Compositions able to indicate when they become inefficient in use

Abstract

The invention concerns a composition aimed to indicate by color change when consumer articles, particularly volatile dispensers, containing or associated with said composition have become inefficient in use.

Description

FIELD OF THE INVENTION

[0001] The invention concerns a composition designed to indicate by color change when consumer articles, particularly volatile material dispensers, containing or associated with said composition, have become inefficient in use.

[0002] The composition is constituted by a volatile liquid phase, a non-volatile polar phase and a useful amount of a dye originally dissolved essentially in the volatile liquid phase, said dye being able to adopt a different color according to the nature of the phase in which it is dissolved or deposited. Optionally, the composition can also contain an effective amount of an acidic compound.

[0003] The invention also concerns the use of said composition in a consumer article, in particular a device intended to diffuse a volatile or partially volatile liquid, more specifically an air freshener.

BACKGROUND

[0004] The use of compositions able to indicate, by changing their color, the loss of efficiency of a consumer article with which the compositions are associated, is quite wide. The usefulness of such compositions is quite apparent, as they allow the visual assessment of the right moment at which the consumer article needs to be renewed.

[0005] The known compositions are used in consumer articles such as air fresheners (e.g. see S.C. Johnson, EP 0309173), packaging films (e.g. see University of Akron, U.S. Pat. No. 5,501,945) or coating films (e.g. see Nippon Photograph Printing, JP 03199964).

[0006] In general, changes in a consumer article during its use or storage, induce the compositions to respond, and therefore to change color, indicating the loss of efficiency. The most commonly occurring variations include pH, redox potential, solvent, pressure or light irradiation changes.

[0007] European patent EP 309173 discloses the use of a homogeneous indicator composition that includes a volatilizable non-aqueous solvent, a soluble polar indicator dye and a soluble proton donating compound. During the evaporation of the volatilizable non-aqueous solvent, the concentration of the proton donating compound progressively increases, thus inducing a gradual pH change, the latter producing a gradual color change indicating the lost of efficiency. A limitation of such a compostion comes from the fact that the preferred proton donors are liquid and therefore must be less volatile than the solvent in order to ensure the functioning of the composition. A further serious drawback of such a composition comes from the fact that the color change, and therefore the information provided to the consumer concerning the efficiency of the article, occurs only gradually and is spread out through the useful life of the article. This gradual change makes it difficult to asses when the article has effectively become inefficient in use.

[0008] The Japanese document JP 03199964 discloses a printable coating film for discoloration in the course of time, formed by an ink containing a powder of (hydro)oxides, a dye, a solvent that has at least one oxygen atom in its formula and a resin for the binder as essential components. In said film, the evaporation of the solvent induces the color changes.

[0009] In order to achieve a good matching between the rate of evaporation of the solvent and the effective life of the associated article, the realization of an efficient film is complex and requires a very careful dosing of the quantity of solvent and of the thickness of the film. Furthermore, as above, the main weakness consists in the fact that the color change is a gradual one, as clearly stated by the authors.

[0010] Despite prior known compositions aimed at indicating when consumer articles have become inefficient in use, there is still a need for compositions which are of simple preparation and able to provide an unambiguous indication of the consumer article status through a clear and unambiguous color change.

DETAILED DESCRIPTION OF THE INVENTION

[0011] The object of the present invention is a composition of simple preparation and to provide a clear and unambiguous indication of the loss of efficiency of consumer articles containing or associated with said composition. As consumer articles, volatile material dispensers are particularly intended.

[0012] The composition of the invention is composed of a volatile liquid phase, a non-volatile polar phase and a useful amount of a dye originally dissolved essentially in the volatile phase, said dye being able to adopt a variable color as a function of the nature of the phase in which it is dissolved or deposited. Preferably, the dye, when dissolved in the volatile liquid phase, is colorless or has at least a color clearly distinct from the color that it assumes when deposited on the polar phase.

[0013] Optionally, the composition can also contain an effective amount oaf an acidic compound, in order to fine tune the moment at which the color change occurs.

[0014] As described above, the composition contains a volatile liquid phase. Said volatile liquid phase will be preferably composed essentially of a volatile material that is intended to be dispersed into the surrounding air by the consumer article with which the composition of the invention is associated. The volatile liquid will preferably be a non-aqueous liquid.

[0015] As the volatile liquid phase, there can be used for example perfumes, in which case the consumer product will be of the air freshener type. Other suitable volatile liquid phases can be a deodorizing or sanitizing agent or insect repellent, or any other volatile material capable of imparting perceptible and desirable benefits to the quality of the air into which it is diffused.

[0016] As the perfume or perfuming ingredients there can be used any ingredient or mixture of ingredients currently used in perfumery. The latter can be made of discreet chemicals; more often, however, it will be a more or less complex mixture of volatile ingredients of natural or synthetic origin. The nature of these ingredients can be found in specialized books of perfumery, e.g. in S. Arctander (Perfume and Flavor Chemicals, Montclair N.J., USA 1969) or similar textbooks of reference, and a more detailed description thereof is not warranted here.

[0017] Although special mention has been made hereinabove of the perfuming effect that can be exerted by the compositions of the invention, the same principles apply to the manufacture of analogous compositions for the diffusion of deodorizing or sanitizing vapors, the perfume base being replaced by a deodorizing composition, a bactericide, an insecticide, an insect repellent or an insect attractant. By the term “sanitizing vapors”, we refer here not only to the vapors of those substances which can enhance the degree of acceptance of the air surrounding the observer, but also to those substances which can exert an attractant or repellent effect toward certain species of insects, for instance toward houseflies or mosquitoes, or else, which can have bactericide or bacteriostatic activity. It goes without saying that mixtures of such agents can also be used.

[0018] As previously mentioned, the polar phase is a material that must allow the dye, when initially deposited on it, to assume a different color from the color said dye assumes when dissolved in the volatile liquid phase.

[0019] The preferred polar phase is a solid material that is non-soluble in the volatile liquid phase, therefore the compositions of the invention are heterogeneous or biphasic. Said solid material can be selected from the group consisting of the metal oxides and hydroxides of the metals in group III and IV of the periodic table. Preferred materials for the polar phase are silica gel, alumina and Florisil® (MgSiO4; origin: Supelco). More preferably the polar phase will be alumina or silica gel.

[0020] The dyes are another component of the composition. As mentioned above, a dye useful for the composition according to the invention must be able to adopt a different color according to the polarity of the phase in which it is dissolved or deposited. Preferably the dye, when dissolved in the volatile liquid phase, is colorless or has a color clearly distinct from the color that said dye assumes when deposited on the polar phase.

[0021] Suitable dyes are such that their affinity for the volatile liquid phase is higher than for the polar phase; e.g. the dye will be preferably dissolved in the volatile liquid phase rather than deposited on the polar phase. The relative affinity of the dye for the two phases will determine the fragrance depletion point at which the color change will appear. The higher the affinity of the dye for the volatile liquid phase, compared to the affinity for the polar phase, the higher will be the depletion of fragrance when the color change appears.

[0022] By the expression “depletion of fragrance” we mean the percentage of volatile liquid phase which has been released into the air surrounding the consumer article containing the composition of the invention.

[0023] As the dye, any current such substance may be employed, provided that it satisfies the criteria cited herein above. Suitable dyes are, as non-limiting examples, those of the following families: diaryl phthalides and their indol derivatives, diaryl sulphophthaleins, and fluorans.

[0024] Preferred dyes are N-[9-(2-carboxyphenyl)-6-(diethylamino)-3H-xanthen-3-ylidene]-N-ethylethamine free base commonly known as Rhodamine B base, 3,3-bis(1-octyl-2-methylindol-3-yl) phthalide, also known as Pergascript® Red I-6B (origin CIBA SC Switzerland), 3,3-bis(1-ethyl-2-methylindol-3-yl) phthalide, 3,3-bis(1-butyl-2methylindol-3-yl) phthalide, 3,3-bis(1-pentyl-2-methylindol-3-yl) phthalide, 3,3-bis(4-dimethylaminophenyl)-6-dimethyl amino phthalide, commonly referred to as crystal violet lactone, 2′-(bisphenylmethyl) amino-6-(diethylamino)spiro-(isobenzofuran-1(3H),9′-(9H) xanthen)-3-one also known as malachite green lactone, 3-(4-diethylamino) phenyl-3-(di(4-octyl) phenylamino) t-(3H)-isobenzofuranone and 2-anilino-3-methyl-6-diethyl-amino fluoran.

[0025] A fourth component of the composition according to the invention is an acidic compound. However as already mentioned, the addition to the composition of said acidic compound is optional.

[0026] This optional fourth constituent can be a liquid or solid compound, but it shall in any case be less volatile than the volatile liquid phase. The acid serves as proton donor and causes the dye to become protonated and to take the form of the colored open-ring acid rather than the colorless lactone.

[0027] Said acidic compound can be selected from the group constituted by the chemicals containing at least a proton donating group such as a carboxylic acid or a hydroxyl group. Preferred acidic materials are lauric, stearic, myristic, palmitic acid or diphenol-dimethyl-methane.

[0028] The above-identified constituents of the composition which is the object of the invention can be admixed in various ratios depending on the nature of the different constituents.

[0029] One can cite, as non-limiting examples and for all types of consumer articles associated with said composition, compositions wherein: a) the dye is present in an amount comprised between 0.007% and 2%; b) the polar phase is present in an amount comprised between 0.5% and 12%; c) the acidic compound is present in an amount comprised between 0% and 20%; and d) the volatile liquid phase constitutes the balance of the composition, percentage being referred to the weight of the composition.

[0030] Preferably compositions wherein: a) the dye is present in an amount comprised between 0.01% and 0.5%; b) the polar phase is present in an amount comprised between 1% and 10%; c) the acidic compound is present in an amount comprised between 0% and 5% and d) the volatile and liquid phase constitutes the balance of the composition, percentage being referred to the weight of the composition.

[0031] Naturally, it is clear to a person skilled in the art that the various components can be admixed in any quantity required to achieve the color change at the desired fragrance depletion point of the article.

[0032] As anticipated above, the composition of the invention can be contained in a consumer article, whereby as a consumer article it is intended here more specifically a volatile material dispenser.

[0033] Such a volatile material dispenser can be, depending on the nature of the liquid phase used in the preparation of the composition, a perfuming or sanitizing device such as an air freshener, particularly of the membrane-type air freshener, a diaper pail freshener, a car freshener, a closet freshener, a cat litter box freshener, a shoe freshener or a garbage pail freshener, an insecticide device or an insect repellent.

[0034] In fact, a container and an adequate composition of the invention will compose said consumer article. The composition will be inside the container and at least a portion of the container surface must be made of a material permeable to the vapors of the volatile liquid phase. The container can be made of any material usable for this kind of consumer article. Naturally said material must be chemically inert toward the composition of the invention.

[0035] During storage, the container in which the composition is enclosed is sealed, in order not to allow diffusion of the volatile liquid phase into the surroundings. The consumer will then activate the consumer article simply by removing the seal, after which the volatile liquid phase will start to diffuse in the surrounding air. Once the volatile liquid phase has evaporated to such an extent that its desired action (e.g. perfuming or insect repellent) starts to fade or has faded to a certain extent, the composition of the invention will change its color, and not before. This technical effect will provide the consumer with a clear and unambiguous information concerning the efficiency in use of the article.

[0036] Preferred consumer article is an air freshener operating at room temperature or in a small oven, such as a “plug-in” air freshener.

[0037] The invention will now be described in further detail by way of the following examples.

EXAMPLES 1

Tuning of the Depletion Point of a Composition According to the Invention as a Function of Dye Concentration

[0038] An air freshener composition has been prepared by mixing the following ingredients in the indicated amounts: 1 Ingredients Parts by weight Fragrance 96 Amorphous fumed silica gel 1)  4 Lauric acid according to table 1 Pergascript Red I-6B ® 2) according to table 1 1) Grade PTG; origin: Cabot Corp., USA 2) Origin: Ciba SC, Switzerland

[0039] Then, 0.25 g of the composition were placed on a 7 cm×7 cm cut piece of aluminum foil. The initial weight of the solution was measured. The solution on aluminum foil was placed in a 55° C. incubator to increase the depletion rate of the fragrance. The sample was observed for any color change every 30 minutes. Once the color change was observed, the sample was then weighed, and the percentage of fragrance depletion calculated. 2 TABLE 1 Influence of the dye/acid concentration on the depletion point of a composition at the moment of the color change of the composition: Parts of acid Parts of dye Depletion point* 0.045 0.005 Not observed 0.068 0.0075 100  0.09 0.01 84 0.27 0.03 78 0.45 0.05 75 0.9 0.1 70 1.35 0.15 66 1.8 0.2 63 2.7 0.3 55 3.6 0.4 49 *percentage of the total fragrance evaporated.

EXAMPLE 2

Examples of compositions for a Plug-in Air Freshener

Composition (A)

[0040] An air freshener composition was prepared by mixing the following ingredients in the indicated amounts: 3 Ingredients Parts by weight Fragrance1) 9600  Amorphous fumed silica gel1) 400 Pergascript Red I-6B ®1)  5 1)As in example 1

Composition (B)

[0041] An air freshener composition was prepared by mixing the following ingredients in the indicated quantities: 4 Ingredients Parts by weigh Fragrance1) 960 Amorphous fumed silica gel1) 40 Lauric acid 3.6 Pergascript Red I-6B ®1) 0.4 1)As in example 1

General Description of the Device

[0042] 5.1 grams of one of the composition as described herein above was placed in a cartridge, one side of said cartridge being composed of Barex® resin (origin: BP Chemicals) used as a reservoir for the fragranced composition, and the other side being a transparent semi-permeable membrane of about 150-180 microns thickness and made of an ethylene ethyl acrylate copolymer, said membrane being used for the diffusion of the fragrance. The cartridge was then placed in an electric heating unit (plug-in type air freshener) to allow diffusion of the fragrance. The unit was plugged in a 120-volt outlet, heating the cartridge to 37° C.

[0043] Note that the cartridge does not necessarily need heat to diffuse the fragrance. Using a more permeable membrane can regulate amount of heat required. It is possible to use a membrane that is permeable enough to allow diffusion of the fragrance at room temperature.

[0044] Observations were made over a 45-day time period. Over this period of time, color change and diffusion of fragrance were recorded.

Results for Composition (A)

[0045] As shown in the following table, such a composition is able to display a clear change of color after 29 days, or at 67% depletion of the fragrance, to indicate when the air freshener starts to become inefficient in use. 5 Time (days) Depletion* Observations  0-20  0 to 50 no color change 21-28 51 to 66 a very slight pink hue starts to develop 29 67 a distinct magenta color is evident 30-45 67 to 85 color became darker and change more obvious *Percentage of the total fragrance evaporated.

Results for Composition (B)

[0046] As shown in the following table, such a composition is able to display a clear change of color after 30 days, or at 68% depletion of the fragrance, to indicate when the air freshener started to become inefficient in use. 6 Time (days) Depletion* Observations  0-22  0 to 52 no color change 23-29 53 to 67 a very slight pink hue starts to develop 30 68 a distinct magenta color is evident 31-45 69 to 84 color became dark and change more obvious** *Percentage of the total fragrance evaporated. **During this period color became much darker then the experiments without acid

Claims

1. A composition intended to indicate by color change when a consumer article containing or associated with said composition has become ineffective in use, said composition being composed of:

a) a volatile liquid phase,

b) a non-volatile polar phase,

c) a useful amount of a dye originally dissolved essentially in the volatile phase, said dye being able to adopt a variable color as a function of the nature of the phase in which it is dissolved or deposited,

d) optionally, a useful amount of an acidic compound.

2. A composition according to claim 1, wherein said polar phase is essentially composed of a solid material selected from the group consisting of the oxides and hydroxides of the metals in group III and IV of the periodic table.

3. A composition according to claim 2, wherein said polar phase is essentially composed of silica gel, silicate, or alumina.

4. A composition according to claim 1, wherein said dye is selected from the group consisting of diaryl phthalides and their indole derivatives, diaryl sulphophthaleins and fluorans.

5. A composition according to claim 4, wherein said dye is selected from the group consisting of N-[9-(2-carboxyphenyl)-6-(diethylamino)-3H-xanthen-3-ylidene]-N-ethylethamine free base, 3,3-bis(1-octyl-2-methylindol-3-yl) phthalide, 3,3-bis(1-ethyl-2-methylindol-3-yl) phthalide, 3,3-bis(1-butyl-2-methylindol-3-yl) phthalide, 3,3-bis(1-pentyl-2methylindol-3-yl) phthalide, 3,3-bis(4-dimethylamino-phenyl)-6-dimethyl amino phthalide, 2′-(bisphenylmethyl) amino-6-(diethylamino)spiro-(isobenzofuran-1(3H), 9′-(9H) xanthen)-3-one, 3-(4-diethylamino) phenyl-3-(di(4-octyl) phenylamino) t-(3H)-isobenzofuranone and 2-anilino-3-methyl-6-diethyl-amino fluoran.

6. A composition according to claim 1, wherein a) the dye is present in an amount comprised between 0.007% and 2%; b) the polar phase is present in an amount comprised between 0.5% and 12%; c) the acidic compound is present in an amount comprised between 0% and 20%; and d) the volatile liquid phase constitutes the balance of the composition, percentage being referred to the weight of the composition.

7. A composition according to claim 6, wherein a) the dye is present in an amount comprised between 0.01% and 0.5%; b) the polar phase is present in an amount comprised between 1% and 10%; c) the acidic compound is present in an amount comprised between 0% and 5%; and d) the volatile liquid phase constitutes the balance of the composition, percentage being referred to the weight of the composition.

8. A composition according to claim 1, wherein said volatile liquid phase is a perfume, a deodorizing or sanitizing agent or an insect repellent, or any other volatile material capable of imparting perceptible and desirable benefits to the quality of the air into which it is diffused.

9. A composition according to claim 8, wherein said volatile liquid phase is a perfume

10. A consumer article in the form of a volatile material dispenser containing a composition according to claim 1.

11. A consumer article according to claim 10, wherein the volatile material dispenser is a perfume dispenser.

12. A perfume dispenser according to claim 11, in the form of an air freshener, a plug-in air freshener, a diaper pail freshener, a car freshener, a closet freshener, a cat litter box freshener, a shoes freshener or a garbage pail freshener.