BACKGROUND OF THE INVENTION Technical Field The present invention relates to the dispensing of fragrances to the atmosphere from a candle product. More specifically, this invention relates to candies which diffuse incense when burning, without the formation of excessive smoke, such as is normally associated with incense.

Background Art Candles have been known and used since the earliest days of civilization.

A typical candle is formed of a solid or semi-solid body of wax, such as paraffin wax or beeswax, and it contains an axially embedded combustible fibrous wick.

When the wick of a candle is lit, the generated heat melts the solid wax, and the resulting liquid wax flows up the wick by capillary action, and is com- busted. This burning cycle becomes self-supporting, for as long as the flame is allowed to burn, and for as long as there is additional wax to fuel the flame.

In addition, wickless candles are known, in which no wick is present, and the flame feeds directly upon the wax, forming a pool of liquid wax, which is consumed by the flame. Most commonly, wickless candles are produced by extrusion, in a taper-shaped form. Wickless candles may also be extruded to form a flexible taper filament, which may be spiral wound for incorporation into a dispensing device, such as an air-freshener or insect control ingredient containing candle.

In recent years, candles have been developed to appeal to the olfactory senses as well as the visual, in that they incorporate fragrancing ingredients. This type of candle usually incorporates a fragrance oil in the wax body, which is released from the liquified wax pool at the location of combustion, by diffusion or

evaporation. However, the amount of fragrance so released is not great, since the temperature of the melted wax pool surrounding a candle flame is only about 60°C, and the wax reduces the vapor pressure of fragrance oils, thereby sup- pressing diffusion of the fragrance. Conventional fragrance candles also have drawbacks due to cost and other considerations. The incorporation of fragrance oil in candle wax is difficult to achieve in a quantity which ensures the release of a suitable level of fragrance into the atmosphere during candle burning. Many fragrance oils include components which also soften candle waxes, resulting in an undesirable loss of rigidity in the candle structure, and limiting the concentration of fragrance oil which may be added to the candle. Aside from the softening of the paraffin wax caused by such fragrance oils, or by conventional coupling agents employed to incorporate complex perfumes into candle wax, it is known that such materials also lower the melting temperature of the wax, and thus the temperature of the pool of melted wax, which correspondingly lowers the rate of volatilization of incorporated perfumes. Further, incorporated fragrance oils tend to migrate and volatilize from the candle prematurely.

Moreover, when such candles burn, there is usually little or no odor of the fragrance oils yielded in the flame, due to the oxidation of the odor ingredients by the flame, which burns the oils, alcohols, or concentrates containing the scents, so that the odors or scents are consumed in the flame of the candle as it burns.

For these reasons, the portion of the perfume in an ordinary fragrance candle which actually diffuses into the atmosphere is generally very small in comparison to the portion which is simply burned away or converted to other, odorless, compounds.

On the other hand, various incenses are known, which possess high degrees of fragrance, and have been utilized in various forms for many years to impart incense to the atmosphere. However, such incenses are conventionally burned with a considerable generation of smoke, and without the visually pleasing aspects of a candle. That is, incense usually is consumed in a smoldering manner, with the release of voluminous amounts of smoke which carry the fragrance, and without the pleasing aspects and light of a candle flame. Previous

attempts to add incense to candles have failed to achieve acceptance, due to poor burning characteristics of such candles, and the large volumes of smoke generated at the flame of such candles. One factor in this failure is the fact that incense compositions are poorly soluble in common candle waxes, such as paraffin, resulting in non-homogenous mixtures. These mixtures show poor burning properties and are inferior in terms of creating a desired ambiance.

Fredericks, in U. S. Patent No. 3, 175, 876, teaches the inclusion of carbo- naceous carriers (i. e. sugars) for scents, which carriers gravitate toward the wick and release scent on the burning and smoldering of the wick. The patent also teaches the previously unsuccessful attempts at inclusion of incense in the candle to be released upon extinction and smoldering of the wicking, but teaches that scents may be carried to the flame, or to a smoldering wick, by incorporation of an appropriate carrier.

Lin, in U. S. Patent No. 3, 898, 039, teaches a fumigant-bearing substrate which in combination with a candle is particularly useful as a fragrance candle, wherein the fumigant is defined as inclusive of fragrances such as perfumes or incense, which may be in the form of a microencapsulated solid, liquid, or gas adhered to the substrate surface. The fumigant is released by diffusion upon exposure of the substrate to the heat of the lighted candle. In this case, the substrate bearing the fumigant is preferably substantially parallel to the longitudi- nal axis of the candle, and is heated by the flame, by both conduction and by radiation, to cause release of the fumigant.

In U. S. Patent No. 4, 427, 366, Moore teaches a scented candle comprising a bowl containing a centered candle surrounded by odorizing chips which release scent in response to the heat of the burning of the candle. Similarly, Ansari et al, in U. S. Patent No. 5, 891, 400, teach a volatile substance dispenser including an inner open-top container for holding a candle, and a surrounding container of a gel containing a fragrance material to be released as a result of thermal energy from the candle.

Thus, there is a continuing interest in the development of improved fragrance candles, and a need exists for acceptable incense burning candles.

BRIEF SUMMARY OF THE INVENTION In one aspect, the invention provides an incense burning candle, in which the incense is incorporated directly into the candle wax, for release upon com- bustion and formation of a liquid pool of wax. That is, the incense incorporated in the candle is released to the atmosphere by volatilization from the liquid pool of wax formed upon burning of the candle, in the same manner that other fragrances are released from fragrance containing candles. The present invention overcomes the difficulty of the low solubility of incense in candle wax by the addition of special components, or coupling agents. Further, the present inven- tion overcomes the problem of the low release rate of the incense, which is the result of low pool temperature, by the proper selection and concentration of incense and coupling agent.

In one form, the present invention comprises a fragrance candle, having a wick, and a candle wax body comprising wax, an incense ingredient, and a coupling agent to enhance the solubility of the incense ingredient in the wax.

In the preferred embodiment of the invention, an incense candle is pro- vided, comprising a candle which diffuses an intense fragrance when burning, the fragrance being released from the pool of melted wax formed from the body of the candle during burning of the candle, said candle comprising wax, a coupler, an incense ingredient, and possible additives.

In another form of the invention, an incense candle comprises a mixture of a coupling fuel, as defined hereinafter, with an incense ingredient and possible additives.

Thus, an object of the present invention is to provide a source of incense which may be released to the atmosphere without the normally associated smoldering and smoke of commonly used incense powder, sticks, cones, or coils.

It is also an object of the present invention to provide a source of intense fra- grancing which provides illumination as well as fragrance, with little or no objec- tionable smoke or soot. It is further an object of this invention to provide a candle, in the form of a jar candle or free standing as a votive, column, or taper candle,

which burns smoothly with a steady and consistent flame and little or no smoke generation, and releases a strong incense fragrance.

These and still other objects and advantages of the present invention will be apparent from the description which follows. The following description is merely of the preferred embodiments. Thus, the claims should be looked to in order to understand the full scope of the invention.

DETAILED DESCRIPTION OF THE INVENTION One or more objects of the present invention are accomplished by the provision of an incense candle product which comprises a candle comprising : (a) between about 75 and 97 weight percent of a candle wax ingredient ; (b) between about 3 and 10 weight percent of an incense ingredient ; (c) between about 0. 1 and 5 weight percent of a coupling agent ; and (d) up to about 10 weight percent of additives ; wherein the incense ingredient is incorporated directly into the candle wax, and is released into the atmosphere by volatilization from the heated pool of fuel.

Other objects of the invention are accomplished by the provision of an incense candle comprising a coupling fuel and an incense ingredient.

The candle product may take the form of a taper candle, a votive candle, or a column candle, or may be contained in a jar or other container. Such candles preferably contain a wick, but could also comprise a wickless taper. The wick, if present, may be any conventional consumable wick material, such as cotton, cellulose, nylon, or paper. The wick may preferably be located in the center of the candle, or may be off-center as desired. The presence of two or more wicks is also within the scope of the present invention. Nonconsumable wicks of an appropriate design, such as fiberglass, could conceivably be used, but in the past have been found to present problems of poor burn characteristics and excessively large flame when employed in conventional candles.

The candle wax ingredient may be selected from commercially available wax media. The combustible body of a candle product typically is a thermoplastic blend of organic materials such as tallow, beeswax, paraffin wax, montan wax, carnauba wax, and microcrystalline wax, and the like, or mixtures thereof. The

wax is preferably a paraffin wax or other less costly wax commonly employed for use in candles, such as tallow or beeswax, and should be present in an amount of from about 75 to 97 weight percent, preferably from about 80 to 95 percent, and most preferably from about 90 to 92 percent. A preferred candle wax of the present invention is a blend of a hydrocarbon wax and a microcrystalline wax, such as IGI Parafflex 4639, a product of The International Group, Inc., believed to comprise a blend of macro-and micro-crystalline paraffin waxes. Other paraffin waxes, like Exxon SRW 128 and similar waxes, can be used in the product according to the present invention provided that an appropriate coupling agent is added, as set forth herein.

The use of a coupling agent, or solubilizer, which is soluble in conventional candle waxes and in which incense ingredients are soluble, has been found to be critical to the incorporation of incense into the candle wax. Absent such a coupling agent, incense fragrances exhibit poor solubility in conventional hydro- carbon waxes, resulting in a poor burning composition which is overly soft for candle formation. Suitable coupling agents for use with incense ingredients may be selected from the group consisting of stearic acid, stearyl alcohol, polyethyl- ene-polyvinyl acetate copolymers, fatty acid esters, soy bean oil derivatives, and the like, or other components of increased polarity to accommodate the high- molecular weight resins present in the incense-type fragrance compositions.

Known coupling agents which have been used in the past, such as di-isopropyl adipate, isopropyl palmitate, d-limonene, linear alcohols having from 8 to 12 carbon atoms, diethyl phthalate, benzyl benzoate, and microcrystalline waxes, are unsuitable for use with the paraffin type waxes preferably employed in candles, due to issues of poor flame characteristics and softening of the wax, among others. In addition, the coupling agents found useful for the present invention have been found to minimize syneresis, i. e. the separation of the fragrance ingredient from the solidified wax in the form of a liquid. In the past, when melted waxes having fragrance ingredients blended therein were allowed to cool, the fragrance oils would separate out from the wax, often forming an unsightly oily surface layer, but also exposing the fragrance oil to the flame per se.

While far less acceptable from a commercial point of view, due to the high cost of the following materials, it is possible to prepare incense candies primarily from fuels or wax substitutes such as stearic acid, stearyl alcohol, fatty acid esters, soy bean oil waxes, and the like, in which incense ingredients are readily soluble, without using conventional candle waxes. In the interest of economy, however, it is proposed that such materials be used only to the extent necessary to achieve a desirable level of incense fragrance incorporation into a less expen- sive candle wax material in which the incense ingredients are not readily soluble.

It is to be noted that such materials as stearic acid and fatty acid esters have been used in the past as additives for candles, due to their favorable burning characteristics, but not for the purpose of solubilizing such materials as incense fragrances. In fact, as indicated, such materials could themselves be used for candle making, with the capability of incorporation of incense fragrances, but at a relatively high cost. When such materials are utilized as the primary source of fuel for a candle flame, either with or without conventional candle wax, they shall be referred hereinafter as"coupling fuels,"and this term shall be understood to encompass not only stearic acid and fatty acid esters, but stearyl-alcohol, soy bean oil waxes, and other such materials capable of both solubilizing incense fragrances and burning as an acceptable candle fuel. Further, the term"coupling fuels"shall be understood to encompass mixtures of conventional wax fuels with relatively high concentrations of coupling agents such as stearic acid, etc., wherein said coupling material is present in concentrations of up to about 75 weight percent, and the fuel element (i. e. a mixture of candle wax and coupling fuel) of the candle comprises from about 80 to about 97 weight percent of the candle, the balance comprising from about 3 to about 10 percent incense, and up to about 10 percent additives. Such fuels are thus distinguished from conventional candle waxes, which exhibit limited capability to solubilize incense fragrances. As previously indicated, however, while such compositions fall within the scope of the present invention, lower concentrations of coupling agent are much preferred.

A preferred coupling agent is available under the trade name ELVAX, a product of DuPont, believed to be a copolymer of vinyl acetate and polyethylene.

Such a coupling agent is necessary to achieve solubility of the incense in the candle wax, but also functions to add oxygen to the composition, improving the burn characteristics and reducing smoking. It is believed that the presence of a coupling agent increases the solubility of high-molecular weight resins present in the fragrance compositions, without compromising the hardness of candle wax.

Additives having increased polarity, and at least partial compatibility with the paraffin wax, like fatty alcohols or fatty acid esters, are also suitable as coupling agents. Natural waxes, based on both fatty acid esters of fatty alcohols and saturated fats, can also be used as coupling agents in the present invention. No paraffin wax, however, can be used as the principle candle wax ingredient in the product without an appropriate coupling agent. The coupling agent should be present in a concentration of from about 0. 1 to about 5 weight percent, preferably from about 0. 5 to about 4 percent, and most preferably from about 1 to 2 percent.

The incense ingredient may comprise any of a multitude of fragrance ingredients, or mixtures thereof, which may be used to create a sensory percep- tion of incense. The term incense ingredient shall be understood to encompass fragrance ingredients and compositions inclusive thereof. The incense ingredi- ents that are essential to achieve such an incense perception include, but are not limited to, myrrh, cedarwood, cedrenol, cedrol, birch, methyl salicylate, fir balsam, sandalwood, santalol, juniper, benzoin, coniferyl benzoate, thyme, thymol, bay, eugenol, myrcene, basil, camphor, methyl cinnamate, cinnamon, cinnamic aldehyde, rosemary, clove, and borneol. Such fragrance materials are frequently referred to as natural resins and are characterized by relatively high molecular weights, and the presence of aromatic, condensed ring structures incorporating the presence of polar groups, such as alcohols, carbonyls, aldehyde, ketones, esters, etc., which are incompatible with paraffin waxes, but are highly soluble in the coupling agents employed in the present invention. Such incense ingredients may be present in concentrations of from about 1 to about 12, preferably from about 3 to about 10 weight percent of the composition of the candle, more preferably from about 5 to about 9 percent, and most preferably from about 6 to about 8 percent. The preferred incense ingredients are selected from the group

consisting of myrrh, cedarwood, methyl salicylate, fir balsam, sandalwood, juniper, coniferyl benzoate, bay, eugenol, cinnamon, cinnamic aldehyde, rose- mary, and clove, and mixtures thereof. Because of the lower volatility of incense- type fragrances, as compared to other more common types of fragrances, the concentration of the incense ingredient in the candle composition is preferably above about 5 weight percent.

The term"incense"has a double meaning in common usage, which may indicate either a characteristic type of resinous, woody, herbaceous odor, pro- duced during the burning and/or smoldering of solid, natural materials (mostly different kinds of wood and herbs, traditionally in the form of a stick, cone, coil or powder) or these materials themselves ; hence the terms"burning incense"or "smelling incense". Incense was traditionally used in ancient cultures (especially in Eastern Asia) for religious practices ; but it has now become popular all over the world as a relaxation aid or form of aroma therapy. The novelty of the present invention is that never before has incense been associated with candle burning.

These two activities were always separate, due to the incompatibility of incense materials with paraffin wax. In the present invention, the applicants have essen- tially"extracted"the incense odor obtained by actually burning incense, and successfully incorporated it into a fragranced candle. Incense candles in accor- dance with the present invention constitute a different form of odor-diffusing device, of a nature much more widely accepted and used among the various cultures of the world than are conventional incense burning devices.

In addition to the candle wax, incense, and coupling agent, other additives which are commonly used in candles may be added, up to about 10 percent by weight of the candle composition. Such additives may include polymeric additives such as thermoplastic resins, adapted for fiber-formation by processes such as extrusion or compression molding, and coloring agents. Other additive ingredi- ents may include UV absorbers (such as UVINUL@, available from BASF, or CYASORB@, available from Cytec Industries, which are believed to be benzo- phenone derivatives), and antioxidants, which may be present to protect any dye

or fragrance from degradation. Preferred ranges of additive are from about 0 to about 7 percent, and most preferably from about 0 to about 1 percent by weight.

When a candle employing a coupling fuel as the principal fuel is prepared, the candle may be prepared in conventional fashion, comprising from about 75 to about 98, preferably from about 80 to about 97 weight percent coupling fuel, from about 1 to about 12, and preferably from about 3 to about 10 percent incense fragrance, and from about 0 to about 10 percent of additives. For such candles, preferred compositions may comprise a coupling fuel, such as stearic acid, in combination with from about 5 to about 9 percent incense fragrance, and up to about 10 percent additives. Most preferred levels of fragrance are from about 6 to about 8 percent, while additive levels are preferably below about 1 percent. As indicated previously, the coupling fuel may also be mixed with a conventional wax composition.

EXAMPLES Candles were prepared, using the compositions as set forth in Table 1, in weight percentages. The process for preparation of the candles of the present invention includes melting the wax, blending in the additives, including the coupling agent, mixing in the incense ingredient (s), and pouring in the form of jar candles. A consumable wick was employed in each of the following examples, placed in each candle before the wax had hardened. Where the copolymer coupling agent (a copolymer of polyethylene and polyvinyl acetate) was em- ployed, the wax was required to be heated to a temperature of from about 150- 165° F. for the additive to dissolve. In Example 5, a soybean oil wax was utilized as a coupling fuel, in which the incense fragrance was highly soluble. However, soybean oil derived waxes are not considered particularly suitable for use as a candle wax, due to relatively high cost, objectionable coloration, and tendency toward cracking upon cooling and solidification.

Candles prepared in accordance with the Examples were burned, and provided a satisfactory perception of incense burning. These candles were readily lit, and burned normally, with the appearance of conventional candles, but with the perception of a strong sandlewood odor released. Such incense odors have not been previously available in the form of a candle, and previously have only been available from conventional incense burning.

TABLE 1 1 2 3 4 5 Candle wax IGI 4639 91. 75 Astor Wax 90. 75 Paraffin wax SRW 128 90. 75 90. 75 Soybean oil Wax 92. 75 Fragrance Firmenich Kamogawa 7. 00 7. 00 7. 00 Firmenich Kyoto 7. 00 7. 00 Coupling agent Copolymer 1. 00 2. 00 1. 00 Stearic acid 1. 00 Stearyl alcohol 2. 00 Additive Uvinul0 3008 0. 25 0. 25 0. 25 0. 25 0. 25

INDUSTRIAL APPLICABILITY The incense candles of the present invention are useful in the home to create a pleasing environment and to provide both light and fragrance to the atmosphere. Such candles may be produced using conventional candle making methods and equipment, and utilize readily available materials in their production.

While the present invention has been described with respect to what is at present considered to be the preferred embodiments, it is to be understood that the invention is not to be limited to the disclosed embodiments. To the contrary, the invention is intended to cover various modifications and equivalent arrange- ments within the spirit and scope of the appended claims. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent formulations and functions.