Note: Descriptions are shown in the official language in which they were submitted.
3~
PATENT
Docket D 8418
FREE FLOWING CONCENTRATE OF PEARLE8CEN~ IMPARTING AGENT8
Field of the Invention
This invention relates to a concentrate in the form of
a free-flowing or pumpable, aqueous dispersion containing
15 to 40% by weight of pearlescence imparting (pearlescing)
components.
Statement of Related Art
Aqueous compositions of surfactants and cosmetic
compositions can be given a pearlescent, aesthetically
attractive appearance by incorporation of substances which,
after cooling, precipitate in the form of fine nacreous
crystals and remain dispersed in the compositions.
Suitable among these pearlescence imparting agents or
pearlescers are, for example, the monoesters and diesters
of ethylene glycol, propylene glycol, and oligomeric
alkylene glycols of this type, or of glycerol, with C1622
fatty acids; fatty acids themselves; and monoalkanolamides
of fatty acids with C2 or C3 alkanolamines. (In this
description, unless the context requires otherwise, the
term "fatty" when applied to a chemical name such as acid
or alcohol means that the chemical includes a hydrocarbon
moiety with a straight chain of at least six carbon atoms
and that at least one of the principal functional group
such as carboxyl or hydroxyl is at one end of such a carbon
chain.)
It is known that the pearlescers mentioned can form
stable dispersions in water or in aqueous surfactant solu-
tions and that the concentrated pearlescent dispersions
obtained in this way can be added without heating to other
compositions for which a pearlescent appearance is desired,
so that pearlescence can be obtained in these compositions
into which a pearlescent concentrate is incorporated
without any need for repeating the heating and cooling
originally necessary to form the pearlescent crystals.
Pearlescent concentrates based on the pearlescers
mentioned above are known, for example, from DE-A-16 69
152, from JP-56/71021 (Chem. Abst:r. 95/156360), from DE-A-
34 11 328 and DE-A-35 19 081. The pearlescent concentrates
known from DE-A-16 69 152 contain anionic surfactants to
stabilize the dispersion in its liquid state. However, the
presence of ionic surfactants is undesirable in many appli-
cations of such pearlescent concentrates because incompat-
ibility with formulation constituents of opposite ionicity
can arise and can adversely affect the stability of the
dispersion.
In addition, the pearlescent concentrates known from
these publications contain fatty acid monoalkanolamides or
dialkanolamides as part of the pearlescers. However,
alkanolamines and derivatives thereof have recently been
suspected of participating in the formation of nitros-
amines, with the result that efforts are being made to
avoid alkanolamines and alkanolamine derivatives in the
formulation of cosmetic compositions.
However, omission of the fatty acid alkanolamides from
the known pearlescent concentrates leads to a distinct
reduction in the pearlescent properties. For example, it
was proposed in applicants' German patent application 37 24
547.3 to use pearlescent concentrates containing substan-
tially linear, saturated fatty acids as the pearlescing
component. However, distinctly higher concentrations of
such pearlescing components are required to obtain
satisfactory pearlescence in the end product.
The pearlescent concentrates known from JP-56/71021
are attended by the disadvantage that they are not free-
flowing and do not form stable, free-flowing dispersions
upon dilution with water. This makes the concentrates very
difficult to handle and process on an industrial scale.
Therefore, there is still a need for pearlescent con-
centrates having high concentrations of pearlescing com-
ponents as stable as those in JP-56/71021 but which are
free-flowing, thus readily pumpable, and which may be
incorporated into products to be given a pearlescent
appearance, irrespective of the! content of ca~ionic or
anionic components in the products. In addition, it should
be possible, if desired, to formulate these concentrates
without alkanolamides and to provide the end product with
the desired pearlescence, even with lower concentrations
of pearlescing components therein than are required for
pearlescers according to German patent application 37 24
547.3.
Description of the Invention
It has now been found that all the requirements stated
above are satisfied by a pearlescent concentrate in the
form of a free-flowing, aqueous dispersion which is charac-
terized by a content of
(A) 15 to 40% by weight of pearlescing components,
(B) 5 to 55% by weight of nonionic, ampholytic, and/or
zwitterionic emulsifiers and
(C) 0.1 to 5% by weight of low molecular weight,
polyhydric alcohols.
Particularly advantageous properties are exhibited by
pearlescent concentrates containing
(A) 20 to 30% by weight of pearlescing components,
(B) 15 to 30% by weight of nonionic, ampholytic and/or
zwitterionic emulsifiers, and
(C) 0.5 to 3% by weight of low molecular weight,
polyhydric alcohols.
Pearlescing components are to be understood as nacre-
ous forms of fusible fats or waxes which crystallize out in
the form of fine, pearlescing substances upon cooling of
their aqueous solutions or emulsions from a point above the
melting point of the fusible fat or wax to a point below
its solidification point in a temperature range of from
about 30 to 90~C.
Preferred pearlescing components are
(Al) esters corresponding to formula (I):
R (CnH2n)X OR (I),
in which R1 represents a linear C1422 fatty acyl group,
R2 represents hydrogen or a group from the same class
as R1, n = 2 or 3, and x is a number from l to 4;
(A2) monoalkanolamides corresponding to general formula
(II):
R3 - CO - NH - X (II),
in which R3 represents an alkyl group containing 8 to
22 and, more preferably, 8 to 18 carbon atoms and X is
CH2 CH2 OH~ -CH2-cH2-cH2-oH~ or -C(CH3)2-oH;
(A3) linear, saturated C1622 fatty acids; and
(A4) ~-ketosulfones corresponding to general formula (III):
Rs
R4 - CO - CH - SO2 - CH2 - R6 (III),
in which R4 represents a C1121 alkyl or alkenyl group,
and either each of Rs and R6 represents a hydrogen atom
or R5 and R6 together represent an ethylene group so
that the moiety
R5
- CH - SO2 - CH2 - R6
represents a tetrahydrothiophene dioxide derivative.
The pearlescent concentrates according to the inven-
tion may consist exclusively of one single chemical
compound from any one of these classes, may be mixtures of
representatives of only one of these classes of compounds,
or may be mixtures of representatives of any two or more of
these classes of compounds.
Suitable esters (Al) corresponding to the general
formula R1(OCn*n)XOR2 are, for example, the monoesters and
diesters of ethylene glycol and propylene glycol with
higher fatty acids, for example with palmitic acid, stearic
acid or behenic acid, or the diesters of diethylene glycol
or triethylene glycol with such fatty acids. Also suitable
are mixtures of monoesters and diesters of the glycols
mentioned with fatty acid mixtures, for example with
hydrogenated tallow fatty acid or with the saturated C1418
fatty acid fraction of tallow fatty acid. The ethylene
glycol monoester(s) and/or diester(s) of palmitic and/or
stearic acids are particularly preferable.
Preferred monoalkanolamides (A2) are the monoethanol-
amides. These compounds may all contain the same alkyl
radicals. However, it is morle common commercially, and
satisfactory for use in this invention, to produce the
alkanolamides of fatty acid mixtures from natural sources,
for e~ample coconut oil fatty acids, so that corresponding
mixtures are present in regard to the alkyl radicals, and
alkanolamide mixtures derived from such mixtures are highly
suitable for use in this invention.
Suitable linear fatty acids (A3) are, for example,
palmitic acid, stearic acid, arachic acid, or behenic acid,
although it is also possible to use technical fatty acid
cuts consisting entirely or predominantly of C1622 fatty
acids, for example palmitic/stearic acid fractions of the
type obtained from tallow fatty acid by separation of the
fatty acids liquid at +5C or palmitic/stearic acid frac-
tions of the type obtainable by hydrogenation of tallow
fatty acid.
The B-ketosulfones (A4) of general formula (III) have
the advantage over the known ethylene glycol monoesters and
diesters that the pearlescence of the compositions shows
higher heat stability, i.e. the compositions retain their
pearlescence for several hours on heating to temperatures
above 50C and, in some cases, to temperatures above 70C.
Further information on the B-ketosulfones mentioned can be
found in German patent application 35 08 051.
According to the invention, it is preferred to use the
highly pearlescing compounds of classes (Al) and (A2).
Pearlescent concentrates in which at least 70% by
weight and more especially at least 90% by weight of the
pearlescing components consist of ethylene glycol distea-
rate are particularly preferred.
Suitable emulsifiers (B) are nonionic, ampholytic
and/or zwitterionic surface-active compounds characterized
by a lipophilic, preferably linear, alkyl or alkenyl group
and at least one hydrophilic group. The hydrophilic group
may be either an ionic group or a nonionic group.
Nonionic emulsifiers contain, for example, a polyol
group, a polyalkylene glycol ether group or a combination
of a polyol group and a polyglycol ether group as the
hydrophilic group.
Preferred pearlescent concentrates are those which
contain as emulsifiers nonionic surfactants from the group
consisting of
(B1) adducts of an average of from 2 to 30 moles of
ethylene oxide and/or an average of 0 to 5 moles of
propylene oxide with each mole of linear C822 fatty
alcohols, C1222 fatty acids, and/or with alkyl phenols
containing 8 to 15 carbon atoms in the alkyl group,
the total moles of ethylene oxide and propylene oxide
combined averaging not less than two per mole of
lipophilic group containing alcohol, acid, or alkyl
phenol;
(B2) C1218 fatty acid monoesters and diesters of adducts of
an average of from 1 to 30 moles of ethylene oxide
with each mole of glycerol;
(B3) glycerol monoesters and diesters and sorbitan mono-
esters and diesters of saturated and unsaturated C818
fatty acids and of acids that are adducts of from 1 to
30 moles of ethylene oxide with each mole of saturated
and unsaturated C818 fatty acids;
(B4) C818 alkyl mono- and oligo-glycosides and
oligo(oxyethylene) homologs thereof; and
(B5) adducts of an average of from 10 to 60 moles of
ethylene oxide with each mole of castor oil and/or
hydrogenated castor oil.
Individual compounds or mixtures of compounds from any
of these classes are suitable for use in the invention.
The adducts of ethylene oxide and/or propylene oxide
with fatty alcohols, fatty acids, alkyl phenols, glycerol
monoesters and diesters and sorbitan monoesters and dies-
ters of fatty acids or with castor oil are known commer-
x L~ ~3
cially available products. They are homolog mixtures of
which the average degree of alkoxylation corresponds to the
ratio between the quantities of ethylene oxide and/or
propylene oxide and substrate with which the addition
reaction is carried out.
Cl218 fatty acid monoesters and diesters of adducts of
ethylene oxide with glycerol are known from DE-PS 20 24 051
as oil-restoring agents for cosmetic compositions. C818
mono- and oligo-glycosides, their production and their use
as surfactants are known, for example, from US-A 3,839,318,
US-A 3,707,535, US-A 3,547,828, DE-A 19 43 689, DE-A 20 36
472 and DE-A 30 01 064 and from EP-A 77 167. They may be
prepared in particular by reaction of glucose or oligo-
saccharides with primary C818 alcohols. So far as the
glycoside residue is concerned, both monoglycosides, in
which a cyclic sugar residue is attached to the fatty
alcohol by a glycoside bond, and also oligomeric glycosides
having a degree of oligomerization of up to, preferably, 8
are suitable. The degree of oligomerization is a statisti-
cal mean value on which a homolog distribution typical ofsuch technical products is based.
The compounds of group (Bl) are particularly preferred
nonionic emulsifiers (B) for the purposes of the invention.
Zwitterionic surfactants may also be used as the
emulsifiers (B). Zwitterionic surfactants are surface-
active compounds which contain at least one quaternary
ammonium group and at least one -C00 or -S03 group in the
molecule. Particularly suitable zwitterionic surfactants
are the so-called betaines, such as the N-alkyl-N,N'-
dimethyl ammonium glycinates, for example coconut alkyldimethyl ammonium glycinate, N-acylaminopropyl-N,N-dimethyl
ammonium glycinates, for example coconut acylaminopropyl
dimethyl ammonium glycinate, and 2-alkyl-3-carboxymethyl-
3-hydroxyethyl imidazolines containing 8 to 18 carbon atoms
in the alkyl or acyl group and also coconut acylaminoethyl
hydroxyethyl carboxymethyl glycinate. The fatty acid amide
derivative known by the CTFA Directory ("CTFA") name of
cocoamidopropyl betaine is part:icularly preferred. (The
CTFA ~irectory is published by the Cosmetics, Toiletries,
and Fragrances Association, Washington, DC, U.S.A.)
Other suitable emulsifiers (B) are ampholytic surfac-
tants. Ampholytic surfactants are surface-active compounds
which, in addition to a C8l8 alkyl or acyl group in the
molecule, contain at least one free amino group and at
least one -COOH or -SO3H group. ~rhey are capable of forming
inner salts. Examples of suitable ampholytic surfactants
are N-alkyl glycines, N-alkylpropionic acids, N-alkylamino-
butyric acids, N-alkyliminodipropionic acids, N-hydroxyeth-
yl-N-alkylamidopropyl glycines, N-alkyltaurines, N-alkyl-
sarcosines, 2-alkylaminopropionic acids, and alkylaminoace-
tic acids containing approximately 8 to 18 carbon atoms in
the alkyl group. Particularly preferred ampholytic surfac-
tants are N-coconut alkylaminopropionate, coconut acyl-
aminoethylamine propionate, and C12l8 acyl sarcosine.
According to the invention, the pearlescent concen-
trates may contain representatives of one or more of the
above-mentioned classes of surfactants. Where mixtures are
used, it is preferred to use nonionic and zwitterionic
and/or ampholytic surfactants in a ratio by weight of 5:1
to 1:5.
Pearlescent concentrates according to the invention,
which contain as surfactants only nonionic, zwitterionic,
and/or ampholytic types, have proved to be particularly
universally usable and to be particularly compatible with
aqueous compositions of water-soluble surfactants of any
type and any ionicity and thus are particularly preferred.
If desired, however, the pearlescent concentrates may
also contain anionic or cationic emulsifiers.
Suitable anionic emulsifiers are, for example, alkyl
sulfates and alkyl polyethylene glycol ether sulfates
containing 1 to 6 ethylene glycol ether groups in the
molecule, which are used in the form of their alkali metal,
magnesium, ammonium, mono-, di- or tri-alkanolammonium
salts containing 2 to 3 carbon atoms in the alkanol group.
22~8
Other suitable anionic surfactanls are alkanesulfonates, ~-
olefin sulfonates, ~-sulfofatty acid methyl esters, fatty
alcohol (polyglycol ether) carboxylates, sulfosuccinic acid
mono- and di-al~yl esters, sulfosuccinic acid ester salts,
acyl isethionates, acyl taurides, and acyl sarcosides.
Soaps may also be used as emulsifiers. This may be
achieved, for example, by saponifying a small proportion,
for example 1 to 20% by weight, of linear, saturated fatty
acids by added alkali hydroxide and thus converting them
into an anionic emulsifier~ Preferred anionic surfactants
are the alkyl polyethylene glycol ether sulfates such as,
for example, sodium lauryl polyglycol ether sulfate.
Suitable cationic emulsifiers are quaternary ammonium
surfactants, for example alkyl trimethyl ammonium chlorides
and dialkyl dimethyl ammonium chlorides, for example cetyl
trimethyl ammonium chloride, stearyl trimethyl ammonium
chloride, distearyl dimethyl ammonium chloride, lauryl
dimethyl ammonium chloride, lauryl dimethyl benzyl ammonium
chloride, cetyl pyridinium chloride, and tallow alkyl tris-
(oligooxyalkyl)-ammonium phosphate.
The alkyl groups in the anionic and cationic surfac-
tants mentioned typically contain 8 to 22 and more
preferably 12 to 18 carbon atoms.
The molecules containing alkyl groups used as surfac-
tants may be those of a single chemical compound. However,it is generally preferred to use natural vegetable and
animal starting materials in the production of these
compounds, so that mixtures having different alkyl chain
lengths depending on the particular starting material used
are obtained.
A content of low molecular weight polyhydric alcohols
is crucial to the flowability or pumpability of the
pearlescent concentrates according to the invention.
Preferred low molecular weight polyhydric alcohols contain
2 to 6 carbon atoms and 2 to 6 hydroxyl groups. Alcohols
such as these are, for example, ethylene glycol, 1,2- and
1,3-propylene glycol, glycerol, di- and triethylene glycol,
erythritol, arabitol, adonitol, xylitol, sorbitol, manni-
tol, and galactitol. It is particularly preferred to use
compounds which are liquid at room temperature, most
preferably 1,2-propylene glycol and/or glycerol.
In the case of pearlescent concentrates containing
less than about 30% by weight pearlescing components, a
content of low molecular weis~ht polyhydric alcohols of
approximately 1~ by weight has proved to be sufficient in
many cases. This applies part:icularly when 1,2-propylene
glycol and/or glycerol is used as the alcohol component.
In addition to the components mentioned above, the
pearlescent concentrates according to the invention must
contain water. Commercially available preservatives may be
added in small quantities to protect the concentrates
against bacterial and fungal attack. In addition, the
concentrates may contain small quantities of buffers, for
example citric acid and/or sodium citrate, to stabilize and
adjust the pH to values in the range from 2 to 8.
The pearlescent concentrates according to the inven-
tion are usually and preferably pumpable at least over a
temperature range of 5 to 400 C and remain stable in
storage for prolonged periods, i.e. for at least about 3
months.
The pearlescent concentrates according to the inven-
tion are preferably prepared by initially heating com-
ponents (A), (B) and (C) together to a temperature ap-
proximately 1 to 30 C above the melting point. In most
cases, this will be a temperature in the range from about
60 to 90 C. Water heated to substantially the same
temperature is then added to this mixture. Where an ionic
water-soluble surfactant is used as the emulsifier, it may
be preferred to dissolve it in the aqueous phase and to
introduce it together with the water into the mixture. The
aqueous phase may also contain any buffer substances
desired in dissolved form. The dispersion formed is then
cooled with continuous stirring to room temperature, i.e.
to around 25C. In most cases, the viscosity of the
2~8
pearlescent concentrate is so low that there is no need to
use special stirring units, such as homogenizers or other
high-speed mixers. Any temperature-sensitive preservatives
should be added only after coo]ing to temperatures below
40 C and pre~erably only just be~ore the end of the
cooling period at a temperature of the order of 30 C.
The pearlescent concentrates according to the inven-
tion are suitable for the production of opaque-to-
translucent and pearlescent, liquid aqueous compositions of
wa~er-soluble surfactants. They may be incorporated, for
example, into liquid detergents, such as dish washing
detergents, liquid light-duty detergents and liquid soaps,
but are preferably incorporated in liquid personal hygiene
and body-care compositions, such as for example shampoos,
liquid hand and body soaps, shower bath compositions, bath
additives (foam baths), hair rinses, and hair dyes.
To produce pearlescence, the pearlescent concentrates
according to the invention are generally added to clear
aqueous compositions at 0 to 40 C in a quantity of 1 to
10 % by weight and more preferably in a quantity of 1.5 to
5 % by weight of the composition and are dispersed therein
with stirring. A dense and metallically lustrous to
slightly lustrous and extremely dense pearlescence can be
obtained, depending on the composition and the
concentration used.
The following Examples are intended to illustrate the
invention without limiting it in any way.
Examples
Free-flowing pearlescent concentrates having the
compositions shown in Table 1 were prepared. The
percentages by weight shown in Table 1 are for the active
ingredients, even when solutions of the active ingredients
were actually used to make the compositions shown, as
indicated in the explanations given in footnotes for the
ingredients identified in the main part of the Table by
O ~ a
S L~ V,RS ~ o
oD 3 u~ o 1~: 0 ~
V a V ,~ ~ V x
C ~ ~ N ~/ I ~= a,a -- v
a ~ ~ I O ~ ~ , a
~1 ~ u~ 0 ~
~ O O ~ O , "~ ~ I v ~ ~--V e O
. . ~ ~ ~ ~ o ~ V_ ~ a~ ~
E- ~1 1~1 ~ I ~1 ,.~ ~ I u~ Ll~ ~ ~ V C ~ ~ j V
o ~ ~ e N V V I V
o ~ ", ~ ~ a ~ ~ ~ O ~ o
a ~3 ' 8
12
trade mark names.
The quantities of components A, B, and C specified in
Table 1 were heated to a temperature of 75'~. Water heated
to 75 D C was added to this melt:~ The dispersion was then
cooled with continuous stirrin~ to 25C, the preservative
being added at a temp~ra-ture of 30C.
Comparison Example composition mixtures C9, C10, and
Cll were also prepared. Except 3`or the absence of component
C, each comparison mixture Cx had the same composition as
the corresponding composition x. The viscosities of some
of the pearlescent concentrates according to the Examples
and the ~omparison Examples were measured with a Brookfield
RVF Viscosimeter, spindle 5, at 10 revolutions per minute,
at the particular temperature at which the mixture had been
stored. The storage temperatures and measured viscosity
values (in millipascal seconds) are shown in Table 2. The
results show a definite reduction in viscosity from the
addition of alcohol.
Application Examples
(See footnotes after last example.
Al) Shampoo containinq anionic surfactants
Component % by weight
Fatty alcohol (C1-14) polyglycol
(2 E0) ether sul~ate, sodium salt,
about 30% in water (CTFA name:
sodium laureth sulfate) 40.0
N-coconut acylamidopropyl dimethyl
glycine, 30% in water (CTFA name:
cocamidopropyl betaine) 10.0
Cetiol HE7 2.0
Pearlescent concentrate Example 9 3.0
Sodium chloride 0.8
Water balance0
Table ~: Viscosity Values
Mixture No. Temperature, Storagetime, Viscosity,
C_ days _ mPa.s
2 10 1 14400
2 25 1 6000
2 40 1 14000
7 10 :l 14000
7 25 :L 5600
7 40 :L 8000
9 10 1~ 14000
C~ 10 14 22000
9 25 1 6000
C9 25 1 11200
9 25 7 5200
C9 25 7 12000
9 25 14 5200
C9 25 14 12000
9 40 14 14000
. C9 40 14 20000
14 16000
C10 10 14 22000
1 6000
C10 25 1 11200
7 6000
C10 25 7 12000
14 6400
C10 25 14 12000
14 13600
C10 40 14 20000
2~
A2) Foam bath containing anionic surfactants
Component % by weight
Fatty alcohol (C12 ,4) sulfate,
magnesium salt, about 30% in
water (CTFA name: Magnesium lauryl
sulfate) 40.0
N-coconut acylamidopropyl dimethyl
glycine, 30% in water (CTFA name:
cocamidopropyl betaine)lO.O
Sulfosuccinic acid monolauryl
polyglycol (3 EO) ester, 40% in
water (CTFA name: disodium laureth
sulfosuccinate) 4.5
Cetiol~ RE7 2.0
Pearlescent concentrate Example 7 3.0
Sodium chloride 0.3
Water balance
20 A3) Hair treatment containing cationic surfactants
Component % by weiqht
Quaternium0 528 2.0
Cetiol~ HE7 0.5
Viscontran0 HEC 30000 PR950.0
Pearlescent concentrate Example 2 5.0
Citric acid 0.2
Water balance
Notes for the Application Examples
7 Polyol fatty acid ester (CTFA name: PEG-7-Glyceryl
Cocoate) (HENKEL)
8 Tris-(oligooxyethyl)-alkyl ammonium phosphate, 50% in
water (HENKEL)
9 Hydroxyethyl cellulose, 2% in water (AQUALON)
