Note: Descriptions are shown in the official language in which they were submitted.
~ 9~
TOILET SOAP BAR COMPOSITION
WITH ALKYL POLYGLYCOSIDE SURFACTANT
Field o~
This invention relates to a toilet soap bar composition
and, especially a complexion soap product. In particular, the
invention relates to a soap or soap/synthetic detergent
composition in bar form which is hard and machinable with
reduced wet-cracking and which provides improved lather, skin
feel, and skin moisturization properties.
Background of the Invention
Soaps made from mixtures of animal fats and vegetable
oils have been made and available for many years. Today, on the
American market, most of the personal or toilet soap bars or
cakes are made from a mixture of tallow and coconut oil or from
the fatty acids obtained from such oils. Such products have been
accepted by consumers but it is recognized that the consumer will
respond positively to improvements ln certain properties of such
soaps. Furthermore, from the point of view of the manufacturer,
improvements in physical properties leading to reduced defects,
such as cracking or splitting during the manufacturing process,
such as machining, molding, shaping, and the like, would be
highly desirable. For the consumer, in particular, improvements
in wet-cracking resistance, foaming power, rinsing ease,
lathering properties, skin feel, skin moisturization, and
mildness are especially important characteristics. Furthermore,
for many types of consumers and for specific applications, the
~04~91
transparency or tranlucency characteristics of a soap bar are
also highly desirable.
Representative of some of the more recent patent art
relating to soap bar products, mention can be made of ~.SO Patent
4,923,627 to David Joshi, 4,767,560 to Gregorio Gervasio,
4,265,778 to Gerard Sonenstein, all assigned to Colgate-
Palmolive, the assignee of the subject application; and U.S.
Patent 4,678,593 to Ridley, and ~PA 0,311,343 to Dawson, both
assigned to Proctor & Gamble.
It has also been known to include alkyl polyglycoside
surfactants in detergent compositions. For instance, U.S.
Patents 4,536,318 and 4,599,188, both to Ramon Llenado, disclose
foaming compositions containing alkyl polysaccharide surfactant
l and co-surfactant mixture. These patents state that the foaming
I compositions may be used in soap bars in addition to other types
of products. U.S. Patent 4,536,319 to Payne relates to a
homogeneous granular detergent composition containing an alkyl
polysaccharide with detergent co-surfactant, wa~er-soluble
l neutral or alkaline salt and water with optional detergent
I builders.
¦ In applicants' commonly assigr.ed copending application
¦Serial No. 07/369,538, filed June 21, 1989, a detergent laundry
¦bar containing a non-soap anionic surfactant mixture and from
¦about 2 to about 25~ of an alkyl polysaccharide nonionic
surfactant is described.
As far as the present inventors are aware, the
advantages of alkyl polyglycoside surfactants in soap bar
formulations were not recognized nor appreciated in the prior
art.
Z043g91
S~ y_~_the Inv ntion
Accordingly, the present invention provides a toilet
bar composition comprising a soap or soap/synthetic detergent
mixture incorporating a small amount of alkyl polyglycoside
nonionic surfactant to produce toilet bars that are hard but
machinable and which e~hibits reduced wet-cracking.
The present invention also provides such toilet bars
providing improved lather, skin feel, and skin moisturization
properties making it highly desirable for a complexion soap
product.
Still further, the present invention in a preferred
embodiment thereoE is in the form of a highly translucent soap
bar product.
The soap bar products of the present invention also
provide improved lime soap dispersion and improved foaming
characteristics.
Detail ~
F~e~ e~ n~ n~
As used herein, the term "toilet bar" includes both
conventional soap bar compositions, superfatted soap bar
compositions and also mixed soap/synthetic anionic detergent bar
compositions. Furthermore, the term "bar" includes both
conventional bar or cake forms which may have generally
rectangular or oval or circular cross-sections, as well as
tablets, sticks, and the like.
The compositions generally contain from about 45~ to
~about ~5~, more preferably from about 55~ to about 88% of soap,
i.e. soluble alkali metal salt of a C8 to C24, preferably Clo to
¦C~o fa ty acid and from 0 to about 45~, preferably from about 0
,
: , . : ' - :
~ 3~
to about 35% by weight of a non-soap synthetic anio-lic
surfactant. In highly preferred embodiments of the invention,
free fatty acids of fats or oils of the same general carbon
content as the fatty acid component of the soap may be
incorporated in the soap composition. Such superfatted soaps or
superfatted soap/synthetic anionic detergent compositions can
provide soap bars of improved mildness wherein the "added" fats
and/or oils and/or fatty acids can be added to the compositions
as such or can result from a portion of the fatty components and
oils used to make the soap being intentionally not saponified.
Generally, only small amounts of from about 0.5 to 203,
preferably from about l to 10%, especially from 2 to 8% of the
free fatty acid, fat or oil, will provide the desired effect.
Fatty acid soaps suitable for use herein can be
obtained from natural sources, such as, for instance, plant or
animal esters (e.g. palm oil, coconut oil, babassu oil, soy bean
oil, castor oil, tallow, whale or fish oils, grease, lard and
mixtures thereof). The fatty acid soaps can also be
synthetically prepared (e.g. by the oxidation of petroleum, or by
the hydrogenation of carbon monoxide by the Fischer-Tropsch
process). Resin acids, such as those present in tall oil, may
be used. Naphthenic acids are also suitable.
Sodium and potassium soaps can be made by direct
saponification of the fats and oils or by the neutralization of
the free fatty acids which are prepared in a separate
manufacturing process. Particularly useful in the present
invention are the sodium and potassium salts of mixtures of fatty
acids derived from coconut oil and tallow, i.e. sodium and
potassium tallow and coconut soaps, and especially the sodium
tallow and coconut soaps. For example, 60/40, 75/25, or 85/15
blends of tallow/coco soaps are especially useful. More
generally, blends of tallow/coco soaps at ratios of from 10/90 to
90/10 can be used with advantage.
Generally, tallow fatty acids can be derived from
various animal sources and generally comprise Erom about 1 to
about ~% myristic acid, about 21 to 32~ palmitic acid, about 14
to 31~ stearic acid, and 0 to 4% palmitoleic acid, about 36 to
50~ oleic acid, and about 0 to 5% linoleic acid. Coconut oil
refers to fatty acid mixtures having an approximate carbon chain
length distribution of: ~% Cg, 7~ Clo, 48% C12~ 17% Cl~ 8~ C16
2% C18, 7% oleic, and 2 ~ linoleic acids. Other sources having
similar carbon chain lengths, such as palm kernel oil and babassu
kernel oil are considered to Eall within the term coconut oil.
The fatty acid soap may also be formed from the
topped, distilled coco fatty acid from which the lower carbon
chain length acids have been totally or substantially removed,
such as disclosed in U.S. Patent 4,767,560, the disclosure of
which is incorporated herein in its entirety, by r~ference
thereto.
The compositions herein generally take the form of a
toilet bar wherein the soap is at least partially in beta-phase
form. For instance, in preferred embodiments, the soap is at
least about 20~, more preferably at least about 50%, and
especially at least about 70% in the beta-phase form.
When the soap bar cOmpOSition is comprised of a mixture
of fatty acid soap and non-soap synthetic anionic surfactant, the
anionic surfactant may be any of those conventionally included in
toilet bar products. Examples of such non-soap anionic
surfactants include the salts of higher fatty alcohol sulfates
1 wherein the higher fatty alcohol is generally of from about 10 to
.
~' '~ .,''~"'.
~ 3~
18 carbon atoms and which may be ethoxylated with from about 0 to
10 moles ethylene oxide, preferably 0 to 5 moles ethylene oxide,
such as 2 or 3 moles ethylene oxide per mole of Eatty alcohol.
Other useful anionic surfactants include the sulfated and
sulfonated detergents, such as the hiyher fatty acid
monoglyceride sulfates of from 10 to 18 carbon atoms in the fatty
acid moieties, the paraffin sulfonates, olefin sulfonates, and
branched and linear alky] benzene sulfonates of from about 10 to
18 carbon atoms in the lipophilic groups thereof. Of these, it
is generally preferred to incorporate those anionic surfactants
which are most biodegradable. These anionic surfactants are
normally employed as their water-soluble salts and preferably as
the sodium salts, although the cation portion may also be one or
more of potassium, ammonium, magnesium, and calcium or an organic
cation, such as mono-, di- or triethanolamine. The sodium salts
will normally constitute more than 50~, preferably more than 75%,
and most preferably all or substantially all of the cation of
both the fatty acid soap and the synthetic anionic detergent
surfactants.
A further essential component of the toilet bar
composition is an alkyl polysaccharide nonionic surfactant.
Incorporation of the alkyl polysaccharide, especially alkyl
polyglucoside, nonionic surfactant in the soap bar composition
provides a product with improved hardness, lather, skin feel, and
moisturization, as well as improved translucency of the product
bars and better lime dispersion and overall cleaning properties.
Glycoside surfactants suitable for use in the practice
of the present invention include those of formula:
RO~RlO~y(Z)y (A)
` ~3~
wherein R is a monovalent organic radical (e.g. a monovalent
saturated aliphatic, unsaturated aliphatic or aromatic radical
such as alkyl, hydroxyalkyl, alkenylt hydroxyalkenyl, aryl,
alkylaryl, hydroxyalkylaryl, arylalkyl, alkenylaryl, arylalkenyl,
etc.) containing from about 6 to about 30 (preferably from about
8 to about 18 more preferably from about 10 or 12 to about 16)
carbon atoms; O is an oxygen atom; ~1 is a divalent hydrocarbon
radical containing from 2 to 4 carbon atoms, such as ethylene,
propylene or butylene (most preferably the unit (RlO)y represents
repeating units of ethylene oxide, propylene oxide and/or random
or block combinations thereof); y is a number having an average
value of from O to about 12; Z represents a moiety derived from a
reducing saccharide containing 5 or 6 carbon atoms tmost
preferably a glucose unit); and x is a number having an average
value of from 1 to about 10 (preferably from 1 to about 5, more
preferably from 1 to about 3, and most preferably from about 1.2
to about 2). Generally, the lower values of x (corresponding to
degree of polymerization, DP) of from about 1.2 to 1.4 provide
somewhat better skin feel while higher P values, of say 1.35 to
1.7 often provide better cleaning and foaming and are also
somewhat harder but less translucent.
Glycoside surfactants of the sort mentioned above, and
various preferred subgenera thereof, are fully discussed, for
example, in U.S. Patents 4,483,779 to Llenado, et al. (issued
November 20, 1984) and 4,668,422 to Malik, et al. (issued March
26, 1987) the discussions and descriptions of which are hereby
incorporated herein by reference.
Glycoside surfactants suitable for use herein also
include those of the Formula A above in which one or more of the
~ormally ree ( e. ~ e cted hydro~y~ s o~ the eeccharide
. ;~3~
moiety, Z, have been alkoxylated (preferably, ethoxylated or
propoxylated) so as to attach one or more pendant alkoxy or poly-
(alkoxy) groups in place thereof. In such event, the amount of
alkylene oxide (e.g. ethylene oxide, propylene oxide, etc.)
employed will typically range from about 1 to about 20
(preferably from about 3 to about 10) moles thereof per mole of
saccharide moiety within the Formula A glycoside material.
In glycosides of the Formula A above, the RO(RlO)y
group is generally bonded or attached to a number 1 carbon atom
of the saccharide moiety, Z. Accordingly, the free hydroxyls
available for alkoxylation are typically those in the number 2,
3, 4 and 6 positions in 6-carbon atom saccharides and those in
the number 2, 3 and 4 positions in 5-carbon atom saccharide
species. Typically, the number 2 position hydroxyls in 5-carbon
saccharides, and the number 2 and 6 position hydroxyls in 6-
carbon saccharides, are substantially more reactive or
susceptible to alkoxylation than those in the number 3 and 4
positions. Accordingly, alkoxylation will usually occur in the
former locations in preference to the latter.
Glycoside surfactants especially preferred for use
herein include those of the Formula A above wherein R is an alkyl
group containing from about 12 to about 14 or 16 carbon atoms; y
is zero Z is derived from glucose; and x has an average value of
from 1 to about 3, especially from 1 or 1.2 to about 1.7 or 2.
The amount of unreacted alcohol (free fatty alcohol
ontent) will generally be less than about 2%, e.gr 2.0%, 1.5~,
1.0~, 0.5%, by weight, based on the total glycoside and unreacted
alcohol.
The benefits of the glycoside surfactants employed in
the compositions hereof become noticeable when used in an amount
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ranging from about 1.5 to about 2.3 wt%, preferably from about
1.8 to 2.0 wt~ based on the total composition. ~lowever, even
greater benefits are often observed when the glycoside surfactant
is used in amounts as high as about 20~ by weight of the
composition, especially up to about 12 or 15~, such as 6~, ~%,
10%, etc. Above about 20~ the cost of the product tends to be
too high.
The amount of moisture present in the soap bar
compositions is not particularly critical and may be selected
depending upon the final desired properties of the product as is
well known to those skilled in the art. Generally, amounts of
water ranging from about lO to about 26%, more preferably from
about 15 to 24~, by weight of the composition, will be present.
In the range of moisture of from about 17 to 22%, the products
tend to be more highly translucent to nearly transparent.
However, this range may vary depending on the content of free
fats, fatty acids or oils in the composition which tend to make
the soap bar product less translucent, i.e. let less light pass
through the bar.
In addition to the essential and preferred components
described above, the toilet bar soap composition~ of the present
invention may contain a wide variety of optional materials.
These optional materials include, for example, skin conditioning
components, processing aids, anti-bacterial agents and
sanitizers, dyes, perfumes, pearlescent agents, coloring agents
and the like.
Materials to facilitate the preparation of the instant
toilet bars can also be present. Thus, glycerine, for example,
can be added to the crutcher or amalgamator in order to
facilitate processing. Glycerine, if present, generally
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comprises from about 0.2~ to about 10~ by weight of the inished
bar. Additionally, emulsifiers such as polyglycerol esters te.g.
polyglycerol monostearate), propylene glycol esters and other
chemically stable nonionic materials may be added to the bars to
help solubilize various components, particularly skin
conditioning agents, such as sorbitan esters. Alkali metal
citrates are also valuable herein as plasticizers.
Conventional anti-bacterial agents and sanitizers may
be present. Typical anti-bacterial sanitizers include, for
example, 3,4-di- and 3',4',5-tribromosalicyl-anilides, 4,4'-
dichloro-3-(trifluoromethyl)carbanalide; 3,4,4'-trichloro-
carbanalide and mixtures of these materials. If present, anti-
bacterial agents and sanitizers generally comprise from about
0.5% to about 4% by weight of the finished bar.
Various emollients and skin conditioning agents may
also be present, for example, sorbitan esters, such as those
described in U.S. 3,988,255, lanolin, cold cream, mineral oil,
isopropyl myristate, and similar materials. ~hen present, such
emollients and skin conditioning agents generally comprise from
about 0.5~ to about 5~ by weight of the bar.
The toilet bars may also contain an electrolyte.
Suitable electrolytes include, for example, sodium chloride,
potassium chloride, potassium carbonate, dipotassium monohydrogen
rthophosphate, tetrasodium pyrophosphate, tetrapotassium
yrophosphate, sodium tripolyphosphate, potassium
tripolyphosphate, trisodium orthophosphate, tripotassium
orthophosphate, and sodium and/or potassium formates, citrates,
acetates, and tartrates, and mixtures of the above. Sodium
chloride is especially preferred. The electrolyte level, ~hen
present, is genera]ly from about 0.2~ to about 4.5~ by weight of
the composition,
Acidic materials can be added to the bar to control
free alkalinity. A suitable example is citric acid added at a
S level of about 0.1% to about 3~.
Another desirable ingredient oE the composition, for
aesthetic purposes, is a pearlescent material, such as mica,
titanium-dioxide coated mica, natural fish silver or heavy metal
salts, such as bismuth oxychloride.
The toilet bar soap compositions may also contain any
of the conventional perEumes~ dyes, and coloring agents generally
used in commercially-marketed bars to improve the characteristics
of such products. When present, such perfumes, dyes, and
coloring agents comprise from about 0.2% to about 5% by weight o~
the bar.
The compositions of the present invention may be
prepared in conventional manner, either from neat kettle soap or
from saponified touch-hardened fatty acid blends. In a typical
process, neat kettle soap (i.e. after saponification) and
commercially available alkyl polyglucoside surfactant (present
as, for example, a 50% aqueous solution) are blended together to
provide a composition containing about 70% soap/glycoside mixture
and about 30% moisture at a temperature of about 160F (71C) to
190F (88C). This mixture is passed to a heat exchanger at a
temperature of, for example, 320F (160C) and then is dried,
e.g. by vacuum or spray-drying, to the desired moisture level,
such as 10 to 20 or 25~. The dried soap mixture is then
mechanically worked at elevated temperature, for example, in an
amalgamato-r or over mi]ling rolls until the temperature is raised
to the range of from about 86F (30C) to abo~t 122F (50C),
'': ' ' . ' . :
~ 3991.
preferably from about 95F (35C) to 113F ~45C), e.g. about
104F (40C). I'hereafter, the soap mass is plodded into bar
form. The alkyl polysaccharide anionic surfactant may be, as
described abovel added to the formulation in its liquid form, or
it may be added in its more concentrated powder form, both forms
being commercially available.
The invention will now be described by the following
non-limitative examples. All parts, percents, and ratios are on
a weight basis, unless otherwise specified.
Example 1
Soap bar compositions according to the invention are
~repared as described above in which sodium tallow~coconut
(75/25) kettle soap is mixed with the alkyl polyglucoside (50
aqueous solution) shown below and the mixture is dried in a
Mazzoni spray dryer, the dried soap mixture is admixed with
perfume and dye components in an amalgamator, then milled at
about 40~C to optimize beta-phase soap formation, and finally
plodded into bar form to yield a soap bar containing 1.8~ alkyl
polyglucoside and 20~ moisture. For comparison, a similar
composition, but without any added alkyl polyglucoside (APG)
surfactant is also prepared.
Each of the resulting soap bar products are tested for
translucency, hardness, lather ranking and skin feel ranking.
1 ~
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The results are shown in the following table:
Run No. 1 Run No. 2 Control
APG 3501) APG 5002) (no APG)
Translucency 7.1 . 7.7 5.4
(EV)
Hardness 5.5 6.2 5.6
(mm)(Penetrometer
Test)
Lather 2 1 3
Ranking
Skin Fee 2 1 3
Ranking
.. . .. .
1) Cg/Clo/Cll = 20/40/40, avg. = 10.2, D.P. = 1.8
2) cl2/cl3 = 45/55, avg.=12.55, D.P. = 1.4
From the above, it can be seen that the compositions of
the present invention with as little as 1.8~ o~ the alkyl
polyglycoside nonionic surfactant provide increased
translucency, hardness, and better lather ranking and skin feel
ranking as compared to tlle control without any APG.
Example 2
This example illustrates production oE a superfatted
high APG soap bar composition according to the invention prepared
by blending preformed soap chips with powdery APG at a 91/8
mixing ratio.
The soap chips are formed from a 60/40 tallow/coco
kettle soap as follows:
Part 1 (Pre-blend) P
50/50 coco/stearic fatty acid blend 92.6
di-tert. butyl-para-cresol 0.4
anhydrous lanolin-odorless 7.0
Tot~l
. : :
Part 2~ L P r ~ 3E~
Table salt 6.4
Tap water 93.6
To tal100.0
Part 3
60/40 tallow/coco kettle soap 87.04
Part 1 (pre-blend) 6.15
Part 2 (salt water) 6.81
Total100.00
The part 3 mixture is dried to a moisture level of
about 10~0% ~approximately 23.2% moisture loss or 76.8~ yield).
To 91 parts o~ the resulting dried soap chips 8 parts oE APG 625
(C12/C14/C16 = 68/26/6, glucoside unit content - 1.5 DP, on
average), 0.1 part color and 0.9 part perfume, are added and
formulated into bar form in the same manner as described in
Example 1.
When the soap bar from this composition is subjected to
a wet cracking test by submersing the soap bar in water for
several hours and hanging the bar in the air to dry overnight no
cracks form. In contrast, when the same composition but without
the APG 625 is formed into soap bars by the same procedure,
numerous wet cracks of varying degrees of severity (on a scale of
1 to 5) are observed.
If in the above composition the coco/stearic acid blend
is replaced by an equivalent amount o~ a 50/S0 pal~ kernel
il/stearic acid blend, similar results are obtained.
Similarly, the 60/40 tallow/coco kettle soap may be
replaced by a 60/40 tallow/palm kernel oil kettle soap to achieve
substantially the same results.
1~1
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20'1~991
Similar results are also achieved if the amount of
moisture remaining in the soap bar is increased to lS to 20~ or
more.
