Abstract:
A liquid fuel for a burning utensil such as a lighter, wherein a liquid fuel is upwards absorbed by a burning wick and is burned in the form of a flame at the end thereof, which comprises an alcohol as a main component, 5 wt % or more of a turpentine oil as a coloring agent for the flame and 10 wt % or more of petroleum benzene or n-hexane as a light-up improver for improving the percentage of lighting up. For example, the liquid fuel contains 70 wt % of the main component, 15 wt % of the coloring agent and 15 wt % of the light-up improver. The range surrounded by the points ABCDE in FIG.  1  represents the region for a suitable compounding for the liquid fuel. The above liquid fuel for a burning utensil contains an alcohol as a main component and secures the lighting-up at a low temperature and the sustainability of the effect of coloring a flame.

Description:
CLAIM OF PRIORITY  
       [0001]     This is a U.S. national stage application of PCT/JP/2005/007357 filed Apr. 11, 2005, which is based on Japanese Patent Application Number JP2004-123831, filed on Apr. 20, 2004. 
     
    
     FIELD OF INVENTION  
       [0002]     The present invention relates to a liquid fuel for combustion devices such as a lighter which absorbs a liquid fuel containing alcohols as the principle ingredient through a combustion wick to burn in the flame at its tip. In particular, it relates to improvements in the components.  
       DESCRIPTION OF THE PRIOR ART  
       [0003]     The conventional liquid fuel for combustion devices as in the case of alcohol fuels forms a pale color flame when it is combusted and the drawback is that the flame is hard to see under a bright outdoors. To color the flame, the addition of turpentine oil at 5 to 30 wt % was proposed (e.g., Patent Reference 1).  
         [0004]     Besides alcoholic fuels, the hexane series are commercialized as regular oil-base lighters. The addition of hexane or heptane as a flame colorant to ethyl alcohol as the principle ingredient was also proposed. (e.g., Patent Reference 2).  
         [0005]     [Patent Reference 1] Japanese Unexamined Patent No. 2002-31340  
         [0006]     [Patent Reference 2] Japanese Unexamined Patent No. H10-88156  
       SUMMARY OF THE INVENTION  
       [0007]     If turpentine oil is added as a colorant to the aforementioned alcoholic fuels to prepare liquid fuels, the disadvantage is that the ignition rate at low temperatures decreases due to the fact that the ignition point of turpentine oil is 350 which is relatively higher when compared to the ignition point of ethanol at 13° C.  
         [0008]     In the case of hexane fuels for oil-base lighters, the problems are that the flame length is too high and the goal of producing flame in a fixed length cannot be achieved so that other parts of the materials are heated.  
         [0009]     If petroleum benzine or n-hexane is added as a colorant to the alcoholic fuels, the low temperature ignition rate is improved due to a low ignition point of n-hexane at −22° C., however, volatility of the hexane fuel is high so that the ratio of hexane decreases after use, resulting in a drawback that the coloring effect on the flame is reduced.  
         [0010]     Under the situation mentioned above, the purpose of the present invention is to provide a liquid fuel for combustion devices which can ensure a sustainable effect on low temperature ignition and a flame coloring effect.  
       BRIEF DESCRIPTION OF THE INVENTION  
       [0011]     The liquid fuel of the present invention for combustion devices such as a lighter which absorbs a liquid fuel containing alcohols as the principle ingredient through a combustion wick to burn in the flame at its tip, which is characterized in that said alcohols are used as a principle ingredient, and turpentine oil is added at 5 wt % or greater as a colorant to the flame and petroleum benzine or n-hexane is added at 10 wt % or greater as a combustion rate improving agent to improve the low temperature combustion rate at low temperatures.  
         [0012]     A desirable liquid fuel contains turpentine oil as a colorant at 5 wt % to 40 wt %, said petroleum benzine or n-hexane as an ignition improving agent at 10 wt % to 30 wt %, and methanol-modified ethanol as a principle ingredient in the remaining portion of 40 to 85 wt %.  
         [0013]     Specifically, a liquid fuel containing methanol-modified ethanol as a principle ingredient at 70 wt %, turpentine oil as a colorant at 15 wt %, petroleum benzine or n-hexane as an ignition improvement agent at 15 wt % is most desirable.  
         [0014]     As said ignition improving agent, a mixture of petroleum benzine and n-hexane can be used.  
         [0015]     A desirable liquid fuel consisting of methanol-modified ethanol as a principle ingredient, turpentine oil as a colorant, and petroleum benzine as an ignition improving agent are mixed at ratios in the area enclosed as shown in  FIG. 1 : point A (main component: 85 wt %, colorant: 5 wt %, ignition improving agent: 10 wt %), point B (main component: 65 wt %, colorant: 5 wt %, ignition improving agent: 30 wt %), point C (main component: 40 wt %, colorant: 30 wt %, ignition improving agent: 30 wt %), point D (main component: 40 wt %, colorant: 40 wt %, ignition improving agent: 20 wt %), and point E (main component: 50 wt %, colorant: 40 wt %, ignition improving agent: 10 wt %). The aforementioned ignition improvement agent can be n-hexane or a mixture of n-hexane and petroleum benzine.  
         [0016]     According to the liquid fuel for combustion devices of the present invention, if an alcohol as a major component, turpentine oil as a colorant at 5 wt % or greater, and petroleum benzine or n-hexane or a mixture as an ignition improving agent at 10 wt % or greater are mixed, the effect of the present invention is that the applicable ignition rate as a practical combustion device can be ensured even at a low temperature of −10° C. due to the presence of the ignition improving agent without losing the coloring effect from the colorant added.  
         [0017]     Petroleum benzine or n-hexane is added as an ignition improving agent so that they are not added for the purposes of coloring the flame. Therefore, their effect of improving the low temperature ignitability can be achieved despite the fact that the mixing ratio decreases as the liquid fuel is consumed and as long as the ignition improving agent is present even in a small quantity at the time when the liquid fuel is almost exhausted. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0018]      FIG. 1  is a diagram showing an optimal mixture range for the three-component material of the present invention.  
         [0019]      FIG. 2  is a cross-sectional view of a combustion instrument concerned in one of the embodiments using a liquid fuel of the present invention.  
         [0020]      FIG. 3  is an upper side view showing a state of a starting ignition operation for the combustion instrument shown in  FIG. 2 .  
         [0021]      FIG. 4  is an upper side view showing a state of ignition of the combustion instrument shown in  FIG. 2 .  
         [0022]      FIG. 5  is a diagram showing the relationships among the mixing ratios of three-component material, ignition rates, flame coloring and proper flame length.  
         [0023]      FIG. 6  is a graph showing the ignition rate characteristics relative to the temperature changes in the example of the present invention and in the comparative example. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0024]     One of the embodiments of the present invention will be explained with reference to the drawings.  FIG. 1  shows a three-component status diagram showing the optimal mixing range for liquid fuel.  FIG. 2  is a cross-sectional view showing an embodiment of the liquid fuel combustion devices using a lighter using the liquid fuel of the present invention.  FIG. 3  is an upper side view of the combustion device shown in  FIG. 2 .  FIG. 4  is an upper side view showing an ignition state of the combustion device shown in  FIG. 2 . In the subsequent explanation, based on the application mode of the liquid fuel combustion device, the left side in  FIG. 2  is expressed as a front side and the right side is expressed as a rear side.  
         [0025]     As shown in  FIG. 2  through  FIG. 4 , a liquid fuel combustion device  1  (lighter) is comprised of a fuel tank  2  for storing a liquid fuel, a spacer  4  and bracket  5  installed above the fuel tank  2 , a combustion wick  6  to be combusted while sucking the liquid fuel from the fuel tank  2 , a cap  7  to close the tip of the combustion wick  6  that can be opened or closed, and an ignition means for igniting the tip of the combustion wick  6 .  
         [0026]     The fuel tank  2  is comprised of a tank body  21  formed in a bottomed cylinder shape and a tank upper lid  22  fixed in the upper end opening of the tank body  21 . An inside cotton  3  made of liquid absorptive fiber material (pulp fibers 86%+PP fibers 14%) impregnating the liquid fuel is arranged inside of the tank body  21 .  
         [0027]     The tank upper lid  22  has a circumferential wall matching with the circumferential shape of the tank body  21  around the horizontal wall, and an engagement wall portion to be inserted in the upper end opening of the tank body  21  is formed extending downwardly on the inside of the lower face of the circumferential wall. A tubular combustion wick holder  22   a  extending in the up and down direction is formed at the front side of this tank upper lid  22  and the upper end of the combustion wick holder  22   a  is projected upward. A rod shape combustion wick  6  made of porous polyester is inserted and supported via a sleeve made of liquid crystal polymer  61  in the inside of the combustion wick holder  22   a . The lower end of the combustion wick  6  is projected into the fuel tank  2  and is in contact with the inside cotton  3  to suck up fuel while the upper end is projected upward from the upper end of the combustion wick holder  22   a  and fuel is burned as a flame at its tip. An air passage (air discharging hole) is formed around the outer circumference of the sleeve  61 . At the rear side of the tank upper lid  22 , a cylindrical concavity extending downward is formed where an ignition stone storing portion  41  of the spacer  4  as will be explained later is inserted.  
         [0028]     In the spacer  4 , a flat portion is fixed on the upper side of the circumferential wall of the tank upper lid  22  and a cylindrical ignition stone storage portion  41  extending in an up-and-down direction is installed at the rear side. The upper end of the ignition stone storage portion  41  is projected upward while the lower end extends into the concavity of said tank upper lid  22  to form a bottomed storage hole in the interior where an ignition stone  11  of the ignition means  10  and a stone press spring  12  are stored.  
         [0029]     A bracket  5  made of a metallic plate is installed on the upper portion of said spacer  4 . Along with the spacer  4 , the combustion wick holder  22   a  of the tank upper lid  22  passes through the flat plate portion of the bracket  5 . At both left and right sides at the rear side, a support portion  51  is stood up to form an inclined groove  52  which supports the rotary shaft  15  of the grinder vehicle  13  of the ignition means  10  in a freely rotatable manner. At both left and right sides at the front side, a support portion  53  is stood up to support a cap  7 . The ignition stone storage portion  41  passes through the flat plate portion in the support portion  51 .  
         [0030]     The ignition means  10  has a ring-shaped grinding vehicle  13  forming a grinder surface and a lateral vehicle  14  having a convex/concave shape on the outer circumference which is rotated when igniting that is fixed at both sides of the grinder vehicle  13 . Both are integrally rotated and a rotary shaft  15  is projected through the outer center portion of the lateral vehicle  14  at both sides. This rotary shaft  15  is supported by the support portion  51  of said bracket  5  and the tip of the ignition stone  11  is pressed against the circumferential surface of the grinder vehicle  13  due to the urging force from the stone press spring  12 . Thus, when the lateral vehicle  14  is rotated, sparks are generated towards the combustion wick  6 .  
         [0031]     The cap  7  covers the front half of the upper portion of the liquid fuel combustion device  1  except for the portion of the ignition means  10  to be opened or closed, and an inner cap  71  made of zinc diecast closing the tip of the combustion wick  6  is installed on the interior surface of the cap  7  (outer cap) forming a metallic plate (SPCC). The front edge lower portion of the cap  7  at the opposite side from the grinder vehicle  13  is supported at the support portion  53  using a support shaft  72  in a rotatable manner and the cap  7  is urged in an open direction by the open/close spring  76  of the twist spring. The lower end circular rim portion of the inner cap  71  installed on the inner surface of the cap  7  is pressed against the upper surface portion of the circular member  23  formed on the outer circumferential portion of the combustion wick holder  22   a  such that it seals the tip outer portion of the combustion wick holder  22   a  including the tip portion of the combustion wick  6 .  
         [0032]     As shown in  FIG. 3  and  FIG. 4 , at both sides of the rear portion of the cap  7 , a stopper portion  74  is installed at the tip of the extension portion  73  extending outward from the support portion  51  at the back, and an up-and-down inclination is formed at the projected tip of the stopper portion  74  so that the tip can be stopped at the edge of the rotary shaft  15  projected outward from the inclined groove  52  of the support portion  51 .  
         [0033]     This rotary shaft  15  is supported by the inclined groove  52  of the support portion  51  in a movable state from the stopped position to the released position when brought into contact with the stopper portion  74  by the closing action of the cap  7 . The inclined groove  52  is formed inclined such that the upper edge portion is higher at the front cap  7  side and lower at the back side. The rotary shaft  15  is located at the stopped position when it moves to the upper front of the inclined groove  52  (position in  FIG. 4 ) and it is located at the released position when it moves to the lower back of the inclined groove  52  (position in  FIG. 3 ). In this case, when the rotary shaft  15  is moved to the released position, the center position of the grinder vehicle  13  comes to the center position of the ignition stone  11 .  
         [0034]     The aforementioned rotary shaft  15  is urged upward due to the urging force of the stone press spring  12  and due to this urging force, it moves from the released position to the stopped position. Along with the contact with the lower inclination of the stopper  74  when the cap  7  is closed, the rotary shaft  15  moves from the stopped position to the released position in the downward direction to press the ignition stone  11  and in the backward direction moving away from the cap. When the cap  7  is completely closed, it is released from the lower inclination to move to the stopped position along the upper inclination and stops at the upper side of the stopper  74  to maintain a closed state of the cap  7 . With the operation in the pressing direction in relation to the ignition operation of the lateral vehicle  14 , the rotary shaft  15  moves backward from the stopped position to the released position along the upper inclination of the stopper  74  so that the engagement with the stopper  74  is released.  
         [0035]     An application mode of the lighter  1  in this embodiment will be explained. The said state in  FIG. 2  is a non-use time when the lighter  1  is stored. The rotary shaft  15  is at the stopped position in the upper portion of the stopper  74  of the cap  7  in a fully closed state so that the cap  7  is locked in a closed state.  
         [0036]     When using a lighter  1 , as shown in  FIG. 3 , the lateral vehicle  14  is operated by pressing/rotating for ignition. With the first inclined downward pressing, the lateral vehicle  14  moves to press the ignition stone, and the rotary shaft  15  in the inclined groove  51  moves from the stopped position to the released position sliding the upper inclination of the stopper  74  so that it is released from the stopper  74  while the grinder vehicle  13  rotates and generates sparks due to friction with the ignition stone  11 . Subsequently, as shown in  FIG. 4 , the cap  7  released from the stopped position of the rotary shaft  15  opens due to the urging force of the open/close spring  76  and the tip of the combustion wick  6  is exposed while it catches fire due to said sparks at the same time and a flame colored with turpentine oil as a colorant is generated to start combustion. In addition, as the finger is released from the lateral vehicle  14 , the rotary shaft  15  moves the inclined groove  52  from the released position to the stopped position upward due to the urging force of the stone press spring  12 .  
         [0037]     When extinguishing the fire when finished using the lighter, the cap  7  is closed and the cap  7  covers the flame to put out the fire. As the lower inclination of the stopper  74  of the cap  7  operated to be closed is brought into contact with the rotary shaft  15 , it starts pressing the rotary shaft  15 . As the cap  7  is further operated to be closed, the stopper  74  moves the rotary shaft  15  along the upper edge of the inclined groove  52  downward and backward, namely in the direction from the stopped position to the released position. Moreover, when the cap  7  is further operated to be closed to become in a fully closed state, the rotary shaft  15  moved to the released position is released from the lower inclination of the stopper  74  and further crosses the tip portion and moves to the stopped position upward along the upper side inclination due to the urging force of the stone press spring  12 , so that it is stopped on the upper side inclination of the stopper  74  to be locked in the upper edge of the inclined groove  52  to keep the cap  7  in a closed state.  
         [0038]     Next, a liquid fuel of the present invention that is injected in the said fuel tank  2  and impregnated in the inside cotton  3  is an alcoholic fuel. For example, alcohols prepared from methanol-modified ethanol are used as a principle ingredient and turpentine oil as a colorant is added at 5 wt % or greater for a coloring flame, and petroleum benzine or n-hexane or a mixture of both as an ignition improving agent is added at 10 wt % or greater for the improving low temperature ignition rate.  
         [0039]     In particular, a desirable liquid fuel contains 5 to 40 wt % of turpentine oil as a colorant, 10 to 30 wt % of petroleum benzine or n-hexane as an ignition improving agent, and the remaining 40 to 85 wt % of methanol-modified ethanol as a principle ingredient. Specifically, a liquid fuel containing 70 wt % of methanol-modified ethanol, 15 wt % of turpentine oil as a colorant, and 15 wt % of petroleum benzine or n-hexane as an ignition improving agent is a preferred example of the liquid fuel.  
         [0040]     The content of turpentine oil as a colorant ranges from 5 to 40 wt %. If turpentine oil is less than 5 wt %, coloring of the flame is insufficient, while if it exceeds 40 wt %, the ignition rate at a low temperature decreases. The content of petroleum benzine or n-hexane or a mixture of both as an ignition improving agent ranges from 10 to 30 wt %. If the amount of ignition improving agent is less than 10 wt %, ignition at a low temperature becomes insufficient, while if it exceeds 30 wt %, the flame length becomes longer than the appropriate range. In terms of the proper flame length, the content of the alcoholic ingredient (methanol-modified ethanol) must be present at 40 wt % or greater.  
         [0041]     In  FIG. 5  ( a ) through ( c ), performance of a combustion device when changing the mixing ratio of methanol-modified ethanol as a principle component, turpentine oil as a colorant, and petroleum benzine as an ignition improving agent is summarized as a three-component status diagram.  
         [0042]      FIG. 5  ( a ) demonstrates performance of ignition rates, especially characteristics of ignition rates at low temperatures. With respect to the relationships of the mixing ratios of three-component material and the ignition rates, the hatched area seemed to be the area without any practical problems with low temperature ignition rates. That is, a desirable area is when petroleum benzine contributing in the improvement in ignition rates was 10 wt % or greater and turpentine oil which interferes with low temperature ignition rates was 40 wt % or less.  
         [0043]      FIG. 5  ( b ) demonstrates the conditions of flame color at the point when the fuel was completely exhausted with respect to the colors of the flame. With respect to the relationships of the mixing ratios of three-component material and flame coloring, the hatched area seemed to be the area providing satisfactory visibility of flame color. That is, a desirable area is when the turpentine oil as a colorant was 5 wt % or greater and the methanol-modified ethanol as a principle component was 90 wt % or less.  
         [0044]      FIG. 5  ( c ) demonstrates the range when the flame length ranged from 10 mm to 40 mm when ignited with respect to the appropriate flame length. With respect to the appropriate flame length in relation to the mixing ratios of three-component material, the hatched area seemed to be in the range showing the aforementioned flame length. That is, a desirable range is when petroleum benzine with a high volatility was 30 wt % or less and methanol-modified ethanol as a principle component was 40 wt % or greater.  
         [0045]     Based on the results shown in  FIG. 5  ( a ) through ( c ), the mixing ratios of the three components in the appropriate range satisfying all requirements are summarized in the hatched area in  FIG. 1  as general assessments. That is, said methanol-modified ethanol as a major ingredient, turpentine oil as a colorant, and petroleum benzine as an ignition improving agent are mixed at ratios in the area enclosed by the points A, B, C. D and E: point A (main component: 85 wt %, colorant: 5 wt %, ignition improving agent: 10 wt %), point B (main component: 65 wt %, colorant: 5 wt %, ignition improving agent: 30 wt %), point C (main component: 40 wt %, colorant: 30 wt %, ignition improving agent: 30 wt %), point D (main component: 40 wt %, colorant: 40 wt %, ignition improving agent: 20 wt %), and point E (main component: 50 wt %, colorant: 40 wt %, ignition improving agent: 10 wt %).  
         [0046]     An appropriate range was the range including petroleum benzine at 10 to 30 wt %, turpentine oil at 5 to 40 wt %, and methanol-modified ethanol at the remaining 40 to 85 wt %. The example of the present invention used in the experiment of ignition rates as shown in  FIG. 6  corresponded to Point S in  FIG. 1  and the comparison example corresponded to Point P.  
         [0047]      FIG. 6  is a graph showing the results when liquid fuels in examples of the present invention and comparison examples were injected in the combustion device  1  as shown in  FIG. 2  (number of samples: 10 samples) and each sample was ignited 10 times under various temperature conditions at various measurement points to determine the ignition rates.  
         [0048]     The composition of the liquid fuel in the example of the present invention was as follows: methanol-modified ethanol: 70 wt %, turpentine oil: 15 wt %, petroleum benzine: 15 wt %. The composition of the liquid fuel in the comparison example was as follows: methanol-modified ethanol: 85 wt %, turpentine oil: 15 wt %, and petroleum benzine: 0 wt %, wherein petroleum benzine as an ignition agent to improve the ignition rates was not included.  
         [0049]     According to the results shown in  FIG. 6 , the fuel of the comparison example scarcely ignited at 0° C. or less, while the fuel of the present invention ignited even at −10° C. at an ignition rate of 70% or greater. Actually, the ignition rates were 100% in all fuel samples at a high temperature of 30° C. or greater. However, when the temperature decreased from 30° C., the ignition rate slowly decreased in the case of fuel of the comparison example and the ignition rate sharply decreased at a low temperature of 10° C. or lower, and the ignition rate became almost zero at 0° C. and demonstrated that the ignition was disabled. In contrast, in the case of the fuel of the present invention, the ignition rate was almost 100% at a temperature of 0° C. or greater; the ignition rate slowly decreased as the temperature decreased in a low temperature region below 0° C., but the ignition rate was still adequate for use even at −10° C.  
         [0050]     With respect to the characteristics shown in  FIG. 5  and  FIG. 6 , when h-hexane or a mixture of petroleum benzine and n-hexane was used as an ignition improving agent instead of petroleum benzine alone, similar results were obtained.  
         [0051]     According to the present embodiments, since alcohol fuels are used as liquid fuels, this leads to conservation of resources, the products can be used easily due to the presence of turpentine oil as a colorant for the flame, and due to a low volatility, the coloring ability for the flame can be sustained until all the fuels stored are totally exhausted. In addition, the presence of petroleum benzine or n-hexane as an ignition improving agent secured ignitability even at low temperatures. Thus, liquid fuels for combustion devices proposed in the present invention are suitable for practical uses for combustion devices.  
         [0052]     The invention is to be determined by the following claims: