U.S. patent application number 12/539770 was filed with the patent office on 2011-02-17 for concentrated liquid soap formulations having readily pumpable viscosity.
This patent application is currently assigned to CONOPCO, INC., d/b/a UNILEVER, CONOPCO, INC., d/b/a UNILEVER. Invention is credited to Badreddine AHTCHI-ALI, Kevin HERMANSON, Florencio V. RATUISTE, Martin Swanson VETHAMUTHU.
Application Number | 20110039745 12/539770 |
Document ID | / |
Family ID | 43531941 |
Filed Date | 2011-02-17 |
United States Patent
Application |
20110039745 |
Kind Code |
A1 |
HERMANSON; Kevin ; et
al. |
February 17, 2011 |
CONCENTRATED LIQUID SOAP FORMULATIONS HAVING READILY PUMPABLE
VISCOSITY
Abstract
The present invention provides concentrated soap compositions
formulated in such a manner that, quite unpredictably, despite high
concentration of soap, they have viscosity which allows them to be
pumped from, for example, consumer packaging (e.g., bottles) and/or
transit or storage points during manufacture (e.g., pipes, storage
tanks, etc.).
Inventors: |
HERMANSON; Kevin; (Hamden,
CT) ; RATUISTE; Florencio V.; (Union, NJ) ;
VETHAMUTHU; Martin Swanson; (Southbury, CT) ;
AHTCHI-ALI; Badreddine; (Newtown, CT) |
Correspondence
Address: |
UNILEVER PATENT GROUP
800 SYLVAN AVENUE, AG West S. Wing
ENGLEWOOD CLIFFS
NJ
07632-3100
US
|
Assignee: |
CONOPCO, INC., d/b/a
UNILEVER
Englewood Cliffs
NJ
|
Family ID: |
43531941 |
Appl. No.: |
12/539770 |
Filed: |
August 12, 2009 |
Current U.S.
Class: |
510/159 ;
510/437 |
Current CPC
Class: |
A61K 8/463 20130101;
C11D 17/08 20130101; A61Q 19/10 20130101; C11D 10/04 20130101; C11D
9/267 20130101; C11D 3/2079 20130101; C11D 9/007 20130101; A61K
8/44 20130101; A61K 8/361 20130101 |
Class at
Publication: |
510/159 ;
510/437 |
International
Class: |
C11D 9/26 20060101
C11D009/26; A61K 8/36 20060101 A61K008/36 |
Claims
1. Concentrated soap composition comprising: (a) >50% by wt.
fatty acid soap; (b) free fatty acid at a concentration such that
soap to free fatty acid ratio on weight to weight basis is 2:1 to
20:1; (c) 0% to 30% by wt. non-soap synthetic surfactant; (d) 10%
to 40% solvent, where solvent includes combination of water, and
co-solvents other than water; wherein both soap and fatty acid
chain comprise a mixture of saturated and unsaturated chain
lengths; wherein soap and fatty acid comprise a mixture of long
(>C.sub.14 to C.sub.30) and short (.ltoreq.C.sub.14) chain
length, and short chain length chains comprise .gtoreq.50% of
mixture; and wherein said concentrated soap has viscosity allowing
it to be pumped from a container, wherein said pumpable viscosity
is defined by a dispensing force less than 300 N at steady state,
measured at 23.degree. C.
2. A composition according to claim 1 wherein ratio of soap to
fatty acid is 2.5:1 to 12:1.
3. A composition according to claim 1 wherein 50% to 100% of the
soap counterion are potassium counterions.
4. A composition according to claim 1 wherein >75% of soap
and/or fatty acids are saturated.
5. A composition according to claim 1 wherein >60% of soap
and/or fatty acids are .ltoreq.C.sub.14.
6. A composition according to claim 5 wherein >75% of soap and
fatty acid chains are .ltoreq.C.sub.14.
7. A composition according to claim 1 further comprising 1% to 15%
synthetic surfactant.
8. A composition according to claim 7 wherein synthetic comprises
at least one anionic.
9. A packaged personal care/personal wash product comprising: (a) a
container or bottle comprising a label or advertising intended for
sale or distribution to consumers; and (b) concentrated soap
composition according to claim 1.
10. A process for preparing the concentrated soap composition
according to claim 1 which process comprises: (a) reacting a soap
stock comprising oils, triglycerides, fatty acids and mixtures
thereof with a neutralizing solution to obtain composition where
ratio of soap to free fatty acid is between 2:1 to 20:1 on weight
basis, and subsequently or simultaneously combining soap stock and
neutralizing solution with 0% to 30% synthetic surfactant, and 10%
to 40% solvent; or (b) mixing already neutralized soap and free
fatty acid to form mixture having ratio of soap to free fatty acid
of 2:1 to 20:1 on a weight basis; and subsequently combining with
0% to 30% by wt. synthetic non-soap detergent and 10% to 40% by wt.
solvent.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to soap formulations,
particularly liquid soap formulations, with high concentration of
soap. Using formulation and processing criticalities, applicants
have found a way in which these high concentration soaps can be
readily dispensed (have correct rheology) from, for example, tube,
bottle, pump or such dispensers.
BACKGROUND OF THE INVENTION
[0002] The rapid growth in human population and the changing
economic environment are placing ever increasing demand on world
water supplies. Because of water scarcity over much of the world,
for example, it is important to prepare liquid cleansing products
with as little water as possible. Low water cleansing products
offer an environmentally friendly cleansing route which lowers
strain on water supply. In the current invention, applicants have
provided precisely such low water (high soap) cleansers, which are
formed by replacing water with a dense liquid crystalline
surfactant phase. Quite unpredictably, these formulations are
formulated in a manner that, despite being concentrated products,
they can be readily dispensed by hand by the end user consumer.
[0003] High concentration soap formulations (i.e., formulations in
which fatty acid soap comprises >50%, preferably >50 to 80%,
more preferably 55 to 80% by wt. and, more preferably, 60 to 80% by
wt. of the formulation) typically have a solid or thick gel-like
rheology at room temperature. Because of this rheology, such
formulations are difficult to pump while in production and are
extremely difficult to use as personal cleansers dispensed from a
tube, bottle, pump or tottle.
[0004] While not wishing to be bound by theory, it is believed that
the thick rheology associated with high concentration liquid soap
composition is the result of the large amount of hexagonal and
solid surfactant phases present in the soap at high
concentration.
[0005] Unpredictably, applicants have found that if the ratio of
free fatty acid to soap (e.g., percent of neutralized soap) in
these concentrated soap/free fatty acid liquid soap formulations
(e.g., percent of soap neutralized) is maintained within defined
critical ranges; and, further, that if (1) concentrations or
percentage of soap with specifically defined preferred counterion;
(2) preferred percentage of saturation versus unsaturation of fatty
acid soap and free fatty acid chain lengths; (3) chain length
distribution of fatty acid soap and free fatty acid; (4) amount
synthetic surfactant (if any); and (5) concentration of solvent
(e.g., water, alkylene, glycol) are all selected and maintained
within critically defined parameters, then the amount or degree of
hexagonal and solid surfactant phase formation can be controlled
such that a highly concentrated liquid soap can be made which has a
pumpable viscosity (as specifically defined below). If these
parameters are not carefully maintained, on the other hand, the
viscosities quickly rise and formulations become difficult or
impossible to pump (again, outside of ranges defined by the
invention).
[0006] It should be noted that when we speak of "pumpable" or
"flowable" viscosity, this is a rheological property which can be
critical at many different stages in the manufacturing or
distribution process. Thus, it can be critical to keep pumpable
viscosity for example in the mixing stage of a manufacturing tank;
in filing and/or discharging fluid to manufacturing or storage
tanks; and/or in filling product into final packaging.
[0007] One great benefit of this invention is that the liquids made
by this specific selected blend of neutralized soap and
unneutralized fatty acids can be made in what would normally be
used as a bar production facility. Unexpectedly, and unpredictably,
applicants have found that the blends of fatty acid and soap used
in the bar production process can be used to produce concentrated
liquids as well (i.e., assuming the criticalities noted above are
maintained).
[0008] In addition, concentrated liquids having the correct
rheology and which are produced by the process of the invention can
be sold as a "concentrated liquid product" whereby the consumer can
be instructed to dilute the product at home (resulting in both
environmentally friendly packaging and tremendous cost savings); or
the concentrated liquid can be transported to a different place and
later diluted as part of the production process. In the latter
case, this allows the producer to produce more cheaply than when
normally making liquid soap/syndet composition (e.g., reduction in
transportation costs due to use of concentrates rather than
transporting heavy water-containing product). As indicated above,
tremendous efficiencies between bars and liquids are also found
because any excess capacity from bar manufacturing sites may be
used to make liquids.
[0009] The key, as noted above, is to obtain a final concentrated
liquid formulation in which variables such as (1) ratio of
neutralized soap to unneutralized fatty acid; (2) counterion; (3)
chain length of fatty acid soaps and free fatty acids; (4)
synthetic surfactant, if any; (5) and solvent are critically
controlled to obtain viscosities below a defined level and defined
by a dispensing force needed to dispense the product. This goal in
turn may be achieved either by controlled neutralization of fatty
acid; or by using mixtures of free fatty acid and fully neutralized
soap such that resulting formulation falls within defined
formulation parameters where this defined pumpable or squeezable
rheology is obtained.
[0010] It should be noted that there is interplay between variables
and these variables can be adjusted as long as the overall goal of
maintaining a low dispensing force is maintained. Thus, for
example, the degree of neutralization or exact percent of long
chain or low chain length soap/fatty acids may be closer to the
upper or lower ranges in which case adjustments can be made to
solvent level or level or synthetic surfactant.
[0011] In one embodiment of the invention, for example, there may
be present only soap/fatty acid and neutralizing solvent such as
potassium hydroxide (e.g., no viscosity reducing co-solvent such as
dipropylene glycol, propylene glycol). Such embodiment would
minimize the level of long chain length, fatty acid/soaps (which
tend to increase viscosity) and certainly ensure their level is
within defined ranges. In another embodiment of the invention, the
concentrate could tolerate higher levels of longer chain length
soaps/fatty acids but would also have some required level of
synthetic surfactant and/or viscosity reducing co-solvent to ensure
the dispensing force is within defined parameters. This second
embodiment is specifically claimed in a co-pending application
filed on the same date by applicants.
[0012] As far as applicants are aware, the art does not disclose
the specific parameters required to obtain concentrated soap
liquids of the invention, or a method of obtaining these liquids
such that the liquid soap has a pumpable, readily pourable
rheology, i.e., measured by dispensing force which is defined in
the protocol. Specifically, there is nothing in the art which would
teach or suggest the person of ordinary skill either that this is a
problem or how to begin to solve such problem.
[0013] GB 699 189 is an example of references disclosing
compositions made by neutralization of fatty acids with caustic
potash. Although the fatty acids of the resulting liquid cleansers
are neutralized, there is no indication of partial neutralization,
or of the resulting critical, specific ratios, of fatty acid to
soap. Further, there is no disclosure that such specific ratios, or
of any of the other criticalities of saturation, chain length, etc.
which are required to obtain the pumpable (e.g., squeezable),
concentrated soap liquids of the invention having defined
viscosity. This reference is typical of many older references from
before 1960.
[0014] More recent references include those which use soap at much
lower levels. Examples of such references include WO 95/13355, WO
05/18760 and WO 97/27279.
[0015] U.S. Pat. Nos. 5,952,286 and 6,077,816, both to Puvvada,
relate to the use of free fatty acid to form lamellar structures in
liquid cleansing products having 9 to 50% surfactant concentration.
Overall concentrations of surfactant in these references are lower
than the overall concentration of surfactant (e.g., soap plus fatty
acid) of the compositions of the invention and the concentrations
of water are higher than those of our invention. Further, there is
no recognition of use of specific ratios of fatty acid to soap or
of other criticalities noted.
[0016] U.S. Pat. No. 7,351,749 to Divone et al. relates to the
process for manufacture of personal care products using
concentrated water phase. The reference is not related to
concentrated soaps or to specific ratios of fatty acid to the
soap.
[0017] U.S. Pat. Nos. 5,296,158 and 5,149,574 to MacGilp disclose
compositions with potassium soap and free fatty acid.
Concentrations of water are 55-90% compared to top solvent
concentration (water/solvent) of 40% in our invention. U.S. Pat.
No. 4,310,433 to Stiros discloses mixtures of neutralized and
unneutralized fatty acids where fatty acids are mixtures of
saturated and unsaturated. The compositions again comprise 50-95%
water, levels of solvent well above those of our invention. Various
other references to MacGilp, (U.S. Pat. No. 5,158,699; U.S. Pat.
No. 5,296,157) also have much higher levels of water/overall
solvent.
[0018] U.S. Pat. No. 5,308,526 to Dias discloses composition with
K.sup.+ soap and free fatty acids. They comprise 35-70% water. The
compositions have much less than 50% soap.
[0019] WO 2004/080431 to Unilever relates to method of preparing
personal care compositions from concentrate. There appears to be no
recognition of a concentrate having critically specific levels of
neutralization (ratio of fatty acid to soap) or other noted
variables which provide a rheology allowing concentrated soap
formulations to be pumped or readily dispensed. The reference also
fails to disclose a separate concentrated liquid (e.g., as separate
stand alone product) which can be sold to consumers for possible
dilution at home.
[0020] GB 2005297 (Unilever) discloses liquid soap compositions
comprising potassium soap, 0-20% glycerol, 5-20% alkylene glycol,
0-10% free fatty acids and 20-50% water. Levels of soap are well
below the 50% level of the subject invention.
[0021] GB1427341 (Unilever) discloses potassium soap crystals in
aqueous glycerin solution comprising 12-40% glycerol and 20-50%
H.sub.2O. Again, levels of soap are well below those of
compositions of the invention.
[0022] JP 2006/282,591 and JP 2002/226,359 relate to face wash
creams. Neither appears to disclose criticality of fatty acid to
soap in combination with other criticalities to yield a high
concentrated, pumpable liquid soap.
[0023] None of the reference discloses high soap (>50% by wt.)
compositions having a critical ratio of fatty acid to soap or
combination with criticalities of saturation, chain length, solvent
etc. to produce pumpable, concentrated liquid soaps. There also is
no reference relating to sale of such specific compositions as
stand alone concentrates with instructions for home dilution.
BRIEF DESCRIPTION OF THE INVENTION
[0024] Unexpectedly, and quite unpredictably, applicants have now
found that, if the ratio of unneutralized fatty acid to neutralized
fatty acid soap (in a concentrate solution where soap comprises
>50%, preferably .gtoreq.60% of concentrate) is kept within a
specific critical window, in combination with other critical
parameters noted below, the resulting concentrate will have a
rheology that allows it to be pumped and/or dispensed. Such
pumpability is defined as a formulation which can be dispensed by a
force of less than 300N at steady state when measured at
temperature of 23.degree. C. Measurement can also be made at
12.degree. C. although, for purposes of the measurement definition,
the temperature is preferably 23.degree. C. Measurement details are
defined in more detail in the protocol below. It should be noted
that, although it is probably not possible for humans, unassisted
by technology, to generate a force of 300N, tubes of varying
orifice size can be designed which allow for dispensing of fluid at
values closer to the upper ranges of Newton force required by the
protocol.
[0025] In one embodiment, the invention relates to a concentrated
soap formulation, which, optionally, can be moved (as an
intermediate for preparation of final product at same or other
site); or which is sold as a "final" product (e.g., to be diluted
by consumer elsewhere). In a second embodiment, the invention
relates to a packaged product containing said concentrated
solution. Finally, in a third embodiment, the invention relates to
a process for preparing concentrated liquids which process
comprises either (a) neutralizing soap stock comprising oils,
triglycerides and fatty acids to provide soap and obtain required
parameters (e.g., ratio of fatty acid to neutralized soap); or (b)
mixing already neutralized soap and free fatty acid to form mixture
having desired criteria.
[0026] In one compositional embodiment of the invention (subject of
the present application), the present application comprises
concentrated soap formulation and does not necessarily comprise
synthetic and/or co-solvent (other than water and/or neutralizing
hydroxide solution). This embodiment comprises: [0027] (a) >50%
by wt. fatty acid soap, preferably >50 to 80%, more preferably
55 to 80%, even more preferably 60 to 80% fatty acid soap; [0028]
(b) free fatty acid at concentration such that soap to free fatty
acid ratio is about 2:1 to 20:1 on a weight basis, preferably 2.5:1
to 12:1. Typically ratio of 2.5:1 to 12:1 reflects a neutralization
(if soap is formed in-situ versus combining fatty acid and already
pre-formed soap) of about 60 to about 90% neutralization; [0029]
(c) 0% to 30%, preferably 1% to 20% by wt., more preferably 1% to
15% by wt. (even more preferably 10% by wt. or below) of synthetic
non-soap surfactant (e.g., used to help reduce viscosity to defined
"pumpable" goal), wherein said synthetic, if used, comprises at
least one anionic surfactant and, more preferably, comprises a
combination of anionic and amphoteric surfactant wherein anionic
comprise more than half of such mixture; although synthetic, if
present, helps serve as a viscosity modifier, if short chain soap
and fatty acid definitely comprise .gtoreq.50% of total, then the
synthetic and/or co-solvent (other than water) are not absolutely
required; and [0030] (d) 10-40% by wt. solvent wherein solvent
includes combination of water and/or co-solvents preferably
selected from alkylene glycols (e.g., propylene glycol, dipropylene
glycol, mixtures, etc.); as noted, where short chain soap and fatty
acid comprise .gtoreq.50%, then co-solvent (other than water) is
not required so, preferably, the 10-40% solvent comprises only
water;
[0031] wherein the soap counterion is preferably potassium and/or
amine based counterion (e.g., sodium counterions can be used, but
tend to increase viscosity);
[0032] wherein soap and fatty acid chains may be a mix of saturated
and unsaturated, but are preferably >75%, more preferably 80% to
100%, even more preferably 96% to 100% and even more preferably
100% saturated;
[0033] wherein soap and fatty acid comprise a mixture of long
(>C.sub.14-C.sub.30) and short (.ltoreq.C.sub.14) chain and
preferably comprise .gtoreq.50%; more preferably >60%, even more
preferably >75% short chain (as indicated above, where short
chain is definitely .gtoreq.50%, synthetic and/or co-solvents are
not required, although of course small amounts, e.g., less than 5%
by wt., preferably less than 3%, more preferably less than 1% of
one or both may be used);
[0034] and wherein the "pumpable" viscosity achieved by maintaining
ratio of soap to fatty acid (e.g., through neutralization) and
maintaining other noted variable within defined parameters is
defined as a dispensing force of less than 300 Newtons (N) measured
at steady state and at a temperature of 23.degree. or 12.degree. C.
as defined in the protocol.
[0035] In a second compositional embodiment of the invention
(subject of co-pending application filed same date), the invention
comprises concentrated soap formulation where short chain fatty
acid and soap (.ltoreq.C.sub.14) is less than 50% total fatty acids
and soap. Long chain (>C.sub.14) may comprise >50% to 80%, or
possibly even more. In this embodiment, viscosity modifier such as
some synthetic and/or co-solvent is required to ensure pumpable
viscosity as defined in the protocol.
[0036] More specifically, this embodiment comprises: [0037] (a)
>50% by wt., preferably >50% to 80%, more preferably 55% to
80% and even more preferably 60% to 80% fatty acid soap; [0038] (b)
free fatty acid in the same ratio as defined for the first
compositional embodiment; [0039] (c) 0% to 30%, preferably 1% to
20%, more preferably 1% to 15%, even more preferably 5% to 15%
synthetic, preferably comprising at least one anionic; and [0040]
(d) 10% to 40% solvent which preferably will comprise 1% to 15%
solvent other than water;
[0041] wherein at least 1% to 10%, preferably at least 2 to 10% by
wt. of total (c) and/or solvent other than water in (d) (i.e.,
there must be present at least 1% synthetic surfactant and/or
solvent other than water) must be present and where such other
solvent is preferably an alkylene glycol;
[0042] wherein counterion and level of saturation are as defined
for first compositional embodiment;
[0043] wherein long chain soap (>C.sub.14) comprises >50% to
80% of fatty acid/soap chain length; and
[0044] wherein pumpable viscosity combined is defined as a
dispensing force of less than 300 Newton (N) at steady state as
defined in protocol.
[0045] In another embodiment, the invention provides a packaged
personal care/personal wash product which comprises: [0046] (a) a
container or bottle comprising a label or advertising intended for
sale or distribution to consumers; and [0047] (b) concentrated soap
formulation as defined in the compositional embodiments of the
invention.
[0048] In this embodiment, the container or a package in which the
container is held may contain instructions to the consumer as to
how and when to dilute the concentrated product for ultimate
use.
[0049] In yet another embodiment, the invention comprises a process
for preparing a concentrated soap liquid according to either
compositional embodiment which process comprises: [0050] (a)
reacting a soap stock comprising oils, triglycerides, fatty acids
and mixtures thereof with a neutralizing solution, preferably a
caustic solution such as KOH, to obtain composition where ratio of
soap to free fatty acid is between 2:1 to 20:1, preferably 2.5:1 to
12:1 on weight basis (generally corresponding to level of 60-90%
neutralization), and subsequently or simultaneously combining soap
stock and neutralizing solution with 0% to 20% synthetic
surfactant, and 10% to 40% solvent; or [0051] (b) mixing already
neutralized soap and free fatty acid to form mixture having ratios
and/or neutralization levels noted above and subsequently combining
with same levels of synthetic surfactant, and solvent also
noted.
[0052] These and other aspects, features and advantages will become
apparent to those of ordinary skill in the art from a reading of
the following detailed description and the appended claims. For the
avoidance of doubt, any feature of one aspect of the present
invention may be utilized in any other aspect of the invention. It
is noted that the examples given in the description below are
intended to clarify the invention and are not intended to limit the
invention to those examples per se. Other than in the experimental
example, or where otherwise indicated, all numbers expressing
quantities of ingredients or reaction conditions used herein are to
be understood as modified in all instances by the term "about".
Similarly, all percentages are weight/weight percentages of the
total composition unless otherwise indicated. Numerical ranges
expressed in the format "from x to y" are understood to include x
and y. When for a specific feature multiple preferred ranges are
described in the format "from x to y" it is understood that all
ranges combining the different endpoints are also contemplated.
Further in specifying the range of concentration, it is noted that
any particular upper concentration can be associated with any
particular lower concentration. Where the term "comprising" is used
in the specification or claims, it is not intended to exclude any
terms, steps or features not specifically recited. For the
avoidance of doubt, the word "comprising" is intended to mean
"including" but not necessarily "consisting of" or "composed of".
In other words, the listed steps, options, or alternatives need not
be exhaustive. All temperatures are in degrees Celsius (.degree.
C.) unless specific otherwise. All measurements are in SI units
unless specified otherwise. All documents cited are--in relevant
part--incorporated herein by reference.
DETAILED DESCRIPTION OF THE INVENTION
[0053] The present invention relates to liquid soap formulations
with highly concentrated amounts of soap, yet which maintain a
viscosity/rheology suitable for these concentrated soaps to be
pumped from a reservoir, container or bottle, as defined by
formulations which can be dispensed by a dispensing force less than
300N at steady state measured at 23.degree. C. and defined using
protocol below. Unexpectedly, applicants have found that, only when
the ratio of neutralized soap to unneutralized free fatty acid is
maintained within strict, critically defined limits, and parameters
such as counterion, saturation, chain length of fatty acids and
soap; solvent and/or synthetic surfactant levels etc. are
controlled, only then is it possible to obtain such concentrated
soap formulations (i.e., >50% soap) which maintain the
characteristics of a suitable pumpable liquid (defined by a
dispensing force as noted).
[0054] In a compositional embodiment, the invention is directed to
the concentrated liquid formulations themselves. Those compositions
are defined by ratios of neutralized soap to fatty acid (which also
correspond to levels of neutralization) where the critical rheology
is obtained. The formulations can be obtained by controlled
neutralization and/or by mixing fatty acids and soap to fall within
the critically defined parameters. One aspect of the compositional
invention is directed to compositions where preferably .gtoreq.50%
of soap/fatty acid have chain length .ltoreq.C.sub.14 and wherein
use of synthetic surfactant and/or certain co-solvents is not
required, and a second aspect (claimed in co-pending application)
is directed to composition having >50% chain length >C.sub.14
and where a minimum level of synthetic and/or co-solvent (e.g.,
alkylene glycol) is required.
[0055] In a second embodiment, the invention is defined by a
packaged consumer product which comprises the packaged bottle or
container comprising the concentrated formulation of the first
compositional embodiment. Preferably, the label provides
instructions to consumers on how to add water to effectively use
the concentrates.
[0056] In a third embodiment, the invention comprises a process for
preparing these unique concentrated soap liquids which process
essentially comprises controlling the neutralization process and/or
reactants to ensure the final product has the criticality defined
ratios which will ensure the unpredictable pumpable rheology.
[0057] The invention is described in greater detail below.
[0058] The composition of the invention comprises as noted, >50%
by wt. fatty acid soap, preferably >50% to 80% by wt., more
preferably 55% to 80%, even more preferably 60 to 80% fatty acid
soap.
[0059] In addition, compositions of the invention comprise free
fatty acid and indeed, it is the ratio of free fatty acid to soap
which helps define (along with other variables discussed below) the
rheology which is required for "pumpability".
[0060] More specifically, the concentration of free fatty acid to
soap (obtained either by controlled neutralization or by simple
mixing) is such that ratio of soap to free fatty acid is about 2:1
to 20:1, preferably 2.5:1 to 12:1. This latter ratio typically
reflects a neutralization (if formed in-situ) of about 60 to 90%
neutralization.
[0061] Further the counterion on soap; the degree of saturation or
unsaturation; chain length distribution in soap and/or fatty acid,
and levels of synthetic and/or solvent can be critical in
determining final rheology (e.g., what dispensing force is required
for pumping or dispensing). As indicated, depending in particular
on chain length distribution, the levels of synthetic and/or
solvent can also be critical in obtaining the right feeling.
[0062] Although any salt counterion can be used, preferably the
counterion for the soap is potassium. Sodium counterions tend to
increase the viscosity and may raise the viscosity above that
required by the invention depending on interplay of other factors
(for example, use of sodium might require also greater use of
synthetic and/or co-solvent). Amine based counterions
(trialkanolamine, ammonium, etc.) may have similar effect as
potassium and can also be used. Other counterions which may be used
include calcium, magnesium and zinc. As indicated, preferably the
goal is to use counterions which have the least effect on viscosity
and which will allow, together with other factors, pumpability as
defined to be maintained.
[0063] In particular, as noted, it is preferred to use counterions
which are 50% to 100%, more preferably 80% to 100% and even 100%
potassium and/or amine (e.g., trialkanolamine). More preferably,
counterion can be >75%, preferably 80% to 100% potassium.
[0064] It is also preferred to use saturated fatty acid and soap
chains. Saturated chains generally have fewer color (e.g.,
browning) or odor problems and have generally good lather. Some
unsaturates may be used, however, in that they help keep the
product softer or pastier, for example. Typically, it is preferred
to use >75%, more preferably 80% to 100%, even more preferably
96% to 100% and even 100% saturated chains.
[0065] Fatty acids and soaps of chain length C.sub.14 or less are
also generally preferred. Typically, a product of chain length only
above C.sub.14 would have very thick rheology. As discussed above,
however, although having .gtoreq.50% short chain length
(.ltoreq.C.sub.14) is preferred (and is encompassed by first
compositional embodiment of the invention), a composition
comprising <50% C.sub.14 chain length, i.e., having >50% to
80%>C.sub.14 chain length may be used but, in such cases (as in
the second compositional embodiment), a minimum amount of synthetic
surfactant and/or co-solvent (other than water) are used.
Preferably, if solvent is used, it is an alkylene glycol solvent,
such as, for example, dipropylene glycol or propylene glycol. As
also noted above, use of synthetic and/or co-solvent as viscosity
modifiers may also be found if sodium (or other counterion which
may enhance viscosity too much) is used as soap counterion. The key
is to manipulate ratios, counterions, synthetic and/or solvent to
ensure the dispensing force of the resulting solution as per test
described in the protocol is less than 300 Newtons (N) at steady
state when measured at defined temperature.
[0066] Compositions of the invention should also comprise 0% to
30%, preferably 1% to 20%, more preferably 1% to 15%, even more
preferably 1% to 10% by wt. synthetic non-soap surfactant. Again,
in formulation with .gtoreq.50% chain length of .ltoreq.C.sub.14,
no synthetic may be needed whereas, if >50% is >C.sub.14,
some synthetic and/or co-solvent is required.
[0067] While syndet (synthetic detergent) is not required to
produce, for example, a soft paste at 23.degree. C., the syndet can
be used to reduce low temperature viscosity (as can co-solvent, as
noted below), for reasons noted.
[0068] Typically, synthetic surfactant, if present, will comprise
at least one anionic surfactant (e.g., alkyl sulfate or
isethionate). Preferably, the compositions will comprise a
combination of anionic synthetic and amphoteric surfactant (e.g.,
betaine), especially when anionic comprises 50% or greater of such
mixture of synthetics.
[0069] The concentrate compositions of the invention further
comprise 10% to 40% by wt. solvent. The solvent comprises water or
caustic neutralizing solution and may further comprise non-water
co-solvent, e.g., polypropylene glycol.
[0070] Generally, the greater the amount of co-solvent, the less
water required. It is also easy to keep viscosity within required
range as more co-solvent and less water is used.
[0071] Viscosity reducing co-solvents of the invention include
propylene glycol, dipropylene glycol, polypropylene glycol,
ethylene glycol, polyethylene glycol and many other such related
solvents as would be well known to those skilled in the art.
[0072] In one embodiment, glycerin can be used as co-solvent. While
glycerin does not enhance low temperature stability, low viscosity
product can be made with small amounts of glycerin. At levels above
about 10%, higher amounts of co-solvent and/or synthetic surfactant
might have to be used.
[0073] Finally, a suitable pumping viscosity is defined as a
product which requires a dispensing force of less than 300N,
measured as defined in protocol.
[0074] The concentrate formulations of the invention, in addition
to comprising soap/fatty acid, solvent and synthetic surfactant,
may also comprise various benefit agents and/or other ingredients
which can typically be used in flowable, liquid personal care
formulations.
[0075] Benefit agent may be any material that has potential to
provide an effect on, for example, the skin.
[0076] The benefit agent may be water insoluble material that can
protect, moisturize or condition the skin upon deposition from
compositions of invention. These may include silicon oils and gums,
fats and oils, waxes, hydrocarbons (e.g., petrolatum), higher fatty
acids and esters, vitamins, sunscreens. They may include any of the
agents, for example, mentioned at column 8, line 31 to column 9,
line 13 of U.S. Pat. No. 5,759,969, hereby incorporated by
reference into the subject application.
[0077] The benefit agent may also be a water soluble material such
as glycerin, polyols (e.g., saccharides), enzyme and .alpha.- or
.beta.-hydroxy acid either alone or entrapped in an oily benefit
agent.
[0078] The compositions may also comprise perfumes, sequestering
agents such as EDTA or EHDP in amounts 0.01 to 1%, preferably 0.01
to 0.05%; coloring agents, opacifiers and pearlizers such as zinc
stearate, magnesium stearate, TiO.sub.2, mica, EGMS (ethylene
glycol monostearate) or styrene/acrylate copolymers.
[0079] The compositions may further comprise antimicrobials such as
2-hydroxy 4,2'4'trichlorodiphenylether (DP300),
3,4,4'-trichlorocarbanilide, essential oils and preservatives such
as dimethyl hydantoin (Glydant XL 1000), parabens, sorbic acid,
etc.
[0080] The compositions may also comprise coconut acyl mono or
diethanol amides as suds boosters, and strongly ionizing salts such
as sodium chloride and sodium sulfate may also be used to
advantage.
[0081] Antioxidants such as, for example, butylated hydroxyl
toluene (BHT) may be used advantageously in amounts of about 0.01%
or higher if appropriate.
[0082] Cationic conditioner which may be used including Quatrisoft
LM-200 Polyquaternium-24, Merquat Plus 3330-Polyquaternium 39; and
Jaguar.RTM. type conditioners.
[0083] Composition may also include clays such as Bentonite.RTM.
claims as well as particulates such as abrasives, glitter, and
shimmer.
[0084] In a second embodiment of the invention, the invention
relates to a packaged personal care or personal wash product which
comprises a container or bottle which container or bottle comprises
a label (e.g., indicating product logo or insignia) and/or
advertising (e.g., print copy or other form of advertising) and
which is intended for sale or distribution. The product comprises
the soap formulation as set forth in the compositional embodiment
of the invention.
[0085] In a preferred embodiment, the package or container has
instructions which directs the consumer how and when to dilute the
concentrated soap for use at home or elsewhere.
[0086] This packaged product can be used, for example, to save on
cost of transporting a much heavier product to the point of sale
(e.g., market) by the producer of the product and further to save
cost (weight/energy, etc.) of the consumer to transport to their
point of use. Further, it provides an ecologically friendly product
which can be used as a source of advertising and good will.
[0087] In a third embodiment, the invention relates to a process
for making concentrated soap.
[0088] This can be done either by reacting soap stock and fatty
acid to neutralize and obtain ratios as required by the invention
(e.g., in situ) that meet required viscosity targets for obtaining
"pumpability"; and/or by mixing already prepared soap and fatty
acid to obtain same desired ratios. In either case, the fatty acid
and soap (preferred or not) are further reacted with optional
synthetic and with solvent to form final concentrates.
EXAMPLES
Protocol
Rheological Measurement Protocol
[0089] In the rheological measurement used to determine
pumpability, a tube which is 31.4 mm in diameter is used. This tube
is open on one end and sealed at the other end with an orifice
plate which has a hole that is 3 mm in diameter and 12 mm in
length. 150 ml of product is first loaded into the tube through the
open end. A piston is then inserted into the open end of the tube
and the product is pushed through the orifice at a flow rate of 0.5
ml/sec using an Instron universal testing machine. Using the
Instron the force required to achieve this flow rate at steady
state is measured. To account for frictional forces, a second run
is then conducted without any product in the tube at the same
piston velocity. The force required to push the piston without
product is then subtracted from the force required to push the
product through the orifice. This friction adjusted force is
defined as the product dispensing force. According to the subject
invention, products which are defined as "pumpable" require a force
of less than 300 N at steady state. Steady state is defined as the
longest measured interval over which the measured dispensing force
is approximately consistent. In order for the measurement interval
to be considered the steady state interval, more than 0.75 ml of
product must be dispensed during the interval. This Theological
measurement simulates flow from a tube and is a direct
determination of the amount of force required to dispense the
product from a tube. The measurements were conducted at two
temperatures, 23.degree. C. and 12.degree. C. although, for
purposes of keeping definition consistent, the measuring
temperature is preferably 23.degree. C. The temperature was held
constant using a temperature controlled jacket surrounding the
tube.
[0090] In short, pumpability is defined as requiring less than 300N
of force to extrude through an orifice which is 3 mm in diameter
and 12 mm in length as described above. Primarily, the test is to
be conducted at a temperature of 23.degree. C. (e.g., about room
temperature)
Sample Preparation
[0091] The examples were made by first heating the fatty acid blend
in a mixer to a temperature between 65-80.degree. C. Of the total
caustic required 75%-90% was added to the melted fatty acids while
mixing at low speed during a period of .gtoreq.15 minutes. The
mixing speed used was sufficient to thoroughly react the caustic.
Synthetic detergent (SLES, CAPB or sodium lauryl sarcosinate) and
co-solvent (dipropylene glycol, i.e., DPG or PPG-9) were then mixed
into the fatty acid soap blend. After the addition of synthetic
detergent and co-solvents, the remaining caustic was added and the
mixed well. The final product was then cooled to room
temperature.
Definitions:
TABLE-US-00001 [0092] SLES = sodium lauryl ether sulfate CAPB =
cocoamidopropyl betaine PPG = polypropylene glycol HT = hard
topped
EXAMPLES
[0093] Using the rheological protocol noted above, a commercial
soap bar was tested. The soap bar represents the low water soap
formulations which are in the prior art. These formulations have a
high viscosity and can not be dispensed from a tube. The force
which would be required for dispensing a soap bar according to the
applied rheological protocol is 5160 N. This force is well above
the critical range of the subject invention of 0-300 N.
[0094] For the raw materials used in the example formulations the
chain length distributions are given in the table below:
TABLE-US-00002 HT Coconut Lauric Myristic Palmitic Commercial Chain
Length Fatty Acid Acid Acid Acid Stearic Acid Short Chain 0 0 0 0 0
(<C8) (wt %) Capric C10 0 0 0 0 0 (+C8) (wt %) Lauric C12 55.1
100 0 0 0 (+C11) (wt %) Myristic C14 21.9 0 100 2 2 (+C13) (wt %)
Palmitic C16 11.4 0 0 92 45 (+C15) (wt %) Stearic C18 11.4 0 0 6 52
(+C17) (wt %) Long 0.2 0 0 0 0 Saturates >= C19 (wt %) Other 0 0
0 0 1
Examples 1-3 and Comparatives A & B
[0095] For a mixture of short chain potassium soaps, a critical
window of neutrality exists where the soap mixture has a low enough
viscosity (as defined in protocol) for dispensing from a tube. The
examples below (Example 1-3 and Comparatives A & B) show that
for neutralizations where the final soap:fatty acid ratio is
between 2:1 and 20:1, a low viscosity soap mixture is obtained at
room temperature. In all of the examples, more than 75% of the
fatty acid chains used have chain length less than or equal to
C.sub.14.
Examples 1-3 and Comparatives A & B
TABLE-US-00003 [0096] Ingredients by wt % Formulation Number Comp A
1 2 3 Comp B HT Coco Fatty Acid 53.6% 51.4% 0.0% 47.6% 45.9% Lauric
Fatty Acid 0.0% 0.0% 34.1% 0.0% 0.0% Myristic Fatty Acid 21.4%
20.5% 34.1% 19.0% 18.3% KOH (45 wt %) 25.0% 28.1% 31.8% 33.4% 35.8%
Soap:Fatty Acid 1.75 2.74 4.71 10.50 Infinite Solvent Concentration
17% 19% 22% 23% 25% Dispensing 412 232 53 38 1061 Force @
23.degree. C. Dispensing 1106 Force @ 12.degree. C. % of Fatty acid
and 16.4% 16.4% 0.0% 16.4% 16.4% soap with chain length >
C.sub.14 % of neutralization 60% 70% 80% 90% 100% of final
composition
[0097] As seen from examples above, when soap to fatty acid ratio
was in ranges of invention and percent of fatty acid and soap
having chain length .ltoreq.C.sub.14 is greater than or equal to
50% (Example 1-2), the dispensing force was clearly less than 300N
(defining pumpable viscosity). When outside such ratios
(Comparative A has ratio of 1.75 and comparative B has infinite
ratio), dispensing force is well above 300N. It is noted that these
compositions comprise no solvent other than water and no syndet and
that, measured at 12.degree. C., viscosity is not pumpable as
defined.
Example 4 and Comparative C
[0098] If more than 50% of the used fatty acid has a chain length
greater than C.sub.14, the soap mixture is too thick to be
dispensed from a tube, even when measured at 73.degree. C.
(Comparative C). However, with the addition of co-solvent and
synthetic surfactant (e.g., SLES and CAPB), the viscosity is within
a range which is suitable for tube dispensing (Example 4).
TABLE-US-00004 Ingredients by wt % Formulation Number Comp C 4 HT
Coco Fatty Acid 29.5% 0.0% Lauric Fatty Acid 0.0% 13.0% Myristic
Fatty Acid 9.5% 12.2% Palmitic Fatty Acid 7.5% 4.5% Stearic Fatty
Acid 22.1% 23.6% KOH (45 wt %) 31.5% 0.0% KOH (85 wt %) 0.0% 13.1%
SLES (70 wt %) 0.0% 9.6% CAPB (28 wt %) 0.0% 8.6% DPG 0.0% 9.0%
Water 0.0% 6.4% Soap:Fatty Acid 9.74 10.58 Dispensing Force @
23.degree. C. 383 38.8 % of Fatty acid and soap with 51.83% 51.30%
chain length % >C.sub.14 % of neutralization of final 89.38%
90.14% composition Solvent in final composition 21.88% 30.00%
[0099] As seen, therefore, even though both examples have >50%
of chain length greater than C.sub.14 (which make viscosity
higher), the interplay of solvent and synthetic surfactant brings
the defined dispensing force from well above 300 (383N) to well
below (38.8N).
Examples 5 and 6 and Comparative D
[0100] The viscosity of soap formulations are low enough for
dispensing from a tube at solvent concentrations between 10 and
40%. Comparative D has a solvent concentration below 10% and is not
dispensable from a tube. Examples 3, 5 and 6 have the same fatty
acid blend as Comparative Example D but have a solvent
concentration in the range of 10 to 40%. All of these formulations
have a dispensing force less than 300 N measured at 23.degree. C.
Comparative D has less than 10% solvent and much higher dispensing
force. Comparison of Examples 3 and 6 also shows that the addition
of the co-solvent DPG lowers the dispensing force to below 300N
measured at 12.degree. C. (from 1106N to 70N). This demonstrates
that co-solvent can be used to improve low temperature
dispensability.
TABLE-US-00005 Ingredients by wt % Formulation Number Comp D 5 6 HT
Coco Fatty Acid 56.5% 37.2% 43.4% Myristic Fatty Acid 22.5% 14.8%
17.3% KOH (45 wt %) 0.0% 26.1% 30.4% KOH (85 wt %) 21.0% 0.0% 0.0%
DPG 0.0% 0.0% 8.9% Water 0.0% 21.9% 0.0% Soap:Fatty Acid 10.49
10.50 10.50 Solvent Concentration 8.9% 40.0% 30.0% Dispensing Force
@ 23.degree. C. 19094 269 56.8 Dispensing Force @ 12.degree. C. 70
% of Fatty acid and soap with 16.45% 16.45% 16.45% chain length
>C.sub.14 % neutralization of final 89.97% 89.98% 89.98%
composition
Examples 7-9
[0101] Like co-solvents, synthetic surfactant can also be used to
reduce or maintain the dispensing force below 300 N, particularly
low temperature dispensing. Examples 7-9 are two formulations which
demonstrate the effect of synthetic surfactants on partially
neutralized soap formulations. When compared to Example 3, the
addition of synthetic surfactants reduces the dispensing force at
both 23.degree. C. and 12.degree. C.
TABLE-US-00006 Ingredients by wt % Formulation Number 7 8 9 HT Coco
Fatty Acid 37.8% 37.8% 37.8% Myristic Fatty Acid 15.1% 15.1% 15.1%
KOH (45 wt %) 26.5% 0.0% 0.0% KOH (85 wt %) 0.0% 14.0% 14.0% SLES
(70 wt %) 9.5% 9.5% 0.0% CAPB (28 wt %) 8.5% 8.5% 0.0% Sodium
Lauryl Sarcosinate (30 wt 0.0% 0.0% 30.1% %) DPG 0.0% 3.0% 3.0%
Water 2.6% 12.1% 0.0% Soap:Fatty Acid 10.50 10.49 10.49 Solvent
Concentration 30.0% 30.0% 30.0% Syndet Concentration 9.0% 9.0% 9.0%
Dispensing Force @ 23.degree. C. 51.5 11.2 6.7 Dispensing Force @
12.degree. C. 460 91 482 % of Fatty acid and soap with 16.45%
16.45% 16.45% chain length >C.sub.14 % of neutralization of
final 89.98% 89.97% 89.97% composition
* * * * *