WO2005028598A1

WO2005028598A1 - Fuel composition which produces a coloured flame

Info

Publication number: WO2005028598A1
Application number: PCT/EP2004/010570
Authority: WO
Inventors: Gérard Carnelle
Original assignee: Moner Valley Investments Llc
Priority date: 2003-09-23
Filing date: 2004-09-21
Publication date: 2005-03-31
Also published as: EP1518917A1

Abstract

The invention relates to a colourless or light-coloured fuel composition which produces a coloured flame when burnt in a lighting device. The inventive composition contains: between 78 and 98 wt.- % of a mixture of propylene glycol and water, comprising between 2.5 and 12 wt.- % water; up to 9 wt.- % butanol; up to 4 wt.- % of a colouring agent which is selected from sodium and/or lithium salts of formic and acetic acids; and up to 9 wt.- % boric acid which is used as a colouring agent, on condition that at least one of the two colouring agents is present. Said composition is perfectly stable and non-toxic and provides the desired colours when burnt.

Description

Combustible composition producing a colored flame.

Description.

The present invention relates to a combustible composition producing a color flame. Such a composition can be used in particular in a lighting device of the immersed wick type when it is liquid or in a device of the candle or candle-gel type when it is solid.

More particularly, the invention relates to such a liquid or solid composition for use in a lighting device for decorative, religious or other use, producing a colored flame. A lighting device comprising a reservoir containing a combustible liquid, a wick partially immersed in said liquid and possibly a wick holder has been known since antiquity.

More recently, in order to satisfy decorative, religious or other needs, efforts have been made to produce combustible solutions which provide, during their combustion, a colored flame. Many efforts in this direction have been made without, however, a completely satisfactory result from the point of view of combustion, safety, economy, conservation (stability) and / or coloring having been achieved. got. To be convinced, it suffices to observe the market which does not yet have such liquid or solid fuel solutions or satisfactory lighting devices.

The Applicant has therefore endeavored to develop a combustible composition for a lighting device of the aforementioned type comprising a combustible composition producing a colored flame during its combustion. More particularly, it sought, for decorative purposes, such compositions which are colorless or weakly colored in the absence of combustion.

[0005] A combustible composition producing a color flame by thermal oxidation-ionization must comprise at least one combustible component and one colorigenic component. If this composition is to be in the form of a liquid, it is conventional to use as combustible component primary or secondary alcohols, polyols or other oxygenated molecules having a limited number of carbon atoms (see on this subject the US Patent 3,726,731). The combustion of the mixture takes place in two stages: the liquid combustible component first passes into the gaseous phase under the effect of the heat given off, then the gases thus obtained combine with atmospheric oxygen and enter into combustion. The heat released by said combustion has the effect, on the one hand of allowing the vaporization of an additional quantity of combustible component thus feeding the flame and, on the other hand, of ionizing the colorigenic component. In the case of a liquid composition, it is also essential that the colorigenic component is distributed in the combustible component in a homogeneous manner so that the coloring of the flame is constant during the combustion of the entire composition. In general, however, the coloring agents are in the form of solids which are poorly soluble in the liquids constituting the combustible component. It has been suggested to form a suspension, an emulsion or other, but never, the ideal homogeneity was observed.

Other factors taken into account for the preparation of the compositions in accordance with the present invention are the following: the mixture must be sufficiently flammable (sufficiently low flash point) while respecting the limits imposed by safety. Safety standards indeed impose a flash point which cannot be lower than 55 ° C. In addition, for conservation and safety reasons, the mixture must not be too volatile (low saturation vapor pressure at room temperature). In addition, it must have good diffusion capacity in the wick so that it is not consumed too quickly. Finally, the mixture cannot include substances considered toxic or being classified as such by the European community such as methanol in an amount greater than or equal to 10% by weight, or even harmful, such as ethylene glycol in an amount greater than or equal at 25% by weight. The state of the art already informs some attempts to use propylene glycol in combination with water (see for example the patent CH-A-449 555 or the French patent application FR-A-2 727 688). No favorable results have been observed with the compositions described in these documents when propylene glycol is used. The disclosed compositions cause the flame to suffocate fairly quickly. It has also been proposed (USP-A-3 107 511) to add propylene glycol to compositions based on polymerized alcohols. Such compositions either do not burn or ignite with extreme difficulty and give a crackling flame. These bleak results have dissuaded those skilled in the art from continuing on this path.

To meet the constraints set out above, the inventors determined that the composition should contain the following constituents in fairly precise weight proportions that it was not possible to predict in the light of the state of the art: from 78 to 98% by weight of a mixture of propylene glycol and water comprising from 2.5 to 12% by weight of water; up to 9% by weight of butanol; up to 4% by weight of a colorigenic agent chosen from the sodium and / or lithium salts of formic and acetic acids; and up to 9% by weight of boric acid as a colorigenic agent with the proviso that at least one of the two colorogenic agents is present.

Other additives aimed at changing the rheological properties of the mixtures can obviously be added as long as the proportions indicated above are respected. For example, an oil can be added (for example, a biomass oil type oil can be added) or paraffin to provide an oily composition (for use in an oil lamp for example). In order to provide a solid composition (for use as a candle for example), the composition can be hardened by means of a composition of a block copolymer of SBS type (styrene-butadiene-styrene) and an isocyanate used. works at a rate of 1 to 5% by weight. These compositions could also be gelled, for example using a composition of a triblock copolymer of the SE / BS type (styrene-ethylene / butylene-styrene) and an isocyanate for obtain an “elastomer” type gel or using a carbopol for a conventional gel. The use of propylene glycol in combustible compositions has already been mentioned in the state of the art such as for example in US patent 3,790,332, but, due to its very high hygroscopy has been rejected. To date, there are no compositions on the market comprising propylene glycol.

Surprisingly, the Applicant has been able to demonstrate that this high hygroscopy of propylene glycol did not constitute a problem and could, on the contrary and provided that the composition includes certain specific constituents in very precise weight ratios, contribute to improving the properties of the composition. The main effect of the water present in the liquid fuel composition according to the invention is to lower the combustion temperature. The inventors have noticed that this is not a drawback if certain particular constituents are present in very precise weight ratios. This water may already be present in propylene glycol so that there is no need to resort to the purchase of an anhydrous product which is particularly expensive. The water may also come, in whole or in part, from the water of hydration of the colorigenic agent. Finally, water can also be added directly to the composition. As soon as the composition comprises water in a relatively large quantity and well determined from its preparation, there is no longer the risk of seeing the composition change due to the hygroscopy of one of its constituents and the compositions according to the 'invention have exceptional stability compared to known compositions.

The colorogenic agents according to the invention are the sodium and / or lithium salts of formic and acetic acids (alone or as a mixture) and boric acid. The quantity and nature of the agent used will depend on the color which it is desired to impart to the flame. Liquid formulations 1 to 6 according to the invention and 7 to 10 provided for comparison have been tested. The compositions tested are listed in Table 1.

The compositions of Examples 1 to 6 are liquid and provide a result corresponding perfectly to the expectations expressed above: the flame observed does not suffocate and is well supported; the color is clearly visible and remains constant; finally, the wick is almost not consumed. It will be noted that the flash points of these compositions are all between 72 and 82 ° C. and that these do not comprise any toxic product. Therefore, these compositions are perfectly acceptable from a commercial point of view. The compositions of Examples 1 and 4 burn with a red color, those of Examples 2 and 5 with a green color and those of Examples 3 and 6 with an orange color.

Composition 7 burns with a red flame, but very quickly chokes while crackling violently. Likewise, composition 8 suffocates fairly quickly and produces smoke. It is suspected that the large amounts of water used in these compositions are responsible for these phenomena. Composition 9 could not even be ignited. Composition 10 takes extremely difficult and crackles violently. There is a very unstable red flame. Example 11

The composition of Example 2 was gelled into an elastomer by incorporating into it 3% by weight of a block copolymer of the SE / BS type grafted with approximately 2% by weight of maleic anhydride. The solution obtained is thermo-reversible and has a viscosity η of approximately 1000 cPs at temperature. room. The gel thus obtained burns with a green flame. The flame observed does not suffocate, is well supported; the color is clearly visible and remains constant. No smoke is observed.

Example 12

The composition of Example 5 was gelled into an elastomer by incorporating into it 2.5% by weight of a composition of a triblock copolymer of the SE / BS type and of an iosocyanate. The solution obtained has a viscosity η of approximately 1000 cPs at room temperature. The gel thus obtained is thermo-reversible and burns with a green flame. The flame observed does not smother, is well supported; the color is clearly visible and remains constant. No smoke is observed. Example 13

The composition of Example 4 was mixed with biomass oil in an amount of 10 parts (by weight) of the composition according to the invention for 90 parts (by weight) of oil. The mixture thus obtained was poured into an oil lamp and burned with a red flame. The observed flame does not suffocate, is well supported. In the context of this example, the visibility of the flame can be further improved by saturating the lithium acetate mixture (addition of approximately 1% by weight).

Example 14 The composition of Example 6 was hardened by incorporating therein 1% by weight of an SBS block copolymer. The composition obtained is pasty and can be shaped so as to produce a candle by incorporating therein a suitable wick. The candle thus prepared burned with an orange flame. The observed flame does not suffocate, is well supported.

Claims

Claims.

1. Colorless or weakly colored combustible composition producing, during its combustion, a colored flame comprising - from 78 to 98% by weight of a mixture of propylene glycol and water comprising from 2.5 to 12% by weight of water ; - up to 9% by weight of butanol; - up to 4% by weight of a colorigenic agent chosen from the sodium and / or lithium salts of formic and acetic acids; and - up to 9% by weight of boric acid as a colorigenic agent with the proviso that at least one of the two colorogenic agents is present.

2. Combustible composition according to claim 1, characterized in that it contains, as the colorigen agent, a mixture of lithium acetate and formate.

3. Fuel composition according to claim 2, characterized in that it contains 1% by weight of a mixture of lithium acetate and formate.

4. Combustible composition according to claim 1, characterized in that it contains, as colorogen, a mixture of sodium acetate and lithium formate.

5. Combustible composition according to claim 4, characterized in that it contains 1% by weight of a mixture of sodium acetate and lithium formate.

6. Mixture comprising 10% by weight of a composition according to any one of the preceding claims and 90% by weight of a biomass oil.

7. Mixture comprising any one of the compositions of claims 1 to 5 with paraffin.

8. Gel obtained by gelification of any one of the compositions of claims 1 to 5 with a gelling agent, preferably a block copolymer of the SE / BS type (styrene-ethylene / butylene-styrene).

9. Material obtained by gelification hardening of any one of the compositions of claims 1 to 5 with a hardening agent, preferably a block copolymer of SBS type (styrene-butadiene-styne).

10. Candle obtained by shaping the material according to claim 9 and adding a wick.