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Description  |
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This invention relates to a nonionic shampoo, useful for washing human hair
and leaving it in desirable condition. More particularly, it relates to a
liquid shampoo comprising a plurality of nonionic surface active agents
and being essentially free of ions, which is capable of washing the hair
satisfactorily and leaving it in a manageable state.
Prior art shampoos have usually been based on anionic detergents but have
sometimes included nonionic and amphoteric components, too and sometimes
have even included cationics. Also, shampoos based largely or primarily on
nonionic detergents have been suggested but these have usually included
ionic materials, such as salts, acidic or basic materials or materials
which may be considered as being anionic or cationic. It is known that
anionic materials are capable of breaking salt linkages of keratins and
various ionic surface active agents have been shown to be capable of
rupturing the keratinic disulfide bond and thereby solubilizing
proteinaceous material from the keratin. Disulfide rupture may take place
because the ionic materials can alter the isoelectric points of proteins,
such as keratin, from normal, at which they are usually most stable and of
maximum strength. The isoelectric point of hair varies among individuals
but in the absence of added electrolyte the keratin does not significantly
react with acids or alkalies near the neutral point, e.g., about 6.5 to
7.5, and thus remains in desired isoelectric condition.
The shampoo of the present invention, preferably being essentially free of
ions and comprising only nonionics as surface active agents therein,
allows washing of hair without destroying or adversely affecting the salt
or disulfide bonds of the keratin and without changing the isoelectric
point of the hair, thereby allowing shampooing to be effected without
destruction or weakening of the hair. Although various nonionic shampoos
may be made in accordance with this invention a preferred product may be
based on a mixture of three components, an amine oxide, a polyethoxylated
hexitan ester and either a higher alkoxy polyoxyethylene ethanol or an
alkyl glycoside or a mixture thereof, in certain proportions in water,
preferably deionized water (although other suitable aqueous media may also
be employed), and with the shampoo being essentially free of ions. Thus,
in accordance with this aspect of the present invention, a nonionic
shampoo comprises: (A) about 3 to 25 or 30% of a di-lower alkyl or hydroxy
lower alkyl mono-higher alkyl or higher acylamido lower alkyl amine oxide
or a mixture thereof wherein the lower alkyls are of 1 to 4 carbon atoms
and the higher alkyl is of 10 to 20 carbon atoms; (B) about 2 to 20 or 30%
of a polyoxyethylene hexitan mono-higher fatty acid ester having about 10
to 20 carbon atoms in the higher fatty acyl thereof and about 5 or 10 to
100 mols of ethylene oxide per mol; (C) about 6 to 30% of a nonionic
detergent selected from the group consisting of higher alkoxy
polyoxyethylene ethanols wherein the higher alkoxy is of about 10 to 20
carbon atoms and the ethylene oxide content, including the CH.sub.2
CH.sub.2 O-- of the ethanol, is about 6 to 20 mols per mol, and higher
alkyl glycosides, the alkyl of which is of about 10 to 20 carbon atoms,
and mixtures thereof; and (D) about 25 to 89% of water. Usually such
percentages are 4 to 25, 4 to 15, 10 to 25 and 35 to 82, respectively. In
another aspect of the invention it has been found that component C may be
replaced by a combination of about 1 to 6% of a higher fatty acid lower
alkanolamide wherein the higher fatty acid is of about 10 to 20 carbon
atoms and the alkanolamide is a monoalkanolamide or dialkanolamide, the
alkanol of which is of 2 to 3 carbon atoms, and about 0.05 to 1% of
polyacrylamide. Usually the percentages of such components will be within
the ranges of 1.5 to 4 and 0.1 to 0.5, respectively. In a further
embodiment of the invention the mentioned percentages of higher fatty acid
lower alkanolamide and polyacrylamide may be added to the formula of the
first composition, making a 5- or a 6-member composition, exclusive of
water content. The percentage of water present, preferably dionized water,
will be about 25 to 89% and frequently and preferably is within the 60 to
75% range.
The compositions described above are preferred embodiments of the present
invention but in a broader sense the invention may be considered as
including nonionic shampoos containing significant proportions of nonionic
surface active agents, e.g., a detergent or a plurality of detergents and
a foaming agent or a plurality of foaming agents, in an aqueous medium,
which are essentially free of ions and are of about a neutral pH. Such a
product will preferably have a pH in the range of 6.5 to 7.5, more
preferably 6.8 to 7.3, and will preferably contain a polyacrylamide and,
optionally, a higher fatty acid alkanolamide.
The amine oxide is essentially nonionic in the pH range of the shampoo.
While that pH may be in the 5 to 10 range of commercial products and can
still result in a useful shampoo, normally it is within the range of 6.5
to 7.5, preferably 6.8 to 7.3 and most preferably about 7.0. The amine
oxide is a surface active material, usually possessing a detersive action
in addition to its foaming properties. Of the amine oxides that are useful
the di-lower alkyl mono-higher alkyl amine oxides are best and in these
the lower alkyls will usually be of 1 to 4 carbon atoms with the higher
alkyls being of 10 to 20 carbon atoms, preferably with the lower alkyls
being of 1 to 2 carbon atoms and the higher alkyls being of 12 to 16 or 18
carbon atoms. Preferably both of the lower alkyls are the same and more
preferably they are methyl and the higher alkyl is myristyl. Examples of
other amine oxides that may be employed include diethyl myristyl amine
oxide, dimethyl lauryl amine oxide, dimethyl cetyl amine oxide, methyl
ethyl myristyl amine oxide and diethyl cetyl amine oxide. Of course, as
with the other components of the present composition, the amine oxides
will usually be chosen for desired solubility in the aqueous medium
employed and for compatibility with the other components of the shampoo.
While the preferred amine oxides are the di-lower alkyl mono-higher alkyl
amine oxides, such as are described above, other amine oxides of
equivalent surface active properties may also be utilized. Thus, included
among these are the products sold under the trade names Ammonyx, e.g.,
Ammonyx MO, Aromox, Barlox, Chemadox, Conco X, Culverox, Empigen OB,
Empigen OY, Hipochem L3A, Romine FLS, Romine FST, Schercamox, Standamox
01, Textamine Oxide LM, Textamine Oxide MP and Varox 743. The identities
of such materials are given in McCutcheon's Detergents and Emulsifiers,
1969 Annual. Although such materials may have been classified as nonionic,
amphoteric and cationic, under the conditions of use and in the present
liquid shampoos they are essentially nonionic. Of course, the preferred
components of the present shampoos are those amine oxides which are
normally liquid and water soluble and which function as foaming agents,
foam stabilizers and detergents but for the purpose of this application
the amine oxides will be considered to be foaming agents and/or foam
stabilizers, both of which are considered under the generic description of
foaming agents. Some of the amine oxides described may have the lower
alkyls thereof replaced by hydroxy-lower alkyl radicals, e.g.,
2-hydroxyethyl, and some may have the higher alkyl mixtures thereof
derived from natural materials such as coconut oil and tallow, preferably
hydrogenated. In some cases, when a particular higher alkyl is specified
in the amine oxide molecule, really a mixture is employed, averaging in
chain length the same as the specified alkyl. For example, myristyl may be
a blend of alkyls of 12, 14 and 16 carbon atoms. Also, while some
unsaturated substituents may be present, normally it is preferred that
these be saturated or essentially saturated. In addition to the preferred
amine oxides there may also be employed amido amine oxides and
polyethoxylated amine oxides, the former of which are marketed under the
trade name Textamine Oxide 1839 and Textamine Oxide TA. The latter amine
oxides are described in various issued patents, included among which are
U.S. Pat. Nos. 3,098,794; 3,206,512; 3,356,727; 3,449,430; 3,697,452; and
3,943,234. These and the Detergents and Emulsifiers publication previously
mentioned are hereby incorporated by reference.
Although it is often preferred to use the di-lower alkyl mono-higher alkyl
amine oxides (fatty alkyls are much preferred, too), one may also use the
amine oxides wherein the lower alkyls or one such group are/is replaced
with hydroxy lower alkyl, e.g., hydroxyethyl, hydroxypropyl and/or the
higher alkyl is replaced with higher acylamido lower alkyl, e.g.
cocoamidopropyl. Thus, the amine oxide may be selected from such group and
mixtures of the members thereof.
The polyoxyethylene hexitan mono-higher fatty acid ester has from 10 to 20
carbon atoms in the higher fatty acyl thereof and 4 to 100, preferably 10
to 80 mols of ethylene oxide per mol. Preferably, the hexitan is sorbitan,
although mannitan and other hexitans are also often useful, the higher
fatty acyl will be of 10 to 16 or 20 carbon atoms, more preferably of 12
to 16 or 18 carbon atoms and most preferably of about 12 carbon atoms, and
the number of ethoxies will be from 15 to 80, often preferably about 20.
Especially useful is an Atlas Chemical Industries, Inc. product sold under
the trade name Tween 20, also known as polysorbate 20. Similarly useful
products are sold under similar identifications, such as Tweens 40, 60, 65
and 80, all of which are nonionic surface active agents wherein the higher
fatty acyl is lauroyl, palmitoyl, stearoyl or oleyoyl and the number of
the mols of ethylene oxide per mol is about 20. Also useful are the
polyesters, e.g., the triester Tween 85, but saturated products are
preferred. However, of these materials the polyoxyethylene sorbitan
monolaurate of the Polysorbate 20 type is usually favored. When the ester
includes 80 mols of ethylene oxide per mol it will be preferred that the
esterifying fatty acid be of 12 to 14 carbon atoms. Various others of such
nonionic surface active agents are listed at page 30 of the Detergents and
Emulsifiers reference previously mentioned, under Section 32 thereof. In
some instances, there may be substituted for the ethoxylated compounds the
corresponding non-ethoxylated surface active agents, sold under the Span
trademark, and of such materials sorbitan monolaurate (Span 20), a liquid,
is preferred. Preferably it will not be employed to replace more than half
of the polyethoxylated materials or, stated differently, the content
thereof will not exceed that of the polyethoxylated sorbitan monoester in
the present shampoos.
The higher alkoxy polyoxyethylene ethanol component of the present liquid
shampoos is one wherein the higher alkoxy is of 10 to 20 carbon atoms and
the ethylene oxide content thereof, including the CH.sub.2 CH.sub.2 O-- of
the terminal ethanol, is 6 to 20 mols per mol. Preferably the higher
alkoxy is of 10 to 15 carbon atoms and the ethylene oxide content is from
8 to 15 mols per mol. The higher alkoxy may be higher fatty alkoxy or
linear alkoxy or may be a more highly branched alkoxy, such as is
obtainable from Oxo alcohols made from short chain olefins such as
propylene, butylene or isobutylene or mixtures thereof. A preferred
compound of this type is that marketed under the trade name Emulphogene
BC-720 but other such materials sold under the Emulphogene name and
identified as BC-610 and BC-840 may also be employed. Examples of
additional materials within the description given are those sold under the
trade names Neodol 45-11 (a condensation product of a higher alcohol of
about 14.5 carbon atoms and about 11 mols of ethylene oxide per mol of
alcohol), Tergitols 15-S-7, 15-S-9 and 15-S-12, Pluradots HA-440 and 540,
Plurafacs B-26 and C-17 and Alfonics 1218-60 and 1618-65. However, of the
described materials those preferred are of the Oxo alcohol polyethoxylate
type, such as Emulphogene BC-720. As examples thereof there may be
mentioned tridecyl polyethoxylate of 10 or 15 ethylene oxide groups per
mol, tetradecyl polyoxyethylene condensate of 15 mols of ethylene oxide
per mol and dodecyl polyoxyethylene condensate of 10, 15 and 20 mols of
ethylene oxide per mol. U.S. Pat. Nos. 2,934,568; 2,965,678; and 3,682,849
describe such suitable detergents and are hereby incorporated by
reference.
The alkyl glycosides, among which may be mentioned the glucosides,
mannosides and galactosides, are preferably higher alkyl glycosides, with
the alkyl thereof being of 10 to 20 carbon atoms, preferably of 10 to 14
carbon atoms and more preferably of about 12 carbon atoms. The alkyl is
also preferably saturated and linear, although branched alkyls may be
satisfactory too. However, they are not readily biodegradable and in this
respect are less preferable for this and other components of the present
compositions. Of the glycosides the glucosides are preferred and of these
that named Surfactant CG-1 by Rohm and Haas is most preferred. Various
useful glycosides are described in U.S. Pat. No. 3,721,633 and similar
useful materials are mentioned in U.S. Pat. No. 2,974,134, both of which
are hereby incorporated by reference. However, it is contemplated that
there may be substituted for such materials various other similarly acting
sugar ethers, esters and acetals, preferably being the mono-derivatives,
although di- and tri-derivatives may also be of use. Similarly,
polyoxyethylene derivatives of the sugars or sugar alcohols may also be
employed, e.g., with 6 to 20 mols of ethylene oxide per mol, as may be
the sugar alcohol analogs of the glycosides.
The higher fatty acid lower alkanolamide wherein the higher fatty acid is
of 10 to 20 carbon atoms and the alkanolamide is a monoalkanolamide or
dialkanolamide, the alkanol of which is of 2 to 3 carbon atoms, functions
in the present nonionic shampoos as a foam stabilizer, viscosity and flow
regulator and bodying agent. Preferably the alkanolamide will be a
monoalkanolamide and more preferably it will be a monoethanolamide. Also
preferably the higher fatty acid will be of 10 to 14 to 10 to 16 carbon
atoms and may be derived from natural oils, such as coconut oil or
hydrogenated coconut oil. Thus, among examples of suitable alkanolamides
there may be mentioned coconut oil fatty acids monoethanolamide or
cocomonoethanolamide, coconut oil fatty acids diethanolamide, lauric
myristic diethanolamide, lauric monoethanolamide and lauric
monoisopropanolamide.
Polyacrylamide has been described in U.S. Pat. No. 3,001,949, wherein it is
employed in an anionic shampoo. However the polyacrylamide used in the
present invention is of a higher molecular weight, that for the preferred
polymer, marketed by Dow Chemical Corp. under the trade name Separan
NP-10, being of a molecular weight of about 1,500,000. The preferred
molecular weight range is 100,000 to 3,000,000, more preferably 1,000,000
to 2,000,000, but polymers of molecular weights as low as 1,000 and as
high as 5,000,000 may also find use although they will usually constitute
only minor proportions of mixtures of polyacrylamides. The polyacrylamide
or other such polymer or lubricity improving constituent should be water
soluble (or at least soluble in the detergent or surface active agent
mixture of the shampoo) and should remain soluble therein on storage. In
addition to polyacrylamide, other lubricant materials such as silicones
and lactates, e.g., myristyl lactate, may be used, some of which materials
are sold under the names Ceraphyl 28 and Ceraphyl 50.
With the compositions mentioned above there is preferably employed a
preservative, which may be a small proportion of hydrogen peroxide or
formaldehyde, usually added as a 30% aqueous solution. It is found that
the hydrogen peroxide maintains the amine oxide - hexitan ester -
polyoxyethylene ethanol ether or glycoside products free from
discoloration during lengthy storage (such formulas may also contain the
alkanolamide and polyacrylamide) and it has the advantage of doing this
without adding any ionic material to the shampoo. For the amine oxide -
hexitan ester - alkanolamide - polyacrylamide formulations formaldehyde is
usually the preferred preservative, but it may also be used in the
previously mentioned compositions. Freedom from discoloration is also
promoted by use of deionized water or water of comparable low ionic
content and the use of such water obviates its contributing unwanted ionic
compounds to the shampoo. To help to prevent discoloration of dyes and
other components that are usually present in shampoos there will usually
be present a benzophenone, such as benzophenone-1 or other substituted
benzophenone compound, to serve as an ultraviolet light absorber, thereby
preventing the ultraviolet light from adversely affecting various other
ingredients of the shampoos and undesirably changing the color thereof.
Among such ultraviolet light absorbers those preferred are the
Uvinuls.RTM., products of GAF Corporation. Preferred Uvinuls include those
numbered 400, 490, D-49, M-40 and D-50, which are normally used in such
small quantities that lack of water solubility is not a serious
disadvantage. However, Uvinul MS-40, the water soluble derivative of
Uvinul M-40, is a preferred water soluble ultraviolet light absorber.
These products are effective in the range of 200 to 400 millimicrons and
do not darken or decompose upon prolonged exposure to intense ultraviolet
light rays. Rather than utilizing the substituted benzophenones, all of
which are referred to in the present claim as benzophenones, because it is
that part of the molecule which is most significant as an ultraviolet
light absorber, one may employ other ultraviolet absorbers, such as the
substituted acrylonitriles, of which Uvinuls N-35 and N-539 are examples.
The employment of color stabilizers, such as hydrogen peroxide,
formaldehyde and benzophenone derivatives, is more important in the case
of clear shampoos, a most preferred class of embodiments of this
invention; however, one may also utilize them in opaque, translucent or
emulsion shampoos.
The particular combination of amine oxide and hexitan monoester, with
polyoxyethylene ethanol ether and/or alkyl glycoside optionally present,
furnishes a balanced, completely nonionic surface active agent system
which has desirable foaming, lathering and detersive properties despite
the fact that nonionic surface active agents are usually deficient in such
properties. The alkanolamide, in the particular combination recited,
improves the foam and lather characteristics, while also exerting
desirable modifying effects on the product flow characteristics and hair
treatment and the polyacrylamide acts similarly, improving the lubricity
of the foam and the feel of the hair treated and exerting some thickening
effect on the shampoo. However, despite the presences of the alkanolamide
and the polyacrylamide in the shampoos, it is very often desirable to
further improve the viscosity and pour properties of the liquid shampoos
and to accomplish this it has been found to be useful to include in those
compositions a polyethylene glycol higher fatty acid ester of an average
molecular weight in the range of 2,000 to 8,000, preferably 4,000 to
7,000, and most preferably, about 6,000, wherein the fatty acid moieties
thereof are each of 12 to 20 carbon atoms, preferably of 16 to 20 carbon
atoms and most preferably of about 18 carbon atoms. It is preferred that
the polyethylene glycol ester be a diester and most preferred of these
compounds is the polyethylene glycol distearate of an average molecular
weight of about 6,000.
As was previously mentioned, the water employed is preferably deionized and
most preferably is completely ion-free. However, sometimes ordinary tap
water may be utilized, providing that it is comparatively low in ionic
content so that the product resulting is essentially free of ionic
materials and has a conductivity below 5,000 micromhos/cm. Preferably the
conductivity will be below 1,000 micromhos/cm. which corresponds to about
0.5 g./l. of NaCl. Most preferably, conductivity readings will be 200
micromhos/cm. or lower.
In addition to maintaining the ionic content of the water low the various
other components of the shampoo are also held low in ionic constituents so
as to maintain the ionic content of the final product low, like that of
the deionized water mentioned. As a result, the present shampoo leaves the
hair clean, yet manageable and of desirable feel, combability, gloss,
strength, appearance, sheen and manageability.
In addition to the previously mentioned constituents of the liquid shampoo
one may also employ normal and conventional adjuvants, providing that they
are non-ionic. Thus, there may be used various coloring agents and
perfumes; thickeners, such as hydroxypropylmethyl cellulose, methyl
cellulose, polyvinyl alcohol and polyvinyl pyrrolidone; pearlescing agents
and opacifiers; solvents, such as ethanol, preferably in the form of a
specially denatured alcohol such as SD-40, and glycols (ethylene glycol is
useful as a clarifying agent, to prevent high and low temperature
cloudings of desirably clear shampoos); lubricants, such as mineral oil
and higher fatty alcohols, e.g., cetyl alcohol, stearyl alcohol;
antibacterial materials; preservatives; etc. The proportion of such
adjuvant materials, in total, will normally not exceed 10% of the shampoo,
preferably being no more than 5% thereof and often being less than 2%
thereof. The percentages of most of such individual components will be
less than 2%, often being less than 1%.
The proportions of the various components of the nonionic liquid shampoo
are maintained within the certain ranges given for best effects. Thus, in
the amine oxide - hexitan monoester - polyoxyethylene ethanol ether or
alkyl glycoside compositions, there are about 3 to 30%, preferably 4 to
25%, more preferably 5 to 10% and most preferably about 7.5% of the
mentioned type of substituted amine oxide; about 2 to 30%, preferably 4 to
15%, more preferably 5 to 10% and most preferably about 7.5% of
polyoxyethylene hexitan mono-higher fatty acid ester; about 6 to 30%,
preferably 10 to 25%, more preferably 15 to 20% and most preferably about
17% of the higher alkoxy polyoxyethylene ethanol or alkyl glycoside or
mixture thereof; and about 25 to 89% preferably 35 to 82%, more preferably
60 to 75% and most preferably about 64% of water. The higher fatty acid
lower alkanolamide, when present (which is highly desirable), is within
the range of about 1 to 6%, preferably 1.5 to 4% and most preferably is
about 2.5%. Similarly, the polyacrylamide, when employed (also highly
preferred), is about 0.05 to 1% of the product, preferably 0.1 to 0.5% and
most preferably about 0.2%. The hydrogen peroxide or other stabilizer
content is normally within the range of about 0.01 to 0.5%, preferably
being 0.05 to 0.5%, more preferably 0.1 to 0.3% and most preferably about
0.2% for hydrogen peroxide but it may be lower e.g., 0.01 to 0.3%, for
other preservatives, such as formaldehyde. Such figures are on active
ingredient bases as charged. Products employed preferably omit all ionic
materials.
For the amine oxide - hexitan monester - alkanolamide - polyacrylamide
shampoos the ranges of proportions of constituents are about 3 to 30%,
preferably 4 to 15%, more preferably 5 to 10% and most preferably about 8%
of the di-lower alkyl or hydroxyalkyl mono-higher alkyl or acylamido lower
alkyl amine oxide, about 2 to 30%, preferably 10 to 30%, more preferably
15 to 25% and most preferably about 19% of the polyoxyethylene hexitan
mono-higher fatty acid ester, about 1 to 6%, preferably 1.5 to 4%, more
preferably 2 to 3% and most preferably about 2.5% of higher fatty acid
lower alkanolamide, about 0.05 to 1%, preferably 0.1 to 0.5%, more
preferably 0.1 to 0.3% and most preferably about 0.2% of polyacrylamide
and about 25 to 89%, preferably 35 to 82%, more preferably 60 to 75% and
most preferably about 67% of water. The contents of polyethylene glycol
higher fatty acid ester, ethylene glycol (anti-clouding agent), when
present formaldehyde and benzophenone compound, in preferred compositions
of this type are respectively about 0.2 to 8%, preferably 0.5 to 5%, more
preferably 1 to 3% and most preferably about 2%; about 0.5 to 5%,
preferably 1 to 5%, more preferably 1 to 3% and most preferably about 2%,
about 0.01 to 0.2%, preferably 0.01 to 0.1%, more preferably 0.01 to 0.05%
and most preferably about 0.03% of formaldehyde; and about 0.01 to 0.2%,
preferably 0.01 to 0.1%, more preferably 0.01 to 0.05% and most preferably
about 0.03% of benzophenone compound.
The proportions of the various surface active components to one another,
within the percentage ranges previously given, will normally be controlled
to maintain a desired balance of properties in the product. Thus, in the
first type of shampoo (with the polyoxyethylene oxide ethanol and/or
glycoside) the proportion of amine oxide:polyoxyethylene hexitan
mono-higher fatty acid ester:higher alkoxy polyoxyethylene ethanol and/or
alkyl glycoside will usually be 1:0.5 to 2:1 to 4, with the total
proportion of the nonionic detergents, e.g., last three mentioned surface
active agents, to amine oxide being in the range of 1:1 to 7:1. For the
second type of shampoo, omitting the polyoxyethylene ethanol ether and/or
glycoside and including alkanolamide and polyacrylamide, the proportion
ranges of the amine oxide to hexitan monoester will usually be 1:1 to 5,
with such proportions to alkanolamide and polyacrylamide usually being
1:0.0 to 0.5 and 1:0.1 to 0.05.
In a broader aspect of the present invention other nonionic surface active
agents may be employed in the aqueous medium, including at least one
which, like the amine oxide (it may be the amine oxide), is a foaming
agent or is primarily a foaming agent and at least one of which is a
detergent or primarily a detergent. The total of nonionic surface active
agents including any alkanolamide present, is usually within the range of
11 to 90%, preferably 15 to 50% and more preferably 20 to 40%, with the
balance, except for the alkanolamide and polyacrylamide and the mentioned
adjuvants, being water. Of course, the percentages will usually be
adjusted to provide sufficient water or water-solvent system to
satisfactorily dissolve all the shampoo components, and in this respect it
should be kept in mind that liquid nonionic components will normally be
employed when water contents are low. In this described broader aspect of
the invention, although it will be preferred to employ the same surface
active agents as were previously described or equivalents thereof, such as
were previously mentioned, a wide variety of detergents may be
substituted, at least in part, for the mentioned detergent components.
Thus, preferably at least 50% of the detergent components of the shampoos
will be polyoxyethylene hexitan mono-higher fatty acid ester (with higher
alkoxy polyoxyethylene ethanol and/or alkyl glycoside) and at least 50% of
the foaming agent component will be amine oxide. Other useful nonionic
detergents and nonionic foaming agents (nonionic at the pH of the shampoo)
include higher and middle alkyl phenol polyoxyethylene ethanol of 5 to 30
mols of ethylene oxide per mol; ester analogs of the ethers previously
described; block copolymers of ethylene oxide and propylene oxide such as
those sold under the trademark Pluronic; and various others of the
well-known nonionic detergents, such as those sold under the trademarks
Plurafac C-17; Igepal CO-710; Conco XAM; Triton X-100; Glucamate Sesq. 15X
(also 10X, 100X, 40X, 100X and 120X); and Igepal RC-630. Other nonionics
are described in the reference Detergents and Emulsifiers, previously
mentioned, especially in classes 5, 7, 8, 10, 11, 32 and 34, appearing at
pages 23-32. Such materials are described in more detail elsewhere in the
reference, as indicated.
In such broad aspect of the invention it is also desirable to employ the
nonionic polyacrylamide but other thickening and foam modifying agents may
also be utilized, such as Carbowax, Polyox, polyvinyl alcohol or methyl
cellulose, so long as such are soluble and stable and contain no ionics.
Foam stabilizing equivalents of the alkanolamides are also useful in this
broader aspect of the invention and it is desirable to utilize the same
proportions, previously described for the various components, so that the
content of the plurality of nonionic surface active agents is about the
same. When, in accordance with a broader aspect of the invention, the
foaming agent is an amine oxide, it contains at least 12 carbon atoms
(aromatic amine oxides are contemplated as sometimes useful) and the
amount of the (plurality of) nonionic detergent(s) present is from 1 to 7
times the amount of such amine oxide. In such case the pH is from 6.5 to
7.5 and the water content is in the range of 25 to 89%, with the more
preferred ranges being as previously given. Preferred compositions under
this broader aspect of the invention include as one of the nonionic
detergents the polyoxyethylene hexitan mono-higher fatty acid ester. Such
compositions will also preferably include the polyacrylamide and,
optionally, alkanolamide of the type mentioned and in the proportions
previously given.
The present shampoos are readily made by simple mixing methods from readily
available components which, on storage, do not adversely affect the entire
composition. Thus, the products are capable of being made in desired clear
form or in cloudy, opaque or opalescent form. The viscosities are
adjustable by changing the total percentage of active ingredients and by
modifying the percentages of polyacrylamide and other adjuvants. Also,
solvents and thickeners may be utilized. In all such cases the product
made will be pourable from a relatively narrow mouth bottle (1.5 cm.
diameter) and the shampoo will not be so thin as to run off the hair or
hands like water during use. The viscosity of the shampoo will normally be
about that of glycerin at room temperature, e.g., about 1,000 centipoises,
but the viscosity may be in the broader ranges of 250 to 2,000 and 50 to
5,000. Its viscosity may approximate those of commercially acceptable
shampooes now on the market. Instead of measuring viscosity directly, as
by a viscosimeter, one may employ standard laboratory flow tests, in which
flow times through a restriction or tube length under a reproducible head
are measured. The shampoo viscosity and the shampoo itself remain stable
on storage for lengthy periods of time, without color changes or settlings
out of any insoluble materials.
The product, especially in its preferred forms, has unexpectedly desirable
properties. For example, the foam quality and lubricity is comparable to
standard shampoos based on triethanolamine lauryl sulfate. Further, such
shampoos clean the hair exceptionally well and leave it easy to comb,
manageable and of low raspiness. Upon running comparative experiments the
preferred products are found to be superior to a leading commerical
anionic-based shampoo by both laboratory and practical use tests, with
respect to being less drying, leaving the hair with a softer feel, being
less raspy during wet combing, producing fewer split ends after
shampooing, and being easier to comb and causing less flyaway effect. Such
preferred experimental products are also preferred for foam appearance and
for foam stability, compared to the control commercial product. Another
preferred experimental shampoo of the invention is significantly better
than the same commercial product in being less drying, leaving the hair
with a softer feel and leaving it easier to comb, having less fly-away
effects and in appearance and feel of the foam. Additionally, the present
shampoos are non-irritating the the conjunctiva although they desirably
cause a smarting to warn of their presence. Foam volume and build-up rate
are not superior to those of most of the commercial products based upon
anionic detergents, but the experimental formulations are generally
preferred on an overall basis compared with such commercial shampoos. The
desirable differences in properties leading to such general preference are
attributed at least in part to the nonionic and non-ionic nature of the
product and the balanced contents of the nonionic detergent(s), foaming
agent and other functional components described.
In particular, as has been stressed, it is important that the ionic content
of the shampoo be minimized and this is usually accomplished by using
components that are low in ionic contents or in which such content is nil.
It has been found that commercial shampoos of the anionic types have
conductivities in the range of 20,000, to 52,000 micromhos/cm. but the
present products of the invention have conductivities below 5,000, usually
below 2,000 and preferably below 1,000 micromhos/cm. Thus, using a formula
including Emulphogene BC-720 a reading of 750 micromhos/cm. results while
with a product based on Surfactant CG-1 the reading is 1450 micromhos/cm.
The conductivity of a preferred amine oxide - hexitan ester -
alkanolamidepolyacrylamide shampoo of the invention is 721 micromhos/cm.
Comparatively, the conductivity of deionized water is 3 and that of tap
water ranges from 200 to 1,000 micromhos/cm. These conductivity readings
correspond to about 0.5 g./l. of NaCl per 1,000 micromhos/cm. All readings
are taken on a Hach Conductivity Meter, Model No. 2511, using the
micromhos/cm. scale.
Although the non-ionic nature of the invented products is considered of
great importance in producing the desired hair washing and conditioning,
etc. results, it and the particular mixtures of components recited may
also contribute significantly in making the present shampoos of desired
thickness and foaming power. That the shampoos should be good foamers and
of increased viscosity is unexpected in view of the facts that nonionic
detergents usually are poor foamers and of low viscosity. Also, in aqueous
systems mixtures of nonionic surface active agents often tend to gel but
the present compositions do not. They remain gel-free at desired initial
viscosity during usual lengthy storage periods before use .
The unexpectedly good foaming power of the nonionic shampoo is measurable
by a standard test used in the laboratories of the assignee of the present
invention. In this test artificial sebum is used to simulate the effects
of washing human hair. The sebum is a complex mixture of 45% of mixed
saturated and unsaturated fatty acids, 10% paraffin, 15% spermacetti, 20%
olive oil, 5% of cholesterol and 5% of squalene. 15 Grams of the shampoo
to be tested are diluted with deionized water to 100 grams and are added
to a 150 ml. beaker after 3 grams of the artificial sebum has been smeared
over the beaker wall. The diluted shampoo is then heated to 42.degree. C.
with stirring and is transferred quickly to a 500 ml. graduated cylinder
at the same temperature. The cylinder is then shaken 20 times, preferably
mechanically, using a special machine, but manual shaking may be employed
too. At the completion of the shaking the cylinder is uncapped, set
vertical and a stop-watch is started. The level of the foam where it is
most uniform is read and when the water line reaches the 100 ml. mark on
the graduate the watch is stopped. The mentioned foam height is a measure
of the foaming power of the shampoo under actual use conditions and the
time is indicative of the foam stability. By this test an Emulphogene
BC-720 formula, at 15% dilution reads 250 ml. and 22 seconds and a CG-1
formula at the same dilution reads 275 ml. and 24 seconds. Similar foaming
effects result from the amine oxide - hexitan monoester - alkanolamide -
polyacrylamide shampoos of this invention. In contrast, shampoo based on
only a nonionic detergent of the type employed, in the same total
detergent quantity, reads about 50 ml. and 7 seconds. To be a good product
it is considered that the reading for foaming power should be at least 150
ml. and preferably it is at least 200 ml. with maximum at about 450 ml.
The following examples illustrate but do not limit the invention. Unless
otherwise mentioned, all parts in the examples and elsewhere in the
specification are by weight and all temperatures are in .degree. C.
EXAMPLE 1
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Parts
______________________________________
Emulphogene BC-720 (Tridecyloxy polyethoxy ethanol
17.3
of ten ethoxy groups, mfd. by GAF Corp.,
100% active ingredient)
Tween 20 (Polyoxyethylene (20) sorbitan monolaurate,
7.5
mfd. by ICI Industries, 100% active ingredient)
Ammonyx MO (Myristyl dimethylamine oxide, mfd. by
25.0
Onyx Chemical Co., 30% active ingredient in
water)
Cocomonoethanolamide (85% active ingredient)
2.5
Separan NP-10 (water soluble polyacrylamide of
0.2
molecular weight of about 1,500,000, mfd. by
Dow Chemical Co., 100% active ingredient)
Hydrogen peroxide (30% aqueous solution)
0.5
Perfume 1.0
Deionized water (3 micromhos/cm. conductivity)
46.0
______________________________________
A shampoo of the above composition is made in the following manner. First,
the Emulphogene BC-720 is added to a clean mixing tank, with the agitator
on, and the Ammonyx MO, Tween 20 and cocomonoethanolamide are added
sequentially, with continued agitation. The mix is then heated to
68.degree. C., until the cocomonoethanolamide is melted and/or dissolved.
The hydrogen peroxide solution is then admixed with the mentioned
nonionics and mixing is continued for about 1/2 hour, in which time the
perioxide destroys any free amines or other harmful impurities that may be
present. The mix is then cooled to 38.degree. C.
In a separate mixer the Separan NP-10 is gradually added to the formula
weight of deionized water, with the mixer on. Addition is effected
carefully and slowly (the polyacrylamide is sprinkled in) to avoid the
production of "fish eyes" in the mix. After dissolving of the
polyacrylamide the solution thereof is added to the first mixing tank with
agitation and is blended with the nonionics, such mixings being at room
temperature. Subsequently the perfume is admixed with the balance of the
composition and mixing is continued for another 1/2 hour.
The product made is an excellent shampoo of desired viscosity, foaming
power, foam stability, low conductivity and good shampooing effects. The
viscosity is about 1,000 centipoises at 21.degree. C. and the
conductivity, using the Hach Conductivity Meter, is 750 micromhos/cm. The
foaming power is 250 ml. and the foam stability is 22 seconds, by the test
method previously described. In comparison, a | | |
