; and the sum of the R.sub.1 's=--CH.sub.2 COOH(52%); --H(48%).
75.0 g of the compound of Example 2b) was placed into a 3-neck reaction
vessel equipped with a condensor, mechanical stirrer and thermometer. To
the flask was added, sequentially with stirring, 7.9 g of potassium
hydroxide and 4.81 g of sodium hydroxide. The resultant mixture was then
stirred for one hour, while the temperature was maintained between
50.degree. and 55.degree. C. 28.1 g of sodium monochloroacetate was then
added to the mixture in four equal portions over a two hour period, while
the exotherm was controlled to 65+/-5.degree. C. After the addition was
complete, the reaction was allowed to proceed for 20 hours, after which
time the reaction mixture was diluted with 50ml of water and 75ml of a 10%
sulfuric acid solution. Phase separation yielded the title compound as an
amber oil.
EXAMPLE 5
Nonaethoxy nonylcatechol acetic acid
##STR12##
where x+y=9; and the sum of the R.sub.1 's=--CH.sub.2 COOH(58%); --H(42%).
63.2 g of the compound of Example 2c) was placed into a 3-neck reaction
vessel equipped with a condensor, mechanical stirrer and thermometer. To
the flask was added, sequentially with stirring, 5.3 g of potassium
hydroxide and 3.21 g of sodium hydroxide. The resultant mixture was then
stirred for one hour, while the temperature was maintained between
50.degree. and 55.degree. C. 18.7 g of sodium monochloroacetate was then
added to the mixture in four equal portions over a two hour period, while
the exotherm was controlled to 65.degree..+-.5.degree. C. After the
addition was complete, the reaction was allowed to proceed for 20 hours,
after which time the reaction mixture was diluted with 50ml of water and
75ml of a 10% sulfuric acid solution. Phase separation yielded the title
compound as an amber oil.
It should be understood that in all of the examples above, the indicated
number of ethyleneoxy units are average values.
EXAMPLE 6
To demonstrate the ability of the carboxyalkylated derivatives of the
instant invention to sequester metal ions, they were evaluated by
determining the constants of stability of the complexes formed by the
calcium utilizing potentiometric titrations with electrodes selective
toward the calcium ion in question. During these titrations, the quantity
of calcium ion complexed by a known quantity of sequestering agent was
measured and the result of the measurement was used to calculate the
constant of the complex (Kca) employing the following equation:
##EQU1##
where L=ligand or sequestrant and [L free]=[L tot]-[Ca tot]+[Ca free]. At
high ratios of [Ca tot]/[L tot], the ligand became saturated with Ca ion
and a linear increase in [Ca free]resulted. This line was extrapolated
back to [Ca free]=0 and [Ca tot]at that point represented a measure of
calcium binding capacity. Below are the results obtained on the compound
of Example 4:
______________________________________
[Ca] total K.sub.Ca
log K.sub.Ca
______________________________________
0.00099 134.6 2.13
0.00476 41.3 1.62
0.00909 21.9 1.34
______________________________________
From the above results, it is clear that the compound of Example 4 exhibits
excellent calcium binding ability. Moreover, it should be noted that the
compound of Example 4 exhibits surprising effectiveness at low calcium ion
concentrations. For purposes of comparison, hexaethoxy nonylphenyl was
evaluated and found to be devoid of calcium binding ability.
EXAMPLE 7
The following represent typical formulations useful as detergent
compositions:
______________________________________
Percent
A B C
______________________________________
Solid
compound of Example 4
50 30 35
sodium tripolyhosphate
-- 20 --
sodium silicate (Na.sub.2 O:SiO.sub.2 = 1:2.5)
6 6 6
LAS (linear alkylbenzene sulfonate)
-- -- 15
sodium carboxymethyl cellulose
0.3 0.3 0.3
sodium sulfate 13 13 13
fluorescent dye 0.16 0.16 0.16
water 8 8 8
miscellaneous balance .fwdarw.
.fwdarw.
Liquid
compound of Example 4
30 18 21
tetrapotassium pyrophosphate
-- 12 --
sodium silicate (Na.sub.2 O:SiO.sub.2 = 1:1.6)
3.8 3.8 3.8
LAS -- -- 9
sodium carboxymethyl cellulose
0.3 0.3 0.3
perfume 0.2 0.2 0.2
water 65.7 65.7 65.7
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