JPH0465489A - Liquid fuel regenerating colored flame - Google Patents

Abstract

PURPOSE:To obtain a liquid fuel readily ignitable, stably combustible, generating stable colored flame, by blending a liquid fuel containing a specific lower alcohol, generating colored flame, with a specific amount of water. CONSTITUTION:(A) A liquid fuel containing a 1-4C lower alcohol such as methyl alcohol, ethyl alcohol, propyl alcohol or butyl alcohol, generating colored flame, is blended with (B) <=15 wt.% water to give the objective liquid fuel. A liquid such as a boric ester having compatibility with an organic solvent is usable as a coloring agent in an arbitrary blending ratio.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to the composition of liquid fuels that produce colored flames.

(Prior Art) When generating a colored flame, a method that utilizes a flame color reaction is generally used. In this flame reaction, salts such as alkali metals and boric acid are thrown into a flame either directly or dissolved in an appropriate solvent, and the volatilized metal atoms are thermally excited and emits visible light at a wavelength of

(Problems to be Solved by the Invention) Attempts have been made to apply this flame color reaction to lighting fuels, etc., but they suffer from poor ignitability and low color visibility (
It is easy to see in a dark place, but it is difficult to see when the surrounding area is bright or the background is a white color or a solid color.For these reasons, it is not commercialized very often.

The critical point of a fuel that is characterized by the generation of colored flames lies in its low color visibility. Color visibility depends on the concentration of color formers (compounds containing alkali metals, boric acid, etc. that exhibit a flame reaction) contained in the fuel, so theoretically, increasing the color former concentration will improve color visibility. It is possible to increase. However, in reality, it is difficult to increase the concentration of the color former indefinitely because it is limited by the solubility of the color former. In particular, the types of color former compounds that exhibit solubility in organic solvents, which are the main components of fuel, are limited, and their solubility is often very low.

In addition, the petroleum-based liquid fuel normally used as a fuel produces an intense orange-colored flame derived from the high-temperature emission of carbon contained in the fuel during its own combustion, so it does contribute to the brightness of the flame. However, it is a major hindrance to the desired coloration of the flame reaction. On the other hand, if a lower alcohol, which hardly colors the flame by itself, is used as a fuel so as not to cause an orange flame due to the fuel itself, it will not interfere with the flame color reaction, but it will produce an especially red or purple color. For light-colored flame color reactions such as yellow and blue, the transparency of the flame is too high or the brightness of the flame is too low, which also makes it difficult to obtain good color visibility.

Therefore, the following three problems must be solved when introducing a flame reaction to liquid fuel.

(1) Dissolution of color forming agent into organic solvent, which is the main component of fuel Generally, compounds containing metal elements that exhibit a flame reaction are mostly water-soluble, and few are soluble in organic solvents.

Furthermore, even if it is soluble in an organic solvent, its solubility is low and it is difficult to obtain an effective flame color.

(2) Reducing the orange flame color of the organic solvent itself, which is the main fuel component. Petroleum-based liquid fuels used as fuel usually emit orange flames due to high-temperature luminescence of free carbon when burned. , which interferes with the flame reaction.

Furthermore, when lower alcohols are used as fuel, other problems occur such as generation of orange flame, excessive transparency of the flame, and insufficient brightness of the flame.

(3) Decreased flame transparency and increased flame brightness (improved color visibility) When using lower alcohols that do not have a noticeable flame color in the fuel itself, the flame transparency may be too high or the flame brightness may be increased. The brightness is too low and visibility is low.

(Means for solving the problem) First, as for the organic solvent that is the main fuel, it is required that it does not inhibit the coloration caused by the original flame color reaction, so the main fuel that can be used is necessarily lower alcohol. limited to. At that time, methyl alcohol, ethyl alcohol, propyl alcohol, which is an alcohol having 1 to 4 carbon atoms,
Preferably, butyl alcohol is used. Although it is possible to visually recognize the flame color reaction even when lower alcohols with carbon numbers of 5 or more are used, as the number of carbon atoms increases, the orange color derived from the high-temperature emission of free carbon becomes stronger, so the original color tone becomes The flame becomes orange, and it becomes difficult to see the flame reaction. Therefore, by using a lower alcohol having 1 to 4 carbon atoms, it is possible to solve the problem listed in (2) above.

Next, regarding the dissolution of the coloring agent in the organic solvent of the fuel (i.e., lower alcohol having 1 to 4 carbon atoms in the case of the present invention), the coloring agent should be a liquid such as a boric acid ester that is compatible with the organic solvent. For certain substances, it can be used as is in any mixing ratio.

However, most of the compounds that can be used as color formers are solid, and their mixing and dissolving ratios in alcohol are limited by their solubility. Among compounds containing metals that exhibit a flame reaction, acetates and various organic complexes are relatively well soluble in alcohol, but they generate carbides during combustion, which adhere to the combustion wick and impede stable combustion. , undesirable. On the other hand, carbonates, halides, inorganic salts, etc. do not produce carbides, so they do not cause the problems mentioned above, but most of them have very low solubility in alcohol, so it is difficult to obtain sufficient color development. Can not. Therefore, conventionally, compounds that stably dissolve, burn, and develop color have been extremely limited. Conventionally, the following compounds have been known as such compounds.

(A) Green color former borate ester (trimethyl borate, triethyl borate, tributyl borate, etc.) (B) Red color former lithium bromide or lithium acetylacetonate (C) Purple color former cesium carbonate In order to solve the above-mentioned problems, research was conducted on the main fuel and the coloring agent, and it was found that the solubility of the inorganic salt coloring agent could be increased by adding water to the fuel. The presence of water in the fuel makes it possible to use salts that are originally water-soluble as color formers, thereby expanding the range of color formers available. for example,
Chloride containing a metal element that exhibits a flame reaction does not dissolve at all in organic solvents, let alone alcohol, but can be dissolved by the presence of water in the fuel.

(Function) According to the above means, by incorporating a small amount of water into the fuel, it becomes possible to improve the dissolution of the color former. Furthermore, by including water in the fuel, when the fuel burns, the water is emitted into the flame as water vapor, causing diffuse reflection at the tip, which reduces the transparency of the flame and also reduces the flame. It also increases the brightness. That is, not only good coloring occurs in a dark place, but also coloring becomes easily visible in a bright place.

(Example) Next, the present invention will be explained in detail.

First, a sample fuel containing water and ethyl alcohol, which is a lower alcohol having 1 to 4 carbon atoms, was prepared as shown in the following table. Additionally, as a comparative example, a sample fuel containing no water was also prepared.

Uses strontium chloride hexahydrate. The weight of crystallized water contained in this compound is included in the water component cost.

In the fuels with the compositions of Examples 1 and 2, the color formers rubidium chloride and strontium chloride were completely dissolved, whereas in the samples with the compositions of Comparative Examples 1 and 2, the color formers were not completely dissolved. Insoluble matter remains.

Both samples having the compositions of Example 3 and Comparative Example 3 were completely dissolved.

The following table shows a comparison of the results of igniting a sample solution prepared with the above composition in the wick of an oil lighter.

**Rubidium chloride and strontium chloride are "poorly soluble" and "trace amount" respectively in ethyl alcohol, and because they are soluble in ethyl alcohol, albeit in a very small amount, they exhibit a slight flame reaction.

As is clear from Examples 1 and 2, by making the fuel composition contain water, water-soluble inorganic salts that could not be mixed and dissolved in organic solvents can be dissolved and the solubility can be increased. This makes it possible to use it as a coloring agent.

In addition, from Example 3 and Comparative Example 3, by making the fuel composition contain water, "flame visibility", which was a concern when using lower alcohols, was improved (by reducing the transparency of the flame, Even light-colored flames can now be clearly seen.

Further, regarding the above-mentioned ignition conditions, the following table shows the results of tests regarding the influence of the water content in the fuel on the ignition performance.

Fuel: Ethyl alcohol (special grade reagent) Ignition conditions: The wick of an oil lighter is impregnated with fuel containing water in any proportion, and ignited with a flint.As shown in the table above, water is added to maintain ignitability. It is natural that the content of alcohol must be regulated, but a combination of water and alcohol has sufficient ignition performance up to about 2wt%.

Furthermore, similar results can be obtained with methyl alcohol, butyl alcohol, propyl alcohol, etc. in addition to the ethyl alcohol used in the above examples.

(Effects of the Invention) As detailed above, according to the present invention, the following effects can be obtained by incorporating a small amount of water into the liquid fuel.

(1) It becomes possible to increase the types and amounts of color formers that can be dissolved in fuel.

(2) The water vapor released during combustion causes diffuse reflection on the tip, making it possible to reduce the light transmittance of the flame and at the same time increase the color brightness of the flame.

(3) For the above-mentioned reasons, the color visibility of the flame can be improved, so lower alcohols having 1 to 4 carbon atoms, which had problems with color visibility and brightness, can now be used as fuel.

(4) Since a lower alcohol that hardly colors the flame by itself can be used as a fuel, it becomes possible to obtain the beautiful color development that is inherent in the flame color reaction.

applicant

Claims (1)

[Claims] A liquid fuel that generates a colored flame, characterized in that it contains 15 wt% or less of water based on the total amount of the liquid fuel that generates a colored flame, which contains a lower alcohol having 1 to 4 carbon atoms.