CA2111457A1 - Method and apparatus for dispensing volatile components of an air treating gel - Google Patents

Abstract

2111457 9303775 PCTABS00020 A dispenser for dispensing volatile products present in a gel (3) in which the gel is anchored to the dispenser throughout the perimeter of an emanating surface (21) of the gel from which the volatile products are dispensed. The emanating surface is replenished from a reservoir (5) of gel within the dispenser while the emanating surface remains substantially stable and free of shrinkage as result of its anchorage to the container. The anchoring means may be a porous material (19) or appropriately shaped flanges (23) and openings (27) adjacent the emanating surface in the structure of the dispenser.

Description

WO 93/03775 X ~ P~/V~91/06~2~

~1--METHOD AND AP~ARATIJS FOR DISPENSIN(; VOLATILE
COMPONENTS OF AN AI:E~ TREATING GEL
This invention relates to dispensing deviGes and m~re particularly to dispensing devices and methods for 5 controlled release of air treating materials fxom a device that uses a gel reservoir. The in~rention has particular application for ~ase with so-called continuous action air freshening units and will be described in connection with such application although other applications are 10 contemE~lated.
The cc)ntrolled dispensing o~ f ragrance and the capacity to c:reate an odor impression in a substantially closed space is the primary s~oncern OI all the methc?dologies which have addr~ssed the area of air 15 freshenirlg and fragrance di~Efusic~n. The importance of a controlled relaas~ not only manif~sts itself from the point of view of fragrance s:election, but also proves to be i~nportant when concern over thP functional life o~ the unit is considere~. Economic,ally viable devices must be 2a efficient in their perrormanc:e due to high C:05tS oft~n associated with fra~rance. Premature rel~ase of the fragrance not only creates a potential fQr excess odor production in the early stages of the product's functional life, but also diminishes the reservoir of fragrance which 25 can be drawn upon in the latter stages of the performanc::e life of the device. Dif~usion methodologies are frequently compared over a given time frame with identical loadings of fragrance so that criti ::al, e:ontrolled ~aluations may be made with regard to o~or intensity and 30 produc:t longe~ity. Superior technol9gies will be tho~e *hat~a,e able to produce a greater odor impre5sion over a longer peri~d for a gi~ren fragrance loading than similarly inte~ded methodologies.

SUBSTITUTE Sld~ET

W093/03775 PCT/US9~/06025 i ~ I ..g~ e3 7

2--Solid compositions in which a fragrance or perfume is dispersed within a matrix formed by a gelling agent offer a particularly desirable and relatively low cost commercial delivery method for continuous action fragrance release devices~ Gels can commonly range from being very soft solids to what is termed "ringing gels", which have greater mechanical i~tegrity.
Typically the gel ~ase ~omprises by weight of said substrat from about 0.5 to about 10% of a gel-forming agent, on an anhydrous basis; water in an amount effective to subsequently hydrate said gel-~orming agent; and ~rom about 0.2 to about 5% of ~aid perfume constituent.
S~itable gel-forming agents include carrageenan, algins, agars~ and other carbohydrates such a~ amylose, and sodium carboxymethylcellulose. .
The compositions preferably include up to about 5% of a viscosity control agent, and may further include as other optional constituents gelling aids such as potassium chloride, h~mectants, perfume fixatives, extender , preservatives, freeze-thaw stabilizers, and dye.
Air treatin~ gels pro~ide an effective means for the gradual introduction into the air of volatilizable air treating components, including for example, air ~reshening and odor counteractant components. In commercial use of ~uch gels, it has generally been the practice to pre-fashion bodies or slugs o~ gels having a suitable shape and contour, and then place the preformed bodies in a desired container or dispenser.
~he prior art is replete with designs of dispensers for dispensing ~he volatile component~ o~ such gel~ wi~h desig~s'varying from simple housin~s for slugs of gel, within which the slug is allowed to deform at will during the dispensing operation with the housi~g not only being designed to support the slug, often with mea~s for Sl!BSTIT~TE SHEET

,. . . ,.. , ,.. . ~. ,.. ~ . . , , ... . . , . ,, , . .. ~, . .. . . . ...

W~93/~3775 2 1 1 1 4 S 7 PCT/US91/06025 attachment to a desired surface, and to visually obscure the slug as it deforms in what is usually not a very aesthetically pleasing manner J to relatively expensi~e designs involving a multiplicity of close tolerance parts de~igned to control dispensation and activation of the dispen~er using various mechanisms including penetr~ble diaphragms and selective filter membranes designed to permit transmission of`evaporated volatile components of the gel only.
13 The closest prior art to the present invention is the use of a simple open topped container for a gel carrying ~olatile components which are di~pensed to the air fro~
the exposed surface of the gel through the open top of the container. While such an arrangement is economical to produce the product is not very attractive because as the volatil~ co~ponents are allowed to evaporate the gel will shrink towaxd the bottom of the container, draw away from the side walls and crack in 21~ u~attractive manner. In addition with such arxangements it is frequently not possible to readily determine when the supply of volatile material is exhausted. Additionally, the ~hrinkage of the gel in suoh container provides a varying dispensing surface and results in a sub5tantially uncontrolled variation in dispensation of the volatile components.
A variation of this simple container is found in U.S.
Patent No. 4,157 r 787 in which the contain~rs open top is covered by a layer of ~orous material.
It is an object of the present invention to provide a method and apparatus by the use of which a simple SUBSTITUT~ SHEE7 .. , .. . . .. ~ .. . . ~ ~ . ... ... . ... . . . . . .

W093/03775 16~ 4 S 7 Pcr/~S91/06025 inexpensive open topped container may be used for the dispensation of the volatil~ components of t~e gel into the air from a ~urface of sub5tantially constant area without significant ~isual signs of shrinXage of the gel apparent in this gel surface yet with a clear indication ac to when the volatile components of the gel are about to be or have been exhausted.
It is a further obj~ct of the pres~nt invention to provide such method and apparatus in which the dispenser is easily filled during manufacture an~ is sealed hermetically until dispensation of the volatile components of the gel contained therein is desired.
According to the invention there is provided a dispenser for dispensing volatile products by e~aporation from an emanating surface of a g21, comprising an open topped container defining an opening from which the volatile products may be dispensed from said eontainer having attaehment means, disposed within the container adjacent the op~ning around the entire perimeter thereof, ~0 for purposes of anchoring the gel adjacent said opening to the container to define an emanating surface of the gel adjacent the opening whereby during u~e, shrinkage of the gel will occur within the container as the ~el within the container acts as a reservoir supplying the stationary emanating sur~ace.
Also according to the invention there is provided a process ~or pr~viding a stable emanating sur~ace of gel for the dispensation of volatile products therefrom comprising anchoring the gel to a s~ructure surrounding the emanating surface and providin~ a reservoir of gel to reple~i~h the emanating surface as ~olatile products are dispensed.
The invention will now be described, by way of example, with reference to the accompanying drawings, in which:

SU~S~TUT~ SEET

WO 93/03775 ~ L 1 4 ~ 7 --5 ~
Figure 1 is a diagr~Lmmatic cross-section of a prior art open topped cc)ntainer dispenser immediately after the surface c>f gel therein has been exposed to the air for dispensation of volatile components thereof;
Figure 2 is a diagrammatic cross-section of the prior art dispenser of Figure 1 afl:er the period of use illustrating the shrinkage of the gel from the walls of the con~ainer and the cracking of the gel with the resulting cha~es in dispensiny sur~ac:e area and with the resulking unattractive appearanl::e of the gel;
Figure 3 is a diagrammatic cros~-sectiorl o~ a dispenser according to the present invention shown inverted in the process of being f illed;
Figure 4 is a diagrammatic cross ~ section of the dispenser of Figure 3 after being f illed shown upright at the time of activation to co.mmence the dispensation of volatile components therefrom;
Figure 5 i5 a diagrzlmmatic cross-section of the dispenser shown in Figure 4 after a period of time has elapsed during whic:h Yolatile componen~s have been dispensed from the gel in th~ c:ontainer, thi~ figure additionally illustrates a perforated cover for the container;
Figure 6 is a diagramm~tic cross ses:tion of the 2~ dispenser of Figure 4 shown when the volatile components of the gel are substantially exhausted;
Figure 7 is a perspective YieW OI a dispenser acf~ording ts Figure 4 shown emp'cy prior to f illing .
Figure 8 is a fragmentary perspective view of t~e portion of the dispenser of Figure 4 adjacent the opening ther.~ on section line 8-8;
Figure 9 is a fragmerltary perspecti~e view of the portion adj a ::ent th~ opening 9f an alternative embodiment to the dispenser shQwn in Figure 4;

SUB~IIIU~S~ET ~

WO 93/03775 1 1 ~ ~ 7 Pcr/us~l/060~5 Figure 10 is a view similar to that of Figure ~ of a further alternative embodiment; and Figure 11 is fragmentary cross sec:tion of a portion of yet further alternative embodiment of the dispenser S shown in Figure 4.
With ref erence f irst to prior art Figures 1 and 2, an open topped container 1 shown ~illed with a fragranc2 dispensing gel 3 (Figure 1) and after fragranc:e has been dispens~d for a p~riod of time (Figure 2) with th~
10 unsightly and c:hangi~g dispensing area resulting from shrinlcage from the walls o~ the container al~d the crat::kin~
o~ the gel. ~:
Now with reference to the present invention referens::e is f irst made to Figures 3 through 6 . P" wide mouth 15 plas~ic cylindrical ~ontainer 5 defines a circular opening covered, prior tc) filling and acti~ation, by an imperviou plastic she~t 9 sealing by Rngag~ment with the perimater of the opening ?. It will be appreciatea that the plastic sh~et 9 ~::ould be replaced by a domed cap s alingly attac:hed to th~ corltainer 5, the cap being removable to activate the dispenser. The bottom 11 of the container defines a filling aperture 13 through which gel composition 3, which has been heated until liquified, is poured from a nozzle lS (Figure 3) to fill the container~
The filling aperture 13 is sealingly closed by a plug 17 once the container is filled and in the inverted p~sition shown in Figure 3. Inside the container 5 adjacent the perimeter 9~ opening is an open celled porous polyethylene band 19 ~ixedly attached to the container. It will be :~
appreciated that this band may be, for example, fixed by adhesi~e) welded, molded in during the molding of the container or may even be a porous portion of the contain~r material itsel~. The snly requirement is that the band 19 act in use as a integral part of the cont~iner. The band SUBSTITUT~ SHEET

~ .. ; , W093~0377~ 7 PCT/~S9l/06025 has a width sufficient to provid2 the desired attachment of the gel without fear of separation of the gel from the band as it seeks tc shrink during operation and insufficient to prevent the gel in the l~wer portion of the cQntainer from being drawn to the emanating surface 21. ~ width of about 15 to 30% of the diameter o~ the opening and/or about 20 to 40% of the height of the container is appropriate. Upon the filling of the container 5 with the liquified gel, that gel penetrates the interstices of the b~nd l9 and upon setting becomes anchored to that band. Following the setting of that g~l and the positioning of the plug 17 in the filling aperture 13 the dispensing unit i5 ready for packagin~ and distribution without loss of volatile components of the lS gel prior to activation of the dispenser.
The band l9 provides an a~tachment for the gel so hat the emanating ~urface 21 o~ the gel, during operation of the dispenser remains inl:act, stable and in close proximity to the top of the container. This is in contras,t to the natural tendency of the gel which is to shrink dimensionally in al l directions. Wi hout the benefit of the attachment to the band the gel would shrink and collapse within the confines of the container~ The ban~, by providing attachment for the upper most p~rtion of the gel, allows the gel, which is not affixed to the band, to act as a reservoir as it continually ~eeds the emanatin~ surface andl at the same time, shrinks in the process~ However, the shrinkage takes place within the confines of the container and causes virtually no change-in thP surface area of the emanatinq surface in distinctcontfa~t to the commercially a~ailable units in which the ~ully exposed gel shrinks in a very unattractive manner.
The band, due to the atta~hment it provides, allows the use of the dispenser in either the upright orientation, SU~STITUTE SHET

WO93/0377S '~ j'7 P~US~I/0602s illustrated in Figures 4, 5 and 6, the inverted position shown in Figure 3 or any other desired orientation, f or example attached to a wall by the base of the container.
It will be appreciated that, apart from its attachment to 5 the band lg, the gel does not attach itself to the interior surface of the container and i5 thus free to act as a reservoir to replenish the emanating surf ace . The flexible plastic: sheet 9 will deform upon the filling of the unit to defirle an emanatirlg surface which in the first 10 instance is domed so that any slight shrinkage whic:h might occur initially in the emanating surface upon activatio will result in a substantially flat surface (Figure 5~
which is substantially f lush with the perimeter of the ~pening 7 . It will be appreciated that this f lat surfa ::e 15 might further shrink slightly to forra a slight concavity but that the domed 5hape formed in the initial fillin~
will minimize the axterlt to which this concavity forms.
To activate the dispenser, the plastic sheet 9 is peeled away ~rom the opening (F.igure 4 ~ thus exposing the 20 emanatirlg surface of the gel . The volatile omponents of the gel can now evaporate fr~m the emanating sur*ace into the surrounding air with any initial shrinkage of the emanating surf ace con i:ributinq to produce the subs~antially flat surface shown in Figure 5. As the 2 5 volatile components continue to evaporate f rom the surface t the gel shrinks from the bottom 11 of the container ts: contirlually supply the emanating sur~ace with the ~rolatile components for dispensation. A decorative cover with openings is shown in Figure 5 and this may 30 optionally be provided for decorative purposes, although it is~ neces5ary or even preferable in the operation of the dispen5er of this invention. As th~ gel becomes exhausted the gel will shrir~c starting from the bottom of the c:ontainer ar~d continually diminish in size as the SUBSTITUT~ SHEET

WO ~3/03775 ~ a 7 PCr/US91/060~5 volatile components evaporate through the surface of the gel which is exposed to the air. On~e all of the volatile components have been depleted the non-volatile portion of said gel composition will e:ome to the reside within the 5 conf ines of the absorbent band ( Figure 6 ~ . In a transparent plastic housing in which the absorb~nt attachment band 19 is opague, the unit from a side perspective will appear` empty and thus a clear indication that replaceTnent is neces~;ary.
The band 19 is preferably a semi-rigid porou~
material such as porous polyethylena adhesi~rely attached to the inside of the container adiacQnt the opening 7.
However, it will be appre ::ia~ed that other porous materials slach as a non-woven, woven and felted fabrics as well as foamed polymeric materials can be used in place of the porous plastic as t:ould a band ha-ting a plurality of loops projecting therefrom. Alternative s:~onstructions of the container pro~riding means for at~achment of the gel to the container ad; acent the opening are shown, }: y way of example, in Figures ~, 10, and 11~ In Fi~ure 9 a pl~rality of circumferentially spac:ed longitudinally extending f langes 2 3 are provided with opening~; there behind which will hold the gel captive ~ once set . The circumferential flanges 23 may be attac:hed ~o the exterior ~5 wall of the container 5 by webs 25, although these webs 25 axe not essential. The webs, it will be apprec:iated, need not be of rectangular cross-section as showrl but could be of ~ny other c:ross-section inc:ludinq webs with curved walls and conical cross sections to minimize the amoun~ of

3 0 gel held captive behind the f larlges 23 without destroying the-~n~egrity of the attachment.
i~ variation of this is shown in Figure 10 in whic:h the flanges 23 are of frust~ronical cross-5et:tion with the smallest width being integral with the w~lll of the ~ . , SUBSTITUTE SR~ET

W093/03775 jr~ 1 ~ 1 4 ~ ~

container 5 to form dov~ tail openings 27 extending longitudinally of the container from the opening toward the base 11. The longitudinal lengkh of the flanges 23, as with the porous band, is sufficient to pro~ide the necessary attachment of the gel to the container adjacent the opening 7 while allowin~ the gel between the flanges and the base ll freedom to shrink from the container to supply the emanating su~face~ -A further embodimPnt is shown in Figure 11 in whi h a plurality of annular flanges 29 extend from the opening longitudinally toward the base ll to define therebehind annular cavities 31 to provide the desired attachment of the gel in this area of the container to that containerO
In this embodiment, a threaded exterior portion is provided adjacent the opening 7 for attachment of a decorative cover, such as that illustrated in ~igure 5.
While the band of porous plastic described with ~:
reference to Figures 3, 4, 5 and 6 may be rectangular în cross-section, one variation is to provide a tapered portion adjacently opening 7 (see Figure 8~ to increase the area of the emanating surfalce.
The dispenser of this inv~ntion is suitable for use, for example, in applications involYing carrageenan type air freshening gel cQmpositions (examplified hereinafter by formula 1) and metal~ic stearate gel compositions (examplified hereinafter as formula 2~.

SU~STITUT~ SHEET

. ~ , ~, . , . . ,. ... ;.

WOg3/03775 PCT/U~91/06025-: ~ .
14 ~ ~ ~

Formula 1 Inqredients Percent (by weight) Gellinq A~ent *Colloid 878 (TIC Gums, Inc.~ ~.7 Co-Sol~ents!Solubilizers Propylene Glycol 3~0 Polyethylene Glycol E-400- 4.0 Dipropylene Glycol Methyl Ether 9~0 Sodium Stearate 1~0 .:;.

Air Treatina Aqents ;;:
Fragrance Oil 3.5 SD Alcholol 40 (95%) 3~0 .~
Preservative ~ -.
Kathon CG ~Rohm & Haas Co~) 0.1 `~

~ueous Medium :.
Water 100. 0 *Colloid 878 is a dry blended mixture of carra~eenan, guar ~ `;
gum and salt.
-The term "carrageenan" is used herein to denote a sulfate polysaccharide. The sulfated polysaccharides o~ the -:```.
present invention are well known to the prior art and : -detailed discussions concerning their use in air freshener applications can be found in U.S. Patent No. 4,056,612;
2,927,055 and Canadian Pat. No. 895,825.

SUBSTITUTE SHEET `

WO 93/03775 ~ 7 Formula 2 Inqredients Percent [by wei~ht) 5 ~ Lhlg_~,J~
Sodium Stearate 5.0 co--solvents/Sulub~ e~
Propylene Glycol 10.0 ~ .
Diethylene Glycol Methyl Ether 30.0 Fragrance Oil 3.0 SD Alcohol 40 (95~) 10.0 Aqueous Medium Water 42.0 100 . O

A further discussion of metallic stearate air freshening gels can be ~ound in the British Patent No. 1,517,967.

It will be appreciated that the dispen~er of the present invention i5 not limited to the use of these eompositions and that it couId be readily adapted to any air treating gel which is Pilled in a li~uid state and which upon setting becomes solidified.
Apart from providing a constant emanating surface area, the arrangement of the present invention ensures that the emanating sur~ace is exposed to any ambient air curre~ whi~h help create a more perceptible odor awareness in a closed environment.
The functional aSp2C~S of the dispen er of the present invention, namely its functional life and o~or SUBSTITUTE SHEET

WO 93/03775 ~ 5 ~ PCI/US91/06025 intensity, are functions of the size of the reservoir, fragranc::e loading in the gel and the arPa of the emanating surf ace . These variables can be c:hosen to c:reate a unit with a functional life of from 1 to 6 weeks, or even more, 5 and suite~l for dispensing air treating agerlts in either a small space or a whole room. The dispenser may be of a relatively small size due to the concentrated f ormulation which utilizes a fragrance concentration of 3 . ~% as opposad t~ typical air freshening gel~ which have only a 10 1% fragrance load. According~y, the disp~nser c:an deliv~r the same amount of fragrance from a ~omewhat smaller reservoir .

SUBSTITUTE SHEET

Claims (11)

I claim:

1. A dispenser for dispensing volatile products by evaporation from a fully exposed emanating surface of a gel, comprising an open topped container having a perimeter defining an unobstructed opening from which the volatile products may be dispensed, said container having an annular attachment means, defining a plurality of interstices, disposed within the container adjacent the opening around the entire said perimeter thereof, said attachment means interstitially anchoring the gel around and adjacent said unobstructed opening of the container to define and sustain the emanating surface of the gel adjacent to the opening throughout the useful life of the dispenser, whereby during use, shrinkage of the gel will occur within the container as the gel within the container acts as a reservoir supplying the emanating surface wherein the attachment means is a band of porous material into the interstices of which liquidfied gel, entering the dispenser, can penetrate to form the desired anchoring of the gel once it has set.

2. A dispenser according to claim 1 further comprising an impervious membrane sealingly engaging the container about the perimeter of the opening to hermetically seal the container prior to use to dispense the volatile products.

3. A dispenser according to claim 1 wherein the container includes a wall portion defining the opening and a base closure including a filling aperture through which the liquified gel may enter the dispenser, a closure plug, for sealingly closing the aperture, being provided to sealingly close that aperture once a desired quantity of the gel has been placed in the dispenser.

4. A dispenser according to claim 2 in which the membrane is shaped to define a domed emanating surface in the gel received in the dispenser while the dispenser is in an inverted orientation,

5. A dispenser according to claim 1 wherein the porous material is one of open celled foam, woven fabric, non-woven fabric, felted textile, porous plastic, a fabric with a plurality of loops extending from a surface thereof or, a porous portion of the material of the container.

6. A dispenser for dispensing volatile products by evaporation from a fully exposed emanating surface of a gel, comprising an open topped container having a perimeter defining an unobstructed opening from which the volatile products may be dispensed, said container having an annular attachment means, defining a plurality of interstices, disposed within the container adjacent the opening around the entire said perimeter thereof, said attachment means interstitially anchoring the gel around and adjacent said unobstructed opening of the container to define and sustain the emanating surface of the gel adjacent to the opening throughout the useful life of the dispenser, whereby during use, shrinkage of the gel will occur within the container as the gel within the container acts as a reservoir supplying the emanating surface wherein the attachment means is integrally formed with the container and comprises a plurality of flanges defining said interstices between the flanges and an adjacent wall portion of the dispenser adjacent the opening to captively engage the gel in the dispenser.

7. A dispenser according to claim 6 wherein the flanges extend longitudinally of the dispenser from the opening.

8. A dispenser according to claim 6 wherein the opening is circular and is defined by a cylindrical wall portion of the dispenser, the flanges being annular flanges in the wall portion adjacent the opening.

9. A process for providing a stable emanating surface of gel for the dispensation of volatile products therefrom comprising interstitially anchoring the gel to an annular structure surrounding the emanating surface, providing a reservoir of the gel to replenish and sustain the emanating surface, as said volatile products are dispensed throughout the useful life of the dispenser wherein the anchoring of the gel to a dispenser structure is achieved by allowing the gel in a liquified condition to penetrate the interstices of a porous band disposed about the emanating surface adjacent thereto and allowing the gel to solidify following said penetration.

10. A process according to claim 9 wherein said emanating surface initially is convex.

11. A dispenser according to claim 1 comprising a perforated decorative cover disposed in spaced relationship to and over said fully exposed emanating surface.