U.S. patent application number 10/505819 was filed with the patent office on 2005-07-07 for air-freshening device.
Invention is credited to Blondeau, Philippe, Dumas Krikorian, Sandrine, Picci, Sebastien, Quellet, Christian.
Application Number | 20050145711 10/505819 |
Document ID | / |
Family ID | 27675657 |
Filed Date | 2005-07-07 |
United States Patent
Application |
20050145711 |
Kind Code |
A1 |
Blondeau, Philippe ; et
al. |
July 7, 2005 |
Air-freshening device
Abstract
An air-freshening device comprising a container open at one end,
containing an aqueous phase and a hydrophobic phase comprising a
volatile material, preferably a fragrance, and covering said open
end a breathable film. Aforementioned air-freshening devices may
also find use in combination with electrical heating vapour
dispensing devices.
Inventors: |
Blondeau, Philippe; (Paris,
FR) ; Quellet, Christian; (Biel, CH) ; Dumas
Krikorian, Sandrine; (L'Isle Adam, FR) ; Picci,
Sebastien; (Kingersheim, FR) |
Correspondence
Address: |
NORRIS, MCLAUGHLIN & MARCUS
875 THIRD AVE
18TH FLOOR
NEW YORK
NY
10022
US
|
Family ID: |
27675657 |
Appl. No.: |
10/505819 |
Filed: |
March 2, 2005 |
PCT Filed: |
January 30, 2003 |
PCT NO: |
PCT/CH03/00076 |
Current U.S.
Class: |
239/60 ;
424/76.3; 424/76.4 |
Current CPC
Class: |
A61L 9/12 20130101 |
Class at
Publication: |
239/060 ;
424/076.3; 424/076.4 |
International
Class: |
A24F 025/00 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 28, 2002 |
EP |
02004584.5 |
Claims
1. An air-freshening device comprising a container having an open
end, the container holding a composition comprising an aqueous
phase, and a hydrophobic phase comprising a fragrance, and said
open end is covered by a breathable film.
2. The air-freshening device of claim 1 wherein said composition
comprises more than 10% by weight of water.
3. The air-freshening device of claim 1, wherein the container
holding a composition comprises of lower aqueous phase, and an
upper hydrophobic phase comprising a fragrance.
4. The air-freshening device of claim 1 wherein the composition is
in the form of an emulsion.
5. The air-freshening device of claim 1 wherein the breathable film
is selected from the group consisting of monolithic films and
micro-porous films.
6. The air-freshening device of claim 5 wherein the monolithic film
is a copolymer comprising soft segments formed by polyether units
selected from the group consisting of polyethylene glycol,
polypropylene glycol, polytetramethylene glycol, and mixtures
thereof.
7. The air-freshening device of claim 1 wherein the monolithic film
is selected from poly(ether-co-amide) films and
poly(ether-co-ester) films.
8. The air-freshening device of claim 1 having a space between the
upper surface of the composition and the lower surface of the
breathable film.
9. The air-freshening device of claim 1 wherein a non-breathable
material is releasably fitted over the breathable film.
10. A method of manufacturing the air-freshening device of claim 1
comprising the steps of filling an aqueous phase in a container;
adding on top of the aqueous phase a hydrophobic phase comprising
the fragrance; and covering the open end of the container with a
breathable film; and optionally fitting a non-breathable film over
the breathable film.
11. A method of releasing fragrance to ambient air comprising
exposing the air-freshening device of claim 1 to the ambient
air.
12. The air-freshening device of claim 1 wherein the weight ratio
of water to fragrance in the composition is about 9:1 to about
1:9.
13. The air-freshening device of claim 1 wherein the weight ratio
of water to fragrance in the composition is about 7:3 to about
3:7.
14. The air-freshening device of claim 13 wherein the weight ratio
of water to fragrance in the composition is about 4:1 to about
2:3.
15. The air-freshening device of claim 6 wherein the amount of the
soft segments is between 15% and 40% by weight of the film.
16. The air-freshening device of claim 15 wherein the amount of the
soft segments is between 20% and 30% by weight.
17. The air-freshening device of claim 8 wherein the space between
the upper surface of the composition and the lower surface of the
breathable film is not greater than 3 cm.
18. The air-freshening device of claim 17 wherein the space between
the upper surface of the composition and the lower surface of the
breathable film is not greater than 1 cm.
19. The air-freshening device of claim 1 wherein: (a) the weight
ratio of water to fragrance in the composition is about 9:1 to
about 1:9; (b) the breathable film is a monolithic film and is a
copolymer comprising soft segments formed by polyether units
selected from the group consisting of polyethylene glycol,
polypropylene glycol, polytetramethylene glycol, and mixtures
thereof, wherein the amount of the soft segments is between 15% and
40% by weight of the film; (c) there is a space between the upper
surface of the composition and the lower surface of the breathable
film and said space is not greater than 3 cm.
20. The air-freshening device of claim 1 wherein: (a) the weight
ratio of water to fragrance in the composition is about 4:1 to
about 2:3; (b) the breathable film is a monolithic film and is a
copolymer comprising soft segments formed by polyether units
selected from the group consisting of polyethylene glycol,
polypropylene glycol, polytetramethylene glycol, and mixtures
thereof, wherein the amount of the soft segments is between 20% and
30% by weight of the film; (c) there is a space between the upper
surface of the composition and the lower surface of the breathable
film and said space is not greater than 1 cm.
21. The air-freshening device of claim 5 wherein the breathable
film has soft segments which are formed by polyether units and
dicarboxylic acid.
Description
[0001] The invention relates to a fragrance composition for the
controlled release of volatile substances into the ambient air, and
to air-freshening devices containing the same.
[0002] There is an increasing demand for fragrance release systems,
which provide a pleasant, natural aroma during a long period of
time, e.g. 4 to 6 weeks, without significant changes of the
fragrance strength and/or fragrance character during usage.
[0003] Gel compositions to control the degree of fragrance release
from air-freshening devices are known. One of the first gels has
been made from seaweed extracts, e.g. carrageenan. However, these
gels can hold only a relatively small concentration of fragrance
oils and have poor fragrance-release characteristics. The European
Patent Application No. 0 631 788 discloses a gel-like fragrance
composition which comprises an aqueous gel comprising an aqueous
fluid and a gelling agent incorporated in an oil-absorbable resin
carrying a fragrant material. It is stated therein that it is
possible to achieve a well-balanced volatile emission for a long
period, independently of the perfume character. These aqueous gel
compositions may contain up to 20% by weight of a fragrant
material. In the last years, other gelling agents that are able to
hold much higher concentrations of fragrance oils have been used.
The U.S. Pat. No. 5,643,866 discloses a crystal clear,
self-supporting, highly concentrated gel, comprising fragrance
oils, glycols and dibenzylidene sorbitol acetal (DBSA) as gelling
agent. Said gels can be loaded up to 80% with fragrance oils. U.S.
Pat. No. 5,780,527 discloses a rigid dry and transparent gel
obtained by reacting, in the presence of a fragrance composition, a
liquid polymeric material with a cross-linking agent.
[0004] Non-gel like fragrance compositions are widespread in
combination with electrical heated vapour dispensing devices, or in
combination with other means, e.g. a wick, to control the release
of the fragrance. Typically, a solvent is used to support the
controlled release of the fragrance. For example the European
Patent Application No. 1 078 640 describes a single-phase aqueous
air freshening composition comprising 30% to 60% glycol ethers used
in an air freshener device comprising a wick.
[0005] Several devices for perfuming ambient air having a sheet of
permeable polymeric material are described, for example in EP 0 093
262, U.S. Pat. No. 5,788,155 and EP 1 082 969. The prior art is
silent on the nature of the fragrance containing composition and
the effect that this may have on the performance of fragrance
release.
[0006] There remains a need to provide air-freshener systems that
are both aesthetically pleasing in design and which give still
improved fragrance release in terms of duration and fragrance
quality. We however made the surprising discovery that a breathable
film performs very well in combination with a composition
comprising an aqueous phase, and a hydrophobic phase containing the
fragrance, in delivering a quantity of fragrance into the ambient
air in a controlled and sustained manner.
[0007] Therefore, in a first aspect, the invention provides an
air-freshening device comprising a container having an open end,
the container holding a composition comprising an aqueous phase,
and a hydrophobic phase comprising a fragrance, and said open end
is covered by a breathable film which permits of egress of the
fragrance and water-vapour.
[0008] Surprisingly we found that the addition of water to a
fragrance not only influences the life-cycle of the air-freshening
device but also is important for the essentially continuous release
of the fragrance. The air-freshener device permits of strong
fragrance release and the character of the released fragrance does
not substantially alter over a long period of time, e.g. 4 to 6
weeks. We have found that the present of water influences the
impact and quality of the released fragrance and leads to higher
evaporation profile measured by the weight lost of the product over
a time period of use as is more specifically illustrated in the
examples. The rate of evaporation and therefore the life-cycle of
the air-freshening device may be varied depending on the ratio of
water to fragrance. In a preferred embodiment, the weight ratio
between water to fragrance is about 9:1 to about 1:9, more
preferably about 7:3 to about 3:7, most preferably 4:1 to about
2:3.
[0009] The strength of a fragrance can be evaluated by the
measurement of the odour value, or by sniffing. The odour value of
a fragrance material is defined as the ratio of the vapour pressure
and its mean odour threshold concentration. The odour threshold
concentration can be measured by standard methods, for example
described by ASTM E679-91. To calculate the odour value of a
fragrance composition the vapour pressure and odour threshold
concentration of the fragrance has to be determined. Because of the
time-consuming and elaborate nature of methods to determine the
odour value the analysis of the fragrance strength by sniffing is
preferred, as is well known in the perfumery arts.
[0010] The character of a fragrance (the so-called hedonic
character) relies on the contribution of all components of a
fragrance through evaporation. Highly volatile fragrance components
(so-called Top Notes) are responsible for the initial impression of
a fragrance. Less volatile fragrance components (so-called Middle
Notes, also known as Heart Notes, and so-called Bottom Notes, also
known as Base Notes) are responsible for the long-lasting
impression of a fragrance. A fragrance's character depends on the
harmonisation of Top Note, Middle Note, and Bottom Note. Clearly,
it is highly desired that the released fragrance character does not
significantly change during use of an air-freshening device over a
prolonged period of time. The air-freshener devices of the present
invention may permit substantially the same ease of passage to all
fragrance ingredients irrespective of their physicochemical
properties such as volatility and thus leads to the balanced nature
of the fragrance emitted from the device. Without wishing to be
bound by any theory applicant believes that due to the addition of
water to the fragrance the developed water-vapour in a headspace of
the device acts as a carrier for the fragrance to pass through the
breathable film irrespective of their volatility.
[0011] The term breathable film as used herein means a polymeric
film that allows water-vapour, but not water in the liquid phase,
to pass through it. There are two different classes of breathable
films known namely micro-porous films and monolithic films.
[0012] Micro-porous films are such films with small pores that
permit passage of water-vapour. Typically, they comprises
micropores having pore sizes of e.g. down to about 10 .mu.m. The
small size of the pores prevents the penetration of liquid phase
water across the film, but the interconnected pore structure allows
the transmission of water-vapour. Micro-porous films may be made
from, e.g. polyolefins, polytetrafluoroethylenes (PTFE) and
precipitated polyurethanes.
[0013] Monolithic films are based on copolymers having so called
hard and soft segments. The hard segments may be polyesters, for
example glycol, propanediol or butanediol units and dicarboxylic
acid units connected by ester functional groups; polyurethanes; or
polyamides, for example polyamid 6 (PA-6), polyamid 11 (PA-11), or
polyamid 12 (PA-12). The soft segments, responsible for the
water-vapour transmission, may be formed by polyether units, for
example polyethylene glycol (PEG), polypropylene glycol (PPG) or
polytetramethylene glycol (PTMG) or mixtures thereof, and
dicarboxylic acids, such as, for example terephtalic acid.
Monolithic films based on polyester block hard segments are
described in U.S. Pat. Nos. No. 5,800,928, 4,725,481, and
6,001,464; Monolithic films based on polyurethane hard segments are
described in U.S. Pat. Nos. 5,800,928 and 6,001,464; Monolithic
films based on polyamide hard segments are described in U.S. Pat.
Nos. 5,800,928 and 5,506,024; all of which are incorporated herein
by reference.
[0014] Parameters including molecular weight of the soft segment
and the glass transition temperature influence the flexibility of
the film. Therefore, the molecular weight of the soft segment is
preferably between 600 and 4000 g/mol. The glass transition
temperature is preferably below 0.degree. C. The amount of the soft
segment may vary widely depending on the particular properties
desired. However, in a preferred embodiment the amount of the soft
segment may be between 15% and 40% by weight of the film,
preferably between 20% and 30% by weight. The soft segment formed
by polypropylene glycol is preferred. Most preferred are soft
segments formed by polyethylene glycol, or a mixture of
polyethylene glycol and polypropylene glycol.
[0015] Examples of monolithic breathable films are
poly(ether-co-amide), e.g. PEBAX.RTM. by Atofina and
poly(ether-co-ester), e.g. HYTREL.RTM.60 by DuPont.
[0016] Properties such as the hydrophilic nature of the film, its
crystallinity and the presence and amount of certain additives,
e.g. filler, may affect the breathability of the film. By
breathability) is meant the water-vapour transmission rate (WVT) or
water-vapour permeability (WVP). Its measuring unit is g/m.sup.2/24
h and it is calculated by measuring how many grammes of
water-vapour pass through one square meter of film in 24 hours. A
variety of test methods have been developed to measure this
property, for example ASTM E96 and DIN 53 122. Although most
standard methods are of similar concept there are variables, e.g.
temperature and relative humidity of the test environment, the
principle of the test method, i.e. upright dish water method,
upright dish desiccant method, inverted cup method, and inverted
water method, that have an influence on the calculated water-vapour
transmission rate. Consequently, the results from different methods
are not directly comparable.
[0017] The breathable film according to the present invention
preferably may have a thickness from about 10 .mu.m to about 50
.mu.m more preferred from 15 .mu.m to about 40 .mu.m.
[0018] The container according to the present invention may be made
of any material that is commonly used for air-freshener devices,
e.g. glass or plastic. Such materials are preferred, which are
stable in the presence of fragrance materials, e.g. essential oils.
The container may be of any shape or configuration subject to it
having an open end and capable of receiving aqueous and oil phases.
Preferably, in the filled container the upper liquid surface does
not abut the surface of the breathable film. Rather, in a preferred
embodiment there should be a space between the upper surface of the
liquid phase and the lower surface of the breathable film in which
a head-space of fragrance and water-vapour may develop. This space
is preferably not greater than 8 cm, more preferably not greater
than 3 cm, for example between 1 cm and 2 cm, most preferably not
greater than 1 cm.
[0019] The breathable film may be attached to the container in a
sealed relationship utilising any conventional means, such as an
adhesive, heat seal or the like. Such means are preferred which
form a strong bond between the film and the container to avoid the
leakage of the liquid composition.
[0020] The hydrophobic phase according to the present invention
consists of fragrance. A fragrance according to the present
invention is a mixture of fragrance materials selected from such
classes as acids, esters, alcohols, aldehydes, ketones, lactones,
nitriles, ethers, acetates, hydrocarbons, sulfur- nitrogen- and
oxygen-containing heterocyclic, polycyclic and macrocyclic
compounds, as well essential oils of natural or synthetic origin.
Such fragrance materials are described, for example, in S.
Arctander Perfume Flavors and Chemicals Vols. 1 and 2, Arctander,
Montclair, N.J. USA 1969. The fragrance optionally may comprise
odourless liquids such as dipropylene glycol, propylene glycol,
diethylphtalate, benzyl benzoate, triethylcitrate,
isopropylmyristate, carbitol, and hexylene glycol, or mixtures
thereof. The appropriate choice of the liquid not only depends on
the amount in which it may be used but also on the nature of the
fragrance as will be fully appreciated by the person skilled in the
art. Preferably, the fragrance comprises not more than 20% by
weight of these liquids. A fragrance may contain residual water
either due to the presence of a solvent or due to the production
process. It is to be understood that in the context of the present
invention water has to added addition to any residual water that
may be present to form a composition according to the present
invention. In an preferred embodiment the composition according to
the present invention comprises more than 10% by weight of water,
more preferably more than 25% by weight, most preferably between
50% and 90% by weight of water. A skilled person will be aware that
effects may also be achieved with low fragrance concentrations.
Thus, a composition comprising 95% by weight of water or even more,
e.g. 98%, may also be used to form a composition according to the
present invention.
[0021] Optionally, the hydrophobic phase may comprise a lipophilic
dye, for example Puricolor.RTM. blue FBL5, Puricolor.RTM. blue
ABL9, Puricolor.RTM. green U3 or Puricolor.RTM. yellow AYE23 from
Ciba.
[0022] For air-freshening devices fragrances are preferred
comprising a high amount of fragrance material having a vapour
pressure greater than 1000 .mu.g/l. These fragrance materials are
classified as Top Notes and may be selected from acetate C6
hexylic, acetophenone, alcohol C6 hexylic, aldehyde C7 heptylic,
aldehyde C9 isononylic, allyl caproate, allyl oenanthate, amyl
butyrate, amyl vinyl carbinol, anapear, benzaldehyde, benzyl
formate, benzyl methyl ether, bornyl acetate liquid, butyl acetate,
camphene, carbitol, citronellal, cresyl methyl ether para, cyclal
C, cymene para, decenal-4-trans, delta-3 carene, diethyl malonate,
dihydro anethole, dihydro myrcenol, dimethyl octenone, dimetol,
dimyrcetol, dipentene, estragole, ethyl acetate, ethyl
acetoacetate, ethyl amyl ketone, ethyl benzoate, ethyl butyrate,
ethyl caproate, ethyl isoamyl ketone, ethyl isobutyrate, ethyl
methyl-2-butyrate, ethyl oenanthate, ethyl propionate, eucalyptol,
fenchone alpha, fenchyl acetate, fenchyl alcohol, freskomenthe,
geranodyle, guaiacol, hexenal-2-trans, hexenol-3-cis, hexenyl
acetate, hexenyl-3-cis butyrate, hexenyl-3-cis formate,
hexenyl-3-cis isobutyrate, hexenyl-3-cis methyl-2-butyrate,
hexenyl-3-cis propionate, hexyl butyrate, hexyl isobutyrate, hexyl
propionate, hydratropic aldehyde, isoamyl propionate, isobutyl
isobutyrate, isocyclocitral, isopentyrate, isopropyl
methyl-2-butyrate, isopulegol, leaf acetal, lime oxide, limetol,
linalool oxide, linalool, manzanate, melonal, menthone, methyl amyl
ketone, methyl benzoate, methyl camomille, methyl hexyl ketone,
methyl pamplemousse, methyl salicylate, nonanyl acetate, ocimene,
octenyl acetate, pandanol, pinene alpha, pinene beta, prenyl
acetate, terpinene gamma, terpinolene, tetrahydro citral,
tetrahydro linalool, tricyclal, and valerolactone gamma.
[0023] Fragrance materials having a vapour pressure between 10
.mu.l/l and 1000 .mu.g/l are classified as Middle Notes and may be
selected from acetal E, acetal R, acetanisole, adoxal, agrumex,
alcohol C10 decylic, alcohol C11 undecylenic, alcohol C12 lauric,
alcohol C8 octylic, alcohol C9 nonylic, aldehyde C11 undecylenic,
aldehyde C11 undecylic, aldehyde C12 lauric, aldehy, aldehyde iso
C11, allyl amyl glycolate, allyl cyclohexyl propionate, ambrinol,
amyl benzoate, amyl caproate, amyl cinnamic aldehyde, amyl phenyl
acetate, amyl salicylate, anethole synthetic, anisyl acetate,
anisyl alcohol, anther, aubepine para cresol, benzyl acetone,
benzyl butyrate, benzyl isobutyrate, benzyl isovalerate, benzyl
propionate, bergamyl acetate, berryflor, boisiris, butyl butyro
lactate, butyl cyclohexanol para, butyl cyclohexyl acetate para,
butyl quinoline secondary, carvone laevo, caryophyllene, cashmeran,
cedrene epoxide, cedroxyde, cedryl methyl ether, celery ketone,
centifolyl, cetonal, cetone alpha, cinnamic aldehyde, cinnamyl
acetate, citral dimethyl acetal, citrodyle, citronellol,
citronellyl acetate, citronellyl butyrate, citronellyl formate,
citronellyl isobutyrate, citronellyl nitrile, citronellyl
oxyacetaldehyde, citronellyl propionate, clonal, coniferan,
creosol, cresyl acetate para, cresyl isobutyrate para, cumin
nitrile, cuminic aldehyde, cuminyl alcohol, cyclamen aldehyde
extra, cyclogalbanate, cyclohexyl ethyl acetate, cyclohexyl
salicylate, cyclomethylene citronellol, cyperate, damascenone,
decahydro naphthyl formate beta, decalactone delta, decalactone
gamma, decatone, decyl methyl ether, delphone, dihexyl fumarate,
dihydro ambrate, dihydro cyclacet, dihydro eugenol, dihydro
farnesal, dihydro ionone beta, dihydro jasmone, dihydro linalool,
dihydro terpineol, dimethyl anthranilate, dimethyl benzyl carbinol,
dimethyl benzyl carbinyl acetate, dimethyl benzyl carbinyl
butyrate, dimethyl phenyl ethyl carbinol, dimethyl phenyl ethyl
carbinyl acetate, diphenyl methane, diphenyl oxide, dipropylene
glycol, dupical, ebanol, ethyl caprylate, ethyl cinnamate, ethyl
decadienoate, ethyl linalool, ethyl linalyl acetate, ethyl
octenoate-2, ethyl pelargonate, ethyl phenoxy acetate, ethyl phenyl
acetate, ethyl phenyl glycidate, ethyl salicylate, eugenol pure,
eugenyl acetate, famesene, fennaldehyde, fixambrene, floralozone,
floramat, florol, floropal, folenox, folione, folrosia, fraistone,
fructone, fruitate, gardenol, gardocyclene, georgywood, geraniol,
geranitrile, geranitrile T, geranyl acetate, geranyl acetone,
geranyl butyrate, geranyl crotonate, geranyl formate, geranyl
isobutyrate, geranyl propionate, givescone, glycolierral, guaiyl
acetate, gyrane, heliotropine crystals, hexenyl-3-cis benzoate,
hexenyl-3-cis hexenoate, hexenyl-3-cis salicylate, hexenyl-3-cis
tiglate, hexyl benzoate, hydroxycitronellal dimethyl acetal,
indoflor, indole pure, indolene, ionone beta, irisantheme, irisone
alpha, ironal, irone alpha, irone E, irone F, iso E super,
isobornyl propionate, isobutyl benzoate, isobutyl phenyl acetate,
isobutyl quinoline-2, isobutyl salicylate, isocaryol acetate,
isoeugenol, jasmal, jasmin lactone delta, jasmin lactone gamma,
jasmolactone, jasmone cis, jasmonyl, kephalis, kohinool, labienone,
lactoscatone, lemarome N, lemonile, lierral, lilial, linalyl
acetate, linalyl butyrate, linalyl formate, linalyl isobutyrate,
linalyl propionate, lindenol, majantol, mayol, menthanyl acetate,
metambrate, methoxy phenyl butanone, methyl acetophenone, methyl
cinnamate, methyl cinnamic aldehyde, methyl decalactone gamma,
methyl diantilis, methyl diphenyl ether, methyl ional beta, methyl
isoeugenol, methyl octalactone, methyl octyl acetaldehyde, methyl
octyne carbonate, methyl phenyl acetate, methyl quinoline para,
moxalone, myraldene, neofolione, nerol C, neryl acetate, nonadyl,
nopyl acetate, octahydro coumarin, octalactone delta, octalactone
gamma, orcinyl 3, orivone, osyrol, oxyoctaline formate, parmavert,
peach pure, pelargol, phenoxanol, phenoxy ethyl alcohol, phenoxy
ethyl isobutyrate, phenyl ethyl acetate, phenyl ethyl alcohol,
phenyl ethyl butyrate, phenyl ethyl formate, phenyl ethyl
isobutyrate, phenyl propionic aldehyde, phenyl propyl acetate,
phenyl propyl alcohol, pinoacetaldehyde, plicatone, precarone,
prunolide, pyralone, radjanol, resedal, rhodinyl acetate,
rhubafuran, rhubofix, rhuboflor, rosalva, sandalore, scentenal,
skatole, spirambrene, stemone, strawberry pure, styrallyl
propionate, syringa aldehyde, tangerinol, terpinene alpha, terpinyl
acetate, terranil, tetrahydro linalyl acetate, tetrahydro myrcenol,
tridecenonitrile, tropional, undecatriene, undecavertol, veloutone,
verdol, verdyl acetate, verdyl propionate, vernaldehyde, vetynal,
vetyvenal, and viridine.
[0024] Fragrance materials having a vapour pressure below 10
.mu.g/l are classified as Bottom Notes and may be selected from
2-benzyl-4-methanol-1,3-dioxolane, aldrone, ambrettolide, ambroxan,
benzophenone, benzyl benzoate, benzyl cinnamate, benzyl phenyl
acetate, cepionate, cetalox, citronellyl ethoxalate, civettone,
cresyl caprylate para, cresyl phenyl acetate para, cyclohexal,
diethyl phthalate, dione, dodecalactone delta, dodecalactone gamma,
ethyl maltol, ethyl vanillin, ethylene brassylate, eugenyl phenyl
acetate, evernyl, fixolide, florhydral, galaxolide, geranyl phenyl
acetate, geranyl tiglate, grisalva, hedione, hexyl cinnamic
aldehyde, hexyl salicylate, isomethyl cedryl ketone, laitone,
linalyl benzoate, linalyl cinnamate, linalyl phenyl acetate,
maltol, maltyl isobutyrate, methyl cedryl ketone, methyl dihydro
isojasmonate, muscone, myraldyl acetate, nectaryl, okoumal, orange
aldehyde, oranile, peonile, phenyl ethyl benzoate, phenyl ethyl
cinnamate, phenyl ethyl phenyl acetate, propyl diantilis,
rosacetol, rosaphen, sandela, thibetolide, timberol, triethyl
citrate, undecalactone delta, vanillin, vanitrope, and
velvione.
[0025] For air-freshening devices fragrances are preferred
comprising from about 15% to about 80% by weight Top Notes, more
preferably from about 25% to about 60% by weight.
[0026] The aqueous phase according to the present invention may be
water, for example distilled water. Other excipients optionally
present in the aqueous phase are salts, for example sodium chloride
and magnesium sulfate to minimize the migration of water soluble
fragrance materials. Other excipients, e.g. water soluble dyes may
also be present in the aqueous phase.
[0027] In order to prevent evaporation of fragrance during storage,
the device may have fitted over the container and the breathable
film, a non-breathable material, such as an aluminium foil,
polyolefine films, ethylene acrylic acid copolymer films,
polyethylene terephtalate films, or ethylen vinyl acetate films,
which may be easily removed prior to use.
[0028] In a particular preferred embodiment of the present
invention, the composition held in the container comprises an upper
hydrophobic phase comprising a fragrance, and a lower aqueous
phase.
[0029] In an alternative embodiment, the composition comprising the
hydrophobic phase and the aqueous phase is provided as an
emulsion.
[0030] The emulsion may optionally comprise a surfactant such as
for example non-ionic surfactants, e.g. Neodol 91-8 from Shell
Chemicals and Cremophor RH40 from BASF.
[0031] The invention has been described in terms of releasing
fragrance. However, the device according to the invention may
deliver other ingredients such as insect repellents, insect
attractants, or materials having insecticidal activities, substance
having antimicrobial activities, or mixtures thereof. In addition
to these active principals, fragrance compositions may comprise
excipients such as dyes and UV-absorbers.
[0032] For manufacturing a device according to the present
invention the container may be filled in a first step with the
aqueous phase followed by adding on top of the aqueous phase the
hydrophobic phase. If the hydrophobic phase and the aqueous phase
is provided as an emulsion, in a first step both phases may be
prepared separately and then mixed together to form an emulsion,
according to a process well known in the art, followed by filling
the resulting emulsion into the container. After filling the
container the open end of the container is covered by the
breathable film, which itself might be covered by a removable
impermeable film for storage.
[0033] While the invention has been illustrated and described with
respect to an air-freshening device for the controlled release of
volatile substances at room temperature, it will be apparent to
those skilled in the art that the device may also find use in
combination with electrical heated vapour dispensing devices.
[0034] The invention is illustrated by the following examples.
EXAMPLE 1
Preparation of Different Types of Air-Freshening Devices and
Evaluation of There Fragrance Strength
[0035] A fragrance composition having citrus and spicy top notes
with floral and middle notes and ambery and musky bottom notes was
used in all examples.
[0036] Comparative Product A (Liquid Fragrance Composition
Comprising a Cellulose Wick)
[0037] Blend under stirring at room temperature 8.0 g fragrance and
8.0 g of Neodol (manufactured by Shell). Then, add 34 g water, 25 g
dipropyleneglycolmethyleter, and 25 g ethyl alcohol. Stir until the
solution becomes clear. Pour 70 g of the solution into a glass
container and insert a wick, made of cellulose in the middle of the
container. The one end of the wick is in contact with the solution
and the other end of it is in contact with the ambient air to
supply the ambient air with fragrance.
[0038] Comparative Product B (Solid Gel Fragrance Composition
Comprising a Gelling Agent)
[0039] Blend at room temperature 1.735 g Lithene N4-9000-1 OMA from
Revertex Ltd with 8.0 g fragrance together. Add under stirring
0.265 g of Crodamet O2 from Revertex Ltd. Stir for about 10 minutes
and pour 7 g of the composition into a glass container.
[0040] Product C (Liquid Fragrance Composition According to the
Present Invention)
[0041] Pour 17.4 g water into a glass container and add 5.6 g
fragrance. Seal the container with Pebax.RTM. MV 6100 film from
Atofina.
[0042] Product A, B, and C were evaluated in booths.
[0043] The fragrance strength of each of the products was evaluated
by an expert panel of 20 members by sniffing. The result was
entered on a scale from 1 to 5, wherein 5 is very strong, 4 is
strong, 3 is moderate, 2 is weak, and 1 is very weak. The average
value is shown in Table 1.
1 TABLE 1 Comp. Product A Comp. Product B Product C Fresh product 2
4 4.5 After 1 week 2 4 4 After 2 weeks 1 3 4 After 4 weeks 0.5 2
4
[0044] The fragrance strength of Product C is at all stages better
than the fragrance strength of the comparison products, i.e. the
wick system (Comp. Product A) permits at each age of the product
only a weak egress of the fragrance and the gel system (Comp.
Product B) releases a strong fragrance up to one week but the
strength of the fragrance decreases over the period of time and was
described to be weak after 4 weeks.
EXAMPLE 2
Evaluation of the Fragrance Character by Headspace
[0045] The ambient air in the booths of Product A, B, and C,
prepared according to Example 1 were collected as fresh products,
and 1, 2 and 4 weeks after preparation. Then the samples were
analysed by GC/MS. The results are shown in Table 2. The principles
of the headspace analysis is described in the Journal of
Agriculture and Food Chemistry, Vol. 19, No. 6 (1971), page
1049-1056.
2 TABLE 2 Fresh After After After Product 1 week 2 weeks 4 weeks
Comp. Product A Top Note 95% 87% 82% 77% Middle Note 4.7% 12% 16.2%
21.4% Bottom Note 0.3% 1% 1.8% 1.6% Comp. Product B Top Note 95%
74% 68% 72% Middle Note 4.6% 24% 30% 25.3% Bottom Note 0.4% 2% 2%
2.7% Product C Top Note 93.5% 93% 92% 91% Middle Note 6% 6% 6.5%
6.2% Bottom Note 0.5% 1% 1.5% 1.8%
[0046] The concentration of the Top Notes decreases markedly for
the comparative products, i.e. the wick system (Product A) and the
gel system (Product B), whereas the concentration of the Top Notes
remains very high for Product C during the evaluation period of 4
weeks.
EXAMPLE 3
Evaluation of the Fragrance Performance
[0047] Pour water into a glass container and add fragrance
according to the mixture scheme given in Table 3 and seal the
container sealed with Pebax.RTM. MV 6100 film from Atofina.
3 TABLE 3 Water Fragrance (parts per weight) (parts per weight)
total Mixture A 0 100 100 Mixture B 30 70 100 Mixture C 50 50 100
Mixture D 80 20 100
[0048] Mixture A, B, C and D were evaluated by an expert panel in
terms of strength and quality and resulted in the following
ranking: Mixture D was better than Mixture C and Mixture C was
better than Mixture B. The weakest was mixture A. If no water is
added, Mixture A, the fragrance performance is very weak.
EXAMPLE 4
Evaluation of the Weight Lost
[0049] The weight lost of a glass container containing Mixture A
(comparative product) and a container containing Mixture C from
Example 3 have been measured on a daily base for a 30 day period.
The results are shown in FIG. 1.
* * * * *