AU2006201740A1 - Dissemination Apparatus - Google Patents

Description

DISSEMINATION APPARATUS r- This invention relates to apparatus for the disseminating of volatile liquids into an atmosphere.

One very common method apparatus for disseminating a volatile liquid, such as a fragrance or an insecticide, into an atmosphere consists of a porous transfer member, such as a porous wick, that is in contact with a reservoir of volatile liquid. Liquid rises up this wick and evaporates into I the atmosphere. This system has drawbacks, such as the low surface area for evaporation and the tendency for the wick to fractionate complex mixtures, such as fragrances, so that some components are disseminated earlier than others and the full effect of the fragrance is lost.

It has been proposed to overcome this disadvantage by using external capillaries, that is, capillary channels cut or moulded into a suitable substrate. One example is described in United States Patent 4,913,350, in which an external capillary channel-containing member is inserted into a liquid. In another embodiment, described in United Kingdom Patent Application GB 0306449, there is fitted to a known transfer member a capillary sheet, that is, a sheet extending essentially perpendicularly from the transfer member and comprising channels of capillary dimensions, to which volatile liquid can pass and travel along for evaporation. This sheet generally contacts the transfer member by means of a hole in the sheet through which the transfer member protrudes and within which it fits snugly, at least some of these channels contacting the transfer member such that liquid can transfer from the member to the sheet ("liquid transfer contact").

Although this technology offers significant advantages over the porous wicks of the art, these advantages have never been completely realized. It has now been found that it is possible to obtain the full benefits of the technology by adherence to certain fundamental parameters. The invention therefore provides an apparatus adapted to disseminate volatile liquid into an atmosphere from a reservoir, the transfer to atmosphere being at least partially achieved by means of a transfer member having external capillary channels, characterised in that

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O 2 at least 30% by weight of the materials comprising the volatile liquid have a molecular weight of 175 maximum and the volatile liquid has a surface tension of less than dynes/cm; and The transfer member is of plastics material having a surface energy of less than dyne/cm.

By "at least 30% by weight" is meant all the components of the liquid, including any solvent cI present.

10 When the active is a fragrance it can be composed with one or more compounds, for example, natural products such as extracts, essential oils, absolutes, resinoids, resins, concretes etc., but also synthetic materials such as hydrocarbons, alcohols, aldehydes, ketones, ethers, acids, esters, acetals, ketals, nitrites, etc., including saturated and unsaturated compounds, aliphatic, carbocyclic, and heterocyclic compounds. The molecular weights range from around 90 to 320. Such fragrance materials are mentioned, for example, in S. Arctander, Perfume and Flavor Chemicals (Montclair, NJ., 1969), in S. Arctander, perfume and Flavor Materials of Natural Origin (Elizabeth, 1960) and in "Flavor and Fragrance Materials--1991", Allured Publishing Co. Wheaton, Ill. USA.

Some non-limiting examples of useful volatile materials whose molecular weight is less than 175 are: Material Molecular Weight ethyl acetate 88 iso-amyl alcohol 88 2-methylpyrazine 94 cis 3-hexenol 100 C6-aldehyde 100 C6 alcohol 102 ethyl propionate 102 benzaldehyde 106 \O Va 0 0 ci ci

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¢-q benzyl alcohol 108 C7-aldehyde 114 methyl amyl ketone 114 iso amyl formate 116 ethyl butyrate 116 Indole 117 acetophenone 120 phenyl ethyl alcohol 122 styralyl alcohol 122 Veltol IM 126 methyl hexyl ketone 128 3-methyl 3-methoxy butanol 128 ethyl amyl ketone 128 octenol JD 128 prenyl acetate 128 C8-aldehyde 128 amyl acetate 130 cinnamic aldehyde 132 phenyl propyl aldehyde 134 cinnamic alcohol 134 terpinolene 136 phenyl acetic acid 136 phenyl propyl alcohol 136 alpha pinene 136 benzyl formate 136 anisic aldehyde 136 d- limonene 136 Triplal T 138 Cyclal C m 138 Melonal M 140 \O Va 0 0 tc ci 0^ tc Va 0 0 ci 0,

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^0 0 0~ C-9 aldehyde 142 iso nonyl aldehyde 142 cyclo hexyl acetate 142 ethyl caproate 144 hexyl acetate 144 coumarin 146 methyl cinnamic aldehyde 146 cuminic aldehyde 148 benzyl acetone 148 geranyl nitrile 149 cuminyl alcohol 150 benzyl acetate 150 Heliotropine n 150 thymol 150 neral 152 synthetic vanillin 152 synthetic citral 152 rose oxide 154 geraniol 154 allyl caproate 156 Rosalva m 156 tetrahydro myrcenol 158 yara yara 158 diethyl malonate 160 methyl cinnamate 162 Jasmorange a 162 benzyl propionate 164 eugenol 164 ethyl vanillin 166 dihydrojasmone 166 O Va

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0t geranic acid 168 methyl laitone 168 methyl nonyl ketone 170 methyl tuberate 170 hexyl butyrate 172 octyl-3-acetate 172 hydroxycitronellol 174 Fructone 174 Some non-limiting examples of useful materials that can be used that have a molecular weight higher than 175 are: Material Molecular Weight benzal glyceryl acetal 180 anisyl acetate 180 terpinyl formate 182 geranyl formate 182 methyl diphenyl ether 184 delta undecalactone 184 allyl amyl glycolate 186 amyl caproate 186 FraistoneM 188 Pelargene 188 Florhydral 190 ethyl hexyl ketone 190 ethyl phenyl glycidate 192 Verdyl acetate

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M 192 dihydro beta ionone 194 iso-butyl salicylate 194 allyl cyclo hexyl propionate 196 \O Va 0 0 ci ci

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¢-q myrcenyl acetate 196 citronellyl oxyacetaldehyde 198 citral dimethyl acetal 198 beta naphthyl iso butyl ether 200 tetrahydro linalyl acetate 200 amyl cinnamic aldehyde 202 Fruitaflor T 202 Lilial 'M 204 damascenone 204 methyl ionone 206 Cashmeran "M 206 Ebanol T 206 phenoxy ethyl iso butyrate 208 iso amyl salicylate 208 Sandalore 'I 210 propyl diantilis 210 benzyl benzoate 212 citronellyl propionate 212 myristic alcohol 214 Gelsone IM 214 hexyl cinnamic aldehyde 216 butyl butyryllactate 216 amyl cinnamate 218 hydroxycitronellal dimethyl acetal 218 beta methyl ional 220 Vetiverol 'M 220 hexyl salicylate 222 geranyl crotonate 222 methyl jasmonate 224 linalyl butyrate 224 O Va

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oI Hedione M 226 Timberol 226 Floramat 228 benzyl salicylate 228 Fixal TM 230 Cetone V M232 cis carveol 232 Iso E Super 234 muscalone 234 geranyl tiglate 236 Cetalox 236 linalyl valerate 238 benzyl cinnamate 238 Thibetolide M 240 phenyl ethyl phenylacetate 240 phenyl ethyl salicylate 242 Boisambrene 242 jasmonyl 244 Phantolid M 244 methyl cedryl ketone 246 AldroneTM 248 amyl cinnamic aldehyde dma 248 Dione M 250 cedryl formate 250 ambrettolide 252 phenyl ethyl cinnamate 252 benzyl iso eugenol 254 hexadecanolide 254 Novalide T 256 citronellyl ethoxalate 256 \O Va 0 0 ci

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^0 0 0., Fixolide 'M 258 GalaxolideIM 258 rose acetate 262 ambrate 262 iso caryl acetate 264 cinnamyl cinnamate 264 ethyl undecylenate 266 Ethylene Brassylate IM 272 triethyl citrate 276 dihexyl fumarate 284 Okoumal 'M 288 musk ketone 294 alpha Santalol IM 300 geranyl iso valerate 312 The solvent of the volatile liquid can be selected from many classes of volatile compounds that known to the art, for example, ethers; straight or branched chain alcohols and diols; volatile silicones; dipropylene glycol, triethyl citrate, ethanol, isopropanol, diethyleneglycol monoethyl ether, dipropylene glycol, diethyl phthalate, triethyl citrate, isopropyl myristate, etc., hydrocarbon solvents such as Isopar T M or other known solvents that have previously been used to dispense volatile actives from substrates. These solvents in general have a molecular weight between 20 and 400. They are selected specifically for each volatile liquid to achieve the performance and safety, VOC and flash point) specified.

When the active is an insect repellant it can be composed of one or more compounds such as pyrethrum and pyrethroid type materials commonly now used in mosquito coils are likely to be the most useful for this purpose. Other insect control actives can be used, such as the repellants DEET, essential oils, such as citronella, lemon grass oil, lavender oil, cinnamon oil, neem oil, clove oil, sandalwood oil and geraniol.

When the active is an antimicrobial it can be composed of one or more of compounds such as essential oils such as rosemary, thyme, lavender, eugenic, geranium, tea tree, clove, lemon O 9 0 grass, peppermint, or their active components such as anethole, thymol, eucalyptol, famesol, menthol, limonene, methyl salicylate, salicylic acid, terpineol, nerolidol, geraniol, and mixtures thereof, benzyl alcohol, ethylene glycol phenyl ether, propylene glycol phenyl ether, propylene carbonate, phenoxyethanol, dimethyl malonate, dimethyl succinate, diethyl succinate, dibutyl succinate, dimethyl glutarate, diethyl glutarate, dibutyl glutarate, dimethyl adipate, diethyl adipate, dibutyl adipate, or mixtures thereof one or more aldehydes selected from cinnamic aldehyde, benzaldehyde, phenyl acetaldehyde, heptylaldehyde, octylaldehyde, decylaldehyde, undecylaldehyde, undecylenic aldehyde, dodecylaldehyde, tridecylaldehyde, methylnonyl o aldehyde, didecylaldehyde, anisaldehyde, citronellal, citronellyloxyaldehyde, cyclamen

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10 aldehyde, alpha-hexyl cinnamic aldehyde, hydroxycitronellal, alpha-methyl cinnamic aldehyde, methylnonyl acetaldehyde, propylphenyl aldehyde, citral, perilla aldehyde, tolylaldehyde, tolylacetaldehyde, cuminaldehyde, Lilial T, salicyl aldehyde, alpha-amylcinnamic aldehyde and Heliotropine TM Other volatile actives can be used alone or in combination with the above actives, for example decongestants such as menthol, camphor, eucalyptus etc., malodor counteractants such as are trimethyl hexanal, other alkyl aldehydes, benzaldehyde, and vanillin, esters of alpha-, betaunsaturated monocarboxylic acids, alkyl cyclohexyl alkyl ketones, derivatives of acetic and propionic acids, 4-cyclohexyl-4-methyl-2-pentanone, aromatic unsaturated carboxylic esters, etc.

Care must be taken when designing the volatile liquid in that they pose no danger to the public.

This is done by ensuring that the said volatile liquid has a flashpoint greater than about 60°C as determined by Test Method ASTM D93.

The transfer medium must have external capillary channels, that is, channels of capillary dimensions provided on an external surface of the medium such that a liquid will exhibit capillary flow within them. These may be provided by any suitable means, such as moulding and engraving. The transfer medium may be any suitable form of such medium, but is preferably one of two kinds: C O 01 1. The type in which a member bearing external capillary channels contacts directly a liquid in a reservoir, and the liquid rises in the capillary channels and evaporates into the atmosphere. An example of such a type is described in US 4,193,350 2. A type in which the liquid in the reservoir is taken therefrom by a porous wick in contact with it, there being mounted on the wick a capillary sheet whose external capillary channels are in liquid transfer contact with the wick, the liquid passing from cthe wick to the capillary channels and evaporating into the atmosphere. An example of such an apparatus is described in UK patent application GB 0306449 For the working of this invention, it is essential that the volatile liquid have a surface tension of dynes/cm maximum and that the plastics material have a surface energy of 45 dynes/cm maximunm. It has been found that this combination of parameters allows for an especially good dissemination of a liquid into an atmosphere. The invention therefore also provides a method of disseminating a volatile liquid into an atmosphere by evaporation from a transfer member having surface capillary channels, the volatile liquid being such that at least 30% by weight of the materials comprising it have a molecular weight of 175 maximum, and that it has a surface tension of less than 40 dynes/cm, and the transfer member being of plastics material having a surface energy of less than 45 dyne/cm.

The provision of a volatile liquid having the abovementioned characteristics is well within the skill of the art.

Preferably the liquid has a surface tension of less than 40 dyne/cm, and is more preferably within the range 20-35 dynes/cm. All surface tensions referred to herein are measured on a Fisher Surface Tensiomat model number 21 at It is further preferred that the volatile liquid have a viscosity of less than 10 centistokes per secondat 25 0 C as measured on a Cannon-Fenske Viscometer according to Test Method ASTM D 445.

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1- ^0 0- 11 The plastics materials for use in this invention preferably have a surface energy of from 15-45 dyne/cm. The surface energy of a plastics material is dependent upon its molecular structure and is a measure of the ability of a surface to be wetted. The more inert is a plastics material chemically, the lower is its surface energy. Thus, materials such as polyethylene, polypropylene and PTFE have low surface energies, whereas the plastics with more polar groups have higher surface energies. Preferably the surface energy lies in the range of from 30-45 dynes/cm and more preferably from 30-35 dyne/cm. Some suitable materials for the purposes of this invention are shown in the following table: Material Name Example Supplier Surface Material Trade Energy Name(s) Dynes/cm Polytetrafluoroethylene PTFE TEFLON DU PONT 18 FEP106N Polyethylene PE (HDPE) BOREALIS MG NORTHERN 9641-R PLASTICS Polyethylene PE (LDPE) IPETHENE 320 CARMEL

OLEFINS

Polyethylene PE (LLDPE) LL6201 EXXON MOBIL Polystyrene PS PS 146L NOVA 36

CHEMICALS

Polyvinylchloride PVC 41 Polyethylene terepthalate PET RADITER RADICI 42

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Polycarbonate PC LUPILON S- MITSUBISHI 3000R POLYMERS Polyvinylpropylene PP EXP 058 EXXON MOBIL 32 (TEFLON, BOREALIS, IPETHENE, RADITER and LUPILON are trade marks) Suitable transfer members may be easily fabricated by known means, for example, by the methods described in the abovementioned US 4,913,350 and GB application 0306449.

Va 0\ 12 The invention is further described by the following non-limiting examples.

Example 1.

Capillary sheets ofpolypropylene BP 400Ca 70, measuring 2.5 cm x 7.5 cm and having a surface energy of 32 dyne/cm, were immersed to a depth of 1.25 cm. into 1 Og of a number of vanilla fragrances containing different amounts of volatile materials with a MW less than 175.

The quantity of fragrance diffused into the air was determined by weighing the container with fragrance and capillary. The following results were obtained after 4 days.

Fragrance MW 175 Wt loss g/day Al 14.5 0.35 A2 34.5 0.87 A3 53.6 0.64 A4 61.6 0.69 69.05 1.10 A6 75.6 0.84 A7 81.6 0.86 A8 93.5 0.97 A9 93.5 1.07 This shows that, for effective transmission of fragrance into the atmosphere, the composition must have at least 30% of the fragrance materials with a molecular weight of less than 175.

Example 2 Two frusto-conical polyester wicks were placed in 11.5 g of Al and A2 fragrances in BarexTM containers and allowed to equilibrate overnight. 1.5 mm thick polypropylene external capillary sheets with a central hole that allowed them to be fitted to the wicks were placed thereon, and the quantity of fragrance diffused per day was measured. The results after 6 days are shown below: Va 0\ Fragrance MW 175 Weight Loss g/day Al 14.5 0.4 A2 35.5 For a hybrid system i.e. one in which the transport of the fragrance is via a porous wick and the diffusion is via an external capillary, good diffusion is obtained when the fragrance has a quantity of components with a MW 175 is around 30% or higher Example 3.

Capillary sheets ofpolypropylene BP 400Ca 70, measuring 2.5cm x 7.5 cm external capillary and having a surface energy of 32 dyne/cm, were immersed to a depth of 1.25cm into 1 Og of a series of fragrances having more than 30% components with MW 175, but with different surface tensions. The surface tension was measured at 25 C using a Fisher Surface Tensiomat model number 21.

The quantity of fragrance diffused into the air was determined by weighing the container with fragrance and capillary. The following results were obtained after 2 days: Fragrance Wt Loss Surface tension g/day Dynes/cm B1 1.1 35.6 B2 0.7 38.2 B3 0.5 41.2 B4 0.5 42.2 This shows the advantage of having a surface tension below 40, and preferably below 38, dynes/cm.

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¢-q 14 Example 4.

A capillary sheet of polypropylene BP 400Ca 70, measuring 2.5cm x 7.5 cm and having a surface energy of 32 dyne/cm, was immersed to a depth of 1.25cm into Og of a series of fragrances having more than 30% components with MW 175, but with different viscosities, The viscosity was measured using a Cannon-Fenske Viscometer by ASTM D 445.

The quantity of fragrance diffused into the air was determined by weighing the container with fragrance and capillary. The following results were obtained after 2 days: Fragrance Wt Loss g/day Viscosity Cs/s Cl 0.4 13.7 C2 0.4 11.9 C3 0.4 10.6 C4 0.9 8.2 1.1 For good diffusion, the viscosity of the fragrance should be below 10 Cs/s.

Example Capillary sheets with different surface energies were set up as per example 1 with fragrance D Components MW<175 30, surface tension 37 dynes/cm and viscosity 5.7 Cs/s) and fragrance E Components MW<175 30, Viscosity 2.9 cS/s and surface tension 34.5 dynes/sec), respectively. The fragrances had an oil-soluble dye added and the height to which it rose (as a percentage of the height of the capillary) after 6 minutes was measured and recorded, and is shown in the following tables.

Va 0 0 ci ci 0- 0 ci Va 0- 0ci Table 5 Effect of surface energy on diffusion of fragrance D Plastic Surface Rise 6 min energy dyne/cm PP BP 400 32 100(3) PETG 41 81 PB ABS 46 59 The 100% rise in PP BP 400 was achieved after only 3 minutes.

Table 6 Effect of surface energy on diffusion of fragrance E.

Plastic Surface Rise 6 energy min dynes/cm PP BP 400 32 100(1.2) PETG 41 100(2) PB ABS 46 41 100% rise was found after 1.2 min and 2 min, respectively for PP BP 400 and PETG.

This shows that the surface energy of the plastics material of the external capillary should be below 45 dynes/cm, preferably below 40 dynes/cm.

The invention is further described with reference to the accompanying drawings. It will be appreciated that the drawings are provided for the purpose of comprehending the context in which the present invention may be applied. It will be understood that the present invention will have other applications that will be apparent to those skilled in the art. The accompanying drawings depict particular embodiments and are not meant to limit the invention in any way.

Figure 1 is a perspective view of a one embodiment.

o 16 0 Figure 2 depicts a longitudinal cross-section of a transfer member at the point where it contacts a diffusion surface.

Figure 3 depicts an arrangement wherein surface capillarity is conferred by a porous material affixed to a non-porous surface.

Figure 4 depicts a variety of possible surface capillarity arrangements.

Figures 2-4 are schematic and are not to scale, certain dimensions being exaggerated for the purposes of clarity.

In Figure 1, a reservoir 1 (a bottle or jar) has a neck 2 into which is fitted a rod-like porous wick 3, this being a tight fit into the neck by means of a tightly-fitting elastomeric plug 4 that surrounds the wick. The wick is circular in cross-section and that part of the wick protruding from the reservoir is slightly conical as shown at Figure 2, having a narrower end 5 remote from the reservoir and a broader end 6 closer to the reservoir. This permits the easy mounting on the wick of a diffusion surface 7, which has an aperture 8 of diameter greater than that of end 5 but greater than that of end 6. The aperture 8 is shaped so that it closely matches the frusto-conical surface of the wick, ensuring good contact and liquid transfer. The diffusion surface is a curved sheet of non-porous plastic that bears on its surface a series of open capillaries 9.

In Figure 3, a frusto-conical wick 3 bears a non-porous diffusion surface 10. To this is affixed a capillarity-providing material 11. This material covers that surface of the diffusion surface facing downwards in normal operation and extends into the aperture 8 of the diffusion surface, such that it contacts the wick and is able to absorb and transfer liquid for evaporation. The weight of the diffusion surface acting downwards helps secure the surface and establish a good liquid transfer contact.

In Figure 4, there can be seen a variety of surface capillarities. These are presented by way of example only and they are not limiting of the many practical and ornamental possibilities.

Claims (4)

1. 2. An apparatus according to claim 1, in which the surface tension of the liquid is from dynes/cm.
2. 3. An apparatus according to either claim 1 or claim 2, in which the surface energy of the plastics material is from 15-45 dynes/cm.
3. 4. An apparatus according to claim 3, in which the surface energy lies in the range of from
4. 30-45 dynes/cm. An apparatus according to claim 4, in which the surface energy lies in the range of from 30-35 dynes/cm. 6. An apparatus according to any one of claims 1 to 5, in which the volatile liquid has a viscosity of less than 10 centistokes per second at 7. An apparatus according to any of claims I to 6 in which the transfer member bears external capillary channels, which directly contact a liquid in a reservoir, and the liquid rises in the capillary channels and evaporates into the atmosphere. o 18 O 8. An apparatus according to any of claims 1 to 7, in which the liquid in the reservoir is taken therefrom by a porous wick in contact with it, there being mounted on the wick a capillary sheet whose external capillary channels are in liquid transfer contact with the wick, the liquid passing from the wick to the capillary channels and evaporating into the atmosphere. 9. A method of disseminating a volatile liquid into an atmosphere by evaporation from a transfer member having surface capillary channels, the volatile liquid being such that at least 30% by weight of the materials comprising it have a molecular weight of 175 10 maximum, and that it has a surface tension of less than 40 dynes/cm, and the transfer member being of plastics material having a surface energy of less than 45 dyne/cm.