WO1995004799A1

WO1995004799A1 - Firelighters

Info

Publication number: WO1995004799A1
Application number: PCT/GB1994/001724
Authority: WO
Inventors: Alban Timmons
Original assignee: Alban Timmons
Priority date: 1993-08-06
Filing date: 1994-08-05
Publication date: 1995-02-16
Also published as: AU7272494A; GB9316381D0

Abstract

This invention is concerned with the manufacture of firelighters and, more particularly, firelighters for domestic use. In the prior art method for making firelighters the curable resin and all the other desirable additives are mixed and the liquid hydrocarbonaceous fuel is then stirred into the mixture. The present invention allows a more uniform distribution of the liquid hydrocarbonaceous throughout the firelighters. In one described embodiment the method for making firelighters comprises the steps of producing an acidic emulsion by mixing a liquid hydrocarbonaceous fuel, such as kerosine, with water, a curing agent, and an emulsifying agent, mixing a blend of curable resin, which may comprise urea/formaldehyde, and water, and adding the blend of curable resin and water to the acidic emulsion. In another embodiment a solids material in particulate form, preferably a solids fuel, is included in the emulsion.

Description

FΠIELIGHTERS

This invention relates to firelighters and, more particularly, to firelighters intended for domestic usage.

It is well known in the art to make firelighters by forming an emulsion of a liquid hydrocarbonaceous fuel, water and a curable resin and then adding a curing catalyst for the curable resin, thereby to cure the resin to produce a solid product. In such a product the liquid hydrocarbonaceous fuel defines the discontinuous phase encapsulated within the continuous phase, defined by the cured resin and water.

Urea/formaldehyde type resin is widely used as the curable resin for the mixture and the curing catalyst for the urea/formaldehyde resin is generally a mineral acid, conveniently a hydrochloric, phosphoric or a sulphuric acid.

The liquid hydrocarbonaceous fuel is generally kerosine.

The conventional method for making firelighters material comprises the steps of mixing the curable resin (and any other desired additives), with water and stirring the resulted solution whilst adding the kerosine. The resultant emulsion is relatively stable and many such formulations may be stored for periods of up to two weeks before further treatment.

The further treatment will comprise adding the curing agent for the curable resin, whilst stirring or agitating the emulsion, and it is common in the art to dilute the curing agent.

In this specification all proportions are by weight and all percentages are percentages by weight of the final composition.

The present invention seeks to provide firelighters affording an even distribution of the dispersed fuel phase throughout the firelighter.

According to the present invention there is provided a method for making firelighters comprising the steps of producing an acidic emulsion by mixing a liquid hydrocarbonaceous fuel with water and curing agent and subsequently adding a curable resin to the emulsion.

Preferably the method includes the steps of mixing the resin with water before adding the resin/water blend to the emulsion. In a preferred method for making firelighters an acidic emulsion is formed by mixing a liquid hydrocarbonaceous fuel with water, a curing agent and an emulsifying agent, mixing a blend of curable resin and water, and adding the blend of curable resin and water to the acidic emulsion.

It is also known to add solids to firelighter emulsions prior to curing and solidification. Such solids (particulate) may be fuels in their own rigjit eg coal, peat; or they may be added to control combustion or to effect raw material cost savings and may comprise, for example, sand.

The inclusion of solids in particulate form can be problematic in that there is often a preferential absorption/adsorption of one or more of the components of the emulsion, with consequent destabilisation and breakdown of the emulsion. Whilst it is possible to add solids particulate material to the composition, up to a level of 25% to 30% by weight, the particles of the solids particulate material must have optimum properties in terms of particle size and absortive capacity. Any departure from the optimum can lead to serious processing problems, evidenced in the worst case by complete breakdown of the emulsion and at best by the production of a wet firelighter.

According to this aspect of the invention the method for making firelighters comprises the steps of including in said emulsion a solids material in particulate form.

Preferably the method for making firelighters comprises the steps of mixing a liquid hydrocarbonaceous fuel with water, a curing agent, an emulsifying agent and a solids fuel in particulate form, mixing a blend of curable resin and water and adding the blend of curable resin and water to the acidic emulsion.

Preferably the method for making firelighters comprises the steps of by mixing a liquid hydrocarbonaceous fuel with water, a curing agent, and an emulsifying agent, mixing a blend of curable resin, solids fuel and water and adding the blend of curable resin, solids fuel and water to the acidic emulsion.

In a preferred embodiment the method for making firelighters comprises the steps of reducing the liquid hydrocarbonaceous fuel content of the firelighter material in direct relationship to the solids paniculate fuel content of the material.

Preferably the method for making firelighters includes the steps of selecting the liquid hydrocarbonaceous fuel to comprise kerosine.

Thus, by this means, the proportions of all the other ingredients in the final mixture are substantially unaffected by the addition of the solids particulate material.

According to one aspect of the present invention there is provided a method for making firelighters comprising the steps of mixing a curable resin with water and an emulsifying agent, adding a reduced amount of liquid hydrocarbonaceous fuel to the resin, water and emulsifying agent mixture to form a water rich emulsion and then adding a solids particulate material to compensate for the reduced usage of hydrocarbon fuel adding a curing agent for the resin and then pouring the emulsion into moulds, allowing the mixture to cure and then cutting the moulded material to the desired shape for domestic firelighters.

Preferably the the method includes the steps of arranging the liquid hydrocarbonaceous fuel and the solids particulate material in combination to comprise from 65% to 95% of the composition, more preferably from 75% to 92% of the composition and most preferably, between 80% and 85% of the composition. Preferably the method includes the steps of including the solids particulate material to comprise more than 5% of the final mixture, more preferably between 10% and 40% of said final mixture and most preferably between 15% and 30% of the final mixture.

Preferably the method for making firelighters includes the steps of selecting the emulsifying agent to comprise a solution of a sodium sulphosuccinate.

The present invention also envisages a firelighter, when made by the method according to the invention.

The curable resin used in the emulsion may be any resin which may be cured by reaction with a curing agent, but preferably the resin comprises a urea/formaldehyde type resin pre-condensate or syrup.

Preferably the curable resin comprises from 1% to 10% by weight of the emulsion, preferably between 3% and 7% of the emulsion and most preferably between 3.5% and A.5% by weight thereof.

Preferably the total water content of the emulsion is in the region of 6% to 18%, more preferably from 8% to 14% and most preferably between 10% to 12% of the emulsion.

Preferably the emulsifying agent is present in an amount of from 0.1% to 0.8% of the composition, more preferable between 0.2% to 0.5% and most preferably between 0.25% and 0.35% of the composition.

The emulsion may also include small amounts of thickening or suspending agents, as is well known in the art.

The invention will now be described further by way of the following examples;

Example 1 v

A firelighter composition was made to have the following ingredients and properties.

INGREDIENTS

% by weight of the final composition

1. Kerosine (boiling point 150 degrees C to 255 degrees C) 80.00

2. Urea/formaldehyde resin (58% by weigjit solids) 6.90

3. Soft Water 11.40

4. Bπulsifying agent

( sodium alkyl benzene sulphonate or a sodium sulphosuccinate) 0.30

5. Curing agent (hydrochloric acid [1.3N]) 0.60

6. Combustion controller 0.8 (talc) Method

A blend of the liquid carbonaceous fuel, water, the curing agent and emulsifying agent was mixed at ambient temperate (or any temperature up to 35 degrees C) to form an acidic emulsion.

A blend of the urea/formaldehyde resin and water was then added gradually to the acidic emulsion, whilst stirring, vigorously at ambient temperature (or any temperature up to 35 degrees C). The combustion controller was then stirred into the emulsion and the mixture was poured into moulds, allowed to cure and then cut to the desired shape for a domestic firelighter.

The principal advantages found with the above method were that a good quality emulsion, with even distribution of the kerosine and the other ingredients, was readily obtained and a good control of the resin utilisation was possible.

In the method proposed by the present invention the selected urea-formaldehyde resin may conveniently comprise a resin of low free formaldehyde content.

Further, the method allows for close control of the resin usage and such control, in combination with the use of resins of low free formaldehyde content, assists in πύjiimising the concentration of formaldehyde in the working environment.

Example 2

A firelighter composition was formed with the following ingredients:

INGREDIENTS PROPORTION

(% by weigjit of the final composition)

1. Kerosine (boiling point 150 degrees C to 255 degrees C) 60.00

2. Urea/formaldehyde resin (58% by weight solids) 7.80

3. Soft Water 10.00

4. E__ιuls_Lfying agent

(sodium alkyl benzene sulphonate or a sodium sulphosuccinate) 0.60

5. coal particles 20.00

6. Combustion controller 0.80 (talc)

7. Curing agent 0.80 Method

The urea-formaldehyde resin, water, and the emulsifying agent were mixed together at ambient temperature.

The kerosine, preheated to 35 degrees C, was stirred carefully into the resin, water, and emulsifying agent mixture until a stable, relatively water-rich emulsion was obtained. The combustion controller was then added to the emulsion.

The coal particles were then stirred into the emulsion until a relatively uniform dispersion through the emulsion was obtained.

The curing agent was then stirred carefully into the emulsion mixture until substantially uniformly distributed therethrough.

The mixture was then poured into moulds and allowed to cure before being separated into the desired form for domestic firelighters.

In the method proposed by the present invention the selected urea-formaldehyde resin conveniently comprised a resin of low free formaldehyde content.

Thus, the present invention overcomes the problems of including a relatively high proportion of solids particulate material by preparation of an emulsion which is relatively low in the dispersed liquid hydrocarbonaceous fuel and in which the proportions and performances of the remaining ingredients are unaffected or may be slightly increased by the substitution of the solids particulate material for the liquid hydrocarbonaceous fuel.

Claims

1. A method for making firelighters comprising the steps of producing an acidic emulsion by mixing a liquid hydrocarbonaceous fuel with water and curing agent and subsequently adding a curable resin to the emulsion.

2. A method according to claim 1, comprising the steps of mixing the resin with water before adding the resin/water blend to the emulsion.

3. A method for making firelighters according to claims 1 or 2, comprising the steps of producing an acidic emulsion by mixing a liquid hydrocarbonaceous fuel with water, a curing agent and emulsifying agent, mixing a blend of curable resin and water and adding the blend of curable resin and water to the acidic emulsion.

4. A method for making firelighters according to claims 1, 2, or 3, comprising the steps of including in said emulsion a solids material in particulate form.

5 A method for making firelighters according to claim 4, comprising the steps of mixing a liquid hydrocarbonaceous fuel with water, a curing agent, an emulsifying agent and a solids fuel in particulate form, mixing a blend of curable resin and water and adding the blend of curable resin and water to the acidic emulsion.

6. A method for making firelighters according to claim 5, comprising the steps of by mixing a liquid hydrocarbonaceous fuel with water, a curing agent, and an emulsifying agent, mixing a blend of curable resin, solids fuel and water and adding the blend of curable resin, solids fuel and water to the acidic emulsion.

7. A method for making firelighters according to claims 5 or 6, comprising the steps of reducing the liquid hydrocarbonaceous fuel content of the firelighter material in direct relationship to the solids particulate fuel content of the material.

8. A method for making firelighters according to any preceding claim including the steps of selecting the liquid hydrocarbonaceous fuel to comprise kerosine.

9. A method for making firelighters according to any one of claims 5 to 8 inclusive, including the steps of arranging the liquid hydrocarbonaceous fuel and the solids particulate material in combination to comprise from 65% to 95% by weight of the composition.

10. A method for making firelighters according to any one of claims 5 to 10, inclusive, including the steps of allowing the solids particulate material to comprise more than 5% by weight of the final mixture.

11. A method for making firelighters according to any one of the preceding claim, and including the steps of selecting the emulsifying agent to comprise a solution of a sodium sulphosuccinate.

12. A method for making firelighters according to any one of the preceding claims including the steps of allowing the curable resin to comprises a urea/formaldehyde type resin, pre-condensate or syrup.

13. A method for making fireligjiters according to any one of the preceding claims including the steps of allowing the curable resin to comprises from 1% to 10% of the composition.

14. A method for making firelighters according to any one of preceding claims including the steps of allowing the total water content of the composition to be in the region of 6% to 18% by weight of the composition.

15. A method for making firelighters according to any one of the preceding claims including the steps of allowing the emulsifying agent to comprise from 0.1% to 0.8% by weight of the composition.4.

16. A method of making firelighters according to any one of claims 1 to 15 inclusive, including the steps of pouring the emulsion into a mould, allowing the emulsion to set and then separating the set emulsion into individual firelighters.

17. A firelighter, when made by the method set forth in any one of claims 1 to 16 inclusive.