Note: Descriptions are shown in the official language in which they were submitted.
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PRO-FRAGRANCE COMPOUND
FIELD
The present invention relates to an acetal or a ketal pro-fragrance
compound.
BACKGROUND
Most consumers have come to expect scented laundry products and to
expect that fabrics which have been laundered will also have a pleasing
fragrance. It is also desired by consurners for laundered fabrics to maintain the
pleasing fragrance over time. Perfume additives may make laundry
compositions more aesthetically pleasing to the consumer, and in some cases
15 the perfume imparts a pleasant fragrance to fabrics treated therewith. However,
the amount of perfume carry-over from a detergent solution onto a fabric surfaceis often marginal and does not last long on the fabric surface. In addition, some
perfume delivery systems are not stable under alkaline conditions, such as in
laundry detergent compositions and detergent solutions. Also, fragrance
20 materials are often very costly. Thus, their inefficient use in detergents and
ineffective delivery from detergents to fabric surface usually results in a high cost
to both consumers and detergent manufacturers. Industry, therefore, continues
to seek more efficient and effective perfume delivery in laundry products.
Acetals and ketals have long been known in perfumery. See Steffen
25 Arctander, "Per~ume and Flavor Chemicals," Arctander, N.J., 1969. The ma~ority
of these are methyl and ethyl types, and molecular weighls may range widely.
See, for example, Arctander abstract numbers 6, 11, 210, 651, 689, 1697, 1702,
2480, 2478. However, the known acetals and ketals are generally not desirable
for use in laundry products. For 2478, which is phenylacetaldehyde dicitronellyl30 acetal, molecular weight 414.7, Arctander reports " ... and it is not exaggerated to
say that this acetal is practically abandoned and obsolete in today's perfumery."
For 2480, which is phenylacetaldehyde digeranyl acetal, Arctander reports "the
title material does not offer substantial advantages or unique odor type and it
may be considered of little more than academic interest today." This latter
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material was still commercially available in 1992 as ROSETAL A (Catalogue,
IFF).
Carrier mechanisms for perfume deiivery, such as by encapsulation, are
also known in the art. See for example, U.S. Patent 5,188,753, issued Feb. 23,
5 1993.
Early efforts to delay release of perfumes in detergents include the use of
certain organometallic compounds, such as titanate or zirconate esters. See
U.S. Patent 3,849,326, issued Nov. 19, 1974 and U.S. Patent 3,923,700, issued
Dec. 2, 1975. Limited amounts of titanium or zirconium can be useful as
10 catalysts for synthesizing pro-perfume materials.
Personal care compositions, such as deodorant sticks, comprising "body-
activated" fragrances are also known. The term apparently refers to the
previously known tendency of materials such as acetals derived from perfume
alcohols to hydrolyze under acidic pH conditions thereby releasing fragrance
15 See, for example, U.S. Patent 5,378,468, issued Jan. 3, 1995 and U.S. Patent
3,932,~20, issued January 13, 1976.
Potential fragrance materials for use in such personal care compositions
include particular acetals and ketals, exemplified by propylene glycol vanillin
acetal. The materials exemplified apparently are rather hydrophilic short chain
alcohol or diol derivatives of fragrance aldehydes and upon hydrolysis, deliver
one mole of the aldehyde per mole of the potential fragrance material. This
development is designed to be incorporated with a personal care product vehicle,resulting in clear deodorant sticks and the llke and the compositions containingthe potential fragrance materials are applied directly to the substrate (i.e. skin);
therefore, the deposition problems resulting from the dilution, rinsing, etc.,
associated with the laundry process are not at issue.
Factors affecting substantivity of fragrance materials on fabrics are
discllssqd in Estcher et al. JAOCS 71 p. 31-40 (1994).
Laundry detergents are used in dilute aqueous form and contain
numerous detergent adjuncts such as synthetic detergents, builders, enzymes
and the like which are capable of micellizing, or solubilizing the pro-fragrance.
Further, the laundry process includ~s rinsing, and someli",es drying with
tumbling machines after washing. The rinsing tends to remove the useful pro-
fragrance material deposited. The tumble-drying further exacerbates the
problem of delivering adequate residual fragrance to textile fabric surfaces.
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The pro-fragrance compounds of the present invention can be used for a
variety of products wherein the conventional fragrances are used. These are, forexample, such as shampoos, conditioners, detergent hard surface cleaner,
deodorants, cat litter, and the like.
Based on the foregoing, there is a need for a pro-fragrance compound
with improved dispersability in aqueous solutions. Especially, pro-fragrance
compound used for detergent composition further can be enhanced deposition
on fabric surfaces in the wash solution, and enhanced retention on the washed
surface during rinsing. None of the existing art provides all of the advantages
10 and benefits of the present invention.
SUMMARY
The present invention is directed to a pro-fragrance compound selected
from the group consisting of an acetal, a ketal, and mixtures thereof, wherein at
15 least one of a parent aldehyde, ketone, or alcohol of the pro-fragrance acetal or
ketal is a fragrance compound, having a CLogP of less than about 4. The
CLogP is the logarithm to base 10 of the Octanol/Water Partition Coefficient of
the pro-fragrances.
These and other features, aspects, and advantages of the present
20 invention will become better understood from a reading of the following
description, and appended claims.
DETAILED DESCRIPTION
While the speciricdlion concludes with claims particularly pointing out and
25 distinctly claiming the invention, it is believed that the present invention will be
better understood from the following description.
All percentages and ratios used hereinafter are by weight of total
composition, unless otherwise indicated.
All measure"ler,ls referred to herein are made at 25~C unless otherwise
30 specificd.
All percentages, ratios, and levels of ingredients referred to herein are
based on the actual amount of the ingredient, and do not include solvents, fillers,
or other materials with which the ingredient may be combined as a commercially
available product, unless otherwise indicated.
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All publications, patent applications, and issued patents mentioned herein
are hereby incorporated in their entirety by reference. Citation of any reference
is not an admission regarding any determination as to its availability as prior art
to the claimed invention.
As used herein, "comprising" means that other steps and other
components which do not affect the end result can be added. This term
encompasses the terms "consisting oft' and "consisting essentially of."
PRO-FRAGRANCES
As used herein, "pro-fragrance" compound means a compound which may
l0 or may not be odoriferous in itself but which, upon hydrolysis, produces a
desirable odor which is characteristic of one or more of its hydrolysis products.
This term includes mixtures of pro-fragrance compounds and further
encompasses the term "pro-perfume." Acetals and Ketals can be considered as
derivable from aldehydes or ketones in combination with alcohols. These
15 aldehydes, ketones and alcohols are herein termed "parents" or "parent
compounds" of the acetal or ketal. At least one parent of any of the instant
acetals or ketals is a fragrance compound.
The pro-fragrance compound of this present invention has CLogP of less
than about 4, wherein the CLogP is the logarithm to base 10 of the
20 OctanolN~ater Partition Coefficient of the pro-fragrance compound. The pro-
fragrances having the CLogP of less than about 4 give good dispersibility in theaqueous solution. Without being bound by theory, it is believed that the CLogP,
as described herein, can be lower when the number of alkoxy moiety included in
the pro-fragrance compound is increased.
These pro-fragrance compounds can further be characterized as having a
molecular weight of at least about 170 and a half-life of less than 60 minutes
when measured at pH 0 by the Hydrolysis Half-life (t-1/2) Test as described
herein.
The preferred pro-fragrances can be cyclic or acyclic having at least 3
30 oxygens. Preferably, the cyclic pro-fragrance compound has at least two
alkoxylate moiety and the acyclic pro-fragrance compound has at least 4
alkoxyiate moiety.
An important class of the pro-fragrance compounds herein are those
derived from a fragrance or non-fragrance alcohol, particularly C6-C20
(preferably C1 1 -C20, more preferably C14-C1 8 alcohols) saturated or
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unsaturated, linear or branched aliphatic alcohols, commonly referred to as
detergent alcohols and a fragrant Cg- or higher unsaturated aldehyde or a
fragrance ketones.
Preferably, parent alcohols of the present invention have at least one
S alkoxy moiety. Due to increasing the member of alkoxy moiety as described
above, the pro-fragrances having the CLogP of less than about 4 give good
dispersibility in detergent solution. The preferred parent alcohols can include the
alkoxylates of detergent alcohols, mono-alkyl ethers of short-chain
polyalkoxylates, polyols including those which are alkoxylated with ~ to 30 groups
10 of ethylene oxide or propylene oxide. Preferred parent aldehydes or ketones
herein, will be derived from a parent aldehyde having molecular weight above
about 80.
More generally, a wide range of acetals and ketals are included within the
invention. Many fragrant aldehydes, ketones, and alcohols which are suitable
15 parents for the present acetals and ketals are known to the art. See, for example,
Arctander's compilation referenced hereinabove for fragrant parents. These will
be also obtainable commercially from perfume houses such as IFF, Firmenich,
Takasago, H&R, Givaudan-Roure, Dragoco, Aldrich, Quest, and others.
Acetals
The pro-fragrances of the present invention include an acetal. The acetal
can be used to deliver fragrance aldehydes, fragrance alcohols, or both,
preferably to deliver fragrance aldehydes derived from parent aldehydes.
Acetals suitable in the present invention include the following structure:
H
R1~l--X
y
25 X and Y are derived from a starting alcohol and R1 and the H is derived from a
starting aldehyde.
X and Y in the above general structure which can be either fragrant
alcohols or non-fragrant alcohols includes variable alkoxy moieties. X and Y canbe the same or different allowing the delivery of more than one type of fragrant30 alcohol. When the alcohols are non-fragrant alcohols, it is preferred that they are
C6-C20 alcohols, especially fatty alcohols, which may optionally be modified by
ethoxylation or propoxylation. X and Y can be simple alcohols containing a
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single OH group, or can be polyols containing 2 or more OH groups, more
preferably, diols.
In general, alcohols can be saturated, unsaturated, linear or branched,
alkyl, alkenyl, alkylaryl, alkylalkoxylate derivatives with one or more alcohol
groups. The alcohols may contain additional functionality such as amines,
amides, ethers, or esters as a part of their structure.
Preferably, the acetal of the present invention can be cyclic or acyclic, and
may contain one or more acetal groups through derivatizing one or more
aldehydes. The terms cyclic and acyctic in this context refers to the presence or
10 absence of a covalent bond connecting moieties X and Y of the acetal. X and Yof the cyclic acetals form a ring structure and have at least two alkoxylate
moieties. The preferred acyclic acetals having at least four alkoxylate moietiesincorporate linear alcohols.
The cyclic acetals are derived from polyols. Preferred polyols include
15 those which are alkoxylated with 1 to 30 units of ethylene oxide or propyleneoxide. Nonlimiting examples of the polyols include, for example, sorbitol,
glucose, sucrose, and other saccharides.
The acyclic acetals are derived from mono-alcohols. Preferred mono-
alcohols containing a single OH group can include the alkoxylates of detergent
20 alcohols and mono-alkyl ethers of short-chain polyalkoxylates. Preferably, the
mono-alkyl ethers of short-chain polyalkoxylates include C1-Cs alkyl moiety.
Nonlimiting examples of the parents alcohols include ethyl alcohol, propyl
alcohol, butyl alcohol, lauryl alcohol, and myristyl alcohol.
R1 and the H of the above general structure are is derived from a starting
25 aldehyde. In general, both fragrant and non-fragrant aldehydes incorporated into
the instant acetals can be aliphatic, allylic or benzylic. The aldehydes can be
saturated, unsaturated, linear, branched, or cyclic. The structures can include
alkyl, alkenyl, or aryl moieties, as well as additional functional groups such as
alcohols, amines, amides, esters, or ethers.
Preferably, acetals herein, will be derived from a parent aldehyde having
molecular weight above about 8û.
Many fragrant aldehydes and alcohols which are suitable parents for the
present acetals and ketals are known to the art. See, for example, Arctander's
compilation referenced hereinabove for fragrant parents. Nonlimiting examples
35 of the fragrant parent aldehydes include but are not limited by the following
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examples: hydratropaldehyde, p-t-bucinal, FloralozoneT~, phenylpropanal,
anisaldehyde, cymal, cyclamal, triplal, helional, hexylcinnamic aJdehyde, vanillin,
ethyl vanillin, citral, ethyl citral, citronellal, methyl octyl acetaldehyde, methyl
nonyl acetaldehyde, octanal, decanal, dodecanal, lauric aldehyde,
5 chrysanthal,isosyslocitral, melonal, trans4-decenal, adoxal, hydroxycitronellal,
and iso-hexenyl cyclohexenyl carboxaldehyde.
Specific preferred pro-fragrance acetal compounds are nonlimitingly
illustrated by the following:
y~ <
f
~> <
,~
which is derived from P.T. Bucinal and tripropylene glycol. Also preferred is
~0~
~ ~
JV ~~
which is derived from cyclal c and tripropylene glycol.
Some specific examples of acyclic acetals useful herein include:
O(CH2CH20)6C 12H25
~J\O(CH2CH20)6C12H25
which is derived from P.T. Bucinal and Neodol 6-2~ and
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~=~ O(CH2CH20)70CH3
~ O(CH2cH2O)~cH3
which is derived from P.T. ~ucinal and PEG-300 methyl ether.
Additionally, suitable acetals herein are cyclic acetals derived from the
reaction of fragrance aldehydes with polyhydroxyglucosides, including the
5 polyhydroxyamides. Typical examples of suitable polyhydroxy amides include
the C12-C1g N-methylglucamides. See WO 9,206,154. Other sugar-derived
acetal or ketal parent compounds herein include the N-alkoxy polyhydroxy fatty
acid amides, such as C10-C1g N-(3-methoxypropyl) glucamide.
Ketals
The pro-fragrance compound of the present invention includes a ketal.
The ketal can be used to deliver a fragrance ketone. The discussion for the
ketals herein can be constructed using structural principles analogous to those
used in discussing acetals supra.
Ketals suitable in the present invention include the following structure:
R3
R2~--X
Y
X and Y are derived from alcohols or polyols and R2 and R3 are derived from the
parent ketone, and can be the same or different.
As noted in defining the acetals supra, X and Y for Ketals in the above
general structure which can be either fragrant alcohols or non-fragrant alcohols20 including variable alkoxy moieties. The parent alcohols for the ketals can
include, but are not limited to, those described as the parent alcohols of the
acetals in the section of acetals.
In general, aicohols can be saturated, unsaturated, linear or branched,
alkyl, alkenyl, alkylaryl, alkylalkoxylate derivatives with one or more alcohol
25 groups. The parent alcohols may contain additional functionality such as amines,
amides, ethers, or esters as a part of their structure.
R2 and R3 of the above general structure are derived from the parent
ketone. In general, both fragrant and non-fragrant ketones can be aliphatic,
allylic or benzylic. The ketones can be saturated, unsaturated, linear, branched,
30 or cyclic, preferably including alkyl, alkenyl, or aryl moieties as well as other
functional groups including amides, amines, ethers, or esters.
. ,
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Preferably, ketals herein, will be derived from a parent ketone having
molecular weight above about 80.
Nonlimiting examples of the parent ketones include, for example, irone
alpha, alpha-ionone, beta-ionone, gamma-methyl ionone, methyl beta-naphthyl
5 ketone, cisjasmone, damascenone, alpha-damascenone, benzylacetone, methyl
dihydrojasmonate, methyl amyl ketone, methyl heptyl ketone, methyl hexyl
ketone, methyl nonyl kètone, carvone, cassione, menthone, and geranylacetone.
Other suitable ketones include diketones, e.g. 2,4-pentadione.
The non-fragrant ketone can contain one or more ketone functional groups
10 and such groups can be further derivatized so that the ketal is polymeric. While
polyketals are included herein, they are less preferred than mono- and di-ketals.
Monoketals are most preferred.
Specific preferred pro-fragrance ketal compounds are nonlimitingly
illustrated by the following:
>~
which is derived from alpha-ionone and tripropylene glycol.
Some specific examples of acyclic ketals useful herein include:
\~o(CH2CH20)6C 12H25
~/\O(CH2CH20)6C 12H25
which is derived from 2-octanone and Neodol 6-25 and
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k O(CH2CH2O)~OCH3
O(CH,C1120)70cH3
which is derived from 2-octanone and PEG-300 methyl ether.
The pro-fragrance compounds of the present invention can be used for a
variety of products wherein the conventional fragrances are used. These are, for5 example, such as shampoos, conditioners, detergent hard surface cleaner,
deodorants, cat litter, and the like.
Synthesis of pro-fragrances
Acetals and ketals can be prepared by the acid-catalyzed reaction of an
aldehyde or ketone with an alcohol (or diol), using conventional acid catalysis
10 such as HCI or p-toluenesulfonic acid, or supported sulfonic acid catalysts e.g.,
AMB~RLYST 15TM. See Meskens, F., Synthesis, (7) 501 (1981) and Meskens,
F., Jannsen Chim Acta (1) 10 (1983). Many aldehyde, ketone and alcohols
useful in the synthesis of acetal and ketal pro-fragrances of the present invention
are sensitive to strong acid conditions and can undergo undesirable side
reactions. See Bunton, C.A. et al, J. Org. Chem. (44), 3238, (1978), and Cort,
O., et al, J. Org. Chem. (51), 1310 (1986). It is also known that acetals of alpha,
beta-unsaturated aldehydes can undergo mig,aliGn of the double bond under the
inappropriate selection of the acid catalyst. See Meskens, f., Synfhesis, (7),
501, (1981) and Lu, T.-J, et al. J. Org. Chem. (60), 2931, (199~). For acid
20 sensitive materials, acid catalysts with pKa's among 3 and 4 are the most
desirable to minimize double bond migration while maintaining the reactivity
nece~cary to produce the acetal (or ketal). For example, in the synthesis of
digeranyl decanal, p-toluenesulfonic acid (pKa =1 ) causes undesirable side
reactions with geraniol. Citric acid (pKa1=3.1, pKa2=4.8, pKa3=6.4) can be used
25 to form the acetal without side reactions.
Another technique of avoiding side reactions in preparing acetals and
ketals of acid sensitive material, such as geraniol, is by transacetalization of a
dimethyl acetal or ketal with a higher molecular weight alcohol, using a mild
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11
Lewis acid such as titanium isopropoxide or boron trifluoride etherate as the
catalyst.
TEST METHODS
Calculation of CLogP
The pro-fragrances of the invention are characterized by their
octanol/water partition coefficient P. The octanol/water partition coefficient of a
pro-fragrance is the ratio between its equilibrium concentration in octanol and in
water. Since the partition coefficients of the pro-fragrance compounds are large,
10 they are more conveniently given in the form of their logarithm to the base 10,
logP.
The logP of many compounds have been reported; for example, the
Pomona92 database, available from Daylight Chemical Information Systems, Inc.
(Daylight CIS), contain many, along with citations to the original literature.
However, the logP values are most conveniently calculated by the
"CLOGP" program, also available from Daylight CIS. This program also lists
experimental logP values when they are available in the Pon,ona92 d~t~base.
The "calculated logP" (CLogP) is determined by the fragment approach of
Hansch and Leo (cf., A. Leo, in Comprehensive Medicinal Chemistry, Vol. 4, C.
Hansch, P.G. Sammens, J.B. Taylor and C.A. Ramsden, Eds., p. 295, Pergamon
Press, 1990). The r,dy,nent approach is based on the chemical structure of a
compound and takes into account the numbers and type of atoms, the atom
connectivity, and chemical bonding. The CLogP values, which are the most
reliable and widely used esli",ates for this physicochemical property, can be
used in~ead of the experimental logP values in the selection of pro-fragrances.
Determination of Hvdrolysis Half-life (t-1/2)
Hydrolysis half-life is the measurement used to detem~ e the ease with
which the pro-f,dg,al,ce compound undergoes acid hydrolysis and thereby
releases its fragrance component(s) upon exposure to acid conditions. The pro-
fragrance compounds of the invention have a half-life of less than 60 minutes,
under the described hydrolysis conditions at pH 0. Preferably, pro-fragrances ofthe invention have a half-life at pH 2 of less than 60 minutes. For granular
detergents, the more reactive pro-fragrances, that is, those with half-life at pH 2
of less than one minute, are most suitable, although those having a half-life ofless than 60 minutes at pH 0 are also useful. For liquid detergent applications,
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12
pro-fragrances having a half-life of less than 60 minutes at pH 0, and half-lifegreater than one minute at pH 2 should preferably be used.
Hydrolysis half-life is determined by UVN is spectroscopy in a 90/10
dioxane/water system at 30~C by following the appearance of the carbonyl
S absorbance. Because of the hydrophobicity of the pro-fragrance compounds of
the invention, a high dioxane/water ratio is needed to ensure solubility of the pro-
fragrance. The pH of the water used is achieved by using aqueous HCI. The
concentration of the pro-fragrance in the dioxane/water system can be adjusted
to achieve convenient, measurable absorbance changes.
All measurements are carried out using a Hewlett Packard 8452 A Diode
Array Spectrophotometer using quartz 1 cm path length cuvette cells. Materials
used include 1 ,4-dioxane HPLC Grade 99.9% (Sigma-Aldrich), 1N HCI volumetric
solution (J.T. Baker), deionized water filtered with MilliQPlus (Millipore) at
resistivity of 18.2 M Ohm cm. The pH's are measured using an Orion 230 A
15 standardized with pH 4 and pH 7 buffers. The 1N HCI standard is used directlyfor pH 0 conditions. For pH 2 conditions, 1 N HCI is diluted with deionized water.
Pro-r,dg,dnce is weighed out in a 10ml volumetric flask using an analytical
balance (Mettler AE 200) Precision is 1/10 mg. The weighed material is
dissolved in about 8ml dioxane. Both the dioxane solution of pro-fragrance and
20 aqueous acid solution prepared as described supra are pre-heated in their
separate containers to a temperature of 30 + 0.25~C by means of a water-bath.
1.000ml of aqueous acid solution is added to the pro-fragrance solution by
means of an Eppendorf pipetter. This is followed by diluting to the 10ml mark
with dioxane. Hydrolysis time is measured, starting upon addition of the acid.
25 The pro-fragrance solution is mixed for 30 seconds by shaking, and the solution
is tra"s~r,ed to a quartz cuvette. The absorbance of the pro-fragrance solution
(At) is followed at a regular series of time intervals, and the cuvette is kept in the
water-bath at the above-indicated temperature between measurements. Initial
absorbance (Ao) measurements are carried out using an equal concentration of
30 pro-fragrance in a 90/10 v/v dioxane - deionized water solution, and final
absorbance (Af) measurements are taken using the hydrolyzed pro-fragrance
solution after the hydrolysis is complete. The wavelength at which the hydrolysis
is followed is chosen at the wavelength of the absorbance maximum of the
parent aldehyde or ketone.
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13
Reaction half-lifes are determined using conventional procedures. The
observed first-order rate constant (kobs) is determined by slope of the line
provided by plotting the following function vs time (min):
Ln [(Ao - Af)/ (At - Af)]
5 wherein said function is the natural log of the ratio between the absorbance
difference at initial time (Ao) and final time (Af) over the absorbance difference at
time t (At) and final time (Af).
Half-life as defined herein is the time required for half of the pro-fragrance
to be hydrolyzed, and is determined from the observed rate constant (kobs) by
l0 the following function:
Ln (1/2) = -kobs t 1/2
DETERGENT COMPOSITION
The pro-fragrance compound of the present invention can be used for a
detergent composition. P,eferdbly, the pro-fragrance acetal, ketal or mixture
15 thereof can be formulated in the detergent compositions at levels in the general
range about 0.0001% to about 10%, more preferably from about 0.001% to 5%,
more preferably still, from about 0.01% to about 1%.
The pro-fragrance compounds are stable under pH conditions
encountered in the formulation and storage of detergent products which have a
20 pH of from about 7.1 to about 13, and during solution-use of such products. Due
to hydrophilicity and high degree of heteroatom incorporation, these pro-
fragrance compounds give reasonably good deposition from a laundering
solution onto fabrics. Because the pro-fragrance compounds are subject to
hydrolysis when the pH is reduced, they hydrolyze to release their component
25 fragrance compounds when the fabrics (or other surface) upon which they have
been deposited are exposed even to reduced pH such as is present in rinse
water, air and humidity. Such a reduction in pH shouid be at least about 0.1,
preferably at least about 0.5-units. Preferably the pH is reduced by at least about
0.5 units to a pH of about 7.5 or less, more preferabiy about 6.9 or less.
30 Preferably, the solution in which the fabric (or other surface) is washed is
alkaline.
The pro-fragrance compound can be used as the sole fragrance
compound of the present detergent compositions, or in combination with other
pro-fragrances and/or in combination with other fragrance materials, extenders,
35 fixatives, diluents and the like. For example, incorporation of the pro-fragrance
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14
material into a waxy substance, such as a fatty triglyceride, may further improve
storage stability of the present pro-fragrance compounds in granular laundry
detergents, especially those comprising bleaches. In liquid or gel forms of
detergent compositions, hydrophobic liquid extenders, diluents or fixatives can be
5 used to form an emulsion wherein the pro-fragrance compound is further
stabilized by separating it from the aqueous phase. Nonlimiting examples of
such stabilizing materials include dipropylene glycol, diethyl phthalate and acetyl
triethyl citrate. ~ust as there exist hydrophobic perfumery ingredients which can
be used to stabilize the pro*agrance material, there also exist detergency
10 ingredients which also have a perfume stabilizing effect and can be formulated
with the pro-fragrance material. Such ingredients include fatty acid amines, lowfoaming waxy nonionic materials commonly used in automatic dishwashing
detergents, and the like. In general, where pro-fragrances are used along with
other fragrance materials in detergent compositions herein, it is preferred that the
l 5 pro-fragrance be added separately from the other fragrance materials.
Detersive Surfactants
The detergent surfactant can further be used for the detergent
composition in addition to the pro-r,~grdnce compounds of this invention.
Preferably, cor"positions incorporating sy"lh~lic detergent surfactants have a
20 detergent level of from about 0.5% to about 50%, by weight. Compositions
containing soap p,eferably comprise from about 10% to about 90% soap.
Many detergent surfactants which are conventinal for detergent
surfactants can be used. Mixtures of anionic and nonionic surfactants are
especially useful. Other conventional useful su,rd.;tar,ts are listed in standard
25 texts. See also U.S. Patent 3,664,961, issued May 23, 1972.
The detergent compositions herein, preferably, have a pH of from about
7.1 to about 13, more typically from about 7.5 to about 9.5 for liquid detergents
and from about 8 to about 12 for granular detergents when measured at 1%
concentration of the dis~illed water at 20~C.
30 Additional Deterqent Inqredients
In addition to the pro-fragrance compounds herein may further include one
or more additional detergent ingredients, commonly used in detergent products,
such as materials for assisting or enhancing cleaning performance, treatment of
the substrate to be cleaned, or to modify the aesthetics of the detergent
35 composition (e.g., conventional perfumes, colorants. dyes, etc.). Such additional
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ingredients are known to those of skill in the art. The following are illustrative
examples of other detergent ingredients.
Builders - Detergent builders can optionally be included in the
compositions herein to assist in controlling mineral hardness and in the removal5 of particulate soilsSuitable builders include those of U.S. Patent 3,308,067,
issued Mar. 7, ~967; 4,144,226, issued Mar. 13, 1979 and 4,246,495, issued
Mar. 27, 1979. Inorganic as well as organic builders can be used.
The level of builder can vary widely depending upon the end use of the
composition and its desired physical form. When present, the compositions will
typically comprise at least about 1 % builder. Prferebly, liquid formulations
typically comprise from about 5% to about 50%, and granular formulations
typically comprise from about 10% to about 80%. Lower or higher levels of
builder, however, are not meant to be excluded.
Soil Release Agents - Soil Release agents are desirably used in laundry
detergents of the instant invention. Suitable soil release agents include those of
U.S. Patent 4,968,451, issued Nov. 6, 1990; the nonionic end-capped 1,2-
propylenefpolyoxyethylene terephthalate polyesters of U.S. Patent 4,711,730,
Dec. 8, 1987; the partly- and fully- anionic-end-capped oligGmeric esters of U.S.
Patent 4,721,580, issued Jan. 26, 1988; the nonionic-capped block polyester
oligomeric compounds of U.S. Patent 4,702,857, issued Oct. 27, 1987; and the
anionic, especially sulfoaroyl, end-capped terephthalate esters of U.S. Patent
4,877,896, issued Oct. 31, 1989. Another preferred soil release agent is a
sulfonated end-capped type described in U.S. Patent 5,41~,807.
Other Inqredients
The cGIllpositions herein can contain other ingredients such as enzymes,
bleaches, fabric softening agents, dye transfer inhibitors, suds suppressors, and
chelating agents, all well known within the art.
Formulation with Detergents With or Without Conventional Perfumery Materials
While the pro-fragrances of the present invention can be used alone and
simply nixed with essential detergent ingredient, most notably surfactant, they
can also be desirably combined into three-part formulations which combine (a) a
non-fragrance detergent base co",prising one or more synthetic detergents, (b)
one or more pro-fragrance acetals or ketals in accordance with the invention and(c) a fully-formulated fragrance. The latter provides desirable in-package and in-
use (wash-time) fragrance, while the pro-fragrance provides a long-term
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fragrance to the laundered textile fabrics. It is preferred that the pro-fragrance
compound be added separately from the conventional fragrances to the
detergent compositions.
Formulation with other Special-Purpose Fragrance Delivering Compounds
Detergents in accordance with the present invention may further,
optionally, if desired, contain other known compounds having the capability to
enhance substantivity of a fragrance. Such compounds include, but are not
limited to, the aluminum alkoxides such as isobutylaluminium diferanylate as
disclosed in U.S. Patent 4,055,634, issued Oct. 25, 1977; or the known titanate
and zirconate esters or oligoesters of fragrant materials such as those disclosed
in U.S. Patent 3,947,574, issued March 30, 1976 and U.S. Patent 3,779,932,
issued Dec. 18, 1973. When using such organoaluminium, organotitanium or
organozinc derivatives, they may be incorporated into the detergent compositionsof the present invention described herein at their art-known levels.
I 5 Methods of Use
In its method aspect, the present invention can be described as:
A loelllod of delivering residual fragrance to a washed surface which
comprises the steps of
(a) washing said surface in an aqueous solution of a detergent composition
comprising a pro-fragrance compound selected from the group consisting
of an acetal, a ketal, and mixtures thereof, wherein the pro-fragrance
compound having a Clop of less than about 4 and a detersive surfactant,
wherein said detergent composition has a pH of at least 7.1 when
measured as a 1% solution in distilled-water at 20 C;
(b) subsequently exposing said surface to a reduction in pH.
EXAMPLES
The following exa"l,cles further describe and demonstrate embodiments
within the scope of the present invention. The examples are given solely for thepurpose of illusl,alion and are not to be construed as !i",itdlions of the present
invention, as many variations thereof are possible without departing from the
spirit and scope of the invention.
The detergent compositioms shown below can be prepared by any
conventional method well known in the art. A suitable method and formulation
are as follows:
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Example 1
fPreparation of Di(Neodol 23-6.5) P.T. Bucinal Acetal by Acid Catalysis]
A 200 ml single necked, round bottom flask is prepared. A 4.099 portion
of P.T. Bucinal (20 mmol), 60ml of benzene, 22.59 of Neodol 23-6.5 (50 mmol),
and 0.29 of p-toluene sulfonic acid monohydrate (1 mmol, 5 mol%) is added.
The vessel is fitted with a Dean-Stark trap and condenser, and is heated to
reflux. The reaction is continued until an equivalent of water is collected in the
lO Dean-Stark trap. Upon cooling, the reaction mixture is washed several times
with saturated sodium carbonate and water followed by drying with sodium
sulfate. The solvent is removed in vacuo and unreacted parent aldehyde is
removed under bulb-to-bulb dislilldlion at 250~C, 0.2mmHg to yield 19.69 of palebrown oil (80%) identified spectroscopically at the desired material. The Clop of
l5 resulting acetal is less than 4.
Example 2
[Preparation of Tripropylene glycol P.T. Bucinal Acetal by Acid Catalysis]
A 200 ml single necked, round bottom flask is prepared. A 4.099 portion
of P.T. Bucinal (20 mmol), 60 ml of benzene, 4.819 of tripropylene glycol (25
mmol), and 0.29 of p-toluene sulfonic acid monohydrate (1 mmol, 5 mol%) is
added. The vessel is fitted with a Dean-Stark trap and condenser, and is heated
to reflux. The reaction is continued until an equivalent of water is collected in the
2S Dean-Stark trap. Upon cooling, the reaction mixture is washed several times
with saturated sodium carbonate and water followed by drying with sodium
sulfate. The solvent is removed in vacuo and unreacted parent aldehyde is
removed under bulb-to-bulb distillation at 250~C, 0.2mmHg to yield 6.~9 of pale
brown oil (80%) identified spectroscopically at the desired ",a~rial. The Clop of
30 resulting acetal is less than 4.
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Exam~le 3
[Granular Laundry Composition delivering from Di(Neodol 23-6.5) P.T. Bucinal
Acetal]
Pro-fragrance of Example 1 1.0%
C11-C13 Dodecyl Benzene Sulfonate 21.0%
C12-C13 Alkyl Ethoxylate EO 1-8 1.2%
Sodium Tripolyphosphate 35.0%
Zeolite Na 4A 14.0%
Sodium Silicate 2.0 ratio 2.0%
Sodium Carbonate 23.4%
Enzyme (SavinaseT~and/or LipolaseTMfrom Novo) 1.4%
Carboxymethyl Cellulose 0.3%
Anionic Soil Release Agent *1 0.3%
Brightener 0.2%
Silicone Suds Suppressor (Dow Corning Corp) 0.2%
Perfume ~2 0 3%
Sodium Sulfate 0.5%
Moisture balance up to 100%
*1 See U.S. 4,968,451
*2 Peffume composition of the following fom7ula:
Benzyl salicylate 20%
Ethylene brassylate 20%
Galaxolide (50% soJn. in benzyl benzoate) 20%
Hexyl cinnamic aldehyde 20%
Tetrahydro linalool 20%
100%
Example 4
[Laundry Detergent Comprising Pro-Fragrance and Fully-Forrnulated Perfume
Composition having a Conventional Ketal fragrance Component]
A laundry detergent composition is prepared by weighing 98g of laundry
detergent according to Example 4 with the exception that perfume and pro-
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19
fragrance are not included; admixing to said composition 29 of a perfume of
flowery-woody type made up of a mixture of a first premix and a conventional
ketal (not in accordance with essential pro-fragrance as defined herein) as
follows:
First Premix:
Oil of bergamot 7.5 9
Linalool 4 o
Phenyl ethyl alcohol 4.0 9
Benzyl acetate 2.0 g
Citronellol 0.5 9
HedioneTM (a) 10.0 9
Lyral (b) 4.0 9
Hydroxycitronellal 2.5 9
Rose oxide 1 (c) 10% in DPG 2.5 g
Hexyl cinnamic aldehyde, alpha 7.5 g
Patchouly Oil Indonesian 4.0 9
Iso-ETM (b) 2.0 9
Vetiveryl acetate 2.0 9
BrahmanolTM F (c) 2.0 g
Benzyl Salicylate 2~09
cis-3-Hexenyl Salicylate 1.0 9
CedramberTM (b) 1.0 9
Musk Xylene 1.0 g
Indole 10% in DPG 0.5 g
Extract of Opoponax 0.5 9
Extract of Oakmoss 50% in DPG 5.0 9
(a) Firmenich
(b) IFF
(c) DRAGOCO
Total Parts by weight of First Premix: 68.0 9
The first perfume premix is modified by adding to it 32 parts by weight of
5a/5b (80:20) wherein 5a is 5-ethylenedioxy-3 beta-H-isolongifolane and 5b is 5-ethylenedioxy-3 a/pha-H-isolongifolane; these two compounds being
35 conventional perfume ketals not in accordance with the present invention, and
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their synthesis is described in "CYCLIC ISOLONGIFOLANONE-KETALS - THEIR
MANUFACTURE AND THEIR APPLICATION", U.S. Patent 5,426,095, issued
June 20, 1995 to Brunke and Schatkowski, assigned to Dragoco.
1.0g of a pro-fragrance according to Example 2 is mixed into the
5 powdered, perfume-free detergent composition. Finally, about 1.5g of the aboveperfume composition is sprayed onto the mixture of detergent and pro-fragrance,
to complete the fragrance, pro-fragrance laundry detergent composition. The
said composition has a floral-woody character and leaves an improved, long-
lasting scent on textile fabrics washed therewith.
ExamPle 5
[Detergent having the form of a Laundry Bar Comprising Pro-Fragrance]
Pro Fragrance of Example 1 1.0%
Tallow Soap and Coco Soap Mixture (80:20) 44.0%
Linear Dodecyl Benzene Sulfonate 12.0%
Sodium Tripolyphosphate 6.0%
Sodium Carbonate 8.0%
Sodium Sulfate 0 5%
Talc 9-0%
Perfume*1 0.2%
Moisture balance up to 100%
*1 See *2 in Example 3
Example 6
[Liquid Detergent Comprising Pro-Fragrance~
Pro Fragrance of Example 1 1.0%
Sodium C12-C15 Alcohol Ethoxylate E 2.5 Sulfate 18.0%
Neodol 23-9 Nonionicsurfactant 2.0%
C12 Alkyl N-Methylgluca"~ide 5.0%
Sodium Cumene Sulfonate 3.0%
Citric Acid 3 0%
Fatty Acid (C12-C14) 2.0%
Boric Acid 3 5%
Sodium Hydroxide 2.8%
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Ethoxylated Tetraethylene Pentaimine 1.2%
Soil Release Polymer 0.15%
1,2-Propanediol 8.0%
Ethanol 3.6%
Monoethanolamine 1.1%
Minors*1 1.8%
Moisture balance up to 100%
*1 Minors include brightner and enzymes
Although the examples and embodiments described her~in are illustrative
of the invention, those skilled in the art will be able to recognize that variations or
modifications in light thereof are fully within the scope of the invention. In one
such variation, the practioner will minimize the molecular weight while still
15 seeking the advantages of the invention, for example by selecting pro-fragrances
at-1/2 of less than one minute at pH 0.
