U.S. patent application number 14/108591 was filed with the patent office on 2014-04-17 for process for surfactant taste and/or odor improvement.
This patent application is currently assigned to The Procter & Gamble Company. The applicant listed for this patent is The Procter & Gamble Company. Invention is credited to Brian David Clair, John Christian Haught, Marc Alan Hester, Steven Hamilton Hoke, II.
Application Number | 20140105833 14/108591 |
Document ID | / |
Family ID | 46650943 |
Filed Date | 2014-04-17 |
United States Patent
Application |
20140105833 |
Kind Code |
A1 |
Hoke, II; Steven Hamilton ;
et al. |
April 17, 2014 |
Process For Surfactant Taste And/Or Odor Improvement
Abstract
Processes for improving the taste of water-soluble surfactants
using liquid-liquid solvent extraction, said process comprising the
steps of: providing a water-soluble surfactant composition in need
of treatment wherein said water-soluble surfactant composition
comprises a water-soluble surfactant and one or more undesirable
non-polar materials; contacting said water-soluble surfactant
composition with an extraction solvent and water to form an
extraction mixture comprising an aqueous phase and a solvent phase;
and separating the aqueous phase from the solvent phase; wherein
the extraction solvent is selected from solvents having individual
Hansen solubility parameters of a dispersion force component
(.delta..sub.D) ranging from about 15 to about 17 (MPa).sup.0.5, a
polar component (.delta..sub.P) ranging from 0 to about 9
(MPa).sup.0.5 and a hydrogen bonding component (.delta..sub.H)
ranging from 0 to about 11 (MPa).sup.0.5. Treated water-soluble
surfactant compositions produced by such processes and oral care
compositions containing such treated water-soluble surfactant
compositions.
Inventors: |
Hoke, II; Steven Hamilton;
(West Chester, OH) ; Haught; John Christian; (West
Chester, OH) ; Hester; Marc Alan; (Cincinnati,
OH) ; Clair; Brian David; (Ft. Wright, KY) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
The Procter & Gamble Company |
Cincinnati |
OH |
US |
|
|
Assignee: |
The Procter & Gamble
Company
Cincinnati
OH
|
Family ID: |
46650943 |
Appl. No.: |
14/108591 |
Filed: |
December 17, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13564823 |
Aug 2, 2012 |
|
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14108591 |
|
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61514213 |
Aug 2, 2011 |
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Current U.S.
Class: |
424/57 ;
424/49 |
Current CPC
Class: |
A61Q 11/00 20130101;
A61K 8/55 20130101; A61K 2800/805 20130101; B01D 11/0492 20130101;
A61K 8/37 20130101 |
Class at
Publication: |
424/57 ;
424/49 |
International
Class: |
A61K 8/55 20060101
A61K008/55; A61Q 11/00 20060101 A61Q011/00 |
Claims
1. A treated water-soluble surfactant composition comprising from
about 10% to about 94% of water-soluble surfactant, from about 3%
to about 90% water, and less than about 1% of undesirable non-polar
materials, produced by a process for improving the taste of
water-soluble surfactants using liquid-liquid solvent extraction,
said process comprising the steps of: a) providing a water-soluble
surfactant composition in need of treatment wherein said
water-soluble surfactant composition comprises a water-soluble
surfactant and one or more undesirable non-polar materials; b)
contacting said water-soluble surfactant composition with an
extraction solvent and water to form an extraction mixture
comprising an aqueous phase and a solvent phase; and c) separating
the aqueous phase from the solvent phase; wherein the extraction
solvent is selected from solvents having individual Hansen
solubility parameters of a dispersion force component
(.delta..sub.D) ranging from about 15 to about 17 (MPa).sup.0.5, a
polar component (.delta..sub.P) ranging from 0 to about 9
(MPa).sup.0.5 and a hydrogen bonding component (.delta..sub.H)
ranging from 0 to about 11 (MPa).sup.0.5.
2. A treated water-soluble surfactant composition according to
claim 1, wherein the surfactant composition comprises less than
about 2% of undesirable non-polar materials.
3. A treated water-soluble surfactant composition according to
claim 1, wherein the water-soluble surfactant is at least about 20%
soluble in water.
4. A treated water-soluble surfactant composition according to
claim 1, wherein the water-soluble surfactant is selected from
anionic surfactants, zwitterionic surfactants, amphoteric
surfactants, and mixtures thereof and is at least about 30% soluble
in water.
5. A treated water-soluble surfactant composition according to
claim 4, wherein the water-soluble surfactant is selected from
alkyl phosphate surfactants, alkyl phosphate ethoxylated
surfactants, lauryl sulfate surfactants, betaine surfactants,
betaine ethoxylated surfactants, amine oxide surfactants, and
mixtures thereof.
6. A treated water-soluble surfactant composition according to
claim 1, wherein the surfactant is selected from cocoamidopropyl
betaines, alkyl ethoxylated phosphates, mono alkyl phosphates, and
mixtures thereof.
7. A treated water-soluble surfactant composition according to
claim 5, wherein the water-soluble surfactant is an alkyl
ethoxylated phosphate surfactant.
8. A treated water-soluble surfactant composition according to
claim 1, wherein the extraction solvent has individual Hansen
solubility parameters of a dispersion force component
(.delta..sub.D) ranging from about 13 to about 19 (MPa).sup.0.5, a
polar component (.delta..sub.P) ranging from about 2 to about 9
(MPa).sup.0.5 and a hydrogen bonding component (.delta..sub.H)
ranging from about 2 to about 11 (MPa).sup.0.5.
9. A treated water-soluble surfactant composition according to
claim 1, wherein the extraction solvent is selected from ethyl
acetate, water-saturated ethyl acetate, ethyl propionate, ethyl
butyrate, ethyl pentanoate, ethyl caproate, ethyl caprylate, ethyl
pelargonate methyl acetate, methyl propionate, methyl butyrate,
short chain esters, supercritical carbon dioxide, and mixtures
thereof.
10. A treated water-soluble surfactant composition according to
claim 9, wherein the extraction solvent is selected from food grade
ethyl esters.
11. A treated water-soluble surfactant composition according to
claim 10, wherein the extraction solvent is ethyl acetate.
12. A treated water-soluble surfactant composition according to
claim 1, wherein the extraction mixture comprises from about 10% to
about 90%, by weight of the mixture, of water; from about 5% to
about 60%, by weight of the mixture, of water-soluble surfactant;
less than 5%, by weight of the mixture, of undesirable non-polar
impurities; and from about 10% to about 90%, by weight of the
mixture, of solvent.
13. A treated water-soluble surfactant composition according to
claim 12, wherein the ratio of extraction solvent to water-soluble
surfactant in the extraction mixture is from about 1:10 to about
10:1.
14. A treated water-soluble surfactant composition according to
claim 1, wherein the step of separating the aqueous phase from the
solvent phase further comprises centrifuging the extraction
mixture.
15. A treated water-soluble surfactant composition according to
claim 1, wherein the process further comprises mixing the
extraction mixture for a period of from about 10 seconds to about
one minute with vigorous mixing and at ambient temperature before
allowing the mixture to settle into two phases and separating the
aqueous phase from the solvent phase.
16. A treated water-soluble surfactant composition according to
claim 1, wherein the process further comprises the step of heating
a solid impure surfactant material to its melting point before the
step of contacting with an extraction solvent and water.
17. A treated water-soluble surfactant composition according to
claim 1, wherein the process further comprises the step of removing
any residual solvent from the aqueous phase wherein the step of
removing any residual solvent from the aqueous phase includes the
use of an industrial method selected from vacuum stripping (with or
without heat), fractional distillation, wiped-film evaporator,
carbon filtration, or combinations thereof.
18. A treated water-soluble surfactant composition according to
claim 1, wherein the extraction mixture further comprises a phase
separation enhancer selected from salt, pH modifiers, and mixtures
thereof.
19. A treated water-soluble surfactant composition comprising from
about 10% to about 94% of water-soluble surfactant, from about 3%
to about 90% water, and less than about 1% of undesirable non-polar
materials, produced by a process for improving the taste of
water-soluble surfactants using liquid-liquid solvent extraction,
said process comprising the steps of: a) providing a water-soluble
surfactant composition comprising a surfactant selected from alkyl
phosphate surfactants, alkyl phosphate ethoxylated surfactants, and
mixtures thereof and one or more undesirable non-polar materials;
b) contacting said water-soluble surfactant composition with ethyl
acetate and water to form an extraction mixture comprising an
aqueous phase and a solvent phase; and c) separating the aqueous
phase from the solvent phase.
20. An oral care composition having improved consumer acceptance,
wherein the oral care composition comprises a water-soluble
surfactant composition according to claim 1.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to water-soluble surfactant
compositions containing undesirable non-polar materials and
liquid-liquid extraction processes for improving the taste and/or
odor of such compositions.
BACKGROUND OF THE INVENTION
[0002] Traditionally, much effort has been expended to improve the
taste, color, odor or clarity of oral care compositions such as
dentifrice (toothpaste), mouth rinse, and the like. Because of the
nature of such compositions, the taste of a product may often be of
more importance to consumers than the actual or perceived efficacy.
Since many efficacious oral care components have undesirable taste,
color, odor or clarity, efforts to improve these characteristics
are common in the art. For taste, one way to remedy an undesirable
product taste is to add additional components, such as flavors,
that will improve the overall taste experience for the consumer.
However, such remedies can be expensive and it may be difficult to
entirely mask an undesirable taste. Improvement of color or clarity
through dyes or other additives has similar issues.
[0003] Water-soluble surfactants such as alkyl phosphate
surfactants are commercially available for use in a variety of
consumer products, including oral care compositions. These anionic
surface active organophosphate agents have a strong affinity for
enamel surface and have sufficient surface binding propensity to
desorb pellicle proteins and remain affixed to enamel surfaces.
Such properties make these materials desirable for incorporation in
oral care compositions such as toothpaste. However, these materials
have not been widely commercialized in oral care compositions,
despite their desirable properties. One reason for this lack of
commercialization may be the negative taste and/or odor profile
commonly associated with commercially available alkyl phosphate
materials. Although taste may not be a consideration in other
consumer product industries, such as laundry, shampoo or personal
cleansing, it is an important consideration in oral care.
Similarly, while any undesirable odor associated with materials
used in laundry, shampoo or personal cleansing products can
typically be remedied by the addition of perfume, perfume levels
must be kept to a minimum in oral care compositions for consumer
acceptance and could produce further unpleasant tastes when
utilized.
[0004] Purification of surfactant materials through
steam-stripping, vacuum-stripping, and/or carbon filtration
processes is also generally known to beneficially remove impurities
to increase efficacy, minimize undesirable side reactions, and the
like. However, these purification processes have been found to be
insufficient to remedy the unpleasant tastes and/or odors
associated with commercially available water-soluble surfactant
materials.
[0005] Liquid/liquid extractions (LLE) are generally known in the
art as useful for separating components of a mixture, wherein the
constituents have differing polarities which can be separated when
mixed within two immiscible solvents that form a liquid bilayer
after mixing. For example, LLEs are useful for purifying or
cleaning samples which contain impurities of significantly
differing polarity than the majority or desirable component(s) of
the sample. This can be achieved by mixing a sample with a solvent
that is immiscible with the primary liquid in which the sample is
dissolved.
[0006] LLE has been utilized in chemical processing to reduce or
eliminate undesirable by-products or contaminants. For instance,
PCT Patent Application WO 2008005550 to Hoke, et al (Procter &
Gamble) discloses a water washing procedure to remove polar sulfur
impurities from peppermint oils to avoid malodor formation when
formulated in dentifrice containing stannous ions. In U.S. Pat. No.
4,352,829 to Noyes, et al (Procter & Gamble) an ethyl acetate
extraction of caffeine from coffee was shown to be an effective
decaffeination process.
[0007] However, there is still an interest in finding ways to
improve the overall taste and/or odor of water-soluble surfactants
such as those used in an oral care composition that are
efficacious, cost-effective, and desirable to consumers.
SUMMARY OF THE INVENTION
[0008] It has now surprisingly been found that liquid-liquid
extraction processes utilizing solvents such as ethyl acetate may
be useful to significantly reduce the occurrence of non-polar
materials found in water-soluble surfactant raw materials and
thereby improve the surfactant's odor and/or taste profile.
[0009] Without being limited by theory, it is now believed that
water-soluble surfactants previously generally thought to have bad
taste and/or odor profiles stemming from the pure material itself
are in fact surprisingly acceptable in terms of taste and odor. It
has been surprisingly found that non-polar materials commonly
present in commercially available water-soluble surfactant
compositions such as residual alcohols, alcohol ethoxylates,
aldehydes, ethers, ketones, alkylamines, and esters, may be linked
to the majority of the negative taste and odor profiles previously
associated with the surfactants themselves. Since some of these
materials are often used in flavors and perfumes, it was further
surprising that a new process for more efficiently extracting these
materials from the underlying surfactant would produce such
results. For example, dodecanol and dodecanal are commonly taught
to be safe and useful for inclusion in flavors and perfumes, yet it
has been surprisingly found that if included in water-soluble
surfactant compositions at significantly higher levels, these
materials present an unpleasant taste such as bitter, soapy and the
like.
[0010] Further without being limited by theory, liquid-liquid
extraction using the appropriate solvent is more effective than
previously known techniques to purify such surfactants, allowing
for the incorporation of such surfactants into oral care products
with minimal negative taste and/or odor attributes.
[0011] The present invention is therefore directed to a process or
method of improving the taste and/or odor of water-soluble
surfactants using liquid-liquid solvent extraction.
[0012] In one embodiment, the present invention relates to a
process or method for improving the taste of water-soluble
surfactants using liquid-liquid solvent extraction, said process
comprising the steps of: providing a water-soluble surfactant
composition in need of treatment wherein said water-soluble
surfactant composition comprises a water-soluble surfactant and one
or more undesirable non-polar materials; contacting said
water-soluble surfactant composition with an extraction solvent and
water to form an extraction mixture comprising an aqueous phase and
a solvent phase; and separating the aqueous phase from the solvent
phase; wherein the extraction solvent is selected from solvents
having individual Hansen solubility parameters of a dispersion
force component (.delta..sub.D) ranging from about 15 to about 17
(MPa).sup.0.5, a polar component (.delta..sub.P) ranging from 0 to
about 9 (MPa).sup.0.5 and a hydrogen bonding component
(.delta..sub.H) ranging from 0 to about 11 (MPa).sup.0.5.
[0013] In another embodiment, the present invention relates a
process or method for improving the taste of water-soluble
surfactants using liquid-liquid solvent extraction, said process
comprising the steps of: providing a water-soluble surfactant
composition comprising a surfactant selected from alkyl phosphate
surfactants, alkyl phosphate ethoxylated surfactants, and mixtures
thereof and one or more undesirable non-polar materials; contacting
said water-soluble surfactant composition with ethyl acetate and
water to form an extraction mixture comprising an aqueous phase and
a solvent phase; and separating the aqueous phase from the solvent
phase.
[0014] In another embodiment, the present invention relates to such
processes or methods wherein the water-soluble surfactant is at
least about 20% soluble in water.
[0015] In another embodiment, the present invention relates to the
above processes or methods wherein the water-soluble surfactant is
selected from anionic surfactants, zwitterionic surfactants,
amphoteric surfactants, and mixtures thereof and is at least about
30% soluble in water.
[0016] In another embodiment, the present invention relates to the
above processes or methods wherein the water-soluble surfactant is
selected from alkyl phosphate surfactants, alkyl phosphate
ethoxylated surfactants, lauryl sulfate surfactants, betaine
surfactants, betaine ethoxylated surfactants, amine oxide
surfactants, and mixtures thereof.
[0017] In another embodiment, the present invention relates to the
above processes or methods wherein the surfactant is selected from
cocoamidopropyl betaines, lauryl betaines,
capryl/capramidobetaines, sodium lauryl sulfates, mono alkyl
phosphates, amine oxides, and mixtures thereof.
[0018] In another embodiment, the present invention relates to the
above processes or methods wherein the water-soluble surfactant is
selected from cocoamidopropyl betaine surfactants, mono alkyl
ethoxylated phosphate surfactants, mono alkyl phosphate
surfactants, and mixtures thereof. In one embodiment, the
water-soluble surfactant is an alkyl ethoxylated phosphate
surfactant.
[0019] In another embodiment, the present invention relates to the
above processes or methods wherein the extraction solvent has
individual Hansen solubility parameters of a dispersion force
component (.delta..sub.D) ranging from about 13 to about 19
(MPa).sup.0.5, a polar component (.delta..sub.P) ranging from about
2 to about 9 (MPa).sup.0.5 and a hydrogen bonding component
(.delta..sub.H) ranging from about 2 to about 11 (MPa).sup.0.5.
[0020] In another embodiment, the present invention relates to the
above processes or methods wherein the extraction solvent is
selected from ethyl acetate, water-saturated ethyl acetate, ethyl
propionate, ethyl butyrate, ethyl pentanoate, ethyl caproate, ethyl
caprylate, ethyl pelargonate methyl acetate, methyl propionate,
methyl butyrate, short chain esters and mixtures thereof.
[0021] In another embodiment, the present invention relates to the
above processes or methods wherein the extraction solvent is
selected from food grade ethyl esters.
[0022] In another embodiment, the present invention relates to the
above processes or methods wherein the extraction solvent is ethyl
acetate.
[0023] In another embodiment, the present invention relates to the
above processes or methods wherein the extraction mixture comprises
from about 10% to about 90%, by weight of the mixture, of water;
from about 5% to about 60%, by weight of the mixture, of
water-soluble surfactant; less than 5%, by weight of the mixture,
of undesirable non-polar impurities; and from about 10% to about
90%, by weight of the mixture, of solvent.
[0024] In another embodiment, the present invention relates to the
above processes or methods wherein the ratio of extraction solvent
to water-soluble surfactant in the extraction mixture is from about
1:10 to about 10:1.
[0025] In another embodiment, the present invention relates to the
above processes or methods wherein the ratio of extraction solvent
to water-soluble surfactant in the extraction mixture is from about
1:2 to about 2:1.
[0026] In another embodiment, the present invention relates to the
above processes or methods wherein the step of separating the
aqueous phase from the solvent phase further comprises centrifuging
the extraction mixture.
[0027] In another embodiment, the present invention relates to the
above processes or methods wherein the process further comprises
mixing extraction mixture is mixed for a period of from about 10
seconds to about one minute with vigorous mixing and at ambient
temperature before allowing the mixture to settle into two phases
and separating the aqueous phase from the solvent phase.
[0028] In another embodiment, the present invention relates to the
above processes or methods wherein the process further comprises
the step of heating a solid impure surfactant material to its
melting point before the step of contacting with an extraction
solvent and water.
[0029] In another embodiment, the present invention relates to the
above processes or methods wherein the process further comprises
the step of removing any residual solvent from the aqueous
phase.
[0030] In another embodiment, the present invention relates to the
above processes or methods wherein the step of removing any
residual solvent from the aqueous phase includes the use of an
industrial method selected from vacuum stripping (with or without
heat), wiped-film evaporation fractional distillation, carbon
filtration, or combinations thereof.
[0031] In another embodiment, the present invention relates to the
above processes or methods wherein the extraction mixture further
comprises a phase separation enhancer selected from salt, pH
modifiers, and mixtures thereof.
[0032] In another embodiment, the present invention relates to a
treated water-soluble surfactant composition resulting from the
above processes or methods comprising from about 10% to about 70%
of water-soluble surfactant, from about 30% to about 90% water, and
less than about 1% of undesirable non-polar materials, produced by
the processes set forth above.
[0033] In another embodiment, the present invention relates to such
surfactants wherein the surfactant comprises less than about 0.5%
of undesirable non-polar materials.
[0034] In another embodiment, the present invention relates to such
surfactants wherein the surfactant comprises less than about 1% of
total alcohols.
[0035] In another embodiment, the present invention relates to a
treated mono alkyl phosphate surfactant produced by the processes
or methods set forth above.
[0036] In another embodiment, the present invention relates to a
treated cocoamidopropyl betaine surfactant produced by the
processes or methods set forth above.
[0037] In another embodiment, the present invention relates to an
oral care composition having improved consumer acceptance, wherein
the oral care composition comprises a water-soluble surfactant
composition treated by the processes set forth above
[0038] In another embodiment, the present invention relates to use
of liquid-liquid solvent extraction for improving the taste of
water-soluble surfactants wherein ethyl acetate is used as an
extraction solvent.
BRIEF DESCRIPTION OF THE DRAWINGS
[0039] FIG. 1 is a flow diagram of a process for purifying
surfactants using liquid-liquid solvent extraction in accordance to
one embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0040] The present invention relates to a process for improving the
taste of water-soluble surfactants using liquid-liquid solvent
extraction. The process includes the steps of: [0041] a) providing
a water-soluble surfactant composition in need of treatment wherein
said water-soluble surfactant composition comprises a water-soluble
surfactant and one or more undesirable non-polar materials; [0042]
b) contacting said water-soluble surfactant composition with an
extraction solvent and water to form an extraction mixture
comprising an aqueous phase and a solvent phase; and [0043] c)
separating the aqueous phase from the solvent phase; wherein the
extraction solvent is selected from solvents having individual
Hansen solubility parameters of a dispersion force component
(.delta..sub.D) ranging from about 15 to about 17 (MPa).sup.0.5, a
polar component (.delta..sub.P) ranging from 0 to about 9
(MPa).sup.0.5 and a hydrogen bonding component (.delta..sub.H)
ranging from 0 to about 11 (MPa).sup.0.5. The present invention
further relates to improved water-soluble surfactant compositions
produced by the processes herein and oral care compositions
containing such improved surfactants.
[0044] These elements will be discussed in more detail below.
Process for Improving the Taste of Water-Soluble Surfactants
[0045] As used herein, liquid-liquid extraction, also known as
solvent extraction and partitioning, refers to a standard method to
separate compounds based upon their relative solubilities in two
different immiscible liquids, here, water and a solvent. It is an
extraction of a substance from one liquid phase into another liquid
phase. The "liquid-liquid" phrase refers to the two different
immiscible liquids that are mixed as part of the extraction
procedure. As used herein, immiscible refers to the ability of the
two liquids to form at least two layers when mixed together. The
layers may be formed after mixing the two liquids and allowing them
to sit at rest for a variable period of time, or in some instances,
the mixture of the two liquids may be centrifuged and/or cooled
below room temperature in order to assist the separation.
[0046] Typically in liquid-liquid extraction, one of the phases
will be aqueous, and the other a non-polar lipophilic organic
solvent such as ether, MTBE, dichloromethane, chloroform, or ethyl
acetate. Most organic solvents float on top of an aqueous phase,
though important exceptions are most halogenated solvents.
[0047] Equipment typically used in a laboratory setting for
liquid-liquid extraction includes a separatory funnel. In a small
scale plant or lab, batch-wise liquid-liquid extraction methods may
be used, such as by mixing the two liquids and then introducing
them into a large scale separatory funnel. In larger scale plant
production, a multistage continuous counter current extractor may
be used to quickly and easily run multiple extractions in sequence.
In one embodiment, the process includes the use of a machine
selected from centrifugal contactors, thin layer extractors, spray
columns, pulsed columns, and mixer-settlers, and combinations
thereof, in the extraction process.
[0048] In many instances, a separatory funnel has the shape of a
cone surmounted by a hemisphere. It has a stopper at the top and
stopcock (tap), at the bottom. Separating funnels used in
laboratories are typically made from borosilicate glass and their
stopcocks are made from glass or PTFE. Typical sizes are between 50
mL and 3 L. In industrial chemistry they can be much bigger and for
much larger volumes, centrifuges are used.
[0049] To use a separatory funnel, the extraction mixture is
introduced into the separatory funnel through the top with the
stopcock at the bottom closed. The funnel is then closed and shaken
gently by inverting the funnel multiple times. The funnel is then
inverted and the tap carefully opened to release excess vapor
pressure. The separating funnel is set aside to allow for the
complete separation of the phases. The top and the bottom tap are
then opened and the two phases are individually released by
gravitation and separately captured.
[0050] Referring now to FIG. 1, an industrial flow chart detailing
the process 10 of making a water-soluble surfactant and then
improving the taste of water-soluble surfactants using
liquid-liquid extraction, contains a series of steps, step 20
providing fresh surfactant raw material starting materials, step 30
production of the water-soluble surfactant through traditional
means, step 40 quenching the reaction, step 50 optional
intermediate processing and/or cleanup and providing the
water-soluble surfactant composition in need of treatment, step 60
contacting the water-soluble surfactant composition with an
extraction solvent, and water step 70 to form an extraction mixture
containing an aqueous phase and a solvent phase, step 80 separating
the liquid phases with optional centrifuge and optional repeating
of steps 60 and 70, step 90 separating residual volatile solvent
from the aqueous phase by means such as vacuum stripping, heating,
wiped-film evaporation or combinations thereof, step 100,
collecting the improved water-soluble surfactant, step 110
conducting fractional distillation on the organic phase to, step
120 recover the extraction solvent for future use, step 130 to
collect non-polar materials (impurities) and separate into valuable
and 140 unusable non-polar materials (impurities) including the
step of 150 recovering the starting surfactant raw materials for
reuse.
[0051] At step 20 and 30, the water-soluble surfactant raw
material, such as those commercially available, is produced. At
step 60, the process for improving the taste of such water-soluble
surfactant raw material begins by providing the water-soluble
surfactant composition in need of treatment wherein the
water-soluble surfactant composition contains a water-soluble
surfactant and one or more undesirable non-polar materials. By
combining the water-soluble surfactant composition with water and
solvent forming an extraction mixture and then separating the
aqueous phase from the solvent phase in step 80, the treated
water-soluble surfactant may be collected, in step 100.
[0052] In one embodiment, the liquid-liquid extraction process will
use an extraction step in which undesirable non-polar materials are
transferred from the aqueous phase to the solvent phase and then
optionally followed by a scrubbing stage in which the undesirable
non-polar materials are removed from the solvent phase, then
optionally followed by a stripping stage in which any water-soluble
surfactants or other materials are removed from the solvent phase.
The solvent phase may then be treated to make it ready for use
again.
[0053] In one embodiment, the process includes a step of collecting
the water-soluble surfactant from the aqueous phase. In another
embodiment, after the step of collecting the water-soluble
surfactant from the aqueous phase, the water-soluble surfactant is
subjected to one or more of the following: [0054] a) at least one
repeat of the process steps, optionally repeating the steps of the
process at least 3 times, optionally repeating the steps of the
process at least 4 times, in succession; [0055] b) a further
filtration step, optionally using carbon filtration; and/or [0056]
c) incorporation of the water-soluble surfactant into an oral care
composition.
Procedure for Optimizing pH in Preparation for Liquid/Liquid
Extraction
[0057] In one embodiment, the process further comprises a step of
optimizing the pH of the extraction mixture. In such a step, the
solubility of the water-soluble surfactant composition may be
optimized and the polarity difference between the desirable
water-soluble surfactant and undesirable non-polar materials that
are imparting negative aroma, taste and/or color may be maximized.
The pH is an important variable that can be adjusted to maximize
the polarity difference between the desirable water-soluble
surfactant and the undesirable non-polar materials. This is
especially important with classes of compounds that can change from
primarily charged to neutral state and vice versa by pH
manipulation.
[0058] For example, in the case of mono alkyl phosphate
surfactants, a higher pH may be preferable to ensure that the
phosphate groups are largely in the ionized state, thereby
maximizing polarity and water solubility. At the same time, most of
the undesirable non-polar materials found in commercially-available
MAP compositions would not be significantly ionized at typical pHs,
and possess a net hydrophobic character, so in one embodiment, the
pH during extraction is optimized to be in the range of 8-11. In
one embodiment, the process further comprises an extraction pH of
from about 8 to about 11, alternatively from 8 to 10.
[0059] Further, a consideration is to avoid pHs that can initiate
chemical reactivity, for a given extraction mixture comprising an
aqueous phase comprising a water-soluble surfactant raw material
dissolved in water, an undesirable non-polar material, and the
extraction solvent. For example, when using ethyl acetate as an
extraction solvent with mono alkyl phosphate, it is recommended to
maintain extraction conditions in a pH range that will avoid
converting EtOAc to acetic acid and ethanol. In one embodiment,
after extraction, the ethyl acetate should be removed to a level
that will be odorless and also avoid the potential for later
conversion to significant levels of ethanol and acetic acid, the
latter of which may introduce vinegar odors into the raw material.
In one embodiment, after extraction, the ethyl acetate is removed
to a level of less than 50 ppm, alternatively less than 5 ppm.
[0060] General pH optimization can be performed as above. For
refined pH optimization, adjust pH in small increments and perform
a single stage LLE. After single extractions over the target pH
range, analytically measure the amount of water-soluble surfactant
and the amount of undesirable non-polar materials in the extraction
solvent, with prior knowledge of the starting concentrations of
surfactant and non-polar impurities in the water-soluble surfactant
composition. Identify the pH range where the impurity removal into
the solvent phase is optimal and the surfactant retention in the
aqueous phase is also optimal.
Providing a Water-Soluble Surfactant Composition in Need of
Treatment
[0061] Water-Soluble Surfactant
[0062] As used herein "water-soluble surfactant" refers to those
surfactants that are at least partially soluble in water, when
measured at room temperature (25.degree. C.). In one embodiment,
the water-soluble surfactant is at least 10% soluble in water,
alternatively is at least 20% soluble in water, still alternatively
is at least 30% soluble in water, alternatively at least 40%
soluble in water. As used herein in a relative sense,
"water-soluble surfactant raw material" refers to the water-soluble
surfactant itself, absent significant levels of water or
undesirable by-products or starting materials such as those found
in "water-soluble surfactant compositions" as described further
below. Further, as used herein, "extracted water-soluble surfactant
composition" or "treated water-soluble surfactant composition"
refers to water-soluble surfactant compositions that have undergone
the processes set forth herein and have some measurable level of
reduction in undesirable non-polar materials versus the untreated
water-soluble surfactant compositions.
[0063] As used herein, "in need of treatment" means that the
water-soluble surfactant composition contains levels of undesirable
non-polar materials higher than what is needed for a particular
product usage. For oral care compositions, water-soluble surfactant
compositions in need of treatment include those water-soluble
surfactant compositions containing about 0.01% or more, by weight
of the composition, of undesirable non-polar materials,
alternatively containing more than about 0.1%, alternatively more
than about 0.5%, alternatively more than about 0.7%, alternatively
1% or more, by weight of the composition, of such materials.
[0064] Identifying a Suitable Water-Soluble Surfactant
[0065] In one embodiment, the process herein includes the step of
identifying a suitable water-soluble surfactant. The step of
identifying a suitable water-soluble surfactant may include the
sub-step of determining the surfactant's water solubility. When
determining the surfactant's water solubility, conditions should be
optimized for solubilizing the surfactant in water, as well as for
minimizing the amount of the desirable raw material that could be
extracted into the solvent phase along with the undesirable,
relatively non-polar impurities. The pH may be adjusted so that
charge will persist on suitable surfactants that are subject to
ionization via pH manipulation in a typical pH range. Temperature
can be raised, if needed, and samples should be vigorously shaken
and/or stirred to facilitate formation of a homogenous solution. If
a surfactant is aqueous soluble at roughly 10% or greater, then it
is a good candidate for taste/odor/color cleanup by LLE to remove
less-polar undesirable compounds.
[0066] To evaluate a surfactant, whose water solubility is in
question, place 10 g solid surfactant into a glass vessel and add
100 mL of distilled, deionized water. Raise the temperature up to
60.degree. C. (or higher if the melting point is higher), if
needed, and shake, stir, or vortex, as appropriate, for up to 30
minutes. If all of the raw material is dissolved, creating a clear
solution, then it is suitable for use in the processes set forth
herein. For objective evaluation of solubility, after heating and
stirring, vacuum filter through a membrane with 10 um pore size.
Weigh solid material recovered on the filter to determine if a
significant amount of surfactant remains undissolved. If needed for
confirmation, utilize a direct analytical measure of the
concentration of the material that is dissolved in the clear
aqueous portion via appropriate analytical method.
[0067] Examples of water-soluble surfactants that may be purified
by the processes herein include cocoamidopropyl betaines, lauryl
betaines, capryl/capramidobetaines, sodium lauryl sulfates, mono
alkyl phosphates, amine oxides, and mixtures thereof.
[0068] Water-soluble surfactants useful herein may, in some
embodiments be selected from anionic surfactants such as alkyl
phosphates. These surface active organophosphate agents have a
strong affinity for enamel surface and have sufficient surface
binding propensity to desorb pellicle proteins and remain affixed
to enamel surfaces. Suitable examples of organophosphate compounds
include mono-, di- or triesters represented by the general
structure below wherein Z1, Z2, or Z3 may be identical or
different, at least one being an organic moiety, in one embodiment
selected from linear or branched, alkyl or alkenyl group of from 1
to 22 carbon atoms, optionally substituted by one or more phosphate
groups; alkoxylated alkyl or alkenyl, (poly)saccharide, polyol or
polyether group.
##STR00001##
Some other agents include alkyl or alkenyl phosphate esters
represented by the following structure:
##STR00002##
wherein R1 represents a linear or branched, alkyl or alkenyl group
of from 6 to 22 carbon atoms, optionally substituted by one or more
phosphate groups; n and m, are individually and separately, 2 to 4,
and a and b, individually and separately, are 0 to 20; Z2 and Z3
may be identical or different, each represents hydrogen, alkali
metal, ammonium, protonated alkyl amine or protonated functional
alkyl amine such as an alkanolamine, or a
R1-(OCnH2n)a(OCmH2m)b-group. Examples of suitable agents include
alkyl and alkyl(poly)alkoxy phosphates such as lauryl phosphate;
PPG5 ceteareth-10 phosphate; Laureth-1 phosphate; Laureth-3
phosphate; Laureth-9 phosphate; Trilaureth-4 phosphate; C12-18 PEG
9 phosphate; Sodium dilaureth-10 phosphate. In one embodiment, the
alkyl phosphate is polymeric. Examples of polymeric alkyl
phosphates include those containing repeating alkoxy groups as the
polymeric portion, in particular 3 or more ethoxy, propoxy
isopropoxy or butoxy groups.
[0069] Zwitterionic or amphoteric surfactants useful in the present
invention include derivatives of aliphatic quaternary ammonium,
phosphonium, and sulfonium compounds, in which the aliphatic
radicals can be straight chain or branched, and wherein one of the
aliphatic substituents contains from about 8 to 18 carbon atoms and
one contains an anionic water-solubilizing group, e.g., carboxy,
sulfonate, sulfate, phosphate or phosphonate. Suitable amphoteric
surfactants include betaine surfactants such as disclosed in U.S.
Pat. No. 5,180,577 to Polefka et al. Typical alkyl dimethyl
betaines include decyl betaine or
2-(N-decyl-N,N-dimethylammonio)acetate, coco betaine or
2-(N-coco-N,N-dimethyl ammonio)acetate, myristyl betaine, palmityl
betaine, lauryl betaine, cetyl betaine, stearyl betaine, etc. The
amidobetaines are exemplified by cocoamidoethyl betaine,
cocamidopropyl betaine (CAPB), and lauramidopropyl betaine. The
unwanted tastes often associated with these surfactants are soapy,
bitter, chemical, and/or artificial.
[0070] Additional suitable polymeric organophosphate agents include
dextran phosphate, polyglucoside phosphate, alkyl polyglucoside
phosphate, polyglyceryl phosphate, alkyl polyglyceryl phosphate,
polyether phosphates and alkoxylated polyol phosphates. Some
specific examples are PEG phosphate, PPG phosphate, alkyl PPG
phosphate, PEG/PPG phosphate, alkyl PEG/PPG phosphate, PEG/PPG/PEG
phosphate, dipropylene glycol phosphate, PEG glyceryl phosphate,
PBG (polybutylene glycol) phosphate, PEG cyclodextrin phosphate,
PEG sorbitan phosphate, PEG alkyl sorbitan phosphate, and PEG
methyl glucoside phosphate. Suitable non-polymeric phosphates
include alkyl mono glyceride phosphate, alkyl sorbitan phosphate,
alkyl methyl glucoside phosphate, alkyl sucrose phosphates. The
unwanted tastes often associated with these surfactants are soapy,
chemical, and/or artificial.
[0071] Water-soluble amphoteric surfactants useful herein further
include amine oxide surfactants Amine oxides are the result of
oxidation of tertiary amines, typically C12-C18 alkyl dimethyl,
N-oxides. For example, amine oxide surfactants useful herein may
include lauryl dimethyl amine oxide; lauryl dihydroxyethyl amine
oxide; cocamidopropyl amine oxide; Lauramidopropylamine oxide;
cetyl dimethyl amine oxide; 3-Lauramidopropyl-N,N-dimethylamine
oxide.
[0072] Water-soluble cationic surfactants useful in the present
invention include derivatives of quaternary ammonium compounds
having one long alkyl chain containing from about 8 to 18 carbon
atoms such as lauryl trimethylammonium chloride; cetyl pyridinium
chloride; cetyl trimethylammonium bromide; coconut
alkyltrimethylammonium nitrite; cetyl pyridinium fluoride; etc.
Preferred compounds are the quaternary ammonium halides having
detergent properties described in U.S. Pat. No. 3,535,421 to Briner
et al. Certain cationic surfactants can also act as germicides in
the oral care compositions disclosed herein.
[0073] In another embodiment, the water-soluble surfactant is
selected from anionic surfactants, zwitterionic surfactants,
amphoteric surfactants, cationic surfactants, nonionic surfactants
and mixtures thereof. In one embodiment, the water-soluble
surfactant is selected from alkyl phosphate surfactants, alkyl
phosphate ethoxylated surfactants, lauryl sulfate surfactants,
betaine surfactants, betaine ethoxylated surfactants, amine oxide
surfactants, and mixtures thereof. In another embodiment, the
water-soluble surfactant is selected from alkyl phosphate
surfactants, alkyl phosphate ethoxylated surfactants, and mixtures
thereof. In one embodiment, the water-soluble surfactant is a mono
alkyl phosphate surfactant.
[0074] In one embodiment, the surfactant is selected from
cocoamidopropyl betaines, alkyl ethoxylated phosphates, mono alkyl
phosphates, and mixtures thereof.
[0075] Water-Soluble Surfactant Composition
[0076] The water-soluble surfactant compositions disclosed herein
contain a water-soluble surfactant and one or more undesirable
non-polar materials. Water-soluble surfactant compositions useful
herein include those commercially available from suppliers such as
Rhodia (located in Spartanburg, S.C., USA), Stepan (located in
Metamoros, Mexico and Winder, Ga., USA), Croda (located in Edison,
N.J., USA) and Clariant (located in Charlotte, N.C., USA). Without
being limited by theory, the presence of the undesirable non-polar
materials are what present these compositions as being in need of
treatment, e.g., the compositions are in need of removing such
undesirable materials. Further without being limited by theory, it
has been surprisingly found that current commercially available
water-soluble surfactants, although purified to varying degrees by
the manufacturers before sale, still contain significant amounts of
undesirable non-polar materials that affect taste and/or color of
the water-soluble surfactant raw material.
[0077] These undesirable non-polar materials may be unreacted
starting materials used in the manufacturing of the surfactants
(such as alcohol and/or amines), the products of side reactions
occurring during the manufacturing process, or oxidation products
(such as aldehydes).
[0078] The water-soluble surfactant composition may further
comprise from about 0.1% to about 90% water, alternatively from
about 10% to about 50%, by weight of the composition, of water.
Typically water-soluble surfactants are commercially available as
aqueous mixtures. The water may be removed in part or in whole from
the water-soluble surfactant composition before conducting the
liquid-liquid extraction processes of the present invention. Where
the water is removed in large degree from the commercially
available composition, it may be necessary to reintroduce water
into the process as part of the extraction mixture.
[0079] Many commonly used water-soluble surfactant raw materials
are produced by commercial suppliers as aqueous solutions at fairly
high concentrations. These surfactants are good candidates for
odor, color, and/or taste improvement by liquid-liquid extraction
according to the processes set forth herein.
[0080] Water-soluble alkyl phosphate surfactant compositions that
may be improved by the processes set forth herein include
commercially available compositions shown in Table 1:
TABLE-US-00001 TABLE 1 Concen- tration (in Aver- Trade- aqueous EO
age Supplier name Alkyl Chain solution) Salt # MW Croda 230K Mono
Laureth 40% Potas- 0 266.317 sium Rhodia L204K Mono Laureth 20%
Potas- 0 266.317 sium Rhodia L213/S Mono Laureth 30% Sodium 1
310.3712 Clariant 340D Di Laureth 40% none 4 442.5305 Rhodia L130
Mono Laureth 100% none 3 398.4774 Rhodia L190 Mono Laureth 100%
none 9 662.7968
Undesirable Non-Polar Materials
[0081] As used herein "undesirable non-polar materials" refers
generally to any non-polar materials that are found in the
water-soluble surfactant composition in need of treatment. In one
embodiment, the undesirable non-polar materials are selected from
residual alcohols, alcohol ethoxylates, aldehydes, ethers, ketones,
alkylamines, amides, and esters.
[0082] In one embodiment, the undesirable non-polar materials may
be off-tasting components selected from impurities, unreacted
starting materials, by-products and/or contaminants. Such
undesirable non-polar materials may be described by consumers as
soapy, bitter, metallic, earthy or dirty, and astringent. Soapy is
typically characterized by the presence of dodecanal or dodecanol.
Bitter taste may occur in the presence of alkyl amines or
alcohols.
Extraction Mixture
[0083] In one step of the process herein, the water-soluble
surfactant composition is contacted with an extraction solvent and
water to form an extraction mixture comprising an aqueous phase and
a solvent phase. In one embodiment, such as in a laboratory-scale
batch process, the extraction mixture is then mixed vigorously for
a period of from about 10 seconds to one minute. After mixing, the
extraction mixture is allowed to rest for a period of from about 15
minutes to about 2 hours. Where multiple extractions are conducted
in succession, the separation time may be shortened to a period of
from about 10 to about 20 minutes.
[0084] In another embodiment, such as on an industrial scale, an
industrial centrifuge extractor such as the BXP 190 manufactured by
Rousselet Robatel may be used to take advantage of the density
differences between two fluids to separate them via centrifugation.
The devices can be operated in a countercurrent setup or as single
stage extractions. Successive continuous extractions using an
industrial centrifuge extractor can occur quite quickly, even in a
matter of seconds, to reach the desired treated surfactant
material.
[0085] The extraction mixture then contains the extraction solvent,
surfactant and undesirable non-polar materials. In one embodiment,
the extraction mixture comprises from about 10% to about 90%, by
weight of the mixture, of water; from about 5% to about 60%, by
weight of the mixture, of water-soluble surfactant; less than 5%,
by weight of the mixture, of undesirable non-polar materials; and
from about 10% to about 90%, by weight of the mixture, of solvent.
In one embodiment, the ratio of extraction solvent to water-soluble
surfactant in the extraction mixture is from about 1:10 to about
10:1, alternatively is from about 1:2 to about 2:1.
[0086] The water included in the extraction mixture may be provided
in the water-soluble surfactant composition itself when obtained as
an aqueous solution from the commercial supplier and/or may be
water that is added during the extraction process. In some
instances, the water level in a water-soluble surfactant aqueous
solution may be reduced before contacting the water-soluble
surfactant composition with the extraction solvent to reduce the
level of solvent needed for the processes herein.
[0087] In one embodiment, the extraction mixture further comprises
a phase separation enhancer selected from salts, pH modifiers, and
mixtures thereof.
[0088] In one embodiment, after the extraction mixture is formed
and contains both an aqueous phase and a solvent phase, the aqueous
phase is then separated from the solvent phase. In another
embodiment, after the two phases are separated, the extraction
solvent is recovered from the solvent phase and reused in
subsequent liquid-liquid extraction processes.
[0089] In one embodiment, during the step of separating the aqueous
phase from the solvent, the temperature is adjusted to improve the
extraction efficiency. As used herein, "extraction efficiency"
refers to the ability of the process to remove undesirable
impurities from the water-soluble surfactant composition in need of
treatment.
[0090] In one embodiment, during the process, the pressure under
which the process takes place is adjusted to improve the extraction
efficiency.
[0091] In one embodiment, the process steps herein are repeated in
succession until the desired amount of undesirable non-polar
impurities is removed. In one embodiment, the treated water-soluble
surfactant composition is collected and the process steps are
repeated at least two times, alternatively at least 3 times, still
alternatively at least 4 times in succession, each time further
reducing the level of undesirable water-soluble impurities.
[0092] In another embodiment, multiple extractions are performed in
series after removal of the extraction solvent from preceding
extraction.
[0093] As used herein, the terms "extract" and "extraction" refer
to the process of removing undesirable components from the
desirable components of the water-soluble surfactant composition.
The undesirable components could be associated with microorganism
removal and/or other impurity or contaminant removal, primarily via
preferential solubility in the extraction solvent.
[0094] As used herein, the terms "removal", "reduce", "reduction",
and their derivatives refer to partial reduction of the number or
concentration of undesirable materials and may be considered in a
relative sense, particularly when multiple repetitions of the
process steps herein are used in succession on the same starting
material.
Extraction Solvent
[0095] As used herein, "extraction solvent" refers to any liquid or
supercritical fluid that can be used to solubilize undesirable
non-polar materials that are contained within a water-soluble
surfactant composition. Organic solvents with acceptable safety
profiles that will form a liquid bilayer with aqueous surfactants
could be used either alone or in combination with other solvents
such as ethyl acetate, ethanol, propylene glycol, PEGs, other
ethers or esters, or other solvents, etc. to achieve a similar
result. One example of a useful supercritical fluid is carbon
dioxide. A range of ratios of solvent to surfactant, a range of
surfactant concentrations, the mixing and/or extraction conditions,
etc. are variables that could be optimized for a particular
application of this general approach.
[0096] Without being limited by theory, when thorough chemical
composition data on the undesirable non-polar materials found in
the water-soluble surfactant composition in need of treatment are
obtained through in-depth chemical characterization and are
well-understood, an investigation can be initiated to determine if
the impurities are primarily responsible for malodors and
off-tastes, or if the surfactants themselves are contributing a
large fraction of the malodors and off tastes.
[0097] Extraction solvents useful herein include those having
individual Hansen solubility parameters of a dispersion force
component (.delta..sub.D) ranging from about 15 to about 17
(MPa).sup.0.5, a polar component (.delta..sub.P) ranging from 0 to
about 9 (MPa).sup.0.5 and a hydrogen bonding component
(.delta..sub.H) ranging from 0 to about 11 (MPa).sup.0.5.
[0098] In one embodiment, the solvent has individual Hansen
solubility parameters of a dispersion force component
(.delta..sub.D) ranging from about 13 to about 19 (MPa).sup.0.5, a
polar component (.delta..sub.P) ranging from about 2 to about 9
(MPa).sup.0.5 and a hydrogen bonding component (.delta..sub.H)
ranging from about 2 to about 11 (MPa).sup.0.5. In one embodiment,
the polar component ranges from about 4 to about 6, in another
embodiment, the hydrogen bonding component ranges from about 6 to
about 9.
[0099] In addition to Hansen solubility parameters, the solvent
will form distinct layers when combined with water and the
water-soluble surfactant composition. In order to quickly determine
whether a solvent will meet this criteria, the following visual
separation test may be used: using a 30 ml glass vial, add 10 mL of
the proposed extraction solvent, 10 mL of a 30% aqueous solution of
the water-soluble surfactant composition, cap the vial, shake
vigorously for 30 seconds, allow to rest for 30 minutes, visually
inspect for visible precipitation and two distinct aqueous layers.
If there is no visible precipitation and at least two distinct
layers are formed, the solvent passes the visual separation test
and may be used as an extraction solvent according to the processes
set forth herein.
[0100] In one embodiment, the extraction solvents useful herein
have a logP value of greater than 0.5.
[0101] Extraction solvents useful herein include ethyl acetate,
water-saturated ethyl acetate, ethyl propionate, ethyl butyrate,
ethyl pentanoate, ethyl caproate, ethyl caprylate, ethyl
pelargonate methyl acetate, methyl propionate, methyl butyrate,
short chain esters and mixtures thereof. In one embodiment, the
extraction solvent is selected from food grade ethyl esters.
[0102] In one embodiment, the extraction solvent is substantially
free of (i.e. comprises no reasonably measurable quantity of) ethyl
lactate, alternatively contains less than 0.0001% of ethyl
lactate.
[0103] Other extraction solvents useful herein include ketones such
as methyl ethyl ketone, ethers such as di-n-propyl ether, lactones,
acetals, and mixtures thereof.
[0104] Other extraction solvents useful herein include those
selected from hexane, cyclohexane, heptane, chloroform, toluene,
methylene chloride, methyl nonafluoroether, ethyl nonafluoroether,
carbon tetrachloride, and mixtures thereof. HFE 7100, HFE 7200, and
HFE 7500 are tradenames of commercially available hydrofluoroethers
available from TCI AMERICA, 9211 N. Harborgate Street, Portland,
Oreg. 97203, U.S.A.
[0105] Mixtures of extraction solvents may also be used.
[0106] In one embodiment, the extraction mixture is substantially
free of (i.e. comprises no reasonably measurable quantity of)
THF.
[0107] In one embodiment, the extraction mixture comprises mono
alkyl phosphate and is substantially free of (i.e. comprises no
reasonably measurable quantity of) 1-octanol and phenoxy
ethanol.
[0108] Extraction solvents useful herein also include supercritical
fluids such as carbon dioxide. As used herein, "supercritical
carbon dioxide" is carbon dioxide that is at a temperature and a
pressure greater than Tr=1 and Pr=1. Tr is T/Tc where T is the
present temperature of the supercritical carbon dioxide and Tc is
the critical temperature. Pr is P/Pc where P is the present
pressure of the supercritical carbon dioxide and Pc is the critical
pressure. Tc, the critical temperature for carbon dioxide (CO2), is
31.1 degrees Celsius (deg. C.), or 304.1 degrees Kelvin (K), and Pc
is 73 atmospheres (atm) or about 1073 pounds per square inch
(PSI).
[0109] In more general terms, supercritical carbon dioxide refers
to carbon dioxide that is in a fluid state while also being at or
above both its critical temperature and pressure. Carbon dioxide
usually behaves as a gas in air at standard temperature and
pressure (STP) or as a solid called dry ice when frozen. If the
temperature and pressure are both increased from standard
temperature and pressure to be at or above the critical point for
carbon dioxide, it can adopt properties midway between a gas and a
liquid. More specifically, it behaves as a supercritical fluid
above its critical temperature (31.1 deg. C.) and critical pressure
(73 atm), expanding to fill its container like a gas but with a
density like that of a liquid. The supercritical fluid region of
the phase diagram is defined as a temperature above the critical
temperature (31.1 deg. C.) to a pressure above the critical
pressure (73.8 bar or 1070 PSI).
[0110] When using a supercritical fluid as the extraction solvent,
it is possible to choose a "batch-type" system or choose a
"continuous-type" system. The batch systems can be used in parallel
or in series, operated on a cyclic basis (at prescribed residence
times), be sequentially loaded, processed, and unloaded, and yield
a sufficient bulk removal efficiency. The "continuous-type"systems
generally refer to a number of batch vessels, operated
sequentially, with the supercritical carbon dioxide gas flow and
the sequential loading, processing, and unloading of the feed and
product solids can be envisioned as counter current flow of the
solids movement from feed to product with respect to the flow of
the supercritical carbon dioxide. The directional loading,
processing, and unloading is opposite to the flow of the
supercritical carbon dioxide. This type of "continuous", counter
current operation is generally referred to as continuous, counter
current, sequencing-batch operation. Therefore, when there are one
or two batch stages, in series or parallel, the term "batch" tends
to be used, and when there are three or more stages, if they
operate in parallel flow to the supercritical carbon dioxide, the
term "batch" is also used. However, when they operate in counter
current flow of the material to be extracted to the supercritical
carbon dioxide, we call them counter current "sequencing-batch"
simulating counter current flows of material feed and desired
product to the flow direction of the supercritical carbon dioxide.
It should be understood that "continuous" can also define a process
in which the feed and solvent are fed continuously through a fixed
system and the products are continuously removed.
[0111] When the supercritical fluid is selected as the extraction
solvent, the separation of the aqueous phase from the solvent phase
may occur by releasing the temperature and pressure placed upon the
supercritical fluid, allowing the fluid to return to a gaseous
state.
[0112] Selection of an Extraction Solvent
[0113] In one embodiment, the process further comprises a step of
selecting an extraction solvent suitable for use with the
water-soluble surfactant in need of treatment.
[0114] Such step includes evaluating the extraction solvent under
consideration with the water-soluble surfactant in need of
treatment. Evaluation of the solvent includes combining the
proposed solvent with the water-soluble surfactant composition in
need of treatment to determine whether the solvent forms a 2-phase
system with the surfactant water mixture. The pH, temperature, or
ionic strength may be adjusted to deliver a good two-phase break,
and also to optimize the extraction efficiency. The extraction
solvent should not cause significant precipitation when combined
with the water/surfactant mixture. Since a successful two-phase
separation will be achieved with suitable extraction solvents, the
solvent polarity is expected to preferentially extract non-polar
impurities into the extraction solvent layer and away from the
aqueous surfactant phase. In one embodiment, the solvent will be
food grade and easily separable from the aqueous/surfactant phase.
Selection of a solvent that is easily recoverable from the
extracted impurities is also desirable, i.e. by fractional
distillation, so that it can be re-used for subsequent
extractions.
[0115] The solvents selected for the solubilization method of this
invention are based upon solubility parameters and cohesion
properties explained by Charles Hansen in "Hansen Solubility
Parameters: A User's Handbook" by Charles M. Hansen, CRC Press
(2007) and in "The CRC Handbook and Solubility Parameters and
Cohesion Parameters," Edited by Allan F. M. Barton (1999). Each
material is defined by three points in 3D space and these three
points are known as the Hansen Solubility Parameters (HSP) which
may be defined as follows.
[0116] Solubility parameters are theoretically calculated numerical
constants which are a useful tool in predicting the ability of a
solvent material to dissolve a particular solute. When the
solubility parameters of a solvent falls within the solubility
parameter range of a solute, i.e., the material to be dissolved,
solubilization of the solute is likely to occur. There are three
Hansen empirically- and theoretically-derived solubility
parameters, a dispersion-force component (.delta..sub.D), a polar
or dipole interaction component (.delta..sub.P) and a
hydrogen-bonding component (.delta..sub.H). Each of the three
parameters (i.e., dispersion, polar and hydrogen bonding)
represents a different characteristic of solvency, or solvent
capability. In combination, the three parameters are a measure of
the overall strength and selectivity of a solvent. The Total Hansen
solubility parameter, which is the square root of the sum of the
squares of the three parameters mentioned previously, provides a
more general description of the solvency of the solvents.
Individual and total Solubility Parameter units are given in
MPa.sup.0.5 or (J/cc).sup.0.5.
[0117] These three parameters can be treated as co-ordinates for a
point in three dimensions also known as the Hansen space. The
nearer two molecules are in this three dimensional space, the more
likely they are to dissolve into each other. To determine if the
parameters of two molecules (usually a solvent and a polymer) are
within range a value called interaction radius (R.sub.0) is given
to the substance being dissolved. This value determines the radius
of the sphere in Hansen space and its center is the three Hansen
parameters. To calculate the distance (Ra) between Hansen
parameters in Hansen space the following formula is used.
(Ra).sup.2=4(.delta..sub.d2-.delta..sub.d1).sup.2+(.delta..sub.p2-.delta-
..sub.p1).sup.2+(.delta..sub.h2-.delta..sub.h1).sup.2
[0118] The Hansen solubility parameters can be calculated by
"Molecular Modeling Pro" software, version 5.1.9 (ChemSW, Fairfield
Calif., www.chemsw.com) or Hansen Solubility from Dynacomp
Software. The solubility parameters of solvents useful herein are
shown in Table 1, below.
TABLE-US-00002 TABLE 1 Disper- Polar- Hydrogen Ra (With Ra (With
sion ity Bonding Ethyl Dodeca- Component (.delta.D) (.delta.P)
(.delta.H) Acetate) nol) ethyl acetate 15.8 5.3 7.2 0 4.5 Carbon
Dioxide 15.7 6.3 5.7 1.8 5.7 hexane 14.9 0 0 9.1 10.0 heptanes 15.3
0 0 9 10.2 benzene 18.4 0 2 9.1 11.8 diethyl ether 14.5 2.9 5.1 4.1
4.3 di-n-propyl ether 15.5 2.3 4.5 4.1 5.7 methylene 18.2 6.3 6.1 5
9.4 chloride carbon 17.8 0 0.6 9.4 12.0 tetrachloride propylene 20
18 4.1 15.5 19.6 Carbonate propylene glycol 15.6 5.6 9.8 2.6 3.9
methyl ether acetate 1,1,1- 16.8 4.3 2 5.7 9.2 trichloroethane
methyl 13.74 3.59 4.14 5.4 5.2 nonafluorobutyl ether* ethyl 14.31
4.36 3.98 4.5 5.5 nonafluorobutyl ether* *Methyl and Ethyl
Nonafluorobutyl Ethers are commercially available from TCI AMERICA,
9211 N. Harborgate Street, Portland, OR 97203, U.S.A.
Aqueous Phase
[0119] As used herein, "aqueous phase" refers to the portion of the
extraction mixture containing water, water-soluble surfactant, and
other water-soluble materials.
[0120] In one embodiment, the processes of the present invention
may further include a step of adjusting the ionic strength of the
aqueous phase up or down to improve the extraction efficiency.
Solvent Phase
[0121] As used herein, "solvent phase" refers to the portion of the
extraction mixture containing the extraction solvent, the
undesirable non-polar materials, and other water-insoluble
materials.
[0122] Generally, the solvent phase and the aqueous phase will be
immiscible.
[0123] In one embodiment, after separation of the aqueous and
solvent phases, the aqueous phase still contains small amounts of
the extraction solvent and the extraction solvent may be further
removed from the aqueous phase by subsequent extraction steps,
evaporation (such as with a rotavapor or open-air, optionally with
a nitrogen stream) or combinations thereof.
Separating the Aqueous Phase from the Solvent Phase
[0124] As discussed more fully above, the separation of the aqueous
phase from the solvent phase may occur using traditional
liquid-liquid extraction techniques. Such separation may be crudely
done based upon the phase break, particularly where multiple rounds
of extraction are planned. On a lab bench or pilot plant scale this
may mean by use of a separatory funnel, while on an industrial
scale, this may mean by use of standard equipment for
centrifugation and separation in a continuous process or in very
large tanks equipped for separation on a batch basis.
[0125] In one embodiment, the step of separating the aqueous phase
from the solvent phase further comprises centrifuging the
extraction mixture.
[0126] In one embodiment, the extraction mixture is mixed for from
about 10 seconds to about one minute with vigorous mixing and at
ambient temperature before allowing the mixture to settle into two
phases and separating the aqueous phase from the solvent phase.
[0127] In one embodiment, the step of separating the aqueous phase
from the solvent phase comprises reducing the heat and pressure
applied to a supercritical fluid, such as carbon dioxide, allowing
the supercritical fluid to return to a gaseous state, and allowing
the gas to escape from the extraction mixture.
[0128] The process may further comprise the step of removing any
residual solvent from the aqueous phase. In one embodiment the step
of removing any residual solvent from the aqueous phase includes
the use of an industrial method selected from vacuum stripping
(with or without heat), fractional distillation, wiped-film
evaporation, carbon filtration, or combinations thereof.
Recovering the Treated Water-Soluble Surfactant
[0129] The processes according to the present invention may further
include a step of recovering the treated water-soluble surfactant
composition from the aqueous phase by evaporation or other
traditional means.
[0130] In one embodiment, the treated water-soluble surfactant
composition contains from about 10% to about 50%, alternatively
from about 20% to about 30% of the treated water-soluble
surfactant, from about 60 to about 90%, alternatively from about
70% to about 80% water, and 1% or less, alternatively 0.7% or less,
alternatively 0.5% or less, alternatively 0.1% or less,
alternatively 0.05% or less, alternatively 0.01% or less, of
undesirable non-polar materials, all by weight of the treated
composition.
[0131] In one embodiment, the treated mono alkyl phosphate
surfactant composition contains 0.7% or less, alternatively 0.5% or
less, alternatively 0.1% or less, alternatively 0.05% or less,
alternatively 0.01% or less, by weight of the treated composition,
of undesirable non-polar materials.
[0132] In one embodiment, the treated cocoamidopropyl betaine
surfactant composition contains 0.1% or less, alternatively 0.07%
or less, alternatively 0.05% or less, alternatively 0.01% or less,
alternatively 0.005% or less, 0.0001% or less, alternatively no
measurable quantity, by weight of the treated composition, of amine
and amide materials.
[0133] In one embodiment, the treated cocoamidopropyl betaine
surfactant composition contains at least 20% cocoamidopropyl
betaine surfactant and 10 ppm or less, alternatively 5 ppm or less,
alternatively 1 ppm or less, alternatively 500 ppb or less,
alternatively no measurable quantity, by weight of the treated
composition, of amine and amide materials.
[0134] In one embodiment, the treated cocoamidopropyl betaine
surfactant composition contains 0.1% or less, alternatively 0.07%
or less, alternatively 0.05% or less, alternatively 0.01% or less,
alternatively 0.005% or less, 0.0001% or less, alternatively no
measurable quantity, by weight of the treated composition, of
undesirable non-polar materials.
[0135] In one embodiment, the treated water-soluble surfactant
composition contains from about 10% to about 50%, alternatively
from about 20% to about 30% of the treated water-soluble
surfactant, from about 60 to about 90%, alternatively from about
70% to about 80% water, and 1% or less of total alcohols, all by
weight of the treated composition.
[0136] In one embodiment, the treated mono alkyl phosphate
surfactant composition contains 0.7% or less, alternatively 0.5% or
less, alternatively 0.1% or less, alternatively 0.05% or less,
alternatively 0.01% or less, by weight of the treated composition,
of total alcohols.
Recycling the Solvent
[0137] In one embodiment, the process further includes a step of
separating the extraction solvent from the solvent phase and
optionally reusing the extraction solvent for further liquid-liquid
extraction processes.
[0138] In one embodiment, the step of recycling the solvent
includes the use of a fractionating column (or distillation tower).
Fractionating columns have been shown capable of separating these
types of streams and removing them for varying uses. An example
process that incorporates a fractionating column step is shown in
FIG. 1. Design of the fractionating column will need to take into
account the potential markets for the varying fractions, throughput
needs for the system, and overall costs. The size and number of
plates used in the distillation tower may be selected with these
factors in mind.
[0139] A fractionating column or fractionation column may be used
in the distillation of liquid mixtures so as to separate the
mixture into its component parts, or fractions, based on the
differences in their volatilities. Fractionating columns may vary
in size and are used in small scale laboratory distillations as
well as for large-scale industrial distillations.
[0140] Fractionating columns help to separate the mixture by
allowing the mixed vapors to cool, condense, and vaporize again in
accordance with Raoult's law. With each condensation-vaporization
cycle, the vapors are enriched in a certain component.
[0141] In a typical fractional distillation, a liquid mixture is
heated in the distilling flask, and the resulting vapor rises up
the fractionating column. The vapor condenses on glass spurs (known
as trays or plates) inside the column, and returns to the
distilling flask, refluxing the rising distillate vapor. The
hottest tray is at the bottom of the column and the coolest tray is
at the top. At steady-state conditions, the vapor and liquid on
each tray reach an equilibrium. Only the most volatile of the
vapors stays in gas form all the way to the top, where it may then
proceed through a condenser, which cools the vapor until it
condenses into a liquid distillate. The separation may be enhanced
by the addition of more trays (to a practical limitation of heat,
flow, etc.).
[0142] Fractional distillation is one of the unit operations of
chemical engineering. Fractionating columns are widely used in the
chemical process industries where large quantities of liquids have
to be distilled. Many fractions can be recovered through this
method and for industrial processes, the limitation is typically
only product requirements and economics.
[0143] Industrial distillation is typically performed in large,
vertical cylindrical columns known as "distillation towers" or
"distillation columns" with diameters ranging from about 65
centimeters to 6 meters and heights ranging from about 6 meters to
60 meters or more. Industrial distillation towers are usually
operated at a continuous steady state. Unless disturbed by changes
in feed, heat, ambient temperature, or condensing, the amount of
feed being added normally equals the amount of product being
removed.
[0144] Other means of recycling the solvent phase include use of a
cyclone separator. It may be possible to use the density
differences of the materials in the solvent phase to drive their
separation. This approach has the advantage of typically being more
economical to install and operate, but may reduce the degree of
separation that can be achieved versus a distillation approach.
Preparing a Solid Water-Soluble Surfactant
[0145] In one embodiment, the process further comprises the step of
heating a solid impure surfactant material to its melting point. In
one embodiment, heating the solid impure surfactant material to a
temperature of from about 25.degree. C. to about 80.degree. C.,
alternatively from about 30.degree. C. to about 60.degree. C.
before the step of contacting with an extraction solvent and
water.
Incorporating into Oral Care Compositions
[0146] The processes of the present invention may further include a
step of incorporating the treated water-soluble surfactant
composition into an oral care composition.
[0147] Oral Care Compositions
[0148] The treated water-soluble surfactant compositions resulting
from the processes according to the present invention, may, in one
embodiment, be incorporated into an oral care composition having
improved taste vs. a water-soluble surfactant untreated by the
processes set forth herein.
[0149] As used herein, "oral care composition" is meant a product,
which in the ordinary course of usage, is not intentionally
swallowed for purposes of systemic administration of particular
therapeutic agents, but rather is retained in the oral cavity for a
time sufficient to contact substantially all of the dental surfaces
and/or oral tissues for purposes of oral activity. The oral care
composition may be in various forms including toothpaste,
dentifrice, tooth gel, subgingival gel, mouthrinse, mousse, foam,
mouthspray, lozenge, chewable tablet, chewing gum or denture
product. The oral care composition may also be incorporated onto
strips or films for direct application or attachment to oral
surfaces.
Procedure for Assessing Extraction Efficacy
[0150] In one embodiment, in conjunction with the processes
according to the present invention, a step of assessing extraction
efficacy is performed on the water-soluble surfactant composition.
Such as step may be performed as follows:
[0151] 1. Supply a water-soluble surfactant composition.
[0152] 2. To the water-soluble surfactant composition, add the
extraction solvent, such as ethyl acetate, all in a separatory
funnel.
[0153] 3. Mix vigorously by shaking the separatory funnel for
approximately 1 minute and then allow the liquid layers to
separate.
[0154] 4. Collect the aqueous layer containing the desirable
water-soluble surfactant.
[0155] 5. Separately collect the solvent layer containing the
undesirable materials and either discard or utilize the solvent and
undesirable materials for other purposes. For example, if the
undesirable materials are starting materials in the water-soluble
surfactant manufacture, they could be isolated and re-used to make
more surfactant. The extraction solvent could be purified for later
re-use in the extraction procedure.
[0156] 6. Analyze samples from both the pre- and post-extracted
oral care component via immersion Solid Phase Microextraction
(SPME) (or LLE) followed by GC-MS (using an Agilent model 6890 GC
& model 5973 Mass Spectrometric Detector, Agilent Technologies,
Wilmington, Del., USA). Compare the impurity levels in the pre- and
post-extracted samples to determine the efficiency of their
removal.
[0157] 7. Smell and/or taste the pre- and post-extracted material
directly or after spiking into an Oral Care product to sensorially
dimension the level of improvement.
EXAMPLES
Example I
Improved MAP L213/S Surfactant
[0158] Undesirable non-polar materials were extracted from MAP
L213/S (a mono alkyl phosphate surfactant in aqueous solution, see
Table 1 above), supplied by Rhodia, using the processes set forth
herein wherein ethyl acetate (supplied by Honeywell Burdick &
Jackson, Muskegon, Mich., USA) was used as the extraction solvent.
The extracted materials were then analyzed and the treated MAP
L213/S was evaluated for taste and odor after the extraction and
shown to be very mild, especially when compared with the starting
MAP L213/S material. The undesirable materials removed from the
ML213/S commercially supplied material are set forth in Table 3,
below. The following process steps were taken:
1. 100 grams of MAP L213/S were placed into a clean 250 mL
separatory funnel. 2. 100 mL of ethyl acetate was added to the
separatory funnel, which was stoppered, and shaken vigorously for
approximately 1 minute. 3. The separatory funnel contents were then
rested for a period of time until they settled into two visibly
distinct layers. 4. The bottom layer (treated MAP L213/S) was
drained from the separatory funnel into a second, clean 250 mL
separatory funnel. 5. The ethyl acetate was separately collected
and set aside for other purposes. 6. A second aliquot of 100 mL of
fresh ethyl acetate was then added to the treated MAP L213/S in the
separatory funnel and the steps 2-5 were repeated for a total of 5
times. 7. After the last extraction step, the aqueous layer was
collected into a round bottom flask, which was then placed on a
rotavapor (model RE111 supplied by BUCHI Labortechnik AG in Flawil,
Switzerland). The water bath of the rotavapor was set at 80.degree.
C. and allowed to run until the ethyl acetate odor is no longer
perceived. 7. The mass of the treated MAP L213/S surfactant was
then obtained and water was added to make up for any mass loss due
to water loss along with the EtOAc removal.
TABLE-US-00003 TABLE 3 Results of Mono alkyl phosphate LLE
treatment with EtOAc Control Reten- (Pre- Post tion extract)
Extract Area Time Peak Peak Reduc- Undesirable Material (Min) Area
Area tion (%) Undecane 3.39 1216114 0 100.0 Dodecene Isomer 4.35
3218343 0 100.0 Dodecene Isomer 4.42 3450618 0 100.0 Dodecene
Isomer 4.46 2311369 0 100.0 Dodecene Isomer 4.57 4329376 0 100.0
Dodecene Isomer 4.66 2547216 0 100.0 Tridecene Isomer 5.09 2406145
0 100.0 Tridecene Isomer 5.15 1220445 0 100.0 Tridecene Isomer 5.19
438095 0 100.0 Tridecene Isomer 5.29 1367495 0 100.0 Tridecene
Isomer 5.38 1114436 0 100.0 Tetradecene Isomer 5.45 674727 0 100.0
Tetradecene Isomer 5.52 1030783 0 100.0 Tetradecene Isomer 5.59
1218184 0 100.0 Tetradecene Isomer 5.63 1589820 0 100.0 Tetradecene
Isomer 5.77 573418 0 100.0 Tetradecene Isomer 5.80 220422 0 100.0
Tetradecene Isomer 5.83 184627 0 100.0 Tetradecene Isomer 5.88
300141 0 100.0 Tetradecene Isomer 5.97 199647 0 100.0 Tetradecene
Isomer 5.99 175759 0 100.0 Tetradecene Isomer 6.06 177721 0 100.0
Pentadecane 6.22 669888 0 100.0 Methyl 4,6-decadienyl 6.61 1023628
0 100.0 ether Hexadecane 6.83 1645290 0 100.0 Dodecanal 7.57
2654710 129439 95.1 Unknown 7.60 776038 0 100.0 Unknown 7.64
1108611 0 100.0 Unknown 7.70 1879031 0 100.0 Methyl
6,8-dodecadienyl 7.80 1223734 0 100.0 ether Unknown 7.84 1463962 0
100.0 Unknown 7.95 3115904 0 100.0 Butyl-substituted 8.04 5371992 0
100.0 tetrahydrofuran Branched alcohol 8.29 1323195 0 100.0
Branched alcohols 8.38 4633193 0 100.0 Branched alcohols 8.48
8500950 0 100.0 Dodecanol 8.88 101956289 932638 99.1 Ethylene
glycol 10.23 55816598 522217 99.1 mondodecyl ether Diethylene
glycol 12.00 31588284 560933 98.2 monododecyl ether Triethylene
glycol 14.90 8518697 264967 96.9 monododecyl ether Average % 99.7
Reduction
[0159] The resulting treated MAP L213/S was then subjected to
comparative taste testing as follows:
[0160] The following MAP L213/S compounds (all based upon the MAP
L213/S surfactant commercially available from Rhodia) were
subjected to a 6 person panel for tasting. Each MAP material was
diluted to a level of 1% surfactant in distilled water and
neutralized to pH 7. 10 mL samples were provided in 15 mL cups to
the panelists. Panelists were instructed to not sample materials
more often than once in the morning and once in the afternoon in
order to provide enough time for the palate to clear between
samples and were instructed to not eat or drink within 15 minutes
before sampling. The panelist was instructed to empty the contents
of the cup into their mouth without swallowing, swish the product
for 10-20 seconds, expectorate, wait 10-20 seconds, and then rate
their perceptions for the following categories on a scale of 0 to
60:1) soapy taste; 2) bitterness amount; 3) other off-taste amount;
4) "soapy taste" intensity; 5) "bitter taste" intensity.
[0161] 176=Rhodia L213/S, lot SW10G-4636 251=Rhodia L213/S, lot
012
[0162] 389=Rhodia L213/S, lot 010
[0163] 462=Rhodia L213/S, lot 011
[0164] 937=Rhodia L213/S, lot 001 extracted with ethyl acetate
pursuant to the process steps set forth above in this Example I
[0165] Control=Rhodia L213/S, lot 001
[0166] As may be seen in Table 4, the control and the comparative
examples 176, 251, 389, and 462, all had significantly higher
ratings for negative taste elements such as the soapy taste,
bitterness amount, other off-taste amount, soapy taste intensity,
and bitter taste intensity than the MAP composition treated with
ethyl acetate according to the processes set forth herein.
TABLE-US-00004 TABLE 4 Attribute n = 6 176 251 389 462 937 CTL
(Comp) (Comp) (Comp) (Comp) (Example I) Soapy 41.25 47.50 33.75
30.42 38.75 12.50 Taste Bitterness 32.50 44.08 42.08 39.58 44.58
5.83 Amount Other 32.50 34.00 24.58 26.25 26.08 3.75 Off-taste
Amount "Soapy 42.08 45.00 32.00 28.75 39.25 7.50 Taste" Intensity
"Bitter 31.25 39.17 41.25 38.75 42.92 3.17 Taste" Intensity
Example II
Improved Cocoamidopropyl Betaine Surfactant
[0167] Undesirable non-polar materials were extracted from
cocoamidopropyl betaine surfactant, supplied by Stepan, Mexico SA
DE CV (Matamoros, MX), using the process steps shown in Example I,
except that 20 grams cocoamidopropyl betaine and 20 mL of solvent
were used (in place of 100 grams of MAP and 100 mL of solvent) and
only 3 repetitions (stages) of steps 2 through 5--substituting the
cocoamidopropyl betaine for the MAP L213/S. The extracted materials
were then analyzed and the treated cocoamidopropyl betaine
surfactant was evaluated for taste and odor after the extraction
and shown to be very mild, especially when compared with the
starting material. The undesirable materials removed from the
commercially supplied material are set forth in Table 5, below.
TABLE-US-00005 TABLE 5 Cocoamidopropyl Betaine - Pre and Post 3
Stages of EtOAc Extraction Control Reten- (Pre- Post tion extract)
Extract Area Time Peak Peak Reduc- Impurity (Min) Area Area tion
(%) -- -- -- -- -- Cyclohexyl benzene 7.43 421510 0 100.0 Dodecanal
7.57 2718310 91634 96.6 Methyl dodecanoate 8.04 3597403 12025 99.7
Benzyl alcohol 8.52 11186150 370371 96.7 Tetradecanal 8.70 396280 0
100.0 Dodecanol 8.87 1590140 319173 79.9 Methyl tetradecanoate 9.11
515756 0 100.0 Biphenyl 9.19 2524375 0 100.0 Diphenyl ether 9.28
8312954 0 100.0 Tetradecanol 9.86 264984 0 100.0 Unknown 10.16
1794756 570477 68.2 N,N- 10.85 737881 0 100.0 Dimethyldodecanamide
Benzoic Acid 11.13 627445 70858 88.7 Dodecanoic acid 11.23 7295585
295959 95.9 N,N- 11.83 300264 0 100.0 Dimethylpalmitamide
Tetradecanoic acid 12.26 2070533 93129 95.5 Dodecanamide 12.80
378693 0 100.0 Unknown 13.66 948057 515784 45.6 Tertiary alkyl
14.26 1761483 495040 71.9 dimethylamine Average % 91.5
Reduction
Example III
Improved Lauryl Betaine Surfactant
[0168] Undesirable non-polar materials were extracted from lauryl
betaine surfactant, supplied by Mason Chemical Company (Arlington
Heights, Ill., USA), using the process steps shown in Example I,
substituting the lauryl betaine for the MAP L213/S and only four
repetitions of steps (stages) 2 through 5 were completed. The
extracted materials were then analyzed and the treated lauryl
betaine surfactant was evaluated for taste and odor after the
extraction and shown to be very mild, especially when compared with
the starting material. The undesirable materials removed from the
commercially supplied material are set forth in Table 6, below.
TABLE-US-00006 TABLE 6 Lauryl Betaine - Pre and Post 4 Stages of
EtOAc Extraction Control Reten- (Pre- Post tion extract) Extract
Area Time Peak Peak Reduc- Impurity (Min) Area Area tion (%)
Dodecene Isomer 4.14 268607 0 100.0 Dodecene Isomer 4.25 269099 0
100.0 Dodecene Isomer 4.36 100143 0 100.0 Dodecene Isomer 4.42
249301 0 100.0 Dodecene Isomer 4.51 210691 0 100.0 Dodecene Isomer
4.61 533604 0 100.0 Dodecene Isomer 4.68 77816 0 100.0 Tertiary
Alkyl Dimethyl 5.83 119401 0 100.0 amine Tertiary Alkyl Dimethyl
6.11 110815 0 100.0 amine 2-Ethyl-1-hexanol 6.18 197861 0 100.0
N,N-Dimethyl-1- 7.05 12603358 1716473 86.4 dodecanamine Average %
98.8 Reduction
Example IV
Improved Sodium Lauryl Sulfate Surfactant
[0169] Undesirable non-polar materials were extracted from sodium
lauryl sulfate surfactant, supplied by Stepan (Winder, Ga., USA),
using the process steps shown in Example I, substituting the sodium
lauryl sulfate for the MAP L213/S and only three repetitions
(stages) of steps 2 through 5 were completed. The extracted
materials were then analyzed and the treated sodium lauryl sulfate
surfactant was evaluated for taste and odor after the extraction
and shown to be very mild, especially when compared with the
starting material. The undesirable materials removed from the
commercially supplied material are set forth in Table 7, below.
TABLE-US-00007 TABLE 7 SODIUM LAURYL SULFATE - Pre and Post 3
Stages of EtOAc Extraction Control Reten- (Pre- Post tion extract)
Extract Area Time Peak Peak Reduc- Impurity (Min) Area Area tion
(%) -- -- -- -- -- Undecane 3.39 1139583 0 100.0 Dodecane 4.16
17065669 1858091 89.1 Dodecene isomer 4.39 9997068 770380 92.3
Dodecene isomer 4.45 5165264 370370 92.8 Dodecene isomer 4.49
1864387 224856 87.9 Dodecene isomer 4.60 6606623 518956 92.1
Dodecene isomer 4.69 4871544 384054 92.1 Tridecane 4.89 434688
91475 79.0 Tetradecane 5.58 6864662 841425 87.7 Tetradecene isomer
5.78 1799963 134020 92.6 Tetradecene isomer 5.84 580558 50299 91.3
Tetradecene isomer 5.88 235342 34614 85.3 Tetradecene isomer 5.97
729601 44650 93.9 Tetradecene isomer 6.06 559398 209913 62.5
Pentadecane 6.23 151876 28738 81.1 Methyl 4,6-decadienyl 6.61
2127943 169814 92.0 ether Hexadecane 6.84 1055440 307915 70.8
1-Chlorododecane 7.31 932377 120438 87.1 Alkyl Benzene 7.72 646264
42187 93.5 Alkyl Benzene 7.79 732825 62895 91.4 Alkyl Benzene 7.95
825458 70947 91.4 Alkyl Benzene 8.22 158968 19055 88.0 Alkyl
Benzene 8.28 857712 82212 90.4 Alkyl Benzene 8.34 313335 14071 95.5
Alkyl Benzene 9.35 120877 0 100.0 Dodecanol 8.87 20170340 8855647
56.1 Tetradecanol 9.85 5956311 2885441 51.6 Hexadecanol 10.77
515519 352413 31.6 Average % 84.3 Reduction
Example V
Dentifrice Compositions
[0170] Dentifrice compositions according to the present invention
are shown below as Examples Va-Vi in Table 8. These compositions
contain surfactants resulting from the process set forth herein in
Examples I-IV. Such compositions have improved taste versus
compositions containing the untreated commercially available
water-soluble surfactants.
TABLE-US-00008 TABLE 8 Dentifrice Examples Ingredient Va Vb Vc Vd
Ve Vf Vg Vh Vi Carbomer 956 0.2 0.3 0.2 0.2 0.2 0.2 0.2 CMC 0.75
0.2 1.0 1.0 1.0 1.0 Color Solution (1%) 0.05 0.05 0.50 0.75 0.18
0.02 0.25 0.05 0.05 Wintergreen Spice 0.15 Flavor Fruit Mint Flavor
0.55 Mint Flavor 0.59 0.45 0.42 1.0 1.2 1.0 1.0 Cinnamon Flavor 0.5
WS-23 0.02 0.05 0.02 WS-3 0.02 0.05 0.02 MGA 0.2 Menthol 0.52 0.55
0.56 0.15 0.58 G-180 0.01 0.03 0.015 0.004 0.01 0.01 0.03 0.008
0.02 Potassium Sorbate 0.004 0.008 0.004 0.004 Poloxamer 407 1.0
0.2 0.2 0.2 0.2 0.2 Polyethylene Glycol 3.0 3.0 3.00 300
Polyethylene Glycol 2.3 600 Propylene Glycol 10.0 Sweetener 0.46
0.5 0.45 0.4 0.58 0.4 0.4 0.4 0.4 Silica Abrasive 22.0 31.0 20.0
21.0 17.0 15.0 15.0 15.0 15.0 Sodium Benzoate 0.004 0.004 0.004
0.004 Silica Thickening 2.0 7.0 7.0 7.0 7.0 Sodium Bicarbonate 1.50
9.0 Sodium Carbonate 0.50 NaOH 50% Soln 1.74 2.20 2.0 2.0 2.0 2.0
Na Lauryl Sulfate 4.0 5.0 3.0 4.0 4.0 3.0 2.0 according to Example
IV Sodium Fluoride 0.243 0.243 0.243 Sodium MFP 0.76 0.76 0.76 0.76
0.76 0.76 Glycerin USP 9.0 11.9 33.0 9.0 99.7% Sorbitol Soln USP
24.3 24.5 4.0 44.7 56.9 43.0 43.0 40.0 38.0 Tetra Na 2.05 5.045
3.85 3.85 Pyrophosphate, Anhydrous Tetra Potassium 6.38
Pyrophosphate (60% Soln) Na Acid 2.1 4.0 1.0 4.3 4.5 4.5 2.0
Pyrophosphate Mono Alkyl 3.5 6.7 3.5 3.5 Phosphate according to
Example I Cocamidopropyl 3.5 Betaine (30% soln) according to
Example II Titanium Dioxide 0.5 1.0 0.25 0.3 0.3 0.2 0.2
TiO.sub.2/Carnauba Wax 0.6 0.3 Prills Xanthan Gum 0.6 0.4 0.45 0.7
0.3 0.3 0.3 0.3 Water QS QS QS QS QS QS QS QS QS
Example VI
Improved Ethoxylated Mono Alkyl Phosphate Surfactant
[0171] Undesirable non-polar materials were extracted from
ethoxylated mono alkyl phosphate (supplied by Rhodia) utilizing a
high pressure carbon dioxide to separate the non-polar materials
from the ethoxylated mono alkyl phosphate. First, 45 ml of the
surfactant was placed into a 100 cc processing bag. The bag was
then engulfed by an additional 100 cc sample processing bag filled
with 6 mm glass beads. The bags filled with the surfactant and
glass beads were placed into a 100 cc sample processing vessel (200
C/10 kspi operation) of the SFE unit. The settings used were:
80.degree. C. for the oven assembly and restrictor valve assembly.
The tank pressure with CO2 was brought to 750 psi and equilibrated
for 10-15 minutes. Then the pressure was set to 3500 psi and
allowed to soak for 10 minutes. After 10 minutes, the
static/dynamic valve was opened and CO2 flow was maintained at a
steady rate of 10 mL/min for 10 min. Alternating static soaking and
dynamic flow steps were completed 10 times at the same pressure and
temperature conditions.
[0172] The extracted materials were then analyzed and the treated
ethoxylated mono alkyl phosphate surfactant was evaluated for taste
and odor after the extraction and shown to be very mild, especially
when compared with the starting material. The undesirable materials
identified as removed from the commercially supplied material are
set forth in Table 9, below.
TABLE-US-00009 TABLE 9 ethoxylated mono alkyl phosphate - Pre and
Post CO2 Extraction Sample Concentration of undesirable CO2
materials (ppm, .mu.g/g) Sample Extraction Dodeca- Dodeca- Dodecyl
# Description Conditions nal nol Acetate VIa DERMALCARE Untreated
94.3 6534.0 62.0 MAP L213/S VIb DERMALCARE Post - 75.6 5256.8 47.6
MAP L213/S Extraction 3500 Psi/80.degree. C.
Sample VIa shows the untreated surfactant had 94.3 ppm Dodecanal,
6534 ppm dodecanol, and 62 ppm dodecyl acetate. After treating the
surfactant in a batch CO2 process as described, the treated MAP
sample VIb contained a reduced dodecanal of 75.6 ppm, a reduced
dodecanol of 5256.8 ppm, and a reduced dodecyl acetate of 47.6
ppm.
Example VII
Improved Amine Oxide Surfactant
[0173] Undesirable non-polar materials were extracted from
N,N-Dimethyldodecylamine N-oxide (amine oxide) surfactant
(.about.30% aqueous solution), supplied by Sigma-Aldrich
Corporation (St. Louis, Mo., USA), using the process steps shown in
Example I, substituting the amine oxide for the MAP L213/S.
Additionally, a different rotary evaporator (model EL131 supplied
by BUCHI Labortechnik AG in Flawil, Switzerland) was used for
removing residual EtOAc. During rotovap, a vacuum was also applied
via rough pump (General Electric model SKC36PN435GX, Fort Wayne,
Ind., USA), which was controlled by manual adjustment of a clamp
added to a teed in segment of hose between the pump inlet and
rotovap. Vacuum was increased to the point where surfactant began
gentle bubbling. By applying vacuum, the rate of residual EtOAc
removal was significantly increased. The pre- and post-extraction
amine oxide materials were then analyzed by immersion SPME GC-MS
(Agilent model 7890 GC & model 5975 Mass Spectrometric
Detector, Agilent Technologies, Wilmington, Del., USA), and the
treated amine oxide surfactant was evaluated for taste and odor
after the extraction and shown to be very mild, especially when
compared with the starting material. GC-MS analyses for this
example were performed at a later time with newer equipment and the
resulting retention times are slightly longer than for other
examples. The undesirable materials removed from the commercially
supplied material are set forth in Table 10, below.
TABLE-US-00010 TABLE 10 Results for Amine Oxide LLE treatment with
EtOAc Control Reten- (Pre- Post tion extract) Extract Area Time
Peak Peak Reduc- Undesirable Material (Min) Area Area tion (%)
Decane 3.45 729450 0 100.0 N,N- 4.198 5799292 0 100.0
Dimethylhydroxylamine Undecane 4.326 1.58E+08 0 100.0 Undecene
Isomer 4.613 2433592 0 100.0 Undecene Isomer 4.663 514924 0 100.0
Undecene Isomer 4.696 4576558 0 100.0 Undecene Isomer 4.731 3314628
0 100.0 Undecene Isomer 4.873 13478025 0 100.0 Undecene Isomer
4.981 7185801 0 100.0 Dodecane 5.262 97542837 275259 99.7 Dodecene
Isomer 5.517 1722855 0 100.0 Dodecene Isomer 5.564 256787 0 100.0
Dodecene Isomer 5.594 1970807 0 100.0 Dodecene Isomer 5.637
1.34E+08 20278565 84.9 Dodecene Isomer 5.686 1713571 0 100.0
Dodecene Isomer 5.749 5157893 0 100.0 Dodecene Isomer 5.847 2337409
0 100.0 Tridecane 6.079 60387770 0 100.0 Substituted
Tetrahydrofuran 6.211 741293 0 100.0 Tridecene Isomer 6.304 934388
0 100.0 Tridecene Isomer 6.373 2370074 0 100.0 Tridecene Isomer
6.411 1509006 0 100.0 Tridecene Isomer 6.514 5357518 0 100.0
Tridecene Isomer 6.61 2493787 0 100.0 Tetradecane 6.808 88989028 0
100.0 Tetradecene Isomer 7.013 648872 0 100.0 Tetradecene Isomer
7.075 793547 0 100.0 Tetradecene Isomer 7.119 51889810 6298997 87.9
Methyl Tetradecane Isomer 7.184 1406294 0 100.0 Tetradecene Isomer
7.209 1387502 0 100.0 Tetradecene Isomer 7.301 1082259 0 100.0
Pentadecane 7.469 10662978 0 100.0 Unknown 7.683 3450057 0 100.0
Methyl 4,6-decadienyl ether 7.863 19513653 0 100.0 Hexadecane 8.094
34907941 0 100.0 Undecanone Isomer 8.166 258835 0 100.0
N,N-Dimethyl-1- 8.304 76976187 228611 99.7 Dodecanamine Undecanol
8.381 5483997 0 100.0 Dimethyl Undecanone 8.421 1533470 0 100.0
Dodecanone Isomer 8.582 394239 0 100.0 Heptadecane 8.681 4445134 0
100.0 Dodecanone Isomer 8.783 537729 0 100.0 Dodecanal 8.824
16858547 3586725 78.7 Substituted Tetrahydrofuran 8.956 4420861 0
100.0 Methyl 6,8-dodecadienyl 9.056 13713367 0 100.0 ether
Octadecane 9.238 23859062 0 100.0 Dodecanoic acid, methyl 9.303
6560940 0 100.0 ester N,N-Dimethyl-1- 9.358 26094804 3499984 86.6
Tetradecanamine Tetradecanone Isomer 9.737 1458218 0 100.0
Nonadecane 9.768 1489949 0 100.0 Unknown Amide 9.864 255865 0 100.0
Tetradecanone Isomer 9.923 589980 0 100.0 Unknown Amide 10.048
341466 0 100.0 Dodecanol 10.137 40526459 856635 97.9 Pentadecanone
Isomer 10.273 4602974 0 100.0 Methyl tetradecanoate 10.374 1435045
0 100.0 Pentadecanone Isomer 10.451 1668318 0 100.0 Tetradecanol
11.128 9874928 0 100.0 N,N-Dimethyldodecanamide 12.113 44118371
65123 99.9 p-Dicyclohexylbenzene 12.445 2523931 0 100.0 N,N- 13.048
14118245 679312 95.2 Dimethyltetradecanamide Dodecanoic acid ester
14.154 24988729 0 100.0 Dodecanoic acid ester 15.662 2168393 0
100.0 Avg % 98.9 Reduc- tion =
[0174] The dimensions and values disclosed herein are not to be
understood as being strictly limited to the exact numerical values
recited. Instead, unless otherwise specified, each such dimension
is intended to mean both the recited value and a functionally
equivalent range surrounding that value. For example, a dimension
disclosed as "20 g" is intended to mean "about 20 g." All
percentages, ratios and proportions herein are on a weight basis
unless otherwise indicated. Except as otherwise noted, all amounts
including quantities, percentages, portions, and proportions, are
not intended to indicate significant digits.
[0175] It should be understood that every maximum numerical
limitation given throughout this specification includes every lower
numerical limitation, as if such lower numerical limitations were
expressly written herein. Every minimum numerical limitation given
throughout this specification will include every higher numerical
limitation, as if such higher numerical limitations were expressly
written herein. Every numerical range given throughout this
specification will include every narrower numerical range that
falls within such broader numerical range, as if such narrower
numerical ranges were all expressly written herein.
[0176] Except as otherwise noted, the articles "a", "an", and "the"
mean "one or more".
[0177] As used herein, "comprising" means that other steps and
other ingredients which do not affect the end result can be added.
This term encompasses the terms "consisting of" and "consisting
essentially of". The compositions and methods/processes of the
present invention can comprise, consist of, and consist essentially
of the essential elements and limitations of the invention
described herein, as well as any of the additional or optional
ingredients, components, steps, or limitations described
herein.
[0178] Every document cited herein, including any cross referenced
or related patent or application, is hereby incorporated herein by
reference in its entirety unless expressly excluded or otherwise
limited. The citation of any document is not an admission that it
is prior art with respect to any invention disclosed or claimed
herein or that it alone, or in any combination with any other
reference or references, teaches, suggests or discloses any such
invention. Further, to the extent that any meaning or definition of
a term in this document conflicts with any meaning or definition of
the same term in a document incorporated by reference, the meaning
or definition assigned to that term in this document shall
govern.
[0179] While particular embodiments of the present invention have
been illustrated and described, it would be obvious to those
skilled in the art that various other changes and modifications can
be made without departing from the spirit and scope of the
invention. It is therefore intended to cover in the appended claims
all such changes and modifications that are within the scope of
this invention.
* * * * *
References