EP0056696B1 - Firelighters - Google Patents

Abstract

Particles of talc having a size greater than 0.1 millimetres are included in a firelighter composition comprising a liquid hydrocarbon fuel emulsified in a resin, to extend burning time, control combustion, and economise on raw materials.

Description

• The invention relates to firefighters.
• A well known firelighter in general domestic use is the so called white firelighter which comprises a solid block and which is based on a kerosine/urea formaldehyde resin system.
• It is known to add powdered talc to such white firelighter composition to control combustion and extend the burning time.
• A typical particle size for powdered talc is 0.05 millimetres.
• Thus a 40 gram piece of white firelighter without talc will burn for about 15 minutes, whereas a 40 gram piece containing 0.6% by weight of such talc will burn for about 22 minutes.
• The longer burn and controlled heat release are of advantage in lighting solid fuels which are difficult to ignite.
• Further, GB-A-1 544 635 discloses a combustible composition comprising a matrix of cured resin having distributed therethrough hydrocarbon oil and also particles of a solid combustible material in which the particles are of size such that at least 95% thereof are retained on a sieve of mesh number 35 (nominal aperture size 0.44 mm); the combustible composition may contain a substance to extend the burning time and one such substance is talc which may be present in an amount up to 1 % w/w of the solid combustible material.
• There is no mention in this specification of the particle size of the talc which may optionally be used in the manufacture of the firelighters disclosed in GB-A-1 544 635.
• EP-A-0 023 829 relates to combustible compositions which may be used as firelighters and the compositions comprise a matrix of solid resin having distributed therethrough combustible liquid, and water characterised in that the composition also contains up to 25% by weight of expanded perlite distributed therethrough; the compositions may contain a certain amount of talc, and one particular group of compositions comprises at least five parts of expanded perlite, from 5 to 25 parts water, from 65 to 85 parts kerosine, and up to 1.2 parts of talc, parts being by weight.
• EP-A-0 023 830 is concerned with ignitable combustible compositions comprising a matrix of solid resin having distributed therethrough combustible liquid, and water characterised in that the composition also contains up to 25% by weight of a particulate non-combustible solid having a specific surface area of not greater than 8 m²/g distributed therethrough; this earlier specification discloses that talc is not satisfactory as the non-combustible particulate material to be used in accordance with this earlier invention but an amount of talc up to 1.2% may be used in addition to the non-combustible particulate material, except when such material is exfoliated vermiculite.
• Neither of the two European Specifications mentioned above makes any reference to the particle size of talc.
• The firelighters with which this invention is concerned utilize a kerosine-in-water emulsion.
• The aqueous phase of this emulsion contains a resin syrup which is caused to set by the use of a catalyst or hardener, thus producing a solid combustible material. Previously, it had not been possible to include more than about 1% by weight of talc in such a firelighter because of a deleterious effect on emulsion stability.
• It has now been discovered that by using talc having a larger particle size relative to the previous typical particle sizes known in the art, greater levels of talc may be included in white firelighters with beneficial results.
• Accordingly the present invention provides a firelighter composition comprising a liquid hydrocarbon fuel emulsified in a resin, the composition also containing particles of talc having a size greater than 0.1 millimetres.
• Preferably the fuel comprises kerosine.
• The talc particle sizes preferably lie in the range 0.2 to 2 millimetres.
• Preferably a material known commercially as talc tailings is used.
• The talc may comprise up to 10% by weight of the composition.
• The advantages conferred on a white firelighter by inclusion of larger particles of talc (e.g. talc tailings) are as follows:
• (i) burning time is further extended.
• (ii) combustion control is increased and the firelighter burns with a reduced flame height. Thus the heat output is used more effectively within the fuel bed rather than being dissipated up the chimney as heat and light.
• (iii) there is an economy of use of essential raw materials, particularly kerosine.
• Effects (i) and (ii) listed above combine to afford a firelighter of superior performance to known white firelighters.
• By way of example, specific embodiments of the invention will now be described, with reference to the following Examples.
Control 1
• Firstly, a control composition was manufactured by making a white firelighter using the following ingredients:-

  
• A piece of this firelighter of dimensions 64.5x31.66x23 millimetres weighed 40 grams and burned for 14 minutes 30 seconds.
Control 2
• A further control composition was made, using the same ingredients as Control 1, but with 0.6% by weight of the kerosine replaced by powdered talc.
• A 40 gram piece of the Control 2 firelighter composition burned for 22 minutes.
Example 1
• A firelighter composition according to the invention was made using the following ingredients:-

  
• The talc tailings were grade AC11 obtained from Richard Baker Harrison Limited of Liverpool.
• A piece of this firelighter of similar dimensions to that of the control firelighters weighed 43 grams and burned for 25 minutes.
• . The Control 2 white firelighter piece was used to ignite a fixed charge of Coalite solid fuel in a room heater. Two pieces were required and a good fire was established 30 minutes after the firelighters were spent.
• The firelighter of Example 1 was used to ignite Coalite under exactly similar conditions. One piece only was required and a good fire was established 15 minutes after the firelighter was spent.
Example 2
• A firelighter was made as Example 1, but an alternative talc tailings material, grade T15 from Richard Baker Harrison Limited, was employed.
• One piece, having the same dimensions as the pieces mentioned above, weighed 38 grams and burned for 24 minutes.
• In neither Example 1 nor Example 2 was the stability of the emulsion affected by the addition of the talc.
• The invention is not restricted to the details of the foregoing Examples.

Claims (6)

1. A firelighter composition comprising a liquid hydrocarbon fuel emulsified in a resin, the composition also containing particles of talc, characterised in that the talc particles have a size greater than 0.1 millimetres.

2. A firelighter as claimed in Claim 1, in which the fuel comprises Kerosine.

3. A firelighter as claimed in Claim 1 or Claim 2, in which the talc particle sizes lie in the range 0.2 to 2 millimetres.

4. A firelighter as claimed in any one of the preceding claims, in which the talc comprises talc tailings.

5. A firelighter as claimed in any one of the preceding claims, in which the talc comprises up to 10% by weight of the composition.

6. A firelighter composition as claimed in Claim 1, comprising the following:-