Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
BACKGROUND OF T~E INVENTION
This in~ention relates to liquid deterge-.t compositi.ons.
More particularly, it rel~tes to liquid detergent compositions
comprising a mi~ture of surface-acti.ve comprun~s h-vin~ e~:ceptional
sudsin~ and r~lildr.ess characteristics.
,
-` ~062580
The quantity and persistence of suds are very
important in light-duty liquid detergent compositions intended
for dishwashing and the like. Frequently, the detergent
capacity of a washing solution is gauged by the user by the
amount of suds present and the persistence of suds for a
reasonable period of time. Since the washing of dishes
frequently constitutes exposure of the hands to a detergent
solution, a suitable detergent composition must additionally
be characterized by mildness to the skin. The attainment
of the combined properties of desirable sudsing and mildness
levels in li;quid detergent compositions is a matter of
- difficult formulation. Liquid compositions having high sudsing
qualities are often harsh on the skin. Conversely, liquid
compositions characterized by desirable mildness to the hands
of the user are frequently deficient in their sudsing and/or
detergent qualities.
The employment of sulfated and neutralized
ethoxylates has become widespread in part because of their
desirable cleaning effects, excellent foam stability, and
low cost. These detergents correspond to the formula
R-(OC2H4~r-OSO3-M
where R is alkyl derived from a high molecular weight alcohol,
M is a salt-forming cation, and r represents an average number
of ethylene oxide groups. The products are derived by
sulfation and neutralization of an ethoxylate derived by
condensation of r moles of ethylene oxide per mole of a high
molecular weight alcohol. Variations in the nature of the
ethoxylate employed are known to cause changes in its sudsing
and mildness properties, and improvements in one of these
qualities have generally been obtained at the expense of the
other. The product having an average ethylene oxide value of
1062580
three (r) has been described in British Patent No. 791,704,
March 12, 1958, as representing an optimum taking both mildness
and detergency into account, and a formulation utilizing
this alkyl triethoxy ether sulfate in combination with other
surfactants to provide a product displaying desirable mildness
and cleaning characteristics is disclosed in Eaton et al.,
U.S. Patent No. 3,179,599, issued April 20, 1965.
Another approach to this problem is represented
by the compositions disclosed and claimed in U.S. Patent
No. 3,793,233 to Rose and Thiele issued on February 19, 1974.
This patent discloses liquid detergent compositions containing
a mixture of an alkyl sulfate and an alkyl ether sulfate in
which 5 to 12 moles of ethylene oxide are condensed with one
mole of a high molecular weight alcohol having 10 to 16 carbon
atoms in the alkyl group.
However, both of these formulations are restricted in
their ability to optimize sudsing and mildness characteristics
by virtue of the broad distribution of ethoxylate species that
results from the base catalyzed alcohol ethoxylation that is
practiced commercially.
Accordingly, it is an object of the present invention
to provide a light duty liquid detergent composition that
displays outstanding mildness properties towards the skin.
It is another object of this invention to provide a light duty
liquid detergent composition having outstanding mildness properties
together with high sudsing characteristics.
SUMMARY OF THE INVENTION
_
The present invention is based in part upon the
discovery that themildness properties of a liquid detergent
composition can be enhanced by the use of an alkyl ether
sulfate derived from an ethoxylated alcohol which has been
-- 106Z580
subjected to stripping to remove unethoxylated and mono-
ethoxylated material. Ethoxylation to a relatively low
level (viz 3 to 4 moles of ethylene oxide per mole of alcohol)
followed by stripping to remove unethoxylated and most of the
mono- and diethoxylated alcohol, results in a material which,
when sulfated and neutralized, provides enhanced mildness
whilst not compromising sudsing to anything like the extent
found hitherto. A combination with a low level of alkyl
sulfate and water-soluble alkali earth metal ions provides
compositions of very satisfactory mildness and sudsing
characteristics.
- Thus the present invention provides a light-duty
detergent composition consisting essentially of:
(a) from about 10% to about 35% by weight of the
composition of a sulfated and neutralized alkyl ether of the
formula
Rl ~ (C2H4)n OSO3
wherein Rl is an al~yl residue which is linear or which
contains 25% maximum of Cl-C3 branching in the 2-position,
the alkyl residue having a mean chain length in the range of
10-15 carbon atoms, at least 65% by weight of said residue
having a chain length within + 1 carbon atoms of the mean,
wherein naV has a value within the range 3.5-6.5, provided
(1) that the total weight of components in the alkyl ether in
which n = 3 to 7 inclusive, shall be not less than 60% of the
total weight of ethoxylated material, and (2) that the total
weight of components in the alkyl ether in which n is 1 or 2
shall be not greater than 16% of the total weight of ethoxylated
material, and wherein M is a monovalent cation selected from
106Z580
alkali metal, ammonium, alkyl- or alkanol-ammonium radicals;
(b) from about 1~ to about 5~ by weight of the
composition of a water-soluble primary alkyl sulfate having
10 to 16 carbon atoms in the alkyl chain;
(c) from about 0.05~ to 1.0~ by weight of the
composition of alkali earth metal ions present as a water-
soluble salt; and
(d) the balance water.
DETAILED DESCRIPTION OF THE INVENTION
Ethoxylated Alkyl Sulfate Component
As previously indicated, sulfated and neutralized
ethoxylate detergents are well known as a class of
surfactants whose preparation and properties are described in
The Journal of the American Oil Chemists Society, Vol. 36,
pages 241-244 (June, 1959), Ibid, Vol. 37, pages 427-430
(September, 1960), Ibid, Vol. 45, pages 733-741 (November,
1968), in addition to the patents listed above.
The primary alcohol precursors of these materials
are derived from natural and synthetic sources. Examples
of suitable primary aliphatic alcohols are the linear primary
alcohols obtained from the hydrogenation of vegetable or
animal oil fatty acids such as coconut, palm kernel, and
tallow fatty acids, or by ethylene build-up reactions and
subsequent hydrolysis of the terminal double bond using
Ziegler-type processes. Preferred alcohols are n-octyl,
n-nonyl, n-decyl, n-undecyl, n-dodecyl, n-tridecyl, n-myristyl,
and n-capryl alcohols.
Suitable alcohol precursors also include primary
alcohols having a proportion of branching on the ~ or 2-carbon
atom, i.e., of the formula:
106Z580
CN3(CH2)n CN CN2N
(¦N2) m
106Z5Y10
wherein m+n is in the range 6-13 and wherein m is 0-4.
In such alcohols at least 60% and preferably 75% by
weigh~ of the alcohol of each specific chain length should be
linear (i.e. m = 0) and the branching preferably comprises
about 50% of methyl groups with smaller amounts of ethyl propyl
and butyl groups. These alcohols, or the aldehydes corres-
ponding thereto, are conveniently produced by reaction of
linear olefins having from 7-14 carbon atoms with carbon mon-
oxide and hydrogen. The reaction can either be controlled to
produce aldehydes (as in the well known Oxo process), which
aldehydes are then hydrogenated to give alcohols, or can be
carried out as a hydroformylation reaction in which the alde-
hydes are hydrogenated in situ to convert them to saturated
C8 15 primary alcohols. sOth linear and branched chain alcohols
are formed from these processes and the mixtures can either be
used as such or can be separated into individual components and
then recombined to give the desired blend.
Typical processes for producing "Oxo" aldehydes which
are then hydrogenated to alcohols are disclosed in U.S.
20 Patents 2,564,456 and 2,587,858 and the direct hydroformylation
of olefins to give alcohols is disclosed in U.S. Patents
2,504,682 and 2,581,988.
It will be apparent that by using a single chain length
olefin as starting material, a corresponding single chain
length alcohol will result, but it is generally more
economic to utilize mixtures of olefins
B
1062580
having a spread of carbon chain length around the desired
mean. This will of course provide a mixture of alcohols
having the same distribution of chain lengths around the
mean.
Primary aliphatic alcohols derived from vegetable
oils and fats and from other petroleum feedstocks having
alkyl or alkylene groups as part of their structure will also
contain a range of chain lengths. This range may extend
over a range of C8 -C20 and beyond and it is therefore normal
practice to separate the products from such feedstocks into
different chain length ranges which are chosen with reference
~ to their ultimate use.
In such mixtures it is desirable for the purposes
of the present invention that this distribution be as narrow
as possible and therefore at least 65% and desirably 80% by
weight of the alcohol mixture should be within + 1 carbon
atoms of the mean chain length. Preferably at least 90~ and
most preferably 95% should fall within ~ 1 carbon atoms of
the mean chain length.
As mentioned previously, commercially available
alcohol precursors normally comprise mixtures of
alcohols, while materials suitable for the purposes
of the present invention must have a narrow distribution
of chain lengths around the given mean in order to
minimize the range of condensates produced upon ethoxylation.
Commercially available primary alcohol blends
satisfying this requirement include the alcohols mar-
keted by Shell International Chemicals Ltd. under the
106Z580
trade mark Dobanol and similar materials marketed under the
trade mark Neodols by Shell Chemical Co., these alcohol
blends having at least 95% by weight of the blend within the
stated carbon chain length range. Suitable alcohol blends
derived from natural fats include the so-called "middle cut"
fraction of coconut fatty alcohol composed of approximately
70% C12, 20~ C14 and 10% C16 alcohol by weight.
It will be appreciated that alkyl ether sulfates derived
from commercially available alcohol comprise a mixture of
water-soluble salts. This mixture comprises a distribution
of alkyl ether sulfate detergent molecules of varying ethylene
oxide content. When a given number, for example, 6 moles
of ethylene oxide are reacted with 1 mole of a high molecular
weight alcohol, the resulting ethoxylated alcohol reaction
product is comprised of a mixture of ether molecules having
varying numbers of ethylene oxide groups. Generally, the
mixture will contain a mixture of ether compounds wherein the
mono-(ethylene glycol) ether derivative is present admixed
with alkyl ether compounds containing a variable number of
ethylene oxide groups extending from alkyl di-(ethylene
glycol) ether to an alkyl poly-(ethylene glycol) ether wherein
the number of ethylene oxide groups is equal to or greater than
about twice the number of moles of ethylene oxide reacted with
the high molecular alcohol.
The species having a number of ethylene oxide groups
equal to the number of moles of ethylene oxide reacted with each
mole of high molecular weight alcohol tends to predominate.
However, the higher the level of ethoxylation, i.e., the greater
the average number of moles of ethylene oxide condensed with
the alcohol, the broader the spread of ethoxylate species in
the
_ g
-IE3
106Z5~0
product. Table 1, lines 1 and 2, shows the differing ethoxylate
distributions of alkyl ether condensates obtained by
ethoxylating one mole of C12 primary alcohol with an average
of 3 and 11 moles respectively of ethylene oxide, the
distribution being expressed as a percentage of the total weight
of the condensate including the unethoxylated portion.
-- 10 --
106Z580
~ I a~ oo ~
~1 o ~
~1 u~ ~ , ....
o I u~
~ ~ o
W I~D ~ ,
CO ~ Cl~
H ~D
C3 ~ N
W ¦ O N 11'7
N ' N ~D
. _ .
I~ ,~ ~ .
o ~1
1~ 0 )
~~ ~ O
~06Z5~0
It can be seen that ethoxylation to an average value
of three moles ethylene oxide per mole of alcohol provides a
relatively high fraction of material having a level of
ethoxylation in the range of 3 to 7 moles and also leaves
significant quantities of unethoxylated (Eo)~ monoethoxylated
(El), and diethoxylated (E2) material. These Eol El and E2
fractions in the triethoxylated material, while providing a
useful sudsing component, are known to be disadvantageous to
skin mildness. On the other hand, ethoxylation to a higher
level, (line 2), while virtually eliminating the unethoxylated
and monoethoxylated species, provides a much lower fraction
- of ethoxylate in the target "mean" range and results in a very
broad spread of ethoxylate levels. Furthermore, some loss in
sudsing performance results as the higher ethoxylates
(E6 and above) provide very little sudsing performance and,
consequently, lower the overall performance of a given weight
of material by a dilution effect.
The relative skin mildness of various ethoxylated
alkyl sulfates is shown in Table II. This sets out skin
irritancy values, assessed by a single application patch
test technique for a series of ammonium linear alkyl ether
sulfates in which the level of ethoxylation was varied from
zero to four, using a synthesis technique which provided a
single ethoxylate species.
In the single application patch test, a 1/2" square
piece of cotton muslin is soaked with the test solution and
applied to the back of the subject for a period of 24 hours.
It is then removed and the skin allowed to recover for a
further 24 hour period, after which time the skin is graded
according to the following scale.
1062580
Grading Scale for Patch Testing
Grade
0 No apparent cutaneous involvement.
1/2 Faint, indistinct erythema, but something
there, or no erythema, but slight dryness.
1 Faint but definite erythema, no eruptions or
broken skin, or no erythema but definite
dryness; may be epidermal fissuring.
2 Moderate erythema, may be a very few papu-
lar eruptions, or isolated reaction like
that of a grade 3 but not involving a
significant portion of the patch area
(e.g., around patch edges but not in the
center). Dryness and epidermal fissuring
are not major determining factors. No
edema.
3 Se~ere erythema and generalized eruptions
(papules, vesicles and/or crusts); entire
patch site affected; reaction confined
to actual patch site. Slight edema may
be present.
4 Prominent edema and/or reaction extendingbeyond the patch area. Characteristics of
grade 3 may be present.
Table II
E2 E3 E4
C10 2.1 1.7 1.4
C12 2.5 1.6 1.4 1.1 0.9
C14 1.4 1.1 ~
---- 106ZS80
It can be seen from Table II above that minimizing the
unethoxylated mono- and diethoxylate species in a neutralized
alkyl ether sulfate will significantly reduce the skin irri-
tancy of the surfactant.
It has now been found that if the starting alcohol
is ethoxylated to a lower than desired "average" level and
the ethoxylate then subjected to "stripping", e.g., by
vacuum distillation, to remove the Eo, most of the El, and
a portion of the E2 components, a material can be obtained
which has a higher average ethoxylate content, but has a
lower level of the less useful higher ethoxylates. Line 3
of Table I illustrates a typical ethoxylate distribution
of such a material.
As previously indicated, commercially available mat-
erials useful in the present invention typically utilize
the '-Neodol" and "Dobanol" alcohol blends, sold respective-
ly by the Shell Chemical Co. and Shell International
Chemicals Ltd., as alcohol precursors. These alcohol
blends are condensed with 2.0 - 4 moles of ethy~ene oxide
in the presence of a minor proportion of a strong base such
as sodium hydroxide or potassium hydroxide using a process
such as that disclosed in U.S. Patent 3,682,849.
Alcohol blends having a mean chain length of 12 carbon
atoms or less such as Dobanol 91, Neodol 01, Neodol 12 are
ethoxylated to give an uptake of about 2.0 to about 3.5 moles,
preferably 2.5 to 3.0 moles of ethylene oxide per mole of
alcohol. Neodol 23 typically requires 2.0 - 4.0 moles, pre-
ferably 3.0 to 3.5 moles of ethylene oxide per mole of
alcohol while Neodol 45 is conveniently ethoxylated to
- 14 -
1062580
give an uptake of about 2,0 to about 4,0 moles, preferably
3.5-4.0 moles of ethylene oxide per mole of alcohol. The
condensation products at this stage have a broad distribution
of ethoxylates and a high level of free alcohol typical of
base-catalyzed ethoxylation reactions and are quite unsuitable
for the purposes of the present invention. Accordingly
distillation or evaporation under sub-atmospheric pressure of
the product to strip the unreacted alcohol and desirably also
a major portion of the lower ethoxylates is carried out in
the manner disclosed in U.S. Patent 3,682,849 in order to
maximize the proportion of ethoxylates lying within the
range 3-7 ethylene oxide groups per molecule of alcohol.
The narrower the distribution of carbon atoms around the mean
alcohol chain length, the simpler will be the stripping
process. Ideally the alcohol blends will be co~posed entirely
of material falling in the stated chain length range so that
there will be no overlap in boiling point between e.g.
unethoxylated alcohol of the highest chain length in the
blend (which is undesirable) and di- or tri-ethoxylated alcohol
of the lowest chain length in the blend (which is useful).
The amount of material to be removed normally lies in the
range of 15-40% by weight of the ethoxylated alcohol and
desirably in the range of 20-30% by weight in order to provide
a narrow distribution of ethoxylates, whilst maintaining an
economic process. This leaves an ethoxylate containing at
least 60% and preferably at least 65% by weight of components
in the E3-E7 range and also containing less than 16~ by weight,
preferably less than 12% and most preferably less than 10% of
El and E2 components, the above percentages being based on
the total weight of ethoxylated species, i.e. excluding the
unethoxylated alcohol.
10625~0
Sulfation of the condensate of fatty alcohol and
ethylene oxide can be carried out batchwise or continuously
employing chlorosulfonic acid or sulfur trioxide. Sulfur
trioxide is normally used either as a liquid complexed with,
e.g. Dioxan, or as a gas where it is diluted with an inert
gas such as air or nitrogen. A temperature of from about 750E
to 1350E is suitable for the sulfation reaction. The sulfated
product is neutralized by reaction with an alkali metal
base, e.g., sodium hydroxide, potassium hydroxide, ammonium
hydroxide, or alkylol-substituted ammonias. Preferred alkylol-
substituted ammonias are mono-, di-, and triethanol amines;
~ mono-, di-, and triisopropanol amines; and mono-, di-, and
triglycerol amines, i.e., those in which the alkylol group
has from 2 to 3 carbon atoms. Depending upon the neutralizing
agent employed in carrying out neutralization of the sulfated
alcohol ethoxylate, M in the hereinbefore described formula
will be a monovalent water-solubilizing cation such as sodium,
potassium, ammonium, triethanolamine, or the like.
The advantages of using a "stripped" alkyl ~ther
sulfate derived from a stripped alcohol ethoxylate are that
it is possible to minimize the level of components known to
be detrimental to skin mildness, namely, the Eo~ El, and E2
materials, while not ethoxylating to an extent that introduces
appreciable quantities of non-useful material, i.e., the higher
ethoxylates. This results in a more economical use of the
feedstock, as less needs to be employed to obtain a given
level of performance.
The level of the "stripped" alkyl ether sulfate
in compositions of the present invention is from about 8%
to about 35% by weight of the composition, preferably from
10% to 30%, and most preferably from 18% to 24% by weight.
- 16 -
106ZS8C~
~lkyl Sulfate Component
Notwithstanding the better sudsing that is
obtainable with stripped alkyl ether sulfates of a given
level of mildness compared to unstripped alkyl ether sulfates
of the same level of mildness, it has been found that a low
level of water-soluble primary alkyl sulfate is necessary to
obtain satisfactory sudsing properties. ~owever, this level
is very much lower than that previously employed, being in
the range of 1~ to 5~ by weight, preferably 2% to 4% by weight
of the composition.
The water-soluble alkyl sulfate component of the
present invention conforms to the general formula
ROSO3-M
wherein R is as defined hereinbefore, and M may be a monovalent
cation as hereinbefore defined or may be a divalent cation
provided by the third essential component of the invention.
Preferred materials are the alkyl sulfates in which the
alkyl group is derived from coconut oil and the synthetic
primary alcohols available under the trade name "Neodol" or
"Dobanol", particularly those having 12 to 13 carbon atoms in
the alkyl chain.
Water-Soluble Alkali Earth Metal Salt Component
Alkali earth metal ions such as magnesium, calcium,
and barium ions form a third essential component of the present
invention. These ions, in combination with the alkyl sulfates
and alkyl ether sulfates, provide compositions having the
desired sudsing performance, particularly in water having low
levels of mineral hardness. One method of introducing the
ions is via direct neutralization of the primary alkyl sulfuric
acids. Alternatively, the ions may be added in the form of
water-soluble salts as solids or more preferably as aqueous
- 17 -
106Z580
solutions during the making process. Typical but non-limiting
examples of water-soluble salts useful in the present invention
are magnesium sulfate, magnesium chloride, calcium chloride,
and barium chloride.
The alkali earth metal ions are utilized at a level
of from about 0.05~ to about 1% by weight, preferably 0.1%
to 0.5~ by weight of the composition. If the alkali metal
ions are added as water-soluble salts, they are conveniently
used at a level of from 0.25% to 3%, preferably 0.5% to 2.0%
by weight of the composition.
Optional Components
The compositions of the invention, in addition to
the presence of the alkyl ether sulfate and alkyl sulfate
components described hereinbefore, can contain water-soluble
detergent compounds. Suitable detergents are those which do
not interfere with the desirable detergent, sudsing and
mildness properties of the compositions of the invention. Such
materials should be employed in non-interfering amounts so as
to avoid the minimization or masking of the advantageous
properties of the combined alkyl ether sulfate and alkyl sulfate
components of the invention. Suitable water-soluble detergents
include anionic (e.g., alkali metal salts of alkyl benzene sul-
fonates, alkyl glyceryl ether sulfonates, olefin sulfonates), non-
ionic (e.g., alkylene oxide condensates of aliphatic and alkyl
- 18 -
_ G 106Z580
aromatic compounds), ampholytic (e.g., sodium 3-dodecylamino-
propionate), and zwitterionic (e.g., 3-(N,N-dimethyl-N-hexa-
decylammonio)propane-l-sulfonate and 3-(N,N-dimethyl-N-hexa-
decylammonio)-2-hydroxypropane-1-sulfonate) detergents. Suit-
able examples of water-soluble detergents are described in
U.S. Patent 3,351,558 (November 7, 1967) at column 6, line
57, to column 9, line 74. Preferred olefin sulfonates are
the olefin sulfonates having from about 10 to about 24 carbon
atoms and obtained by sulfonation of -olefins with gaseous
sulfur trioxide. These include the alkali metal and am-
monium tetradecene and hexadecene sulfonates. Other examples
are described in U.S. Patent 3,332,880 (July 25, 1967).
Preferred detergents herein include the alkyl glyceryl
ether sulfonates such as those described in David D. Whyte
et al, U.S. Patent 3,024,273 issued March 6, 1962 and tri-
alkyl amine oxides such as those disclosed in Drew et al,
U.S. Patent 3,223,647, issued December 14, 1964. Amine
oxides are preferably employed at levels ranging from 1% to
10~, preferably 2~ to 6~ by weight of the compositions while
the alkyl glyceryl ether sulfonates are utilized in amounts
of from 1~ to 8%, preferably 2% to 6% by weight. Mixtures of
these detergents can be employed.
The detergent compositions of the invention can con-
tain any of the usual detergent adjuvants. For example,
solubilizing agents, viscosity control agents such as
toluene sulfonates and xylene sulfonates, perfumes , anti-
tarnishing agents, opacifiers such as ethylene glycol di-
stearate or polystyrene, inert salts such as sodium sulfate,
antiredeposition agents, bacteriostatic agents, dyes,
fluorescers, suds builders, and the like, can be utilized
herein without detracting from the advantageous properties
of these compositions. Suitable solubilizing agents
-- 19 --
~`~ 106Z580
include methyl, ethyl, n-propyl, and isopropyl alcohols and
are employed in an amount of from about 5% to 12% of the
composition of the invention.
An additional component that can advantageously be
included is a modified protein for further enhancing the
mildness properties of the detergent composition. Materials
of this type constitute proteins of molecular weight exceed-
ing 5000, preferably in the range of 20,000 to 200,000, which
have been modified by reaction of the free carboxylic acid
or amino groups with one or more of a variety of functional
groups such as oxyalkylene, acyl, alkyl, aryl, nitro,
mercapto, amido, and the like. A particularly preferred
modification is one in which base-hydrolyzed gelatin of
molecular weight 50,000 to lO0,000 is oxybutylated.
Liquid detergent compositions incorporating such
modified proteins form the subject of Marsh et al, U.S.
Patent 4,115,548, issued September l9, 1978.
The detergent compositions of the invention can be
formulated by conventional methods. For example, the
alkyl ether sulfate, alkyl sulfate, and optional components
can be incorporated into aqueous solution individually or
in combination. The alkyl sulfate and alkyl ether sulfate
components are preferably added in admixture. A preferred
means of effecting simultaneous addition involves preparation
_ situ of alkyl sulfate during the preparation of the alkyl
ether sulfate component.
- 20 -
A
10625~0
The desirable sudsing and mildness characteristics
of the liquid detergent compositions of the invention are
apparent from the following Examples which serve to illustrate
the invention. All parts set forth herein are by weight unless
otherwise indicated.
EXAMPLE I
Three compositions were prepared whose formulations
were as follows:
(1) (2) (3)
NH4AE3S( ) 25.0
4 12 18.75
4 4.75 21.0
NH4AS 6.25 3.1
MgC12 1.1
Lauryl Dimethyl 5.0 5.0 5.0
Amine Oxide
NH4 Coconut Alkyl 4 0 4 0 4 0
Glyceryl Ether Sulfonate
Ethanol 8.75 8.75 8.75
Minors 5.0 5.0 5.0
Perfumes, Viscosity,
Modifiers, Opacifiers,
Color, pH Buffers, Etc.
Water -------- to 100% -----
(a) = Alcohol ethoxylate precursor comprises middle
cut coconut alcohol condensed with an average
of three ethylene oxide groups. (Ethoxylate
distribution as in line 1 of Table 1.)
(b) = Alcohol ethoxylate precursor comprises middle
cut coconut alcohol condensed with an average
of twelve ethylene oxide groups. (Ethoxylate
distribution as in line 2 of Table 1.)
(c) = Alcohol ethoxylate precursor comprises Meodol
23, linear oxo alcohol containing approximately
10% 2-methyl branched of which approximately
30 ~ 95% of the alkyl chains are C12 or C13 groups,
condensed with an average of approximately
- 21 -
106Z580
three moles of ethylene oxide and then stripped
to remove 30~ of the ethoxylate to leave a
material having an average degree of ethoxylation
of 4.75 with approximately 69% of the ethoxylate
in the E3-E7 range and less than 10% of El and E2
components. ~Ethoxylate distribution as in line
3 of Table l.)
In order to evaluate the sudsing ability of these
compositions, 7 cc. of each of the compositions was added to
a dishpan containing one gallon of water of a selected hardness
(2, 7 and 14 grains) at a temperature of 115F, and a pH of 8.
Suds were generated by mechanical agitation (small propeller)
and the suds level measured. A fixed quantity (about 5 grams)
of standardized fatty soil (a triglyceride shortening) was
placed on a dinner plate which was then wa~hed in the test
solution. The plate was re-soiled and washed, repeating this
procedure a total of five times. Five additional sets of five
soiled plates were washed in the solution in like manner,
measuring the foam height after each set. The foam height
after washing each set was expressed in terms of precent of
original suds height and an average of the five percentage
values was computed and is reported below. A difference of
about 5% in foam height is considered significant and noticeable
by the housewife. Results are recorded in the table below for
each water hardness. The rate of suds generation was also
recorded for the solutions with no soil present. In order to
measure this property, a device is used comprising a recirculating
system in which a solution of the composition (7 cc. in one
U.S. gallon) is withdrawn from the bottom of a graduated
cylindrical vessel and pumped back to a downward-facing
orifice located in the vessel above the solution surface. The
solution issues vertically downwardly in a jet which impinges
on the solution surface and generates suds. The volume of
~uds (in ml.) generated after two minutes is measured.
106Z5~30
Composition ~ Origina] Suds Suds Volume
eight After 2 Mins.
Grains Grains
14 7 2 14 7
1 48 46 44 595 595
2 48 47 45.5 585 565
3 49.5 52 46 610 605
As can be seen from the data in the preceding table,
the composition of the invention (Composition 3) is characterized
by sudsing properties (speed and stability) which are superior
to comparable compositions containing an ammonium salt of a
sulfated condensate of one mole middle cut coconut alcohol
and 3 moles ethylene oxide (Composition 1) or an ammonium
salt of a sulfated condensate of one mole middle cut coconut
alcohol and 11 moles ethylene oxide (Composition 2).
Stratum Corneum Test
Solutions of products 1, 2, and 3 (0.2% by weight)
were made up in water of 7 grains mineral hardness (Ca:Mg = 3:1)
per U.S. gallon. A small piece of isolated stratum corneum
10 microns thick and 1/2 cm2 in area was soaked in each product
solution which was maintained at a temperature of 100F. Each
piece was periodically removed from its solution, carefully
dried with blotting paper to remove supernatant moisture and
then weighed on a Cahn Electrobalance, before being immediately
returned to the solution.
The water uptake was measured over a period of
approximately 1-1/2 hours and the results are indicated below
expressed as a percentage increase in the original weight in
each case
~ 1062580
Product --Time Minutes----~
1 0 154 184 199
2 0 88 112 146
3 0 76 84 104
The percentage weight gain is a function of the
extent to which the stratum corneum piece is degraded and hence
penetrated by the solution in which itis immersed. It can
therefore be seen from the above table that the composition
in accordance with the present invention gives rise to a
significantly lower level of degradation than formulae
previously considered to be mild.
Equivalent results to the above are obtained if the
C12-C13 stripped alkyl ether sulfate is replaced by either
of the following: (1) an alkyl ether sulfate derived from an
alcohol ethoxylate precursor comprising a C14-C15 linear
primary alcohol condensed with an average of approximately 4
moles of ethylene oxide and then stripped to remove 27.0%
by weight of the ethoxylate constituted by the lower boiling
fractions (Eo~ El, and E2), to leave a material having an
average degree of ethoxylation of 5.9, having 60% by weight
of E3-E7 components and <6% of El and E2 components; and
(2) an alkyl ether sulfate derived from an alcohol ethoxylate
precursor comprising Dobanol 91 (a linear Cg-Cll primary
alcohol blend) condensed with approximately 2.5 moles of
ethylene oxide and then stripped to remove 34% by weight of
the ethoxylate to leave a material having an average degree
of ethoxylation of 4.1, having 69.7% by weight of E3-E7
components and 15.5% of El and E2 components.
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