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Description  |
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TECHNICAL FIELD
The present invention relates to ether hydroxypolycarboxylate compounds and
a method for making them. The ether hydroxypolycarboxylates are effective
sequestering agents and are useful in detergent compositions for
household, institutional and industrial use.
BACKGROUND OF THE INVENTION
The role of sequestering agents in softening water by complexing the
"hardness" cations in water supplies is well-known. Sequestering agents
are recognized aids in detergent processes because they form a soluble
complex with calcium and magnesium ions which can react with soaps and
other anionic surfactants and otherwise adversely affect detergency.
Polyphosphates such as tripolyphosphates and pyrophosphates are widely
used as ingredients in detergent compositions in part because of their
property of sequestering hardness ions. Such phosphorus-containing
compounds as well as nitrogen-containing compounds, e.g.,
nitrilotriacetates, are highly effective. However, the effect of the
phosphorus content and the nitrogen content of these sequestering agents
upon eutrophication of lakes and streams has been questioned and the use
of phosphates in detergent compositions has been subject to government
scrutiny, regulation or prohibition.
These circumstances have developed a need for highly effective and
efficient phosphorus-free and nitrogen-free sequestering agents and
detergency builders.
The object of the present invention is to provide such a class of compounds
which are useful as sequestering agents, especially when used as builders
in detergent compositions containing surfactants.
U.S. Pat. No. 3,692,685, issued Sept. 19, 1972, to Lamberti et al.
discloses detergent compositions containing an ether polycarboxylate
having the formula:
##STR1##
wherein R is H or --CH.sub.2 COONa
U.S. Pat. No. 4,228,300, issued Oct. 14, 1980, to Lannert, discloses ether
polycarboxlate sequestering agents and detergency builders having the
formula
##STR2##
wherein M is alkali metal or ammonium, R.sub.1 and R.sub.2 are hydrogen,
methyl or ethyl and R.sub.3 is hydrogen, methyl, ethyl or COOM.
U.S. Pat. No. 3,769,223, issued Oct. 30, 1973, to Pearson et al. discloses
1-oxacyclopropane-2,3-dicarboxylic acid (i.e., epoxysuccinic acid) and its
soluble salts as detergent builders.
U.S. Pat. No. 3,776,850, issued Dec. 4, 1973, to Pearson et al., discloses
polymers to be used as detergent builders which are said to have the
formula:
##STR3##
wherein R is hydrogen or other specified radicals and n is from 2 to about
40, preferably from 2 to about 6. The polymers are taught to be prepared
by polymerization of the diethyl ester of
1-oxacyclopropane-2,3-dicarboxylic acid (i.e., epoxysuccinic acid) in the
presence of a boron trifluoride catalyst followed by saponification.
Detergent compositions are exemplified in which n is said to have an
average value of approximately 3 or 4. In fact, the disclosed synthesis
method yields mixtures of materials which contain very low levels of the
n=3 and n=4 components.
It is a purpose of the present invention to provide: (1) new and superior
ether hydroxypolycarboxylate sequestering agents based on epoxysuccinic
acid or salts thereof, (2) detergent compositions containing said
sequestering agents and (3) a method for making said sequestering agents.
More specifically, it is a purpose of the present invention to provide a
process which produces a high yield of ether hydroxypolycarboxylates based
on oligomers of epoxysuccinates or telomers of epoxysuccinates and
tartrates, effective for sequestering multivalent metal cations.
SUMMARY OF THE INVENTION
The invention comprises metal sequestering agent compounds and mixtures of
such compounds represented by the structure:
##STR4##
wherein M is hydrogen or a cation wherein the resultant salt is water
soluble, preferably an alkali metal, ammonium or substituted ammonium
cation, n is from about 2 to about 15 (preferably n is from about 2 to
about 10, more preferably n averages from about 2 to about 4) and each R
is the same or different and selected from hydrogen, C.sub.1-4 alkyl or
C.sub.1-4 substituted alkyl (preferably R is hydrogen), provided that
where there is a mixture at least about 25%, by weight, are compounds in
which n is from about 2 to about 4, and further provided that said
compounds or mixtures thereof have a log K.sub.ca (35.degree. C., 0.1M
ionic strength) of at least about 4.5 at pH 9.5.
Another aspect of the invention is detergent compositions containing from
about 0.5% to about 98%, preferably from about 5% to about 30%, of a
surfactant and from about 2% to about 99.5%, preferably from about 4% to
about 50% of the metal sequestering agent compounds or mixtures defined
hereinbefore or made by the process hereinbelow. The use of such detergent
compositions in aqueous solutions for cleaning fabrics is also an aspect
of the invention.
A preferred process for preparing the sequestering agent compounds of the
invention comprises:
(1) oxidation of a maleate salt, which is optionally prepared from alkaline
hydrolysis of maleic anhydride or a substituted maleate salt, such as a
salt of citraconic acid, to an epoxysuccinate with the general structure
##STR5##
wherein M is a salt-forming cation, preferably alkali metal, and R is
hydrogen, C.sub.1-4 alkyl or C.sub.1-4 substituted alkyl;
(2) treatment with at least about 5% of a molar quantity of calcium
hydroxide, or other alkaline calcium salt, to form compounds of the
general structure
##STR6##
wherein M is a mixture of calcium and other alkaline-forming cations,
preferably alkali metal, and n is from about 2 to about 15 and R is
hydrogen, C.sub.1-4 alkyl or C.sub.1-4 substituted alkyl;
(3) replacement of calcium by alkali metal, such as sodium, or by ammonium,
substituted ammonium or hydrogen can be accomplished by ion exchange; and
(4) optional removal of tartaric acid and its salts (wherein n is 1) can be
accomplished by solubilization (e.g., tartaric acid is soluble in acidic
methanol, but not the sequestering agent compounds of the invention are
not).
The invention also comprises metal sequestering agent compounds made by
this process and detergent compositions containing such compounds.
It should be noted that, as used herein, "metal sequestering agent
compounds" of the present invention includes mixtures of such compounds as
long as they meet the specified size distribution and calcium binding
constant limitations.
DETAILED DESCRIPTION OF THE INVENTION
The essential feature of the process of the invention and the sequestering
agent compounds produced by this process is the use of calcium hydroxide
or other alkaline calcium salts in the oligomerization of epoxysuccinates
or in the telomerization of epoxysuccinates with tartrates or other
hydroxyacids or salts thereof. The use of calcium as described herein
promotes a high yield of the sequestering agent compounds of the invention
when compared with, for example, the boron trifluoride catalyst used in
the process disclosed in U.S. Pat. No. 3,776,850. The mixture of compounds
produced by the process of U.S. Pat. No. 3,776,850 comprises compounds
ineffective or relatively ineffective as sequestering agents and provides
essentially no advantage over a monomeric epoxysuccinate.
One method of preparing the sequestering agent compounds of the invention
comprises reacting a soluble epoxysuccinate with a molar equivalent
quantity of calcium hydroxide in aqueous media, esterification of the
resultant product, separation of the ester from the reaction mixture, and
saponification of the ester to an alkali metal salt.
PROCESS EXAMPLE I
A more practical method of preparing a sequestering agent compound of the
present invention comprises alkaline hydrolysis of maleic anhydride to a
maleate salt, catalytic oxidization to an epoxysuccinate and then
treatment with at least about 5%, preferably from about 10% to about 80%,
of a molar equivalent amount of calcium hydroxide to form a mixture of
alkali metal and calcium salts of the compounds of the present invention.
An example follows:
##STR7##
Maleic anhydride (22.3 g, 0.227 mol, F.W. 98) was dissolved in 32 mL of
water and while this solution was cooled in an ice-bath, 29.3 g (50%
soin., 0.34 mol) of sodium hydroxide solution was added. The resulting
solution was placed in a 500 ml rounded bottom flask which was equipped
with a magnetic stirring bar, pH probe, theromometer and an addition
funnel. This reaction flask was then placed in an oil bath at 60.degree.
C. and when the reaction solution reached 55.degree. C., 27 g of 30%
hydrogen peroxide (0.238 mol) and 0.784 g (0.0024 mol) of sodium tungstate
was added and the pH of the reaction solution maintained at 5-7 by
addition of 9.1 g (50% solution, 0.224 mol) of sodium hydroxide. After
about 40 minutes, an exotherm was noted (50.degree. to 100.degree. C.).
The solution was allowed to cool to 60.degree. C. and maintained at this
temperature for an additional hour. Then 0.84 g (0.0114 mol) of calcium
hydroxide was added to the reaction solution followed by heating to
100.degree. C. for 2 hrs. A sample of the reaction solution indicated that
a substantial amount of epoxysuccinate remained. 0.84 g (0.0114 mol)
additional calcium hydroxide was added and the reaction heated to
100.degree. C. for an additional 2 hrs. The volatiles were then removed by
vacuum, and the resulting solid dried under vacuum at 100.degree. C. for
16 hrs. to give 43.4 g of white solid which comprises a mixture of sodium
and calcium salts of 2,6-dihydroxy-3,5-dicarboxy-4-oxa-1,7-heptanedioic
acid (approx. 5%), higher molecular weight oligomers of epoxysuccinic acid
and tartaric acid (approx. 20%).
Methylmaleic (citraconic acid) and other substituted cisbutenedioic acid
compounds can be substituted for maleic acid in the foregoing reaction.
In one embodiment of the process d,l-tartaric acid or a salt thereof can be
substituted for from about 10% to about 40%, preferably from about 15% to
about 30%, of the epoxysuccinic acid or salt thereof on a molar basis.
This substitution results in a higher yield of compounds wherein n has a
value of 2 and a decreased amount of compounds wherein n has a value
greater than 4. Tartaric acid salts present at the completion of the
reaction can be recovered and recycled. Other hydroxycarboxylates such as
glycolic, malic and gluconic acids can be substituted for tartaric acid in
this embodiment of the process of the invention, but oligomerization of
the epoxysuccinate tends to be the predominant reaction.
PROCESS EXAMPLE II
Disodium epoxysuccinate, disodium d,l-tartrate, calcium hydroxide and water
were mixed in a molar ratio of 0.75: 0.25: 0.5:16. The mixture was
maintained at 80.degree. C. for 30 minutes.
The resultant product on a dry basis contained 70% oligomers of
epoxysuccinic acid salts and 25% tartaric acid salts. Calcium was removed
by acidification to pH 2 and use of an acid ion exchange poly (sulfonated
styrene) resin. The oligomers were precipitated by addition of methanol at
pH 2.5. The tartaric acid remained soluble. The polyepoxysuccinic acid
(PESA) was converted to a sodium salt with NaOH.
The distribution of oligomers on a weight basis was determined to be
approximately:
n=2(51%),
n=3(21%),
n=4(16%)
and
n>4(13%)
A reduction in calcium hydroxide level from a 0.5 molar ratio level to a
0.1 molar level resulted in the following approximate distribution:
n=2(22%),
n=3(21%),
n=4(21%)
and
n>4(35%).
PROCESS EXAMPLE III
Disodium epoxysuccinate, calcium hydroxide and water were mixed in a molar
ratio of 1.0:0.1:16. The mixture was maintained at 80.degree. C. for 30
minutes.
The resultant product on a dry basis contained 93% oligomers of
epoxysuccinic acid (PESA) and 7% tartaric acid salts.
The product can be used without further treatment as sequestering agent.
Alternately, the calcium and tartaric acid can be removed as described in
Process Example II, or by the precipitation of calcium ions with sodium
carbonate, sodium silicate or similar materials.
The distribution of oligomers on a weight basis was determined to be
approximately:
n=2(8%),
n=3(10%),
n=4(13%),
n>4(69%)
An increase in calcium hydroxide level from a 0.1 molar ratio level to a
0.25 molar level resulted in the following approximate distribution:
n=2(20%),
n=3-4(35%),
n=3 to 6(70%),
n>6(10%)
CALCIUM BINDING CONSTANTS DETERMINATION
A computer system (Hewlett-Packard) with digital voltmeters was used to
collect and analyze data from an Orion calcium selective electrode and a
linear syringe buret (Sage Instruments syringe pump plus a linear
potentiometer). An Analog Devices 40J non-inverting operational amplifier
electrometer amplified the calcium electrode voltage and provided
Nernstian behavior of the electrode into the 10.sup.-7 M range. Volumetric
accuracy was better than +/-0.5%.
Three hundred data pairs of [Ca total] vs 10.sup.(E/S), which is a linear
measure of [Ca free], were collected and corrected for diluton during each
titration. S is the Nernst equation slope, ca. 29 mv/decade, and E is the
calcium electrode voltage. Calcium ion was titrated into buffer solution.
L represents the sequestering ligand. A ligand-free standard titration
calibrated the electrode response. A second titration, containing a fixed
concentration of total liquid [L tot] allowed calculation of K.sub.Ca at
various [Ca tot]/[L tot] ratios.
##EQU1##
where [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.
Ionic strength was 0.1M, [Ca tot]=0 to 1.4 mM (0 to 8.2 gr/gal), [Ligand
total]=3.52.times.10.sup.-4 M.
______________________________________
Calcium Ion Binding Constants
(35.degree. C., 0.1 M ionic strength)
Log K.sub.Ca
pH 9.5
______________________________________
Material prepared by Process Example I
5.2
Product prepared by process disclosed in U.S.
3.0
Pat. No. 3,776,850
Nitrilotriacetic acid, sodium salt
5.5
2-oxa-1,1,3 propanetricarboxylic acid, sodium salt
4.3
2-oxa-1,3,4 butanetricarboxylic acid, sodium salt
4.4
Sodium tripolyphosphate 4.9
Sodium citrate 3.5
Sodium epoxysuccinate 3.0
______________________________________
These results demonstrate a clear advantage in calcium binding for a
sequestering agent compound of the present invention relative to prior art
ether carboxylates and sodium citrate, a non-polymeric carboxylate
sequestering agent used as a detergent builder material, as well as the
material produced in U.S. Pat. No. 3,776,850. The compounds of the
invention are approximately equivalent to sodium tripolyphosphate and
sodium nitrilotriacetate in calcium binding, while being nitrogen and
phosphorus-free.
DETERGENT COMPOSITIONS
Detergent compositions incorporating the sequestering agent compounds of
the present invention contain as essential components from about 0.5% to
about 98% of a surfactant and from about 2% to about 99.5% of the
sequestering agent compounds of the present invention as a detergency
builder.
Typical laundry detergent compositions within the scope of the present
invention contain from about 5% to about 30% of a surfactant and from
about 10% to about 80% total detergency builder, of which from about 20%
to 100% by weight of total detergency builder components can be the
sequestering agent compounds of the present invention.
The compositions of this invention are effective over the broad pH range of
from about 6 to about 12. The compositions can be formulated to provide a
desired pH by proper selection of the acid form of appropriate salts or
mixtures thereof. Preferred water-soluble salts of the sequestering agent
compounds are alkali metal salts such as sodium, potassium, lithium and
ammonium or substituted ammonium, e.g. triethanol ammonium. Depending on
the pH of the desired solution, the salts are partially or fully
neutralized.
The detergent compositions of the invention can be prepared in solid or
liquid physical form.
The detergent composition of the invention are particularly suitable for
laundry use, but are also suitable for the cleaning of hard surfaces and
for dishwashing.
In a laundry method aspect of the invention, typical laundry wash water
solutions comprise from about 0.1% to about 1% by weight of the detergent
compositions of the invention.
The Surfactant
The compositions of the invention contain from about 0.5% to about 98%,
preferably from about 2% to about 30% by weight of a surfactant or
mixtures thereof.
Various types of surfactants can be used in the compositions of the
invention. Useful surfactants include anionic, nonionic, ampholytic,
zwitterionic and cationic surfactants or mixtures of such materials.
Detergent compositions for laundry use typically contain from about 5% to
about 30% anionic surfactants or mixtures of anionic and nonionic
surfactants. Detergent compositions for use in automatic dishwashing
machines typically contain from about 2% to about 6% by weight of a
relatively low sudsing nonionic surfactant or mixtures thereof and,
optionally, suds control agents. Particularly suitable low sudsing
nonionic surfactants are the alkoxylation products of compounds containing
at least one reactive hydrogen wherein, preferably, at least about 20% by
weight of the alkylene oxide by weight is propylene oxide. Examples are
products of the BASF-Wyandotte Corporation designated Pluronic.RTM.,
Tetronic.RTM., Pluradot.RTM. and block polymeric variations in which
propoxylation follows ethoxylation. Preferred suds control agents include
mono- and disteryl acid phosphates.
(A) ANIONIC SOAP AND NON-SOAP SURFACTANTS
This class of surfactants includes alkali metal monocarboxylates (soaps)
such as the sodium, potassium, ammonium and alkylolammonium salts of
higher fatty acids containing from about 8 to about 24 carbon atoms and
preferably from about 12 to about 18 carbon atoms. Suitable fatty acids
can be obtained from natural sources such as, for instance, from plant or
animal esters (e.g., palm oil, coconut oil, babassu oil, soybean oil,
castor oil, tallow, whale and fish oils, grease, lard, and mixtures
thereof). The fatty acids also can be synthetically prepared (e.g., by the
oxidation of petroleum, or by hydrogenation of carbon monoxide by the
Fischer-Tropsch process). Resin acids are suitable such as rosin and those
resin acids in tall oil. Naphthenic acids are also suitable. Sodium and
potassium soaps can be made by direct saponification of the fats and oils
or by the neutralization of the free fatty acids which are prepared in a
separate manufacturing process. Particularly useful are the sodium and
potassium salts of the mixtures of fatty acids derived from coconut oil
and tallow, i.e., sodium or potassium tallow and coconut soap.
Soaps and fatty acids also act as detergency builders in detergent
compositions because they remove multivalent ions by precipitation.
Anionic surfactants also include water-soluble salts, particularly the
alkali metal and ethanolamine salts or organic sulfuric reaction products
having in their molecular structure an alkyl radical containing from about
8 to about 22 carbon atoms and a sulfonic acid or sulfuric acid ester
radical. (Included in the term alkyl is the alkyl portion of alkylaryl
radicals.) Examples of this group of non-soap anionic surfactants are the
alkyl sulfates, especially those obtained by sulfating the higher alcohols
(C.sub.8 -C.sub.18 carbon atoms); alkyl benzene sulfonates, in which the
alkyl group contains from about 9 to about 15 carbon atoms, in straight
chain or branched chain configuration, sodium alkyl glyceryl ether
sulfonates; fatty acid monoglyceride sulfonates and sulfates; sulfuric
acid esters of the reaction product of one mole of a C.sub.12-18 alcohol
and about 1 to 6 moles of ethylene oxide and salts of alkyl phenol
ethylene oxide ether sulfate with about 1 to about 10 units of ethylene
oxide per molecule and in which the alkyl radicals contain about 8 to
about 12 carbon atoms.
Additional examples of non-soap anionic surfactants are the reaction
products of fatty acids esterified with isothionic acid and neutralized
with sodium hydroxide where, for example, the fatty acids are derived from
coconut oil and sodium or potassium salts of fatty acid amide of methyl
lauride in which the fatty acids, for example are derived from coconut
oil.
Still other anionic surfactants include the class designated as
succinamates. This class includes such surface active agents as disodium
N-octadecylsulfosuccinamate; tetrasodium
N-(1,2-dicarboxyethyl)-N-octadecylsulfosuccinamate; the diamyl ester of
sodium sulfosuccinic acid; the dihexyl ester of sodium sulfosuccinic acid
and the dioctyl ester of sodium sulfosuccinic acid.
Anionic phosphate surfactants are also useful in the present invention.
These are surface active materials having substantial detergent capability
in which the anionic solubilizing group connecting hydrophobic moieties is
an oxy acid of phosphorus. The more common solubilizing groups are
--SO.sub.4 H, --SO.sub.3 H, and --CO.sub.2 H. Alkyl phosphate esters such
as (R--O).sub.2 PO.sub.2 H and ROPO.sub.3 H.sub.2 in which R represents an
alkyl chain containing from about 8 to about 20 carbon atoms are useful.
These esters can be modified by including in the molecule from one to about
40 alkylene oxide units, e.g., ethylene oxide units.
Particularly useful anionic surfactants useful herein are alkyl ether
sulfates. The alkyl ether sulfates are condensation products of ethylene
oxide and monohydric alcohols having about 10 to about 20 carbon atoms.
Preferably, R has 12 to 18 carbon atoms. The alcohols can be derived from
fats, e.g., coconut oil or tallow, or can be synthetic. Such alcohols are
reacted with 1 to 30, and especially 3 to 6, molar proportions of ethylene
oxide and the resulting mixture of molecular species, having, for example,
an average of 3 to 6 moles of ethylene oxide per mole of alcohol, is
sulfated and neutralized.
Other suitable anionic surfactants are olefin and paraffin sulfonates
having from about 12 to about 24 carbon atoms.
(B) NONIONIC SURFACTANTS
Alkoxylated nonionic surfactants may be broadly defined as compounds
produced by the condensation of alkylene oxide groups (hydrophilic in
nature) with an organic hydrophobic compound, which may be aliphatic or
alkyl aromatic in nature. The length of thee hydrophilic or
polyoxyalkylene radical which is condensed with any particular hydrophobic
group can be readily adjusted to yield a water-soluble compound having the
desired degree of balance between hydrophilic and hydrophobic elements.
Alkoxylated nonionic surfactants include:
(1) The condensation product of aliphatic alcohols having from 8 to 22
carbon atoms, in either straight chain or branched chain configuration,
with from about 5 to about 20 moles of ethylene oxide per mole of alcohol.
(2) The polyethylene oxide condensates of alkyl phenols, e.g., the
condensation products of alkyl phenols having an alkyl group containing
from about 6 to 12 carbon atoms in either a straight chain or branched
chain configuration, with ethylene oxide, the ethylene oxide being present
in amounts of from about 5 to about 25 moles of ethylene oxide per mole of
alkyl phenol. The alkyl substituent in such compounds may be derived from
polymerized propylene, diisobutylene, octene, or nonene, for example.
(3) Materials derived from the condensation of ethylene oxide with a
product resulting from the reaction of propylene oxide and a compound with
reactive hydrogen such as glycols and amines such as, for example,
compounds containing from about 40% to about 80% polyoxyethylene by weight
resulting from the reaction of ethylene oxide with a hydrophobic base
constituted of the reaction product of ethylene diamine and propylene
oxide.
Non-polar nonionic surfactants include the amine oxides and corresponding
phosphine oxides. Useful amine oxide surfactants include those having the
formula R.sup.1 R.sup.2 R.sup.3 N--O wherein R.sup.1 is an alkyl group
containing from about 10 to about 28 carbon atoms, from 0 to about 2
hydroxy groups and from 0 to about 5 ether linkages, there being at least
one moiety of R.sup.1 which is an alkyl group containing from about 10 to
about 18 carbon atoms and R.sup.2 andd R.sup.3 are selected from the group
consisting of alkyl radicals and hydroxyalkyl radicals containing from 1
to about 3 carbon atoms.
Specific examples of amine oxide surfactants include: dimethyldodecylamine
oxide, dimethyltetradecylamine oxide, ethylmethyltetradecylamine oxide,
cetyldimethylamine oxide, diethyltetradecylamine oxide,
dipropyldodecylamine oxide, bis-(2-hydroxyethyl)dodecylamine oxide,
bis-(2-hydroxypropyl)methyltetradecylamine oxide,
dimethyl-(2-hydroxydodecyl)amine oxide, and the corresponding decyl,
hexadecyl and octadecyl homologs of the above compounds.
(C) ZWITTERIONIC SURFACTANTS
Zwitterionic surfactants include derivatives of aliphatic quaternary
ammonium, phosphonium, and sulfonium compounds in which the aliphatic
moiety can be straight or branched chain and wherein one of the aliphatic
substitutents contains from about 8 to 24 carbon atoms and one contains an
anionic water-solubilizing group. Particularly preferred zwitterionic
materials are the ethoxylated ammonium sulfonates and sulfates disclosed
in U.S. Pat. Nos. 3,925,262, Laughlin et al, issued Dec. 9, 1975 and
3,929,678, Laughlin et al, issued Dec. 30, 1975, said patents being
incorporated herein by reference.
(D) AMPHOLYTIC SURFACTANTS
Ampholytic surfactants include derivatives of aliphatic-heterocyclic
secondary and tertiary amines in which the aliphatic moiety can be
straight chain or branched and wherein one of the aliphatic substitutents
contains from about 8 to about 24 carbon atoms and at least one aliphatic
substituent contains an anionic water-solubilizing group.
(E) CATIONIC SURFACTANTS
Cationic surfactants comprise a wide variety of compounds characterized by
one or more organic hydrophobic groups in the cation and generally by a
quaternary nitrogen associated with an acid radical. Pentavalent nitrogen
ring compounds are also considered quaternary nitrogen compounds. Suitable
anions are halides, methyl sulfate and hydroxide. Tertiary amines can have
characteristics similar to cationic surfactants at washing solutions pH
values less than about 8.5.
A more complete disclosure of cationic surfactants can be found in U.S.
Pat. No. 4,228,044, issued Oct. 14, 1980, to Cambre, incorporated herein
by reference.
When cationic surfactants are used in combination with anionic surfactants
and certain detergency builders including polycarboxylates, compatibility
must be considered. A type of cationic surfactant generally compatible
with anionic surfactants and polycarboxylates is a C.sub.8-18 alkyl tri
C.sub.1-3 alkyl ammonium chloride or methyl sulfate.
More complete disclosures of surfactants suitable for incorporation in
detergent compositions of the invention are in U.S. Pat. Nos. 4,056,481,
Tate Nov. 1, 1977); 4,049,586, Collier (Sept. 20, 1977); 4,040,988,
Vincent et al (Aug. 9, 1977); 4,035,257, Cherney (July 12, 1977);
4,033,718, Holcolm et al (July 5, 1977); 4,019,999, Ohren et al (Apr. 26,
1977); 4,019,998, Vincent et al (Apr. 26, 1977); and 3,985,669, Krummel et
al (Oct. 12, 1976); all of said patents being incorporated herein by
reference.
OPTIONAL DETERGENCY BUILDERS
The detergent compositions of the present invention can contain detergency
builders in addition to the ether hydroxypolycarboxylate sequestering
agent compounds described herein.
Suitable additional polycarboxylate detergency builders include the acid
form and alkali metal, ammonium and substituted ammonium salts of citric,
ascorbic, phytic, mellitic, benzene pentacarboxylic, oxydiacetic,
carboxymethyloxysuccinic, carboxymethyloxymalonic,
cis-cyclohexanehexacarboxylic, cis-cyclopentanetetracarboxylic and
oxydisuccinic acids. Also suitable are polycarboxylate polymers and
copolymers described in U.S. Pat. No. 3,308,067, Diehl, issued Mar. 7,
1967, incorporated herein by reference. Particularly suitable are acrylic
acid polymers and salts thereof and copolymers of acrylic and maleic acids
and salts thereof which act as dispersants of particulate materials in
wash solutions.
The polyacetal carboxylates disclosed in U.S. Pat. No. 4,144,226 issued
Mar. 13, 1979, to Crutchfield et al and U.S. Pat. No. 4,146,495 issued
Mar. 27, 1979 to Crutchfield et al can be incorporated in the compositions
of the invention.
Also suitable in the compositions of the invention are the
3,3-dicarboxy-4-oxa-1,6-hexanedioates and the related compounds disclosed
in U.S. Ser. No. 672,302 filed Nov. 16, 1984, and incorporated herein by
reference.
Suitable ether polycarboxylates also include cyclic compounds, particularly
alicyclic compounds, such as described in U.S. Pat. Nos. 3,923,679;
3,835,163; 4,158,635; 4,120,874 and 4,102,903, incorporated herein by
reference.
Polyphosphonate detergency builders comprise a large range of organic
compounds having two or more C--PO.sub.3 M.sub.2 groups, wherein M is
hydrogen or a salt-forming radical. Suitable phosphonates include
ethane-1-h | | |
