Fuel and related compositions – Candle composition
Reexamination Certificate
2001-06-08
2003-11-11
Toomer, Cephia D. (Department: 1714)
Fuel and related compositions
Candle composition
C431S288000
Reexamination Certificate
active
06645261
ABSTRACT:
BACKGROUND
Candles have been known and used for illumination since early civilization. For years, beeswax was has been in common usage as a natural wax for candles, cosmetics and sealing waxes for food preservation. A typical candle is formed of a solid or semi-solid body of combustible waxy material, such as paraffin wax or beeswax, and contains an combustible fibrous wick embedded within the waxy material. When the wick of a candle is lit, the generated heat melts the solid wax, and the resulting liquid flows up the wick by capillary action and is combusted. At present, although many advanced illuminating devices are available, candles are still popularly used for decoration or on a special situation as a holiday.
Over one hundred years ago, paraffin came into existence, parallel with the development of the petroleum refining industry. Paraffin was introduced as a bountiful and low cost alternative to beeswax which has become more and more costly and in more and more scarce supply. Paraffin is simply the leftover residue from refining gasoline and motor oils. Paraffin is presently the primary industrial wax for the following three uses: candles, cosmetics and sealing waxes.
Conventional candles are made from a wax material, such as paraffin. Such candles typically emit a smoke and can produce a bad smell when burning. Many people can not accept such smell. In addition, a small amount of particles (“particulates”) are often created when the candle burns. These particles may affect the health of a human when breathed in. Paraffin soot particles are similar to particles given off by burning diesel fuel, which include a number of polycyclic aromatic hydrocarbons that have been deemed toxic air contaminants.
In addition to these issues, paraffin wax is diminishing in supply as consumer demand increases. New petroleum technology does not produce by-product petro-waxes. This decrease in supply requires importation of petroleum waxes. This coincides with a huge ($2.5 billion) decorative candle market in the U.S. that is growing at about 15% per year.
There is a strong consumer need and demand for alternative natural waxes as an option to toxic paraffin waxes that can be produced at a rate that is cost competitive with toxic paraffin. Accordingly, it would be advantageous to have other materials which can be used to form clean burning base materials for forming candles. If possible, such materials would preferably be biodegradable and be derived from renewable raw materials. The candle base materials should preferably have physical characteristics, e.g., in terms of melting point, hardness and/or malleability, that permit the material to be readily formed into candles having a pleasing appearance and/or feel to the touch, as well as having desirable olfactory properties.
SUMMARY
The fatty acid profile of the triacylglycerol stock which makes up the predominant portion of the present triacylglycerol-based material generally consists predominantly of fatty acids having 18 carbon atoms. The content of shorter chain fatty acids, i.e., fatty acids having 16 carbon atoms or less, in the fatty acid profile of the triacylglycerols is generally no more than about 25 wt. %. The triacylglycerol stock typically has a fatty acid profile including no more than about 25 wt. % fatty acids having less than 18 carbon atoms.
One embodiment of the present invention relates to candles having low paraffin content and methods of producing such candles. The candles are formed from triacylglycerol-based material, a biodegradable material produced from renewable resources. Since the candles are formed from a material with a low paraffin content and preferably are substantially devoid of paraffin, the candles are clean burning, emitting very little soot. The combination of low soot emission, biodegradability and production from renewable raw material makes the present candle a particularly environmentally friendly product.
The candles may be made from pure triacylglycerol or may include minor amounts of other additives to modify the properties of the waxy material. Examples of types of additives which may commonly be incorporated into the present candles include colorants, fragrances, insect repellants, and the like.
Another embodiment of the present invention is a vegetable-based wax comprising up to 100% hydrogenated vegetable oil. Vegetable-based waxes can be formulated to replace petroleum-based waxes used in various applications. For example, candles, cosmetics, or food wrapper coatings. These vegetable-based waxes are non-toxic. For some applications, the vegetable-based waxes have superior properties to the petroleum-based products. The vegetable oil waxes, particularly the hydrogenated soybean oil based wax, of the present invention are cost competitive with paraffin in addition to being non-toxic.
The triacylglycerol-based materials used to form the present candles are semi-solid or solid, firm but not brittle, generally somewhat malleable, with no free oil visible. Such materials typically are formed predominantly from a triacylglycerol stock having a solid fat content of no higher than about 20% at 40° C. (104° F.). The triacylglycerol stock typically is chosen to have a melting point of about 40° C. to 45° C.
In another embodiment of the invention, the melting characteristics of the triacylglycerol-based material may be controlled based on its solid fat index. The solid fat index is a measurement of the solid content of a triacylglycerol material as a function of temperature, generally determined at number of temperatures over a range from 10° C. (50° F.) to 40° C. (104° F.). For simplicity, the triacylglycerol-based materials described herein can be characterized in terms of their solid fat index at 10° C. (“SFI-10”) and/or 40° C. (“SFI-40”). Suitable triacylglycerol stock for use in making the present candles have a solid fat index exemplified by a solid fat content at 10° C. (“SFI-10”) of about 40-60 wt. % and solid fat index at 40° C. (“SFI-40”) of about 2-15 wt. %.
The triacylglycerol-based material generally includes triacylglycerol having a fatty acid profile which typically includes no more than about 25 wt. % fatty acids having less than 18 carbon atoms. In addition, the fatty acid profile of the triacylglycerol typically includes at least about 50 wt. % 18:1 fatty acid and no more than about 20 wt. % 18:0 fatty acid (“stearic acid”). A triacylglycerol stock may also be characterized by its Iodine Value. The triacylglycerol stock used to produce the candles typically have an Iodine Value of about 60 to about 75.
The present application also provides candle beads formed from the triacylglycerol-based material and methods of producing candles using the triacylglycerol-based material.
DETAILED DESCRIPTION
Generally, the wax of the present invention is used in applications like the waxes which it replaces. However, some considerations must be taken into account. The waxes of the present invention are generally processed at lower temperatures than a corresponding petroleum-based wax. This lower energy input is advantageous to cost considerations and may avoid effects such as discoloration of the wax. The wax of the present invention generally burns at a lower temperature than petroleum-based waxes as well. This can be an advantage for an application such as aromatherapy candles. In such an application, the oils can be better able to volatilize without problems such as oxidation.
In one embodiment, the wax of the present invention comprises hydrogenated vegetable oil. Soybean oil is the preferred vegetable oil, but other oils can be used, such as corn, cotton, palm, olive, canola, and the like. Generally, the invention is expected to work for any fatty acids from oil seeds. One of ordinary skill in the art would be able to determine other plant oils which will work. It is expected that combinations of vegetable oils will work as well.
The level of hydrogenation of the oil varies with the end use application. The level of hydrogenation can be correlated with the desired characteristics of the wa
Doucette Melinda Kae
House, III Nathaniel C.
Murphy Timothy A.
Richards Michael L.
Cargill Inc.
Foley & Lardner
Toomer Cephia D.
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