Description of the Prior Art Up to the present, charcoal, instant combustible briquette, methanol, liquified natural gas, liquified propane, butane gas, or the like has been used as fuel for cooking outdoors. However, charcoal or instant combustible briquette is inconvenient to carry, has difficulties in initial ignition, and generates much smoke and odor at the beginning of combustion, while it leaves much amount of ash after combustion to cause trouble of post-treatment, and the heat of combustion is relatively low.

Methanol, which has been widely used for outdoor use, is a highly volatile and inflammable liquid, so that it has difficulties in carrying or keeping. In addition, an individual burner equipped with preheating device for vaporization of methanol is required for combustion.

Though liquified natural gas, liquified propane and butane gas are clean fuels, and have high heat of combustion, they require metal pressureproof vessels for storage and individual combustion

devices, so that they are too heavy and bulky to be used for cooking outdoors.

Plastic fuels prepared by mixing waxes such as paraffin and methanol are also improper as a fuel for cooking outdoors, since they produce much amount of soot derived from waxes and characteristic odor at the time of combustion, and provide insufficient heat of combustion.

SUMMARY OF THE INVENTION The first object of the present invention is to provide a gel- type pocket fuel composition which can be conviently used for cooking outdoors.

The second object of the present invention is to provide a gel -type pocket fuel composition which is properly used for rescue.

The third object of the present invention is to provide a process for preparing the fuel composition which satisfies the first and the second object of the present invention described above.

The pocket fuel composition which satisfies the first and second objects of the present invention comprises 55-95wt% of methanol, 4.5-15wt% of nitrocellulose having not more than 12.2% of nitrification value, 0.5 ~ 5wt% of siloxane, 0-5wt% of starch and 0-20wt% of water.

Methanol having purity of not less than 98% is preferably used, but conventional methanol for fuel may be also used. In a fuel composition according to the present invention, methanol is usually used in an amount of 55-95wt%, preferably 62~83wt%, and more preferably 68~~79wt%. If the amount is less than 55%, it is undesirable because sufficient heat cannot be obtained, while the amount is more than 95%, it is undesirable because the fuel cannot

be readily gellated.

Nitrocellulose used in the present invention is pyroxylin which has 12.2% or less, preferably of nitrification value, and the amount of nitrocellulose is 4.5"-15wt%, preferably 5 and more preferably 6-9wt%. Nitrocellulose having 12.5% or more of nitrification value, which is used in smokeless gunpowder, is insoluble in methanol, so that it cannot be evenly dispersed in methanol. Further it may cause problems in safety, and thus it must not be used in the composition. In case of using nitrocellulose having less than 10.5% of nitrification value, the composition can be readily gellated, but may have poor combustion value. If the amount of nitrocellulose is less than 4.5wt%, flame adhesion is deteriorated, and gellation becomes difficult, while if the amount of more than 15wt%, the duration of combustion is shortened, and the flame may generate spark during combustion, and further the composition is apt to be sollated. Due to nitrocellulose, the composition of the present invention can exhibit good flame adhesion at a high mountain area or at a temperature below 0°C. Thus, the fuel composition is extremely appropriate to be used as a portable fuel for mountain climbers or fuel for outdoor use in winter time.

Pyroxylin is industrially used for preparing lacquer, film or celluloid, and is useful for gellation of the composition according to the present invention. Thus, if necessary for gellation, a part of the amount of said nitrocellulose can be substituted by methyl cellulose, ethyl cellulose, carboxymethyl cellulose, or the like.

The amount to be substituted may be about 1 to 3wt% on the basis of total weight of the composition, however, the substitution is optional in the present invention.

Siloxanes preferably usable in the composition according to the present invention include compounds represented by following structural formula (I):

wherein, R represents hydrogen, oxygen or linear or branched lower alkyl group having 1 to 5 carbon atoms, preferably hydrogen, oxygen or methyl group, and n represents an integer not less than 2.

If R is an aromatic ring, or a group having 6 or more carbon atoms, it is undesirable because the composition generates soot and/ or unpleasant odor during the combustion.

Siloxanes serve to supply oxygen during the combustion of the fuel composition according to the present invention, and thus suppress generation of soot, unpleasant odor or carbon monoxide to lead complete combustion and to increase combustion efficiency.

Further. silicon reduced by combustion serves as an anti-foaming agent, to effectively prevent generation and scattering of foam from the fuel. In addition, siloxanes as described above have low surface tension, and thus, are useful for increasing dispersibility of each component to prepare an uniform composition.

In the composition according to the present invention, the amount of siloxane is 0.5 to 5wt%, preferably 0.5 to 3.5wt%, and more preferably 1 to 3wt%. If the amount is less than 0.5wt%, increase of combustion efficiency cannot be substantially expected, and the effect of enhancing dispersibility is deteriorated. On the other hand, if the amount is more than 5wt%, the decomposition rate during the combustion becomes so high that the duration of

combustion may be shortened, and the composition may be decomposed to deteriorate.

Ingredients which can be optionally added to the fuel composition according to the present invention are described here-in -below: Since nitrocellulose can be fumed in dry state, it is kept with water content of 20% or more. In the composition according to the present invention, such a problem does not matter at all because it comprises 55 ~ 95wt% of methanol. However, the duration of combustion can be extended, safety can be more surely secured, and addition of other optional water soluble ingredient becomes possible, if water is contained in the composition in an amount of 0 to 20wt%, preferably 10 to 20wt%, and more preferably 12 to 16wt% on the basis of total weight of the composition.

However, existence of water in fuel may cause some problem in flame adhesion, so that it is necessary to add starch in an amount of 0 ~ 5 wt%, preferably and more preferably 2 to 4wt% to the composition, in case of using water. Starch which may be contained in the fuel composition according to the present invention absorbs water by swelling, and thus, it prevents water from existing in free state in the composition, to give good flame adhesion, and increases viscosity to facilitate gellation. In case of using the fuel composition according to the present invention for cooking, particularly for roasting, starch also has a role to enhance the flavor of meat and reduce fish-like odor of a fish. In addition, since starch maintains water content of 20% in dry air, and 35% in damp air, it provides the fuel composition with excellent safety.

Besides, in case of using the fuel composition according to the present invention for cooking, saccharides such as sugar,

glocose, fructose, sorbitol or the like may be added in an amount of 0 to 8wt%, to increase viscosity of the fuel composition, give sweet taste to the roated meat, and enhance the flavor.

Natural fruit acid components, which are conventionally employed in soft drinks, for example, citric acid, maleic acid, succinic acid, lactic acid, glutaric acid, oxalacetic acid, fumaric acid, or the like may be added in an amount of 0 to 3wt%. By using the acid, the final pH of the fuel composition according to the present invention can be adjusted in a range of 3.5 to 4.5 to stabilize the siloxane component. In addition, the acid endows fruit-like flavor during combustion.

Now, a process for preparing the fuel composition according to the first and second objects of the invention is described.

Nitrocellulose (4.5-15wt%) having not more than 12.2% of nitrification value and siloxane (0.5-5wt%) were dissolved in methanol (55-95wt%) by adding the compounds by portions under stirring at a temperature between 40 ~ 60°C, to perform the gellation step for preparing the gel-type fuel composition. In order to stabilize siloxane, a step for adjusting pH 3.5 to 4.5 by adding a fruit acid or dilute hydrochloric acid and vigorously stirring the mixture for intimate mixing, should be performed to prepare the fuel composition according to the present invention. In the gellation step, the temperature of methanol should be maintained at not more than 60°C because boiling point of methanol is 64.56°C.

If required, in case of adding water and starch to the composition, a step of swelling starch is separately performed by dissolving 0"-5wt% of starch in preferably 10"-20wt% (on the basis of total weight of the composition) of water at 40 ~ 70°C, before or after performing the gellation step or at the same time of the

gellation step. Then, a mixing step is performed by intimately mixing the swelled solution with the gellated mixture, followed by the step of adjusting pH.

Further, in case of optionally adding saccharide (s) such as citric acid or sorbitol. it is preferable to dissolve the compound prior to the swelling step, as considering the solubility of the compound.

The invention is described in more detail by referring to the Examples and Comparative Examples below, but it should be noticed that the present invention is not restricted to the examples by any means. In the Examples,"%"means"% by weight".

Examples 1-3 and Comparative Examples 1,2 'Heat of Duration ! MethanoI NitroceHuloseOxosiIoxane Starch Watercombustion of ! Icombustion ol. l,Ex. 1 87.5 10 2. 5 6280 32 jEx. 9 1.5 j 3 145700 ! 38 ! Ex. 3 1 68. 0 1 8 3.0! 4 174950 ! 40 Comparative' Ex. 1 ; j 'Gomparative !'i I I Comparative :

Nitrocellulose having 11.5% of nitrification value was used.

The compositions were prepared according to the process described above. The duration of combustion is the value corresponding to 200 g of final gel-type composition.

From the experimental results, the fuel compositions according to the present invention exhibited excellent heat and duration of

combustion as well as uniform intensity of flame, and had a properly gellated state to be charged in a squeezable tube.

On the contrary, the fuel composition of Comparative Example 1 showed about half duration of combustion as compared to that of Example 3, and showed fluctuation of strong and weak flame.

It is considered that this comes from uneven mixing of two components among the prepared composition. In case of Comparative Example 2, it was found that the fuel composition and flame were sparked, and showed insufficient duration of combustion.

The gel-type pocket fuel composition according to the present invention can be conveniently carried by simply charging in a non- pressureproof vessel such as an squeezable tube, a plastic or tin- can vessel. The fuel immediately starts combustion by direct ignition at once upon squeezing it on the ground, ice, snows, rocks or charcoal, and the flame is not affected by humidity or wind.

Further, it requires no individual combustion device, produces no odor or color during combustion, and is unexplosive. It can be well preserved in the shade at a temperature not higher than 70°C.

Thus, the fuel composition according to the present invention is very useful for intitial ignition of charcoal for barbecue, for outdoor cooking, for signal of rescue, for keeping warm at a crisis, or for military use.