Note: Descriptions are shown in the official language in which they were submitted.
BACKGROIJND OF THE INt NTION
The present invention relatels to homogeneou~,
single-phase liquid detergents. More specifically,
10~ liquid compositions comprising an anionic detersive
~- surfactant, ~ nonionic detersive sur~actant; a source
. . .
of magnesium ions, and an alkanolamine are prepared
in a manner which avoids undesirable phase separa-
tion.
lS ~ ~ ~ Heavy-duty, built laundry detergents have hist~r-
ic~lly been provided in the form of granules. More
recently, however, it has been recognized that excellent `
detergency performance can be secured using unbuilt deter-
gents comprising a mixture of detersive surfactants and
materials such as alkanolamines. The advent of such
compositions has made it possible to provide heavy-duty
laundry detergents in liquid form.
1~72852
Liquid detergent compositions offer several
advantages over solid compositions For ex`ample, liquid
compositions are easier to measure and dispense into
a laundering liquor. More importantly, liquid composi-
tions are especially useful for direct application toheavily soiled areas on fabrics, after which the
pre-treated fabrics can be placed in an aqueous bath
for laundering in the ordinary manner.
Typical heavy-duty liquid detergents contain
~ substantial amounts of nonionic surfactants which help
provide grease and oLl removal from synthetic and blend
fabrics. However, many important types of detersive
nonionic surfactants tend to form a separate phase in
li~uid compositions containing substantial amounts of
electrolytes. Of course, phase separation (presumably,
a manifestation of the so-called "salting-out" effect)
is unacceptable when formulating homogeneous liquid
detergents. Accordingly, the presence of electrolytes,
especially water-soluble polyvalent inorganic salts, is
usually avoided when preparing such compositions.
Preferred heavy-duty liquid detergents will also
contain a substantial amount of one or more synthetic
detersive anionic surfactants. The anionic surfactant
helps provide improved cleaning performance over a broad
spectrum of soils and fabric types. Moreover, the
anionic surfactant provides the suds levels desired by
most users of such products.
As noted above, alkanolamines, especially tri-
ethanolamine, are often used in heavy-duty liquid
- ` . . ' :~ . , :
11~7;~:135Z
detergents to adjust pH and to provide a substantial
increment of additional cleaning power.
It is well known in the detergency arts that
certain polyvalent metal cations (especially when used
in combination with synthetic anionic surfactants) can
contribute substantially to detergency performance.
Accordingly, it is desirable to incorporate a source of
such cations into a detergent composition. In particular,
calcium and magnesium salts of various types are useful
detergency boosters, and salts such as magnesium acetate,
the clacium and magnesium halides, magnesium sulfate,
calcium and magnesium hydroxide, and the like, have been
sugges~ed for this purpose, especially in the formulation
of heavy-duty granular detergents.
It has now been discovered that calcium and
magnesium salts cannot be used in random fashion when
preparing homogeneous heavy-duty li~uid detergents since
phase separation will occur. Howev~3r, compositions prepared
in the manner disclosed herein are stable, homogeneous ;
20 liquids. -~
Payne, et al, U.S. Patent 3,998,750, issued
December 21, 1976, discloses homogeneous liquid deter-
gents containing magnesium salts and which can contain -~
small, non-detersive amounts of alkanolamines.
Payne and Jones, British Publication 1,542,696,
published March 21, 1979, discloses liquid detergent
compositions containing a source of magnesium ions and
a controlled sudsing surfactant system.
... .... .
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' ~ .
, ~ , .-' ~ . ,., :. .
, . , .. ~ .
~7Z85~
Hellyer, et al., British Patent 1,524,441 sealed
December 18, 1978, discloses liquid detergent compositions
which contain, inter alia, a source of magnesium ions
and a mixture of surfactants, including anionics and
amine oxides.
It is an object of this invention to provide
homogeneous, heavy-duty liquid detergents which contain
magnesium salts, alkanolamines, anionic surfactants and
nonionic surfactants at levels which provide superior
10 detergency performance. -
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~.1 . .
: . ~C17Z852
, PRIOR ART
The use of magnesium and/or calcium ions in
detergent compositions to provide increased detergency
benefits has been disclosed heretofore.
U.S. Patent 2,908,651, entitled LIQUID DETERGENT
COMPOSITION, October 13, 1959, discloses single-phase,
clear, concentrated liquid detergents containing, inter
alia, alkanolamines, magnesium or calcium salts, alcohols,
and alkyl aryl sulfonates This patent describes in some
detail the problems associated with the preparation of
single-phase, clear liquid detergents.
U.S. Patent 2,691,636, entitled DETERGENT
COMPOSITIONS, October 12, 1954, relates to synthetic
detergent compositions and their use, inter alia, in
their calcium and magnesium form.
U.S. Patent 2,766,212, entitled DETERGæNTS,
October 9, 1956, discloses and claims, inter alia, the
use of polyvalent metals such as the chlorides, sulfates,
acetates, etc., of magnesium, calci~n, etc., in combination
with anionic detergents which are sulfated ethoxylated
alcohols.
U.S. Patent 3,202,613, entitled PROCESS ~OR PRO-
DUCTION OF DETERGE~T COMPOSITIONS, August 24, 1965,
teaches the use of magnesium sulfate in low bulk density
built detergents.
U.S. Patent 3,440,171, entitled SUR~ACE ACTIVE
COMPOSITIONS, April 22, 1969, teaches the use of various
salts, including magnesi~m salts~ as degellants for fluid
mixtures of alkyl benzen~ sulfonic acids and alkanolamines.
-:
... : . . . .: .
.... . - . . . ~ . .... .... .. .... . .. . .
~a072~352
U.S. Patent 3,282,852, entitled HEAVY DUTY ~IQUID
DETER OE NTS, November 1, 1966, teaches, inter alia, hydro-
tropes, nonionics and higher alkaryl sulfonates in their
alkanolamine or magnesium salt form.
~.S. Reissue Patent Re.~7,096, reissued March 23,
1971, teaches a high sudsing detergent composition
comprising a synergistic mixture of olefin sulfonates,
alkyl benzene sul~onates and alkyi ether sulfates and
teaches that magnesium salts of these materials may be
employed
: U.S. Patent 3,718,609, entitled LIQUID DETERGENT
COMPOSITIONS, February 27, 1973, relates to dual layer
l~uid detergents which can contain magnesium surfactants.
U.S. Patent 3,686,098, entitl~d NOVEL DETERGENT
COMPOSITION, August 22, 1972, relates to di-anionic
detergents and the water-soluble calcium, magnesium, etc.,
salts thereof~
As can be seen from the foregoing, polyvalent metal
ions such as calcium and magnesium have been employed in
a variety of detergent compositions. Additional refer-
ences in this regard include the following:
U.S. Patents 3,819,539, June 25, 1974; 3,700,607,
October 24, I972; 3,697,587, October 10, 1972; 3,679,611,
July 25, 1972; 3,679,609, July 25, 1972; 3,634,269,
January 11, 1972; 3,577,347, May 4, 1971 (relating to a
stable, non-gritty cleanser composition comprising a deter-
gent mixture which can be an alkyl benzene sulfonate
and a nonionic surfactant/ certain magnesium salts, and
a chlorine bleach); 3,505,395, Ap~il 7, 1970; 3~384,595,
--, :
.: , , . ~ . , : .
- :, : , - ' ., . - .
- : .: : , .
1C~7;~:~352
May 21, 1968i 3,345,300, Octo~ex 3, 1967; 3,325,412,
June 13, 1967; 3,303,137, February 7, 1967, 3,274,117,
Septem~er 20, 1966; 3,265,624, August 9, 1366 (chlorine
~leach-containing composition); 3,256,202, June 14, 1966;
3,053,771, September 11, 1962; 3,072,580, January 8, 1963;
2,857,370, October 21, 1958; 2,?31,442, January 17, 1956;
2,166,314, July 18, 1939; 2,562,i5~, July 24, 1951;
2,037,566, April 14, 1936; 2,658,072, Novem~er 3, 1953; and
2,717,243, Septemher 6, 1955.
- In addition to the foregoing, U.S. Patents 3,869,399,
issuea March 4, 1975, 3,594,323, issued July 20, 1971, and
the references cited therein, disclose various heavy duty
liquid deterger.ts and the use of high (ca. 1%, and greater)
levels of free alkanolamines therein to enhance detergency
performance.
While the present invention is especially useful
with magnesium salts, surprisingly, the calcîum salts
pxecipitate and are not contemplated for use herein.
.
.
~1~7285Z
SWMMARY OF THE INVENTION
The present invention encompasses an improvement
in the process for preparing a homogeneous (sinsle-phase)
heavy-duty liquid detergent composition which contains
detersive amounts of both anionic and nonionic surfactants,
as well as alkanolamines and magnesium salts, said
improvement comprising:
(a) mixing the surfactant component comprising
a detersive amount of an anionic surfactànt,
or mixtures thereof, in the free acid form,
with sufficient magnesium hydroxide to provide
a mixture characterized by a solution pH of from
about 2 to about 5.5, preferably 3 to 5; and
(b) thereafter admixing sufficient alkanolamine
(preferably triethanolamine) with the fore-
going mixture to provide a finished composition
characteriæed by a solution pH of from about
7 to about ~, preferably 7 to 8.
The compositions prepared in the foregoing manner
contain a detersive amount of a nonionic surfactant o~ the
t~ype disclosed hereinafter. The order of addition of the
nonionic surfactant component is not critical. The
nonionic can be added to the composition before or after
reaction of the anionic surfactant with the magnesium
hydroxide or before or after addition of the alkanolamine.
Most preferably, both the nonionic and the anionic sur-
factants are co-present throughout the process.
.. . . .
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~7;~852
In a preferred process, the mixing steps are
carried out in a liquid medium, especially water or
mixtures of water and water-soluble organic solvents
which also serve as carrier liquids in the resulting
compositions.
The present invention also encompasses liquid
detergent compositions prepared according to the foregoing
process, and their use in cleaning operations,
.
,
~L~7;~852
DETAILED DESCRIPTION OF THE INV~NTION
The process of this invention is designed to
provide stable, homogeneous, liquid detergent composi-
~ions comprising a detersive amount of: a surfactant
component comprising a mixture of detersive anionic and
nonionic surfactants; an alkanolamine, or mixtures of
alkanolamines; and a source of magnesium cations.
The compositions prepared by the present process
~ are specifically designed to pro~ide optimal cleaning
benefits when used in either of the two modes commonly
employed with liquid detergent compositions. First, the
compositions herein can be used as pre-treatment agents
which are applied in concentrated foxm directly onto
fabric stains prior to washing. Second, the instant
composïtions are also useful as detergents for conventional
~hrough-the-wash fabric launderlng operations. Excellent
stain remo~al and soil removal are attained when an
effective amount of the instant compositions is dissolved
in an aqueous washing solution. Typical use concentrations
are usually at leas-t about 0.05% by weight in an aqueous
laundering liquor For through-the-wash fabric laundering,
a concentration in the range of from 0.08% to about 0.50%
(preferably about 1/4 cup per 17-19 gallons of wash water)
by weight of the laundering liquor is generally employed.
Of course, this can be adjusted, depending on the soil
and fabric load and the desires of the user.
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~072~5Z
With regard to pre-treatment efficacy, the
compositions prepared in the manner of this invention
provide oily stain removal from cotton, polyester and
polyester/cotton fabrics which is equal or superior to
similar pre-treatment performance attained with conventional
built anionic detergent compositions. The compositions
herein are comparable in oily stain removal performance
with pure nonionic surfactan~s which are known to be
particularly use~ul in pre-treatment stain removal processes.
~ On the other hand, the compositions herein are equal or
superior to conventional nonionic sur~actants for through-
the-wash oily soil removal tespecially rom cotton)
under standard home laundering conditions. Through-the-
wash detergency performance of the instant compositions
is comparable with that attained with conventional, built
granular anionic detergent compositions.
The present process employs multiple components
which are described in detail, below.
Detersive_Surfactants
The surfactant component of the compositions
prepared according to this invention ultimately comprises~ as
essential ingredients, an anionic detersive surfactant -
and a nonionic detersive surfactant. Additional sur-
factants, e.g., the semi-polar, zwitterionic and ampholytic
surace-active agents well known in the detergent arts,
can optionally be employed herein as suds modifiers, or
for specialized cleaning purposes. Typical anionic,
nonionic, etc., surfactants of the type used hereln are
'~ ~
-- 11 --
.
.: , .
1~7Z~SZ
listed in U.S. Patents 3,332,8~0 and 3,697,364, issued
September 26, 1972, to J. B. Edwards.
In the present process the anionic surfactants
are used in their acid form. The anionics are first
"under-based", i.e., partially neutralized with Mg(OH)2,
! and thereafter neutralized or "over-based" with the alkanol-
¦ amine. By proceeding in this manner, separation of the
finished product (which also contains a detersive amount
of a nonionic surfactant) into what is probably an
aqueous electrolyte/anionic surfactant phase, a nonionic
surfactant phase, and an undissolved solids phase is avoided.
It will be appreciated that commercial anionic
surfactants (free acid form) often contain ca. 3%-5% of
unreacted H2SO~. In such cases addition of sufficient
Mg(OH)2 to neutralize the anionic sur~actant still results
in a pH in the range of 2-3. Of couxse, it is not pos-
sible to state what species (MgSO~/anionic-Mg, etc.
exist in the reaction mixture at this stage. In any
event, this is not important to the practice of this
invention since, in fact, the mixture is being adjusted
in the manner required to provide a clear, stable product.
Accordingly, when using pure or impure anionics the
procedure is the same: first, adjust pH in the acid range
with Mg(OH)2; second, adjust pH to neutrality or basicity
with the alkanolamine.
Non-limiting examples of surfactants suitable for
use in the instant compositions and processes are as
follows.
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r ~ ~7Z~3S2
Anionic Surfactant
. _
The anionic component of the instant detergent
compositions can be an organic sulfuric reaction product
having in its molecular structure an alkyl group containing
from about 8 to about 22 carbon atoms and a sulfonic acid
or sulfuric acid ester group, or mixtures thereof.
(Included in the term "alkyl" is the alkyl portion of
acyl groups.) Examples of this group of synthetic detersive
surfactants which can be used in the present invention
are the alkyl sulfates, especially those obtained by
sulfating the higher alcohols (C8-C18 carbon atoms)
produced from the glycerides of tallow or coconut oil;
and alkyl benzene sulfonates, in which the alkyl group
contains from about 9 to about 14 carbon atoms, in
straight chain or branched chain configuration, e.~.,
those of the type described in U.S. Patents 2,220,099
and 2,477,383. Linear straight chain alkyl benzene
sulfonates in which the average of the alkyl groups is
about 13 carbon atoms, abbreviated as C13LAS, as well
11-2 and C11.8 (avg ) LAS are typically used
Cll-C14 branched chain alkyl benzene sulfonates (AsS),
which are excellent sudsers, can also be used.
.
Examples of commercially available alkyl benzene
suifonates (free acid form) useful in the instant invention
include Conoc A 515, SA 597, and SA 697, all marketed
by the Continental Oil Company, and Calsof ~ AS 99, marketed
by the Pilot Chemical Company.
Other anionic surfactant compounds herein include
the alkyl glyceryl ether sulfonates, especially those
13 -
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~72~3S2
ethers of higher alcohols derived from tallow and coconut
oil; coconut oil fatty acid monoglyceride sulfonates
and sulfates; and a~kyl phenol ethylene oxide ether
sulfates containing about 1 to about 10 units of
ethylene oxide per molecule and wherein the alkyl groups
contain about 8 to about 12 carbon atoms~
Other useful anionic surfactants herein include the
esters of a-sulfonated fatty acids containing from about
6 to 20 carbon atoms in the ester group; 2-acyloxy-
alkane-l-sulfonic acids containing from about 2 to 9
carbon atoms in the acyl group and from about 9 to about
23 carbon atoms in the alkane moietyî alkyl ether sulfates
containing from about 10 to 20 carbon atoms in the alkyl
group and from about l to 30 moles of ethylene oxide;
olefin sulfonates containing from about 12 to 24 carbon
atoms; and ~-alk~loxy alkane sulfonates containing from
about 1 to 3 carbon atoms in the alkyl gro~p and from
about 8 to 20 carbon atoms in the alkane moiety.
Anionic surfactants based on the higher fatty
acids, i.e., ~soaps~ are useful anionic surfactants herein,
but are less preferred than the sulfates and sulfonates.
Higher fatty acids containing from about 8 to about 24
carbon atoms and preferably from about 10 to about 20
carbon atoms and the coconut and tallow soaps can also
be used herein as corrosion inhibitors.
Preferred water-soluble anionic organic surfactants
herein include linear alkyl benzene sulfonates containing
from about 10 to about 18 carbon atoms in the alkyl group;
-- 1~ --
i7Z85~
branched alkyl benzene sulfonates containing from about
10 to about 18 carbon atoms in the alkyl group; the
tallow range alkyl sulfates; the coconut range alkyl
glyceryl sulfonates; alkyl ether (ethoxylated) sulfates
wherein the alkyl moiety contains from about 12 to 18
carbon atoms and wherein the average degree of ethoxyla-
tion varies between 1 and 12, especially 3 to 9; the
sulfated condensation products of tallow alcohol with
from about 3 to 12, especially 6 to 9, moles of ethylene
oxide; and olefin sulfonates containing from about 14 to 16
carbon atoms.
Specific preferred anionics for use herein
include: the linear C10-Cl4 alkyl benzene sulfonates (L~S);
the branched C10 to Cl~ alkyl benzene sulfonates (ABS);
the tallow alkyl sulfates; the coconut alkyl glyceryl
ether sulfonates; the sulfated condensation products of
mixed C10-Cl~ tallow alcohols with from about 1 to about
14 moles of ethylene oxide; and the mixtures of higher
fatty acids containing from 10 to 18 carbon atoms~
It is to be recognized that any of the foregoing
anionic surfactants can be used separately herein or as
mixtures. Moreover, commercial qrades of the surfactants
can contain non-interfering components which are pro-
cessing by-products. For example, commercial C10-Cl4
~s alkaryl sulfonates can comprise alkyl benzene sulfonates,
alkyl toluene sulfonates, alkyl naphthalene sulfonates
and alkyl poly-benzenoid sulfonates~ Such materials and
mixtures thereof are fully contemplated for use herein.
- 15 -
~L~7Z~SZ
' Nonionic Surfactant
The compositions and processes herein also employ
a nonionic detersive surfactant. The presence of the
nonionic surfactant in the li~uid detergent compositions
provided by this invention promotes oily stain removal,
both in their pre-treatment application and through-the-
wash use.
The nonionic surfactants can be prepared by a variety -
of methods well known in the art. In general terms, such
nonionic surfactants are typically prepared by condensing
e~hylene oxide with an -0~ containing hydrocarbyl moiety, ~ -
e.g., an alcohol or alkyl phenol, under conditions o~
acidic or basic catalysis.
Nonionic surfactants for use herein comprise the
typical nonionic sur~ace active agents well known in the
detergency arts. Such materials can be succinctly described
as the condensation products of an alkylene oxide (hydro-
philic in nature), especially ethylene oxide (E0), with
an organic hydrophobic compound, which is usually ali-
phatic or alkyl aromatic in nature. The length of thehydrophilic (i.e., polyoxyalkylene) moiety which is
condensed with any particular hydrophobic compound can
be readily adjusted to yield a water-soluble compound
having the desired degree of balance between hydrophilic
and lipophilic elements, i.e., the "HLB".
The HLB of the ethoxylated nonionics used herein
can be experimentally determined ln well-known fashion,
or can be calculated in the manner set forth in Decker, ;~
.
- 16 -
.,
~.
;tZ8~2
EMULSIONS THEORY AND PRACTICE, Reinhold 1965, pp. 233
and 248. For example, the HLB of the nonionic surfactants
herein can be simply approximated by the term: HLB = E/5;
wherein E is the weight percentage of ethylene oxide
content in the molecule. Or course, the HLB will vary,
for a given hydrocarbyl content, with the amount of
ethylene oxide
Preferred nonionic surfactants for use in the
present compositions and processes are characterized by
an ELB in the range of from 9 to 20, most preferably
10 t~ l~.
Specific, non-limiting examples of suitable
water-soluble nonionic surfactants include the follawing.
The ethylene oxide condensates of alkyl phenols
are a well-known type of water-soluble ethoxylated
nonionic surfactant. These compounds include the
condensation products of alkyl phenols having an alkyl
group containing from about 6 to 18 carbon atoms in
either a straight chain or branched chain configuration,
with EO, said EO being present in amounts from about 3
to about 25 moles of EO per mole of alkyl phenol. The
al~yl substituent in such compounds can be derived,
- for example, from polymerized propylene, diisobutylene,
octene, or nonene. Examples of compounds of this type
include nonyl phenol condensed with about 9.5 moles of
EO per mole of nonyl phenol; dodecyl phenol condensed
with about 12 moles of EO per mole of phenol; dinonyl
phenol condensed with about 15 moles of EO per mole of
'
- 17 -
~` 107Z85;~
phenol; and di-isooctylphenol condensed with about 15
moles of EO per mole of phenol. Commercially av~ lable
nonionic surfactants of this type include I~epa 0-630,
marketed by the GAE Corporation, and Trito~ X-45, X-114,
X-100 and X-102, all marketed by the Rohm and Haas
Company.
The condensation products of aliphatic alcohols
with ethylene oxide are another (and highly preferred)
type of nonionic surfactant used herein. The alkyl chain
o~ the aliphatic alcohol can be either straight or branched,
and generally contains from about 8 to about 22, preferably
9 to 16, carbon atoms. The alcohols can be primary,
secondary, or tertiary. Examples of such ethoxylated
alcohols include the condensation product of about 6
moles of EO with 1 mole of tridecanol; myristyl alcohol
condensed with about 10 moles of EO per mole of myristyl
alcohol; the condensation product of EO with coconut
fatty alcohol wherein the coconut alcohol is primarily
a mixture of fatty alcohols with alkyl chains varying
~rom 10 to about 14 carbon atoms in length and where`in
the condensate contains about 6 moles of EO per mole of
total alcohol; and the condensation product of about 9
moles of EO with the above-described coconut alcohol.
Tallow alcohol ethoxylates ~EO)6 to tEO)ll are similarly
useful herein. Examples of commercially available~ncnionic
surfactants of the ~oregoing type include Tergito~'15-S-9,
marketed by the Union Carhide Corporation; Neodo~ 23-6.5,
marketed by the Shell Chemical Company; and Kyro~EOB,
marketed by The Procter ~ Gamble Company.
'
f~ ~07;~85~ .
The condensation products of ethylene oxide with
a hydrophobic base formed by the condensation of propylene
oxide with propylene glycol constitute another type of
nonionic surfactant. ~he hydrophobic portion of these
compounds has a molecular weight of from about 1500 to
18000 and, of course, exhibits water insolubility. The
addition of poly-E0 moieties to this hydrophobic portion
tends to increase the water-solubility of the molecule as
a whole, and the liquid character of the product is
retained up to the point where the EO content is about
50/O of the total weight of the condensation product.
Examples of compounds of this type ~ clude certain of
the commercially available Pluroni urfactants, marketed
by BASF Wyandotte.
The condensation products of ethylene oxide with
the product resulting from the reaction of pxopylene
oxide and ethylenediamine are another type of nonionic
surfactant useful herein. The hydrophobic "base" of these
condensation products consists of the reaction product
of ethylenediamine and excess p~opylene oxide, said
base having a molecular weight of from about 2500 to
about 3000. This base compound is thereafter condensed
with E0 to the extent that the condensation product
contains from about 40% to about 80% by weight of poly-E0
and has a molecular weight of from about 5,000 to about
11,000~ Examples of this type of nonionic suxfactant
include certain of the commercially available Tetronic
compounds, marketed by BASF Wyandotte.
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72852
The highly preferred nonionic surfactants herein
include the E01-E020 condensates of Cg to C18 primary
and secondary alcohols; the condensates of primary
alcohols are most preferred. Non-limiting, specific examplas
of nonionic surfactants of this type are as follows
(the abbreviations used for the nonionic surfactants,
e.g., C14(E0)6, are standard for such materials and
describe the carbon content of the lipophilic portion
of the molecule and the ethylene oxide content of the
hydrophilic portion): n-Cl~H29(EO)5; n-C14H2g(EO)6;
14 29 7; 14H29(E)l~; n~C15H31(E)6; n-C H (E0) ;
2-C H (EO) 7; n-C15H31 tEO)8; 2 C15H31 ( )8 15 31 9
15 31( )9; n C16~33(E0)9; and 2-C16H33(EO) 9
It is to be recognized that mi~tures of the fore-
goin~ nonionic surfactants are also usleful herein andare readily available from commercial ,alcohol mixtures.
It will be appreciated that the degree of ethoxyla-
tion in the nonionics listed herein can vary somewhat,
inasmuch as average fractional degrees of ethoxylation
occur. For example, n-C15H31(E0)7 can contain small
~uantities f n-C15H31(E)0 and n C15H31( )14
- mercial mixtures will contain portions of materials of
varying EO contents, and the stated E0 content represents
an average. Such mixtures are quite suitable for use
in the present compositions and processes.
Highly preferred alcohol-based nonionic surfactants
are the C14 15(EO)6 9 materials disclosed hereinabove,
~hich are commercially available as mixtures under the
- 2~ -
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~07285iZ
.
names Neodol'45-7 and Neodol ~5-9 from the Shell Chemical
Co. Neodol 45-7 is a liquid at ambient temperatures
(and is more preferred herein for this reason) whereas
Neodol 45-9 is a solid at room temperature. However,
solid nonionics such as Neodol 45-9 are also useful in
the instant liquid compositions-inasmuch as they readily
dissolve therein. Other highly preferred nonionics
include Dobanol 91-8 t"OXO"-based alcohol from Shell)
and Softanol, available from Nippon Shokubei.
When using commercial nonionic mixtures, especially
of lower (Cg-Cl0) alkyl chain length, it is preferred tnat
the un-ethoxylated alcohols and lower (EO)l-(EO)2
ethoxylates be removed, or "stripped", to reduce
undesirable odors~ Stripping can be done in vacuo or
by standard distillation means.
~.
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~C~72~S2
The Alkanolamine
The compositions prepared according to the present
process are neutralized, or preferably over-based, to a
pH above 7 using an alkanolamine In order to secure
optimal detergency performance, it is preferred that the
compositions contain at least 1%, more pre~erably ca.
3%-15%, of free (i.e., unreacted) alkanolamine by
weight of composition.
The alkanolamine compound used herein is preferably
selected from the group consisting of monoethanolamine,
diethanolamine, triethanolamine (most preferred), and
mixtures thereof. These alkanolamine compounds are pro-
duced by the reaction of ethylene oxide with a~monia in
well-known fashion. The pure compounds can be recovered
by standard distillation procedures.
~ The alkanol~mine used in the present compositions
and processes serves at least two purposes. First, the
alkanolamine helps neutralize the free acid form of the
anionic surfactant, presumably to provide, at least in
part, the highly soluble alkanolamine salt. The high
solubility of the alkanolamine-anionic would help explain
the excellent clarity of the liquid detergent products
prepared by the instant process. In addition, the excess
(or "free") alkanolamine, itself, contributes to deter-
gency performance, perhaps by interacting with oily soil~as well as by serving as a buffering agent which helps
maintain the product pH within the de~_red range.
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~072~35Z
Adjunct Surfactants
The compositions and processes herein can
optionally employ various other adjunct sur`factants
which can be used to perform specific cleaniny, suds
modifying, etc., functions. Such optional surfactants
include the various semi-polar, ampholytic, and zwitter-
ionic surface active agents known in the art. ~on-
limiting examples of such materials are as follows.
Semi-polar surfactants useful herein include water-
soluble amine oxides containing one alkyl moiety of fromabout 10 to 28 carbon atoms and two moieties selected from
. - -the group consisting of alkyl moieties and hydroxyalkyl
moieties containing from 1 to about 3 carbon atoms; water-
soluble phosphine oxides containing one alkyl moiety of ;
about 10 to 28 carbon atoms and two moieties selected fromthe group consisting of alkyl moieties and hydroxyalkyl
moieties containing from about 1 to 3 carbon atorns; and
water-soluble sulfo~ides containing one al~yl moiety of
from about 10 to 28 carbon atoms and a moiety selected
from the group consisting of alkyl and hydroxyalkyl
moieties o from 1 to 3 carbon atoms.
~ mpholytic surfactants include derivatives of
aliphatic or ali~hatic derivatives of heterocyclic
secondary and tertiary amines in which the aliphatic
?5 moiety can be straight chain or branched and wherein one
of the aliphatic substituents contains ~rom about 8 to
18 carbon atoms,and at least one aliphatic substituent
contains an anionic water-solubilizing group.
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~7Z852
Zwitterionic surfactants include derivatives
of aliphatic quaternary ammonium, phosphonium and
sulfonium compounds in which the aliphatic moieties
can be straight or branched chain,` and wherein one of
the aliphatic substituents contains from about 8 to 18
carbon atoms and one contains a~ anionic water solubilizing
group.
The foregoing surfactant types are well known ln
the detergency arts.
" .' ' ;` '
;, _
.
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3L~7~:85;2
Carrier
Although useful detergent compositions prepared
in the manner of this invention need only contain the
above-described components (i.e., thick, anhydrous
s compositions), highly preferred compositions herein
contain, in addition to the active detersive components,
a liquid carrier (solvent) selected from the group
consisting of water and mixtures of water and water-solu~le
solvents. It will be appreciated that the partial neu-
tralization of the acid form of the anionic surfactants
using the magnesium hydroxide and the subsequent
addition of alkanolamine can be most easily carried out
when the surfactant is dissolved in a carrier liquid
such as water or water/organic solvent mixtures. ~lore-
over, it is convenient and preferred to use an aqueous
solution o the ma~nesium hydroxide i.n the initial,
under-basing step of the process.
The amount of carrier liq~lid/neutraiization
solvent used herein is preferably chosen to provide a
finished composition which comprises from about 5% to -
70%, preferably 20% to 60%, of carrier by weight of the
total detergent composition. Hi~hly pre~erred composi-
tions comprise from about 25% to 45% by weight of the
carrier liquid, and a correspondin~ amount of liquid is
used in the process.
The presence of the carrier liquid at the above-
disclosed levels in the compositions prepared according
to this process results in several advantages. First,
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:~7Z~52
the physical stability of the detergent compositions
is improved by dilution, and clear points are lowered.
Stated otherwise, compositions formulated using liquid
carriers do not cloud at the low temperatures which are
commonly encountered during shipping or storing of
commercially marketed detergent compositions.
Secondly, liquid carriers, especially water-
alcohol mixtures, help control viscosity and regulate the
gelling tendency which liquid detergent compositions of
the lnstant type exhibit after dilution with water.
Moreover, any tendency to gelation during processing
is substantially avoided.
When an alcohol-water mixt~re is employed as a
liquid carrier solvent herein, the weight ratio of water
to alcohol preferably is maintained above about 2:1,
more preferably ~rom about 3:1 to about 10:1. Higher
alcohol (particularly ethanol) concentrations in the
water-alcohol mixtures used as carriers herein are
pre~erably avoided because of flammability problems which
may arise at such higher alcohol levels.
Any alcohol containing from 1 to about 5 carbon
atoms can be employed in the water-alcohol carrier used
to prepare the instant detergent compositions. Examples
of operable alcohols include methanol, ethanol, propanol,
isopropanol, butanol, isobutanol, and pentanol; ethanol
is highly preferred for general use.
Various liquid or low-melting, water-soluble
poly-ols can also be used in the carriers herein. Such
materials include, for example, polyethylene glycol,
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:. : . ~ : .. , :. . . . . . . , : . .
'1072~35%
especially the ethylene glycols in the molecular weight
range of 500-1500; the polyethoxylated poly-ols commer-
cially available as Carbitol~ glycerines and polymers
thereof; and the like.
Other water-soluble solvents which can be used
herein in a manner similar to the alcohols include:
ketones such as acetone; aldehydes such as propionaldehyde;
ethers such as diethyl ether, and the like; as well as
various natural water-soluble oils which contain such
water-soluble organic solvents.
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... . ...... . . . . . . . .
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Z8SZ
Optional Components
Compositions prepared according to this invention
can optionally contain various non-interfering components
which contribute to overall aesthetics, ease-of-use and
performance. For the most part, such components can be
added at any ti~e during processing, but are preferably
added after the initial under-basing step. Conveniently~
the optionals are added as aqueous or aqueous-alcoholic
solutions.
One type of optional component which can be used
herein is an electrolyte salt. As pointed out in U.S.
Patents 2,580,173 and 3,440,171, electrolyte salts lessen
undesirable gel formation which can occur with concen-
trated detergent compositions. This gel formation most
often occurs, not in the product itself, but in measuring
caps when a small quantity of water comes in contact with
the concentrated composition. ~lot~ever, as noted above,
high levels of electrolytes can cause phase separation
in the instant compositions. To avoid this, non-
interfering electrolyte degellants, i.e., those w~ichdo not contribute to phase separation, can be used
at non-interfering levels~ i.e., generally 1% by weight
of composition, or less. Potassium hydroxide and
potassium chloride are useful herein without causing
phase separation. Potassium hydroxide and/or potassium
chloride, used herein in combination with a water-alcohol
solvent at a level of from about 0.1% to about 0.8% by
weight of composition, can help eliminate gelling problems
without the need for excessively high alcohol levels.
.,:
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~7;~3SZ
.
Other optional, non-essential, non-interfering
components can be added to the compositions prepared
herein to provide improved performance or aesthetic
appeal. For eY.ample, compositions containing a color
stabilizing agent such as citric acid are preferred from
an aesthetic standpoint. Citric acid (or citrate) con-
taining compositions exhibit surprising stability against
the tendency of nonionic/anionic/alkanolamine composi-
tions to develop a reddening upon storage. In addition,
the presence of citric acid in the compositions has
a beneficial effect from the standpoint of eliminating
reddish stains which can sometime~ develop on the outer
surfaces of plastic bottles after sp:illage, seepage or
handling of bottles with hands previously contacted with
the compositions herein. ~n amount of citric acid of up
to about 1% by weight of composition (based on its free
acid form) can be added during processing to obtain these
color stabilizing benefits. A highly preferred range for
the added citric acid is ~rom about 0.05% to about 0.30%
by weight of composition. The citric acid is added after
the initial under-basing step.
Suds modifying agents can be present in the instant
compositions in minor proportions to provide high foaming
or low foaming products, as desired. While the composi-
tions herein inherently provide adequate suds levels,some users desire copious lather from laundry detergent
products. Accordingly, the compositions herein can
optionally contain suds boosters. ~onionic surfactants
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~ILO~Z~2
in the C10 14EO4 9 range are quite useful for this suds
boosting purpose, as are ABS-type anionics Various suds
suppressors, such as the silicones or polyethylene oxide/
polypropylene oxide copolymers known in the detergency
arts,can be used if low-sudsing compositions are desired.
Suds modifiers can be added at any convenient stage in
processing.
Other optional components useful herein are listed
in many commercial publications and include enzymes,
brighteners, bleaching agents, anti-microbial agents,
corrosion inhibitors, perfumes and coloring agents.
Such components usually will comprise no more than about
3% by weight of the total composition. Such components
can be added at any convenient stage of processing.
The fatty acid "soaps" noted hereinabove, especially
oleic acid, are use~ul as product stabilizers and corrosion
inhibitors which protect washer parts.
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~072~352
Preparation and Usaqe
The present compositions are prepared by first
combining the anionic surfactant or anionic mixture
with the magnesium hydroxide base at a ratio which pro-
vides a solution pH (measured as a ca. 0.1% by weightaqueous solution) of from about 2 to about 5.5, prefera~ly
3 to 5. The reactants are simply mixed until the
partial neutralization process is complete. Thereafter,
the under-based anionic surfactant component is neutralized,
or, preferably, over-based, using the alkanolamine to a
p~l in the range from about 7 to about 8.5, preferably 7 to
8 (ca. 0.1% aqueous solution). The resulting mixture of
detersive ingredients can be used per se, or, more
preferably, is prepared and used in a liquid carrier of
the type disclosed hereinabove.
In a highLy preferred mode, the process herein
is carried out in the presence of a carrier liquid ~hich
serves as a reaction solvent for the anionic surfactant
and the Mg(OH)2, and as a carrier in the finished product.
In a typical preparation, an anionic surfactant such as
Cll 2 LAS, acid form, is dissolved in water. The LAS
solution is then added to an aqueous solution of magnesium
hydroxide until a pH in the range of from about 2 to about 5,
more preferably from about 2 to about 3, is reached
Following this, the nonionic surfactant and optional
ingredients are added and the final pH of the solution is
adjusted to the range of 7 to 8 with the alkanolamine.
Preferred detergent compositions herein
have a pH in the range from about 7 to about 8.5,
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- - . : . .................. , . : . . .
.,, . . - : ....
1~7285~
inasmuch as detergency performance of the surfactant
components is increased at pH's at~ or above, substantial
neutrality. Highly preferred compositions are those
containing sufficient alkanolamine to provide a pH in
the range from about 7.0 to about 8.0, and a p~ in
this range is easily achieved using the alkanolamine
at the levels aisclosed herein. (In concentrated
compositions containing magnesium cation~ a pH in the
range much above about 8.5 is preferably avoided,
inasmuch as magnesium hydroxide begins to precipitate
from concentrated solutions above that pH.)
It will be appreciated by those skilled in the art
that the actual "form" in which the anionic surfactant
exists in the finished composition is impossible to
determine with accuracy. Presumably, much of the
anionic is present as the magnesium salt; still
another portion oE the anionic is present as the
alkanolammonium salt. Mixed, complex anionic-magnesium
alkanolamine species may also be present. In
any event, knowledge o~ the exact species in the
compositions is not important, as long as the ingredients
are mixed in the manner described herein.
The following are non-limiting examples of the
process of this invention and compositions prepared
therewith. As can be seen from the examples, highly
preferred compositions herein contain the nonionic and
anionic surfactants at a weight ratio (free acid form of
the anionic~ of from about 5:1 to 1:5, most preferably
3:1 to 1:3.
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r, 1~7~i~352
EXAMPLE I
A stable, clear liquid detergent composition
is prepared using the following detersive ingredients.
The proportions listed reflect the amount of ingredient
present in the final composition.
Parts by Weiqht
Surfactants
Cll 2 LAS, acid form 20.5
Tallow Alcohol (E0)11 6.0
io Dobano ~ 1-8* 19.0
Carrier
Ethanol 8.0
Water ~7.2
Base
Magnesium hydroxide 1.~ - -
Triethanolamine 5.0
Minors
Oleic acid 1.0
Citric acid 0.2
Dye, perfume, etc. 0.2
*Branched "OX0" alcohols in the 9-11 chain length
with an 8 ethoxylate average, available from Shell;
said alcohols being vacuum stripped of the free
alcohols and lower ethoxylates to help control odor.
The composition of Example I is prepared by
dissolving the surfactants in about 75% of the water-
ethanol carrier and adding the surfactant solution
to a solution of magnesium hydroxide dissolved in
the balance of the carrier. The minors are
then added and the pH of the final composition
.
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~7~35Z
is adjusted to 8.2 with the triethanolamine. (Suf~icient
triethanolamine is used to provide ca. 2.5~ by weight
unreacted, i.e., "free"~ triethanolamine in the
composition )
The composition prepared in the manner of
Example I is a clear, stable, single-phase liquid.
The composition of Example I is used at a
concentration of ca. 0.15% by weight in an aqueous
laundering liquor at a temperature of ca. 110F to
launder a mixed load of cotton, cotton/polyester and
polyester fabrics. Oily soils and stains on the fabrics
are substantially removed during the laundering operation,
which is carried out in a standard, top~loading automatic
washer according to manufacturer's instructions.
The composition of Example I :is also characterized
by its excellent suds profile. Accordingly, the composi-
tion is also useful in front-loading machines and in
wringer-type washers at temperatures from about 90F to
about 1~0F.
In contrast with the foregoing, a commercial
li~uid detergent comprising an anionic surfactant, a
nonionic surfactant, free triethanolamine, and a water-
ethanol carrier is modified by the addition of ca. 1.2%
by weight of magnesium chloride. On standing, the
product separates into two distinct phases.
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7Zl55~:
EXAMPLE II
A clear, stable, heavy-duty liquid detergent
composition of the indicated, finished formula is
prepared as follows.
Inqredi ~t % (wt.)
Softano 16.5
Cll 8 LAS, acid form 16.5
Magnesium hydroxide 1.1
Ethanol 9-0
Triethanolamine to pH 8.5
Water Balance
*C12_13 ~avg.) secondary alcohol mix ethoxylated to
an average (E0)12 chain; available from Nippon
Shokubei. The commercial mixture is substantially
free from non-ethoxylated alcohols and short-E0
cthoxylates.
The composition of Example II is prepared by
first partially neutralizing a solution of the Cll 8
LAS dissolved in the water-ethanol with the magnesium ~ ;
hydroxide (pH ca. 3). The Softanol is then added and
the pH of the composition is adjusted to 8.5 with the
triethanolamine. The resulting single-phase composltion
is storage-stable.
An aliquot of the composition of Example II is
poured full-strength onto heavily soiled areas of fabrics.
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IL~7;~:~35Z
The fabrics are rubbed and thereafter placed in a standard,
top-loading automatic washer together with an additional
aliquot of the composition (total composition 1/4 cup).
The machine is operated according to manufacturer's
instructions. After rinsing and drying, oily stains
are found to be removed.
In the composition of Example II, the Cll 8 LAS
is replaced by C12 (avg.) ABS and a high sudsing product
is secured.
In the composition of Example II, one-half the
Cll 8 I~S is replaced by C12 13 ABS and an excellent
moderate-to-high sudsing product is secured~
In the process for preparin~ the composition of
Example II, the triethanolamine is replaced by mono-
ethanolamine and diethanolamine, respectively, and thepH oE the product in each instance is adjusted to ca. 8.5
therewith. Substantially the same results are secured.
What is claimed is:
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