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Claims  |
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What is claimed is:
1. A liquid detergent consisting essentially of a detersive proportion of
about 12 to 22% of water soluble olefin sulfonate salt of a carbon content
in the range of 10 to 20, 10-20% of water soluble alcohol ethoxylate
sulfate in which the alcohol is of a carbon atom content in the range of
10 to 20 and which contains about 1 to 20 ethoxy groups, a foam
stabilizing proportion of at least one foam stabilizer, an anti-gelling
proportion, in combination, of at least one halide and at least one
nitrate, with the proportion of halide being from 2 to 8% and the
proportion of nitrate being from 1 to 15% and with the proportion of
nitrate salt being sufficient to inhibit corrosion of ferrous metals and
ferrous metal alloys which are brought into contact with the liquid
detergent, and an aqueous medium.
2. A liquid detergent according to claim 1 wherein the olefin of the water
soluble olefin sulfonate salt is an alphaolefin, the number of ethoxy
groups per molecule in the alcohol ethoxylate sulfate is from 1 to 10, the
weight ratio of olefin sulfonate to alcohol ethoxylate sulfate is from
0.4:1 to 3:1, the foam stabilizer is a fatty acid alkanolamide wherein the
fatty acid is of a carbon atom content in the range of 10 to 16 and 2 to
7% of such fatty acid alkanolamide is present, and the proportion of
aqueous medium is from 24 to 73%.
3. A liquid dishwashing detergent according to claim 2 comprising about 15
to 20% of alkali metal alpha-olefin sulfonate salt in which the olefin is
of 10 to 16 carbon atoms, 12 to 18% of water soluble alkanol ethoxylate
sulfate in which the alkanol is of 10 to 18 carbon atoms, with the ratio
of alpha-olefin sulfonate to alcohol ethoxylate sulfate being from 0.5:1
to 2:1, 3 to 6% of a mixture of mono- and dialkanolamides in which the
ratio of monoalkanolamide:dialkanolamide is from 0.2 to 3, 2 to 6% of
alkali metal halide, 1 to 5% of alkali metal nitrate and 45 to 67% water.
4. A liquid dishwashing detergent according to claim 3 wherein the
alpha-olefin sulfonate is sodium alpha-olefin sulfonate, the alcohol
ethoxylate sulfate is ammonium alcohol ethoxylate sulfate of 1 to 5 ethoxy
groups per molecule, in which the alcohol is of 12 to 15 carbon atoms, the
alkali metal halide is sodium chloride and the alkali metal nitrate is
sodium nitrate.
5. A liquid dishwashing detergent according to claim 4 with about 15 to 20%
of sodium alpha-olefin sulfonate in which the olefin is of 14 to 16 carbon
atoms, 12 to 18% ammonium alcohol ethoxylate sulfate of 1 to 5 ethoxy
groups per molecule, 3 to 6%, in combination, of lauric myristic
monoethanolamide and lauric myristic diethanolamide in which the
proportions of lauric:myristic in the monoalkanolamide and dialkanolamide
are from 0.3:1 to 10:1 and the proportion of monoalkanolamide to
dialkanolamide is from 0.3 to 1.5, 2 to 4% of sodium chloride, 1 to 4% of
sodium nitrate and 48 to 67% of water.
6. A liquid dishwashing detergent according to claim 5 which contains about
18% of the sodium alpha-olefin sulfonate, about 15% of the ammonium
alcohol ethoxylate sulfate, about 2.4% of lauric myristic monoethanolamide
wherein the ratio of lauric: myristic in the monoethanolamide is about
3:1, about 2% of lauric myristic diethanolamide wherein the ratio of
lauric: myristic in the diethanolamide is about 3:1, about 2.6% of sodium
chloride, about 2% of sodium nitrate and about 58% of water.
7. A liquid dishwashing detergent according to claim 5 which contains about
16.1% of the sodium alpha-olefin sulfonate, about 13.8% of the ammonium
alcohol ethoxylate sulfate, about 1.5% of lauric myristic monoethanolamide
wherein the ratio of lauric:myristic in the monoethanolamide is about 3:1,
about 3.5% of lauric myristic diethanolamide wherein the ratio of
lauric:myristic in the diethanolamide is about 3:1, about 1.8% of sodium
xylene sulfonate, about 0.5% of MgSO.sub.4, about 0.1% of trisodium
hydroxyethyl ethylene diamine triacetate, about 2.5% of sodium chloride,
about 2% of sodium nitrate and about 58% of water.
8. A liquid detergent consisting essentially of a normally gelling or film
forming proportion of at least one water soluble olefin sulfonate
detergent salt and an anti-gelling and anti-filming proportion within the
range of 2 to 12% of at least one salt selected from the group consisting
of halides, nitrates, sulfides, nitrites and salts of aliphatic acids of 1
to 3 carbon atoms, and mixtures thereof.
9. A liquid detergent according to claim 8 wherein the water soluble olefin
sulfonate salt is an alpha-olefin sulfonate of 10 to 20 carbon atoms per
molecule and the anti-gelling and anti-filming agent is a halide.
10. A liquid detergent according to claim 9, suitable for dishwashing,
comprising about 12 to 22% of water soluble alpha-olefin sulfonate salt in
which the alpha-olefin is of 10 to 16 carbon atoms and in which the halide
salt is an alkali metal chloride.
11. A liquid dishwashing detergent according to claim 10 comprising about
15 to 20% of alkali metal alpha-olefin sulfonate salt, 12 to 18% of
alkanol ethoxylate sulfate in which the alkanol is of 10 to 18 carbon
atoms and the number of ethoxy groups per molecule is from 1 to 10, with
the ratio of alpha-olefin sulfonate to alcohol ethoxylate sulfate being
from 0.4:1 to 3:1, 2 to 7% of fatty acid alkanolamide wherein the fatty
acid is of a carbon atom content in the range of 10 to 16 per molecule, 2
to 6% of alkali metal chloride and from 49 to 69% of an aqueous medium.
12. A liquid dishwashing detergent according to claim 11 in which the ratio
of alpha-olefin sulfonate to alcohol ethoxylate sulfate is from 0.5:1 to
2:1, the content of alkanolamide is 3 to 6% of a mixture of mono- and
dialkanolamide in which the ratio of monoalkanolamide:dialkanolamide is
from 0.2 to 3, and which contains 50 to 68% of water.
13. A liquid dishwashing detergent according to claim 12 wherein the
alpha-olefin sulfonate is sodium alpha-olefin sulfonate, the alcohol
ethoxylate sulfate is ammonium alcohol ethoxylate sulfate of 1 to 5 ethoxy
groups per molecule, in which the alcohol is of 12 to 15 carbon atoms, and
the alkali metal halide is sodium chloride.
14. A liquid dishwashing detergent according to claim 13 which comprises
about 15 to 20% of sodium alpha-olefin sulfonate in which the olefin is of
14 to 16 carbon atoms, 12 to 18% ammonium alcohol ethoxylate sulfate of 1
to 5 ethoxy groups per molecule, 3 to 6%, in combination, of lauric
myristic monoethanolamide and lauric myristic diethanolamide in which the
proportions of lauric:myristic in the monoalkanolamide and dialkanolamide
are from 0.3:1 to 10:1 and the proportion of monoalkanolamide to
dialkanolamide is from 0.3 to 1.5, 2 to 6% of sodium chloride and 50 to
68% of water.
15. A liquid dishwashing detergent according to claim 14 which contains an
anti-corrosive proportion of an anti-corrosion agent to prevent corrosion
of stainless steel in contact with the dishwashing detergent.
16. A liquid detergent, suitable for dishwashing, comprising 5 to 11% of a
water soluble alpha-olefin sulfonate salt of 10 to 20 carbon atoms per
molecule and an anti-gelling and anti-filming proportion, from 0.2 to 1.5%
of a halide.
17. A liquid dishwashing detergent according to claim 16, comprising about
6 to 10% of water soluble alpha-olefin sulfonate salt in which the
alpha-olefin is of 10 to 16 carbon atoms and in which the halide salt is
an alkali metal chloride, which is from 0.5 to 1% of the detergent.
18. A liquid dishwashing detergent according to claim 17 which includes a
higher alcohol ethoxylate of about 55 to 60% ethylene oxide content.
19. A liquid dishwashing detergent according to claim 18 in which the
higher fatty alcohol ethoxylate is of an essentially C.sub.10 higher fatty
alcohol and is 2 to 8% of the liquid detergent.
20. A liquid dishwashing detergent according to claim 19 which includes
from 3 to 7% of a higher fatty acid - lower alkanolamide.
21. A liquid dishwashing detergent according to claim 19 wherein the
alkanolamide is substantially all dialkanolamide.
22. A liquid dishwashing detergent according to claim 21 wherein the
alkanolamide is lauric myristic diethanolamide and the ratio of
lauric:myristic is from 0.3 to 10:1.
23. A liquid dishwashing detergent according to claim 22, which comprises
about 8% of sodium alpha-olefin sulfonate in which the olefin is of 14 to
16 carbon atoms, 4% of a higher fatty alcohol ethoxylated nonionic
detergent, 4% of lauric myristic diethanolamide wherein the
lauric:myristic ratio is about 3:1 and about 1% of sodium chloride, in an
aqueous medium.
24. A liquid dishwashing detergent according to claim 23 wherein the
aqueous medium is water.
25. A method of inhibiting gelling and film forming, on standing, of a
liquid detergent composition comprising a detersive proportion of at least
one water soluble olefin sulfonate salt of a carbon atom content in the
range of 10 to 20 and simultaneously making said composition non-corrosive
to ferrous metals and ferrous metal alloys which may be brought into
contact therewith which comprises admixing with the components of such
liquid detergent composition an anti-gelling, anti-filming and corrosion
inhibiting proportion, in combination, of at least one halide salt, the
proportion of such salt being from 0.2 to 8% of the composition produced,
and at least one nitrate salt, the proportion of such salt being from 1 to
15% of the composition.
26. A method according to claim 25 wherein the liquid detergent comprises
at least one water soluble alcohol ethoxylate sulfate in which the alcohol
is of a carbon atom content in the range of 10 to 20 and contains from
about 1 to 20 ethoxy groups, and a foam stabilizing proportion of at least
one foam stabilizer, a gel or film is produced on the surface of the
liquid detergent and at least one alkali metal halide and at least one
alkali metal nitrate are admixed with the detergent to liquefy such gel or
film.
27. A method according to claim 26 wherein the liquid detergent is a liquid
dishwashing detergent which comprises, after the addition of the halide
and nitrate, about 15 to 20% of sodium alpha-olefin sulfonate in which the
olefin is of 14 to 16 carbon atoms, 12 to 18% of ammonium alcohol
ethoxylate sulfate of 1 to 5 ethoxy groups per molecule, in which the
alcohol is of 12 to 15 carbon atoms, 3 to 6%, in combination, of lauric
myristic monoethanolamide and lauric myristic diethanolamide, in which the
proportions of lauric:myristic in the monoalkanolamide and dialkanolamide
are from 0.3:1 to 10:1 and the proportion of monoalkanolamide to
dialkanolamide is from 0.3 to 1.5, 2 to 4% of sodium chloride, 1 to 4% of
sodium nitrate and 48 to 67% of water.
28. A method of inhbiting gelling and film forming, on standing, of a
liquid detergent composition comprising a detersive proportion of at least
one water soluble olefin sulfonate salt of a carbon atom content in the
range of 10 to 20, which comprises admixing with components of such liquid
detergent an anti-gelling and anti-filming proportion, at least 0.2%, of
at least one salt selected from the group consisting of halides, nitrates,
sulfites, nitrites and those of aliphatic acids of 1 to 3 carbon atoms,
and mixtures thereof.
29. A method according to claim 28 wherein the liquid detergent comprises
at least one water soluble alcohol ethoxylate sulfate in which the alcohol
is of a carbon atom content in the range of 10 to 20 and contains from
about 1 to 20 ethoxy groups, and a foam stabilizing proportion of at least
one foam stabilizer, a gel or film is produced on the surface of the
liquid detergent and at least one alkali metal halide is admixed with the
detergent to liquefy such gel or film.
30. A method according to claim 29 wherein the liquid detergent is a liquid
dishwashing detergent which comprises, after the addition of the halide,
about 15 to 20% of sodium alpha-olefin sulfonate in which the olefin is of
14 to 16 carbon atoms, 12 to 18% of ammonium alcohol ethoxylate sulfate of
1 to 5 ethoxy groups per molecule, in which the alcohol is of 12 to 15
carbon atoms, 3 to 6%, in combination, of lauric myristic monoethanolamide
and lauric myristic diethanolamide in which the proportions of
lauric:myristic in the monoalkanolamide and dialkanolamide are from 0.3:1
to 10:1 and the proportion of monoalkanolamide to dialkanolamide is from
0.3 to 1.5, 2 to 4% of sodium chloride, 1 to 4% of sodium nitrate and 48
to 67% of water. |
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Claims |
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Description |
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This invention relates to liquid detergents based on water soluble
alpha-olefin sulfonate detergent salts. More particularly, it is of such a
liquid detergent, highly preferably also containing a higher alcohol
ethoxylate sulfate detergent constituent, which includes a particular type
of anti-gelling agent, preferably sodium chloride, and a nitrate, such as
sodium nitrate, to help prevent gelation and filming of the liquid
detergent on standing and to prevent corrosion of ferrous metal alloys,
such as stainless steels, in contact with the liquid detergent.
Liquid detergents are well known products, made for both light duty and
heavy duty washing applications. Among the advantages of such products are
compactness, ease of packaging and handling, ease of measuring amounts to
be used, rapid solubility and availability in concentrated liquid form,
which is more convenient for certain applications. Almost all the
production of light duty detergents for dishwashing applications is in
liquid form, in which it is readily dispensed in the small quantities to
be used and is easily measured, often by the capful, the small amount
generally utilized for washing a sinkful of dishes and other cooking and
eating utensils. It has been found that alpha-olefin sulfonate detergents,
especially when combined in liquid detergent formulations with alcohol
ethoxylate sulfates, make exceedingly satisfactory liquid detergent
products, which clean dishes effectively and foam satisfactorily. Also,
such products are more readily biodegradable than other detergents having
aromatic nuclei in their molecules. However, it has been noted that liquid
detergents containing alpha-olefin sulfonates tend to form films or gels,
especially at liquid-gas interfaces. Such gels, films or other deposits
are often visible to the consumer at the dispensing openings of containers
of the alpha-olefin sulfonate-based liquid detergents. The appearances of
such films or gels may inhibit dispensing through narrow dispensing
container openings but even if dispensing problems are not experienced,
the appearance of gel particles or films is often found to be
objectionable to the consumer. Accordingly, efforts have been made to
prevent gelation in such products.
The present inventors have discovered several additives which inhibit
gelation and the best of these have been described in previous patent
applications filed by them, such as U.S. patent applications Ser. Nos.
348,873; 349,035; and 349,111, all filed Apr. 9, 1973; and Ser. No.
350,268, filed Apr. 11, 1973, which describe the use of lower aliphatic
sulfonic acids to inhibit gel formations. The disclosures of such patent
applications are hereby incorporated herein by reference. In addition to
the sulfonic acid gel inhibitors of those applications it has been found
that isethionates, such as sodium isethionate, are also useful in
preventing gelation of olefin sulfonate-based light duty liquid
detergents. Various other materials have been tried as gel inhibiting
additives and have been found either to be unsuccessful or to promote
gelation. Thus, it was surprising that the present relatively few types of
materials were found effective in inhibiting such gels and films, either
by completely preventing gel and film formation initially or by noticeably
diminishing development thereof over reasonable periods of open storage of
the liquid detergent. Also, compartively small quantities of these
relatively inexpensive compounds can be used effectively and on the whole,
they are compatible with other detergent components. The effectiveness of
the present materials as anti-gels is unexpected because some of them have
been employed in the past as thickening agents.
In a highly preferred aspect of the invention, the anti-gelling agent
utilized is of the halide type, preferably sodium chloride or lithium
chloride, most preferably the former. However, it has been noted that
stainless steel processing equipment contacted by the detergent product
containing the halide salt may be corroded by it, leading to deterioration
of the equipment and sometimes, to adverse effects on the liquid detergent
due to the unintentional incorporation therein of the ferrous or other
metal ions or corrosion products from the container materials.
Surprisingly, it has now been discovered that nitrate, preferably sodium
nitrate, counteracts the objectionable reaction and inhibits corrosion by
the liquid detergent, while at the same time the nitrate content improves
anti-gelling properties of the detergent liquid.
In accordance with the present invention there is provided a liquid
detergent comprising a detersive proportion, in combination, of at least
one water soluble olefin sulfonate salt of a carbon atom content in the
range of 10 to 20 and at least one water soluble alcohol ethoxylate
sulfate in which the alcohol is of a carbon atom content in the range of
10 to 20 and which contains about 1 to 20 ethoxy groups, a foam
stabilizing proportion of at least one foam stabilizer, an anti-gelling
proportion, in combination, of at least one halide salt and at least one
nitrate salt, with the proportion of the nitrate salt being sufficient to
inhibit corrosion of ferrous metals and ferrous metal alloys which are
brought into contact with the liquid detergent, and an aqueous medium in
which the mentioned constituents are present. In what may be considered to
be a more generic invention, the liquid detergent comprises a normally
gelling or film-forming proportion of at least one water soluble olefin
sulfonate detergent salt and an anti-gelling and anti-filming proportion
of at least one salt selected from the group consisting of halides,
nitrates, sulfites, nitrites and those of aliphatic acids of 1 to 3 carbon
atoms, and mixtures thereof. Also within the invention are methods of
preventing gelation and filming by incorporating the mentioned
anti-gelling agents in the liquid detergent formula and by adding them to
the formulation after the appearance of gel or film.
The olefin-sulfonate, for its desirable detergency, will have a carbon atom
content in the range of 10 to 20 per molecule, preferably from 10 to 16
and most preferably from 14 to 16. Although various water soluble olefin
sulfonate salts may be employed, the alkali metal and ammonium salts are
preferred and of these the most preferred are the sodium salts. The
alpha-olefin sulfonates utilized may be charged to a mixer in which they
are compounded with other ingredients of the liquid detergent
compositions, as an aqueous liquid, normally comprising from 20 to 50% of
active ingredient (the mixture of active detergent products from the
sulfonation of an alpha-olefin, followed by neutralization of the product
and conversion of sultones to alkenyl sulfonates). Generally, the
impurities in such products will be few, usually being minor proportions,
e.g., 1 to 5%, on an active ingredient basis, of sulfates and chlorides,
such as the sodium salts.
A particularly suitable olefin sulfonate detergent, normally called
alpha-olefin sulfonate, for use in the present liquid detergent
compositions, is the sulfonation product of an olefin mixture containing
about 75 to 85% of straight chain alpha-olefin, e.g., olefin of the
formula R-CH=CH.sub.2 where R is aliphatic hydrocarbon, about 8 or 10 to
20% of olefin in which the unsaturation is in a vinylidene group, e.g.,
olefin of the formula
##EQU1##
where R and R' are aliphatic hydrocarbon groups, preferably each having at
least four carbon atoms, and about 5 to 12% of internal olefin, e.g.,
olefin of the formula
R-CH=CH-R',
wherein R and R' are aliphatic hydrocarbyl, preferably alkyl. One preferred
method of preparing such an olefin mixture is by polymerization of
ethylene with a Ziegler-type catalyst to produce a mixture of
alpha-olefins of various chain lengths, separating therefrom a fraction
containing principally C.sub.12 to C.sub.16 alpha-olefins, preferably
C.sub.14 to C.sub.16, and a fraction containing lower molecular weight
alpha-olefins, e.g., of 6 and 8 carbon atoms, and dimerizing the latter
fraction and combining the first mentioned fraction with said dimerized
fraction.
One particularly suitable olefin mixture has an average carbon atom content
of about 14 to 15 per molecule, e.g., averaging 14.2 to 14.7. In a most
preferred form the olefin mixture has less than 10%, e.g., below 5%, such
as 2%, olefins of less than 14 carbon atoms and less than 10%, e.g., below
5%, such as 2%, olefins of more than 16 carbon atoms.
The sulfonation of the olefin may be effected with sulfur trioxide at a low
partial pressure thereof, e.g., below about 100 mm. of mercury, preferably
below about 25 mm. of mercury. The SO.sub.3 may be in gaseous form,
diluted with an inert diluent, e.g., air, or undiluted, in vacuum. It may
also be in liquid form, e.g., in solution in SO.sub.2 at a low
temperature, such as 0.degree.C. The SO.sub.3 :olefin mol ratio is usually
about 1:1 to 1.2:1, preferably less than about 1.12:1, such as about
1.05-1.1:1. The reaction product from the sulfonation may be mixed with a
10 to 15% molar excess of aqueous caustic to effect neutralization of the
sulfonic acids, after which it is heated to effect hydrolysis by ring
opening of the sultones present in the reaction product. The resulting
product typically contains, by weight, about 40 to 80%, preferably about
50 to 70% of alkenyl sulfonate, about 15 to 70%, preferably 20 to 40%, of
hyroxyalkane sulfonate, about 5 to 12% of hydroxyalkane disulfonate and
alkene disulfonate and up to about 7% to about 15% of impurities, which
may include sodium sulfate, free oil and sodium chloride. Examples of
sulfonation processes that may be used are described in U.S. Pat. Nos.
3,462,525, issued Aug. 19, 1969, to Levinsky et al.; 3,428,654, issued
Feb. 18, 1969, to Rubinfeld et al.; 3,420,875, issued Jan. 7, 1969, to
DiSalvo et al.; 3,506,580, issued Apr. 14, 1970, to Rubinfeld et al.;
3,579,537, issued May 18, 1971, to Rubinfeld et al.; and 3,524,864, issued
Aug. 18, 1970, to Rubinfeld et al.
It is also within the broader scope of the invention to use other olefins
as the raw material, e.g., olefins made by cracking petroleum wax,
substantially pure alpha-olefins made by polymerization of ethylene and
olefins made by dehydration of higher alcohols having average chain
lengths and distributions of molecular weights described above. Also, the
average carbon content may be, less preferably, outside the range of about
14 to 16 carbon atoms, e.g., 12, 13, 17 or 18 carbon atoms. Various
olefin-sulfonated mixtures that may be employed to make suitable
sulfonates are described in the application of Harold Eugene Wixon,
entitled Viscosity Reduction of Aqueous Alpha-Olefin Sulfonate Detergent
Composition, filed on the same day as the present application, the
disclosure of which is incorporated herein by reference. The olefin
sulfonate may be wholly or partially in the form of a water soluble salt
other than the sodium salt, such as suitable ammonium, potassium, mono-
di- and triethanolammonium salts or mixtures thereof.
The ethoxylated alcohol sulfate of the preferred compositions may be
produced by ethylene oxide ethyoxylation of a natural alcohol or a
synthetic alcohol produced by the Ziegler or Oxo processes, having from
about 10 to 18 or 20 carbon atoms in the alcohol, preferably about 12 to
15, and with the alcohol preferably being a primary alkanol, sulfating the
reaction product to form the monosulfate and then neutralizing to form the
ammonium salt. The water soluble ethoxylate sulfates will normally contain
from 10 to 20 ethoxy groups, with 1 to 10 being preferred and 1 to 5 being
more preferred. Most preferably there will be 3 or about 3 ethoxy groups
per molecule. Although the higher fatty alcohol lower alkoxylate sulfate
is highly preferably one in which the lower alkoxy is ethoxy, it is
possible to include in such detergent molecules a small proportion, e.g.,
1 to 20%, preferably less than 10% by weight, of propoxy groups instead of
ethoxies, providing that satisfactory water solubility and detergency are
obtained in the product. Generally, when some propoxy is present the
number of ethoxy groups in the molecule may be increased, e.g., by 20 to
50%, to promote water solubility. It is also within the broader scope of
the invention to use other salts, e.g., alkali metal and lower
alkanolammonium salts, such as sodium and triethanolammonium salts.
Typical suitable alkanols have the following distributions of carbon
chains: 0.5% C.sub.10, 33.6% C.sub.12, 0.6% C.sub.13, 61.1% C.sub.14, 0.1%
C.sub.15, 3.6% C.sub.16 and 0.4% greater than C.sub.16 ; 0.7% C.sub.10,
39.9% C.sub.12, 2.5% C.sub.13, 51.9% C.sub.14, 1.4% C.sub.15, 3.4%
C.sub.16 and 0.1% greater than C.sub.16 ; 31.2% C.sub.12, 1.8% C.sub.13,
61.2% C.sub.14, 1.6% C.sub.15 and 3.6% C.sub.16 ; and 0.8% C.sub.11, 18.7%
C.sub.12, 24.2% C.sub.13, 32.3% C.sub.14, 20.0% C.sub.15 and 0.3%
C.sub.16. These are considered to be essentially of 12 to 15 carbon atoms.
The most preferred ethoxylate sulfates, as ammonium salts, have molecular
weights of from about 420 to 460, preferably from 430 to 440, e.g., about
435.
In the liquid detergent, in additin to the alpha-olefin sulfonate active
anionic synthetic organic detergent component and the highly preferred
higher fatty alcohol ethoxylate sulfate, which both contribute detergency
to the product, for increasing the volume of foam produced and for
stabilizing it in the presence of fatty soil, as in actual dishwashing,
there is utilized a foam stabilizing proportion of at least one foam
stabilizer. Such materials are known in the art and often include
viscosity modifying chemicals or thickening agents, such as sodium
carboxymethyl cellulose, polyvinyl alcohol, polyvinyl pyrrolidone and
hydroxypropyl methyl cellulose, as well as natural gums such as Irish
moss, agar agar, alginates and starches, either in natural or chemically
modified forms. However, the best of the foam stabilizers are the lower
alkanolamides, such as those with 1 to 4 carbon atoms in the lower
alkanol. Of the alkanolamides, the mono- and dialkanolamides are better
and of these the ethanolamides are preferred. The higher fatty acyl moiety
of the alkanolamides is normally of 10 to 20 carbon atoms, preferably of
10 to 16 carbon atoms and most preferably of 12 to 14 carbon atoms. In the
most preferred embodiments of the invention the monoethanolamides are
those of mixed lauric and myristic acids, with the proportions of lauric
and myristic being in the range of 0.3:1 to 10:1, preferably about 3:1.
Such proportions are also those utilized for dialkanolamides, such as the
preferred diethanolamides. For best foam boosting and stabilizing effects
a mixture of monoalkanolamide and dialkanolamide, preferably in both cases
the ethanolamides, will be employed, with the proportion of
monoalkanolamide to dialkanolamide being in the range of about 0.2:1 to
3:1, preferably about 0.3:1 to 1.5:1, more preferably about 0.4:1 to
1.3:1. Instead of the described alkanolamides, there may be utilized the
corresponding ethoxylated alkanolamides, which usually contain 1 to 4
lower alkylene oxide groups, preferably one, and almost invariably these
groups will be ethylene oxide although up to 10% propylene oxide can often
be utilized.
The preferred alkanoic acid diethanolamides may be produced by reacting one
mol of the alkanoic acid methyl ester with more than one mol, e.g., an
excess of 5 to 10%, of diethanolamine, in the presence of heat and a basic
catalyst, such as sodium methylate. The ethoxylated diethanolamides may be
made by reaction of the corresponding alkanoic acid diethanolamide with
ethylene oxide or other suitable oxide in the presence of a basic
catalyst, such as sodium hydroxide. The monoethanolamides may be made by a
similar process, utilizing the corresponding monoethanolamine as a
starting material, and similarly, lower alkoxylated monoethanolamides may
be prepared by alkoxylating the monoethanolamides. In all the above cases,
the preferred lauric myristic substitution may be obtained by utilizing
fatty acids from coconut oil, hydrogenated coconut oil, topped coconut oil
or other natural products or from synthetic fatty acids. Typical suitable
alkanoic acids utilized contain up to 1% of C.sub.8-10 , 71.2 .+-.2% of
C.sub.12, 27.8 .+-.2% of C.sub.14 and up to 1% of C.sub.16 chains.
To facilitate blending in of the monoethanolamide, such as lauric myristic
monoethanolamide, it is preferably charged to the mixer for making the
liquid detergent as a blend with water and hydrotrope. The hydrotrope
facilitates dissolving or emulsifying of the monoethanolamide into the
other materials and contributes its solubilizing effects. Preferred
hydrotropes employed include alkali metal and ammonium hydrotrope salts,
such as sodium xylene sulfonate, ammonium benzene sulfonate, potassium
cumene sulfonate, and potassium tolyl sulfonate. The proportions of the
monoalkanolamide, hydrotrope and water in the blend charged may be varied
to suit the particular formulation but usually will include from 25 to 50%
of the monoalkanolamide, 20 to 40% of hydrotrope and 30 to 60% of water,
with a preferable formulation being in proportions of about 5 : 4 : 6,
respectively. Of course, similar hydrotrope blends may be made with the
dialkanolamides, if desired.
The aqueous solvent medium for the liquid detergent components is often
preferably water alone. However, minor proportions of short chain alkanols
of 2 or 3 carbon atoms, such as ethanol and isopropanol, and other
monohydric and polyhydric alkanols or other known solvents may be present
to aid in solubilizing some components of the liquid detergent. Generally,
it will be desirable to limit the proportion of alcohol or such solvent
present to no more than 20% of the product and preferably the alcohol
content is maintained below 10%, with a proportion of less than 5% being
better still. The water employed may be tap water but is preferably of a
hardness less than 100 p.p.m., as CaCO.sub.3, more preferably less than 50
p.p.m. hardness and most preferably, deionized water or similar zero
hardness water or near zero hardness water is employed.
Due to the presence of the alpha-olefin sulfonate (and sometimes because
the preferred supplementary detergent, higher alcohol ethoxylate sulfate
accentuates the problem), the liquid detergent may have a film formed on
the surface thereof on standing or may have bits of gel appearing therein.
These are unsightly to the consumer and may block pouring orifices and
therefore, are objectionable. After formation thereof in a liquid
detergent they may be broken up and caused to dissolve therein by addition
of particular anti-gelling and anti-filming agents to the detergent. In
some cases, it may be desirable to subject a portion of the detergent to
aging tests, as in open beakers, or to a laboratory gelation test known at
the "racetrack test", which is described in the numbered patent
applications previously referred to and incorporated herein by reference,
in which test the path followed by liquid detergent running freely down a
glass plate open to the atmosphere and at a 30.degree. angle to the
horizontal is noted. The shorter the path followed and the wavier the
shape thereof the greater the gelling tendency of the product.
Anti-gelling, anti-filming agent may be added to an aliquot of the product
until it does not exhibit filming and gelling tendencies and then a
proportional amount of the material may be admixed with a larger amount of
the liquid detergent so as to prevent it from gelling or filming
objectionably.
The anti-gelling and anti-filming additive for the present compositions is
preferably sodium chloride but other alkali metal chlorides, including
lithium chloride and potassium chloride, are also useful, at least in
combination with sodium chloride. The lithium chloride is almost as
effective as the sodium chloride, even alone, in preventing gel formation
or in causing the gel or film to dissolve. Corresponding other halides,
such as the bromides, fluorides and iodides, may also be employed but are
not as good as the chlorides. Sodium salts capable of releasing sodium
ions in the detergent medium are found to assist in preventing or limiting
gelation. Although not as effective as the best halides, diminutions in
gel-forming tendencies have been noted when several other materials are
incorporated in these liquid detergent formulations. These include
sulfites, nitrites, nitrates and lower alkanoates. Even sodium sulfate,
sometimes used as a thickener, frequently helps gel-proof these liquid
detergents. Of the given group, the nitrates appear to be most effective
when employed in combination with the halides. For example, sodium nitrate
further increases the antigelling effects due to the use of sodium
chloride. Of the mentioned classes of anti-gellants, preferred embodiments
include sodium chloride, lithium chloride, sodium sulfite, sodium nitrite,
sodium formate and sodium nitrate, especially in conjunction with sodium
chloride. Such materials and other sodium ion-containing anti-gellants and
anti-filmers may be employed in mixture, as may be the various detergents,
foaming agents, hydrotropes, solvents and other components of the liquid
detergent products. Similarly, the cations of the salts may often be
interchanged so long as the final product has the same cation mixture. For
example, there may be employed some ammonium alpha-olefin sulfonate
together with some sodium alcohol ethoxylate sulfate when such mixture
produces essentially the same final detergent product that results from
employment of ammonium alcohol ethoxylated sulfate and sodium alpha-olefin
sulfonate.
When a halide anti-filming agent is utilized and corrosion or possible
weakenings of ferrous metals, ferrous metal alloys, such as stainless
steel, e.g., 18-8, Type 316, 12% Cr or 17% Cr, or other normally corrosion
resistant materials are feared, anti corrosive compounds or corrosion
inhibitors may be utilized. Of these the best are the nitrates, especially
the alkali metal nitrates, e.g., sodium nitrate, but other known corrosion
inhibitors may be employed, too, preferably in supplementation of the
nitrates, e.g., corresponding chromates, phosphates and silicates, as well
as organic sulfides and amines, the latter being especially effective when
the pH of the detergent is acidic or neutral. The best inhibitors, the
nitrates, also exert anti-gelling effects, especially in combination with
halides such as sodium chloride, and therefore the combination of sodium
chloride and sodium nitrate is superior for preventing gelling and
film-formation.
Although the most favored liquid detergent compositions include both the
alpha-olefin sulfonate and alcohol ethoxylate sulfate, useful liquid
detergents may be produced when other detergents are added to these or
when a proportion of the contents of the mentioned primary detergents is
replaced by another or others. Thus, the alcohol ethoxylate sulfate may be
replaced partially by other anionic, nonionic or non-cationic detergents
which are compatible therewith and in some cases, such detergents may be
employed instead of the alcohol ethoxylate sulfates. When biodegradability
is not of great importance, corresponding phenolic ethoxylate sulfates may
be used, with phenol or alkyl phenol moieties replacing the fatty alcohol
moieties of the preferred alcohol ethoxylate sulfate. The alpha-olefin
sulfonate may be the sole detersive constituent in the liquid dishwashing
detergent and when foaming power is not of critical importance to the
performance characteristcs and acceptability of the detergent, the foam
booster of stabilizer may be omitted.
Among the detergents which may be utilized in place of the alcohol lower
alkoxylate sulfate or in supplementation of the alpha-olefin sulfonates
are the anionic detergents, including higher alkyl mononuclear aromatic
sulfonates, such as the higher alkyl benzene sulfonates containing from 10
to 16 carbon atoms in the higher alkyl group in a straight or branched
chain, for example, the sodium, potassium and ammonium salts of various
acids to result in higher alkyl benzene sulfonates, higher alkyl toluene
sulfonates, higher alkyl phenol sulfonates and higher naphthalene
sulfonates; paraffin sulfonates containing about 10 to 20 carbon atoms,
for example, the primary paraffin sulfonates made by reacting long-chain
alpha-olefins and bisulfites; and paraffin sulfonates having the
sulfonated group distributed along the paraffin chain, as described in
U.S. Pat. Nos. 2,503,280, 2,507,088, 3,260,741, 3,372,188 and German
patent 735,096; sodium and potassium sulfates of higher alcohols
containing 8 to 18 carbon atoms, such as sodium lauryl sulfate and sodium
tallow alcohol sulfate; sodium and potassium salts of alpha-sulfofatty
acid esters containing about 10 to 20 carbon atoms in the acyl group, for
example, methyl alpha-sulfomyristate and methyl alpha-sulfotallowate;
ammonium sulfates of mono- or diglycerides of higher (C.sub.10 -C.sub.18)
fatty acids, for example, stearic monoglyceride monosulfate; sodium higher
alkyl glyceryl ether sulfonates; and sodium and potassium alkyl phenol
polyethenoxy ether sulfates of about 1 to 6 ethoxyethylene groups per
molecule and in which the alkyl radicals contain about 8 to 12 carbon
atoms.
Other suitable anionic surface active agents include the C.sub.8 to
C.sub.18 acyl sarcosinates, e.g., sodium lauroyl sarcoside; sodium and
potassium salts of the reaction product of higher fatty acids containing 8
to 18 carbon atoms in the molecule esterified with isethionic acid; and
sodium and potassium salts of the C.sub.8 to C.sub.18 acyl N-methyl
taurides, for example, sodium lauroyl methyl taurate and potassium
stearoyl methyl taurate.
Other types of surface active agents useful in the practice of the present
invention are the nonionic synthetic organic detergents which are
generally the condensation products of an organic aliphatic or alkyl
aromatic hydrophobic compound and hydrophilic ethylene oxide groups.
Almost any hydrophobic compound having a carboxy, hydroxy, amido, or amino
group with a free hydrogen attached to the nitrogen can be condensed with
ethylene oxide, its hydration product, polyethylene glycol, and sometimes
with a minor proportion of propylene oxide also, to form a nonionic
detergent. Further, the length of the polyethenoxy chain can be adjusted
to achieve the desired balance between the hydrophobic and hydrophilic
portions.
The nonionic detergents include the polyethylene oxide condensates of one
mol of alkyl phenol, containing from about 6 to 12 carbon atoms in a
stright- or branched-chain configuration, with about 5 to 30 mols of
ethylene oxide, for example, nonyl phenol condensed with nine mols of
ethylene oxide, dodecyl phenol condensed with fifteen mols of the oxide
and dinonyl phenol condensed with fifteen mols of ethylene oxide.
Condensation products of the corresponding alkyl thiophenols with 5 to 30
mols of ethylene oxide are also suitable.
Also included in the nonionic detergent class are the condensation products
of a higher alcohol, an alkanol containing about 10 to 18 carbon atoms in
a straight or branched chain configuration, preferably with about 5 to 30
mols of ethylene oxide, for example, a mol of mixed lauryl and myristyl
alcohols condensed with about sixteen mols of ethylene oxide.
A very useful group of nonionics is marketed under the trade name Pluronic.
Such compounds are formed by condensing ethylene oxide with a hydrophobic
base formed by the condensation of propylene oxide with propylene glycol.
The molecular weight of the hydrophobic portion of the molecule is of the
order of 950 to 4,000 and preferably 1,200 to 2,500. The addition of
polyoxyethylene radicals to the hydrophobic portion tends to increase the
solubility of the molecule as a whole. The moleculer weight of these block
copolymers will be from 1,500 to 15,000, and the polyethylene oxide
content may comprise 20% to 80% thereof.
The polar nonionic detergents are those in which the hydrophilic group
contains a semi-polar bond directly between two atoms, for example,
N.fwdarw.O, As.fwdarw.O, and S.fwdarw.O. There is charge separation
between the two directly bonded atoms, but the detergent molecule bears no
net charge and does not dissociate into ions. Among the polar nonionic
detergents are open-chain aliphatic amine oxides of the general formula
R.sub.1 R.sub.2 R.sub.3 N.fwdarw.O
For the purpose of this invention R.sub.1 is an alkyl, alkenyl, or
monohydroxyalkyl radical having about 10 to 18 carbon atoms, and R.sub.2
and R.sub.3 are each selected from the group consisting of methyl, ethyl,
propyl, ethanol, and propanol radicals. A preferred example is myristyl
dimethyl amine oxide. Other operable polar nonionic detergents are the
open-chain aliphatic phosphine oxides having the general formula
R.sub.1 R.sub.2 R.sub.3 P.fwdarw.O
analogous to the amine oxides described herein. The amine and phosphine
oxides may be considered to be foaming agents, stabilizers and boosters,
in addition to having detersive or other surface active properties.
Zwitterionic detergents such as the betaines and sulfobetaines having the
following formula are also useful:
##EQU2##
wherein R is an alkyl group containing about 8 to 18 carbon atoms, R.sub.2
and R.sub.3 are each an alkylene or hydroxyalkylene group containing about
1 to 4 carbon atoms, R.sub.4 is an alkylene or hydroxyalkylene group
containing 1 to 4 carbon atoms, and X is C or S:O. The alkyl group can
contain one or more intermediate linkages such as amido, ether, or
polyether linkages or nonfunctional substituents such as hydroxyl or
halogen which do not substantially affect the hydrophobic character of the
group. When X is C, the detergent is called a betaine and when X is S:O
the detergent is called a sulfobetaine or sultaine. Preferred betaine and
sulfobetaine detergents are 1-(lauryl dimethylammonio) acetate,
1-(myristyl dimethylammonio) propane-3-sulfonate and
1-(myristyldimethylammonio)-2-hydroxy-propane-3-sulfonate.
Examples of suitable ampholytic detergents include the alkyl
beta-aminopropionates, RN(H)C.sub.2 H.sub.4 COOM and the long-chain
imidazole derivatives having the following formula:
##EQU3##
wherein R is an acyclic group of about 7 to 17 carbon atoms, W is selected
from the group R.sub.2 OH, R.sub.2 COOM, and R.sub.2 OR.sub.2 COOM, Y is
selected from the group consisting of OH and R.sub.3 OSO.sub.3, R.sub.2 is
an alkylene or hydroxyalkylene group containing 1 to 4 carbon atoms,
R.sub.3 is selected from the group consisting | | |
