Free fatty acid candle

Abstract

A candle comprises a wax composition, wherein the wax composition comprises from 85% to 98% by weight of stearic acid (C18:0) and from 2% to 15% by weight of palmitic acid (C16:0); and wherein the wax composition comprises at least 75% by weight of free fatty acids; wherein said percentages of fatty acid residues refers to free fatty acids and fatty acids bound as acyl groups in esters in the wax composition and being based on the total weight of C4 to C24 fatty acid residues bound as acyl groups and present as free fatty acids present in the wax composition.

Description

[0001] FREE FATTY ACID CANDLE

[0002] FIELD OF THE INVENTION

[0003] The invention relates to candles comprising wax compositions. In particular, the invention relates to the use of certain wax compositions to impart desirable properties to candles formed from said wax compositions and to impart certain advantages to processes for forming said candles.

[0004] BACKGROUND OF THE INVENTION

[0005] Historically, candles were made from various naturally occurring waxes such as beeswax and waxes derived from animal fats such as tallow. Throughout the 20thcentury, candles made from these materials were increasingly replaced by paraffin wax candles. Paraffin is a product of the petroleum industry and was a cheaper and more readily available product to produce candles from. Another advantage of using paraffin candles is that good control of the melting temperature of the wax is provided. As such, paraffin candles are currently the most commonly occurring type of candle.

[0006] In more recent years, it has become desirable to replace paraffin candles with candles made from alternative types of wax. There is an increasing desire to move away from the use of petroleum derived products (and indeed animal derived products) for environmental and sustainability reasons. In view of this, it has been attempted to develop various more sustainable alternatives to paraffin candles such as candle waxes formed from hydrogenated plant derived triglyceride oils, mixtures of fatty acids, and combinations thereof. For example, candle waxes derived from palm oil and hydrogenated soybean oil have been proposed for use. Palm derived candles are less desirable due to the negative public perception of palm derived products for environmental reasons.

[0007] Ideally, candle waxes should be suitable for use in the production of a variety of different types of candles. Molded candles and crown candles are produced by melting a wax composition and pouring the melted wax composition into a mold before the composition is allowed to harden thus forming the candle. Pillar candles are produced by subjecting solid flakes, powders, or granules of the candle wax composition to high pressure so as to form the candle. Tapered candles are produced by dipping a wick into molten candle wax and allowing a thin layer of wax to solidify around the wick. This process is then repeated multiple times until a desired candle thickness is achieved. The different ways in which these candle types are produced can mean that different optimum properties for the candle wax are desirable for each type of candle. For example, in the case of molded and crown candles, the crystallization behaviour (i.e. how the wax crystallizes on cooling) in the mold of the wax composition is important, whereas for pillar candles, this is less of a consideration. In the case of pillar candles, how the solid wax granules behave under the high pressures used in the production processes is more important. It is often difficult to find a candle wax composition that has the optimum properties for use in the production of both molded / crown candles and also pillar candles.

[0008] There remains a need in the art for candle wax compositions that are suitable for forming all types of candle discussed above, that are petrochemical free, non-palm derived, and derived from sustainable sources.

[0009] SUMMARY OF THE INVENTION

[0010] The present invention is based on the surprising finding that certain free fatty acid compositions comprising stearic acid (C18:0) and palmitic acid (016:0) can be used to form high quality candles. Surprisingly, it has been found possible to produce high quality candles of a variety of types from the free fatty acid compositions, such as molded / crown candles and pillar candles. The free fatty acid compositions have also been found to impart various advantages to the production processes for making the candles.

[0011] The use of free fatty acid compositions comprising stearic acid (C18:0) and palmitic acid (C16:0) is advantageous since these free fatty acids can be derived from many sustainable sources (e.g. the many plant oils high in these fatty acids), are non- petrochemical derived, and can be non-palm derived (i.e. where the free fatty acids are derived from a non-palm plant source). The use of these free fatty acids can often also result in cost savings since these fatty acids can easily and cheaply be derived from existing industrial processes (such as vegetable oil processing).

[0012] However, the inventor has found that not any free fatty acid composition comprising the fatty acids mentioned above can be used. It has been found difficult to provide a candle wax derived from stearic acid (C18:0) and palmitic acid (C16:0) that is suitable for the production of both molded / crown candles and also pillar candles. The inventor has found that the properties of free fatty acid compositions comprising stearic acid (C18:0) and palmitic acid (C16:0) are very sensitive to the particular respective amounts of stearic acid (C18:0) and palmitic acid (C16:0) used in the compositions and that this has an effect on the suitability of the compositions for the formation of a variety of types of candle such as both molded candles and pillar candles.

[0013] It has been found that the respective amounts of stearic acid (C18:0) and palmitic acid (C16:0) in the composition has an effect upon the crystallization properties of the composition and the extent to which it shrinks in molds. This is an important consideration in the production of molded candles. At certain concentrations of stearic acid (C18:0) and palmitic acid (C16:0), the wax compositions on cooling do not undergo sufficient shrinkage in the mold to be able to be effectively “demolded” meaning that adhesion of the solidified wax composition to the mold can undesirably occur. These wax compositions are also often too soft for effective candle production, contain cracks and break easily during production. Often such wax compositions also have an oily surface due to phase separation / oiling out of the wax composition. Typically, it has been found that these problems are associated with wax compositions with too low a stearic acid (C18:0) content and too high a palmitic acid (C16:0) content. On the other hand, at certain concentrations of stearic acid (C18:0) and palmitic acid (016:0), the wax compositions have been found to be too hard and brittle and are not sufficiently flexible. Molded candles made from said waxes have been found to break due to the increased brittleness. Where these wax compositions are used to produce molded candles, it has been found that excess shrinkage occurs in the molds. Air is also often trapped within the wax as it crystallizes quickly. These effects contribute to the candle having uneven surfaces, and sometimes the formation of craters in the candle surfaces and / or a cauliflower-like appearance of the surface.

[0014] It has also been found by the inventor that the respective amounts of stearic acid (C18:0) and palmitic acid (C16:0) in the compositions has an effect upon the pressing performance of the candle wax compositions in the manufacture of pillar candles. At certain amounts of stearic acid (C18:0) and palmitic acid (C16:0), a higher pressing pressure has been found to be required which can increase the costs of the production process. Also, due to the higher pressures required, more material is needed to get the desired candle height. The flakes, powders and granules of these wax compositions are also too hard and grainy with insufficient flexibility meaning that they are not stuck together effectively in the pressing step. Pillar candles produced from these wax compositions are also very brittle. These particular problems have also been found to occur where pure stearic acid (C18:0) is used and the compositions do not comprise palmitic acid (C16:0), or where the stearic acid (C18:0) concentration is greater than 98%. The respective amounts of stearic acid (C18:0) and palmitic acid (C16:0) in the wax compositions has also been found to be important for the aesthetic appearance of the candles. As discussed above, uneven surfaces are formed when molded candles are produced from wax compositions with certain stearic acid (C18:0) and palmitic acid (C16:0) amounts present. Additionally, at certain amounts, both molded candles and pillar candles may have an undesirable frosted surface appearance. Without being limited by theory, the frosted surface appearance is believed to be caused by blooming of the fatty acid crystals (i.e. conversion of the fatty acid crystals from one polymorphic form to another).

[0015] The invention is based on the surprising finding that certain free fatty acid wax compositions comprising certain specific amounts of stearic acid (C18:0) and palmitic acid (C16:0) solve or alleviate the problems discussed above.

[0016] According to a first aspect of the invention, there is provided a candle comprising a wax composition, wherein the wax composition comprises from 85% to 98% by weight of stearic acid (C18:0) and from 2% to 15% by weight of palmitic acid (C16:0); and wherein the wax composition comprises at least 75% by weight of free fatty acids; wherein said percentages of fatty acid residues refers to free fatty acids and fatty acids bound as acyl groups in esters in the wax composition and being based on the total weight of C4 to C24 fatty acid residues bound as acyl groups and present as free fatty acids present in the wax composition.

[0017] Surprisingly, it has been found that wax compositions as described above in candles of the invention have excellent crystallization and pressing performance meaning that the wax compositions are suitable for the production of high quality molded and pillar candles, as well as other candle types. The candles also do not crack easily during or after production. The candles also have an improved aesthetic appearance with even surfaces and no frosted appearance. The candles also do not suffer from oily surfaces and the phase separation associated with candles formed from wax compositions with different C18:0 to C16:0 amounts present in theirwax compositions. In the case of molded candles and crown candles, it has been found that the wax compositions effectively demold upon solidification and can easily be removed from the molds, but without the excessive shrinkage found to be associated with certain other compositions. In the case of pillar candles, it has been found that the candle waxes do not require too high a pressure for effectively forming the candles and form candles that are not too brittle. The flakes, powders and granules used in the production of pillar candles have also been found to stick together better as a result of the production process using the wax compositions. Both pillar and molded candles and other types of candles formed from the wax compositions have also been found to have an acceptable aesthetic appearance. An additional advantage of candles of the invention is that they comprise no or only low amounts of unsaturated fatty acids meaning that they are less susceptible to oxidative degradation.

[0018] Preferably, the wax composition comprises from 85% to 95% by weight of stearic acid (C18:0). More preferably, the wax composition comprises from 88% to 95% by weight of stearic acid (C18:0). Most preferably, the wax composition comprises from 90% to 95% by weight of stearic acid (C18:0).

[0019] Preferably, the wax composition comprises from 5% to 15% by weight of palmitic acid (C16:0). More preferably, the wax composition comprises from 5% to 12% by weight of palmitic acid (C16:0). Most preferably, the wax composition comprises from 5% to 10% by weight of palmitic acid (C16:0).

[0020] Most preferably, the wax composition comprises from 5% to 10% by weight of palmitic acid (C16:0) and from 90% to 95% by weight of stearic acid (C18:0).

[0021] In some instances, the wax composition further comprises oleic acid (C18:1). Typically, when included, the oleic acid (C18:1) is present in the wax composition in an amount of from 0.1 % to 12% by weight, preferably from 0.1% to 8% by weight, and more preferably from 0.1 % to 5% by weight.

[0022] In some instances, the wax composition further comprises one or more fatty acid residues having 20 or more carbons. Typically, where the wax composition comprises one or more fatty acid residues having 20 or more carbons, the one or more fatty acid residues having 20 or more carbon atoms are present in the wax composition in a total amount of from 0.2% to 5% by weight, preferably from 0.5% to 4% by weight, and more preferably from 0.75% to 3% by weight. It is believed that the presence of one or more fatty acid residues having 20 or more carbons in the wax composition may aid in further improving the crystallization behaviour of the fatty acid wax composition giving even more improved behaviour in molded candle manufacture. Without being limited by theory, this is believed to be due to the fatty acid having 20 or more carbon atoms exhibiting a crystallization seed effect to the wax composition. In some instances, the wax composition further comprises arachidic acid (C20:0). Typically, if present, the arachidic acid (C20:0) is present in the wax composition in a total amount of from 0.2% to 5% by weight, preferably from 0.5% to 4% by weight, and more preferably from 0.75% to 3% by weight.

[0023] Typically, the wax composition comprises at least 80% by weight of free fatty acids; and preferably at least 85% by weight of free fatty acids. More preferably, the wax composition comprises at least 90% by weight of free fatty acids; and most preferably at least 95% by weight of free fatty acids.

[0024] Typically, the wax composition comprises less than 10% by weight of trans fatty acids; preferably less than 5% by weight of trans fatty acids; and preferably less than 2% by weight of trans fatty acids. More preferably, the wax composition comprises less than 1% by weight of trans fatty acids.

[0025] Typically, the wax composition has an iodine value of less than 30; preferably less than 20; and more preferably less than 10. Still more preferably, the wax composition has an iodine value of less than 5; still more preferably less than 2; and most preferably less than 1. Iodine value can be determined using any suitable technique known in the art. For example, iodine value is determined according to IUPAC 2.205 or AOCS Cd 1C-85. Preferably, iodine value is determined according to IUPAC 2.205.

[0026] Typically, the wax composition has a melting point of from 45°C to 75°C; preferably from 55°C to 70°C; more preferably from 60°C to 70°C; and most preferably from 65°C to 70°C. The melting point can be determined using any suitable technique known in the art. For example, melting point can be determined according to AOCS Cc 18-80 or AOCS Cc 3- 25. Preferably, melting point is determined according to AOCS Cc 3-25.

[0027] Typically, the wax composition has a solid fat content at 40°C of 75 % to 100 %; preferably 85 % to 100 %; and more preferably 95 % to 100 %.

[0028] Typically, the wax composition has a solid fat content at 35°C of 75 % to 100 %; preferably 85 % to 100 %; and more preferably 95 % to 100 %.

[0029] Typically, the wax composition has a solid fat content at 30°C of 75 % to 100 %; preferably 85 % to 100 %; and more preferably 95 % to 100 %.

[0030] Typically, the wax composition has a solid fat content at 25°C of 75 % to 100 %; preferably 85 % to 100 %; and more preferably 95 % to 100 %. Typically, the wax composition has a solid fat content at 20°C of 75 % to 100 %; preferably 85 % to 100 %; and more preferably 95 % to 100 %.

[0031] Typically, the wax composition has a solid fat content at 10°C of 75 % to 100 %; preferably 85 % to 100 %; and more preferably 95 % to 100 %.

[0032] Preferably, the wax composition has:

[0033] (i) a solid fat content at 40°C of from 85 % to 100 %;

[0034] (ii) a solid fat content at 35°C of 85 % to 100 %;

[0035] (iii) a solid fat content at 30°C of 85 % to 100 %;

[0036] (iv) a solid fat content at 25°C of 85 % to 100 %;

[0037] (v) a solid fat content at 20°C of 85 % to 100 %; and

[0038] (vi) a solid fat content at 10°C of 95 % to 100 %.

[0039] More preferably, the wax composition has:

[0040] (i) a solid fat content at 40°C of from 95 % to 100 %;

[0041] (ii) a solid fat content at 35°C of 95 % to 100 %;

[0042] (iii) a solid fat content at 30°C of 95 % to 100 %;

[0043] (iv) a solid fat content at 25°C of 95 % to 100 %;

[0044] (v) a solid fat content at 20°C of 95 % to 100 %; and

[0045] (vi) a solid fat content at 10°C of 95 % to 100 %.

[0046] The solid fat content of the composition can be determined using any suitable technique known in the art. Preferably, the solid fat content is determined according to AOCS Cd 16b-93.

[0047] The melting point of the wax composition is determined according to AOCS Cc 3-25; and the iodine value of the wax composition is determined according to IUPAC 2.205.

[0048] It will be appreciated that for a given wax composition, the iodine value of the composition may be tailored by tailoring the extent of hydrogenation of the composition. For example, a higher iodine value composition with a higher degree of unsaturation may have its iodine value lowered by hydrogenation. It will also be appreciated that the solid fat content of the wax composition and its melting point will be dependent, at least in part, on the iodine value of the wax composition. Typically, a higher iodine value wax composition will have a lower solid fat content and lower melting point, and vice versa.

[0049] The wax composition may comprise free fatty acids derived from any suitable source. Typically, the wax composition comprises free fatty acids derived from one or more plant oils. Preferably, the wax composition comprises free fatty acids derived from shea butter, cotton oil, rice bran oil, palm oil, canola oil, rapeseed oil, coconut oil, com oil, cottonseed oil, olive oil, peanut oil, safflower oil, sesame oil, soybean oil, sunflower oil, linseed oil, palm kernel oil, tung oil, jatropha oil, mustard oil, camelina oil, pennycress oil, castor oil, any faction thereof, or any combination thereof.

[0050] The free fatty acids can be derived from one or more plant oils using standard methods known in the art which will be apparent to the skilled person given the benefit of the present disclosure. Such methods include hydrolysis reactions to produce hydrolysed free fatty acids.

[0051] The term “fat” as used herein refers to glyceride fats and oils containing fatty acid acyl groups and does not imply any particular melting point. The term “oil” is used synonymously with “fat” herein.

[0052] The term "fatty acid", as used herein, refers to straight chain saturated or unsaturated (including mono- and poly unsaturated) carboxylic acids having 4 to 24 carbon atoms. A fatty acid having x carbon atoms and y double bonds may be denoted Cx:y. For example, palmitic acid may denoted C16:0, oleic acid may denoted C18:1. Percentages of fatty acids in compositions referred to herein include acyl groups in tri-, di- and mono-glycerides present in the glycerides and are based on the total weight of C4 to C24 fatty acids. The fatty acid profile (i.e. composition) may be determined, for example, by fatty acid methyl ester analysis (FAME) using gas chromatography according to ISO 12966-2 and ISO 12966.4.

[0053] More preferably, the wax composition comprises free fatty acids derived from shea butter or a fraction thereof. Most preferably, the wax composition comprises free fatty acids derived from shea olein. Preferably, the wax composition comprises at least 75% by weight of free fatty acids derived from shea butter. More preferably, the wax composition comprises at least 80% by weight of free fatty acids derived from shea butter. Still more preferably, the wax composition comprises at least 85% by weight of free fatty acids derived from shea butter. Most preferably, the wax composition comprises at least 90% by weight of free fatty acids derived from shea butter. Particularly preferably, the wax composition comprises at least 95% by weight of wax compositions derived from shea butter.

[0054] Preferably, the wax composition comprises at least 75% by weight of free fatty acids derived from shea olein. More preferably, the wax composition comprises at least 80% by weight of free fatty acids derived from shea olein. Still more preferably, the wax composition comprises at least 85% by weight of free fatty acids derived from shea olein. Most preferably, the wax composition comprises at least 90% by weight of free fatty acids derived from shea olein. Particularly preferably, the wax composition comprises at least 95% by weight of wax compositions derived from shea olein.

[0055] Using free fatty acids derived from shea butter is particularly preferable. Shea stearin is used as a cocoa butter equivalent in the production of chocolate and shea olein is used as a multipurpose oil in bakery, dairy and chocolate industries. Manufacturing and processing of these oils from shea butter often produces free fatty acid side streams that can be used in the coating wax compositions of the invention. This increases the sustainability of wax compositions of the invention since the free fatty acids are sourced from pre-existing industrial processes.

[0056] Preferably, the free fatty acids used in the wax compositions are not derived from palm oil. An advantage of the wax compositions is that they comprise more stearic acid than palmitic acid meaning that they can be derived from non-palm sources that are lower in palmitic acid such as shea butter as discussed above.

[0057] The free fatty acids present in the wax compositions can be derived from any suitable plant oil such as the plant oils discussed above. In some instances, one or more free fatty acids present in the wax compositions may be derived from one or more partially or fully hydrogenated vegetable oils, such as partially or fully hydrogenated versions of the vegetable oils discussed above. Suitable process conditions and methods for hydrogenating vegetable oil so as to form fully or partially hydrogenated vegetable oils are known in the art. Any suitable fat hydrogenation process known in the art can be used to produce fully or partially hydrogenated vegetable oils. For example, hydrogenation processes discussed in EP2196094 can be used.

[0058] Typically, the wax composition comprises palm oil and palm oil derived products in an amount of less than 15% by weight; preferably less than 10% by weight; and more preferably less than 5% by weight.

[0059] Preferably, the wax composition is free of palm oil and any palm oil derived products.

[0060] Typically, the wax composition comprises animal derived products in an amount of less than 15% by weight; preferably less than 10% by weight; and more preferably less than 5% by weight. Most preferably, the wax composition is free of animal-derived products.

[0061] Typically, the wax composition comprises petrochemicals and petrochemical derived products in an amount of less than 15% by weight; preferably less than 10% by weight; and more preferably less than 5% by weight. Most preferably, the wax composition is free of petrochemicals and petrochemical derived products.

[0062] The wax composition may comprise one or more additives. Any suitable additive known in the art for inclusion in candle wax compositions may be included in the wax compositions.

[0063] Typically, the one or more additives comprise one or more perfumes, one or more colorants, or a combination thereof.

[0064] Where the wax composition comprises one or more perfumes, the one or more perfumes are typically present in the wax composition in an amount of from 0.1 % to 15% by weight of the wax composition.

[0065] Where the wax composition comprises one or more colorants, the one or more colorants are typically present in the wax composition in an amount of from 0.1% to 1% by weight of the wax composition.

[0066] Any suitable perfume known in the art for inclusion in candles may be used. Examples of perfumes include fragrance oils and essential oils. Any suitable colorants known in the art may be included in the wax compositions. Examples of dyes that can be used include aniline-based dyes.

[0067] The term candle as used herein is used to refer to a shaped solid block of wax with a central wick protruding from a surface of the candle. The wick is to be lit and burnt using the candle wax of the candle as fuel. Preferably, the wick of the candle also extends throughout the length of the candle from where the wick protrudes at the top of the candle to the bottom of the candle.

[0068] The term wick as used herein is used to refer to a piece of string or cord that holds the flame of the candle when lit. Any suitable wick or wick material known for use in candle production may be used. For example, the wicks may be formed from braided cotton. When the wick of the candle is lit, solid wax is in the immediate vicinity of the flame is melted and is absorbed into the wick by capillary action. When the fuel reaches the flame it is vaporized and combusted. The candle wick may influence how the candle bums. For example, the diameter, stiffness, fire resistance and tethering of the wick may influence how the candle bums. Wicks may also be treated with chemicals to tailor the burning characteristics of the wick. Common chemicals include ammonium salts such as ammonium sulphate or ammonium nitrate.

[0069] Candles according to the invention can be made using any candle making technique known in the art. Suitable candle making techniques for use will be apparent to the skilled person given the benefit of the present disclosure.

[0070] Typically, the candle comprises at least 80% by weight of a wax composition as described above; preferably at least 90% by weight of a wax composition as described above; and more preferably at least 95% by weight of a wax composition as described above.

[0071] The candle can be any type of candle known in the art such as a container candle, pillar candle, crown candle, molded candle, or a tapered candle. Preferably, the candle is a molded candle, crown candle or pillar candle.

[0072] A container candle is a candle where the solid wax is contained within a container. The candle is produced by pouring molten wax into the container; inserting the wick into the molten wax; and then allowing the molten wax to solidify so as to form the candle.

[0073] Molded candles and crown candles are candles that are formed by pouring molten wax into a mold; inserting a wick into the molten wax and then allowing the wax composition to solidify by crystallization. The crystallization behaviour of the candle wax is important for this application. If the wax crystallizes too quickly then excessive shrinkage of the wax composition will occur in the mold leading to uneven surfaces of the candle and a reduced aesthetic appeal. In contrast, where the wax composition is too soft and crystallizes too slowly, insufficient shrinkage of the wax composition will occur in the molding process leading to adhesion of the composition to the mold once solidified.

[0074] Dipping candles are produced by dipping a wick into molten wax and then removing the wick so that it is coated with a thin layer of wax which is allowed to solidify. The dipping process is then repeated so as to build up successive layers of the wax until the candle is of the desired thickness. The crystallization behaviour of the candle wax is also important in the production of dipping candles.

[0075] Pillar candles are formed by subjecting solid granules, powders or flakes of a wax composition to high pressures which causes the granules to coalesce into a solid mass that is the candle. For the production of pillar candles, how the solid flakes of the wax composition behave under pressure is important. It is desired that not too high a pressure is required in order to coalesce the flakes into a candle. If the flakes are too hard and grainy, then greater pressure is required to coalesce them into a candle which can negatively impact the visual appearance of the candle or cause cracks. Often, where the flakes are too hard and grainy, it is also not possible to effectively press the flakes together into a solid mass. Also, due to the higher pressures required, a greater amount of flakes is typically required to produce candles of the desired height. Where the wax compositions are too soft, the resultant candles also often contain cracks and are susceptible to phase separation of liquid present in the candles separating from solid which can result in an undesirable sticky candle surface, and make the formed candles harder to remove from the mold.

[0076] Surprisingly, it has been found that flakes of wax compositions described above do not suffer from the drawbacks discussed above. Flakes, granules and powders of wax compositions described herein have surprisingly been found to exhibit excellent pressing behaviour in pillar candles of the invention. Pillar candles formed from wax compositions described herein have been found not to suffer from phase separation or cracking. Additionally, not too high a pressure is required in order to cause flakes or granules of the wax composition to effectively coalesce into candles.

[0077] According to a second aspect of the invention, there is provided the use of a wax composition as described herein in a candle. Preferably, the candle is as described above in accordance with the first aspect of the invention. As discussed above, an advantage of the candle of the invention is that due to it comprising high amounts of stearic acid (C18:0), the candle wax is highly saturated. This makes the candle more resistive to oxidative degradation. Often, candles formed from wax with higher amounts of carbon-carbon double bonds are more susceptible to oxidation due to reaction of the carbon-carbon double bond. This is often a problem with e.g. candles made from waxes that comprise triglyceride oils or mixtures of fatty acids having high amounts unsaturation in the fatty acid hydrocarbon chains. Accordingly, use according to the invention may comprise using the wax composition to improve the stability of the candle towards oxidation.

[0078] As discussed above, it has surprisingly been found that the wax compositions described herein reduce cracking and breakage of the candle during and / or after production. This is particularly the case for pillar candles and molded candles. Where candles are formed from wax compositions comprising less than 85% by weight of stearic acid (C18:0) and more than 15% by weight of palmitic acid (C16:0), a higher incidence of cracking and breakage of the candles is observed both during and after manufacture. This can be because the wax composition used is not strong enough (typically where the wax composition has too low a C18:0 content), or where the wax composition is too hard and brittle (typically where the C18:0 content is above 98%). In the case of pure stearic acid (C18:0), the candle wax is too hard and brittle and is susceptible to cracking as a result. In the case of pillar candles made from pure stearic acid, the granules or flakes are so hard that under the pressures used in the candle production process, the flakes are too hard to effectively fuse and stick together. This makes the pillar candles more susceptible to cracking after production. In contrast, where the amounts of stearic acid and palmitic acid in the composition are within the limits specified above for candles of the invention, the incidence of cracking during and / or after production is reduced. Accordingly, typically, the use comprises using the wax composition to reduce cracking or breakage of the candle during and / or after manufacture.

[0079] Typically, the use comprises using the wax composition to reduce oiling out and / or phase separation of the candle. Often, with candles manufactured from mixtures of free fatty acids or triglyceride oils, phase separation in the candle can occur which can lead to an undesirable tacky or greasy outer surface of the candle. The phase separation can be due to liquid fatty acids or triglyceride oils separating from solid fatty acid or triglyceride components of the wax composition, or liquid components such as scenting agents / perfumes separating from the wax composition. Surprisingly, it has been found that less phase separation occurs where the candle wax composition comprises the amounts of stearic acid and palmitic acid specified above for candles of the invention. Where the stearic acid and palmitic acid amounts are outside of these ranges, the candles have been found to be more susceptible to phase separation than candles of the invention.

[0080] Typically, the use comprises using the wax composition to improve the visual appearance of the candles after manufacture; such as a reduced white spot (frosting) formation, a reduction in uneven surfaces, or a combination thereof. As discussed above, candles formed from fatty acid candle waxes can often be susceptible to the formation of undesirable white spots on the outer surfaces of the candles which damages their aesthetic appeal. Without being limited by theory, the frosted surface appearance is believed to be caused by blooming of the fatty acid crystals (i.e. conversion of the crystals from one polymorphic form to another). Surprisingly, it has been found that this effect is minimised or eliminated where the candle wax compositions comprise stearic acid and palmitic acids within the ranges specified above for candles of the invention. Where candle waxes comprise stearic acid and palmitic acid in amounts outside these ranges, frosting has been found to be more common. It has also been found that candles of the invention have associated therewith a reduction in uneven surfaces compared to candles comprising stearic acid and palmitic acid in amounts outside of the limits specified above or candles of the invention.

[0081] Typically, the use comprises using the wax composition to reduce adhesion of the candle to surfaces of molds and / or containers used in production of the candle. Surprisingly, it has been found that candles of the invention have associated therewith a reduction in adhesion of the candle to surfaces of molds and / or containers used in production of the candle compared to candles comprising stearic acid and palmitic acid in amounts outside of the limits specified above or candles of the invention. For example, molded candles with lower stearic acid and higher palmitic acid amounts often undesirably adhere to molds meaning that removing the candle from the mold after manufacture can be slower and sometimes impossible. Candles can break when it is attempted to remove them form the mold. Even in cases where this does not occur, the efficiency of production processes for making the candles is negatively affected.

[0082] Without being limited by theory, it is believed that the abovementioned advantages are associated with candles of the invention as properties such as the crystallization properties, titre, shrinkage, refractive index and hardness of the wax compositions are affected by the ratio of stearic acid to palmitic acid present in the compositions. The candles of the invention can be produced using any suitable process known in the art for manufacturing said candles.

[0083] Thus, according to a third aspect of the invention, there is provided a process for producing a candle according to the invention, the process comprising providing a wax composition as described above; and producing a candle therefrom.

[0084] In some embodiments, the candle is a pillar candle, and the process comprises applying pressure to flakes or a powder of the wax composition. In such embodiments, any suitable process of producing pillar candles known in the art may be used, as well as apparatuses for carrying out said processes.

[0085] In other embodiments, the candle is a crown candle or a molded candle, and the process comprises heating the wax composition to a temperature above its melting point so as to form a melted wax composition; providing the melted wax composition in a mold; and cooling the melted wax composition in the mold so as to form the candle. In such embodiments, any suitable process of producing molded candles or crown candles known in the art may be used, as well as apparatuses for carrying out said processes.

[0086] In other embodiments, the candle is a tapered candle, and the process comprises dipping a wick into a melted wax composition and allowing the melted wax composition to solidify around the wick. Preferably, the dipping step is carried out a plurality of times so as to build up successive layers of solidified wax around the wick. The dipping steps can be continued until the candle reaches a desired thickness. In such embodiments, any suitable process of producing tapered candles known in the art may be used, as well as apparatuses for carrying out said processes.

[0087] DESCRIPTION OF THE DRAWINGS

[0088] Figures 1 and 2 depict photographs of candles of the invention.

[0089] Figures 3 to 8 depict photographs of comparative candles.

[0090] DETAILED DESCRIPTION OF THE INVENTION

[0091] The following examples are for illustrative purposes only, and are not intended to limit the scope of the invention in any way. Example 1

[0092] Eight molded candles were produced using conventional processes known in the art for preparing molded candles. Two of these candles were according to the invention and six of the candles were comparative candles. The respective amounts of fatty acids in the candles of the invention and in each comparative candle are indicated in Tables 1 , 2 and 3 below.

[0093] Table 1 Table 2

[0094] Table 3

[0095] A photograph of each candle is shown in Figures 1 to 9 respectively. Figure 1 shows Invention candle 1.

[0096] Figure 2 shows Invention candle 2.

[0097] Figure 3 shows Comparative candle 1.

[0098] Figure 4 shows Comparative candle 2.

[0099] Figure 5 shows Comparative candle 3.

[0100] Figure 6 shows Comparative candle 4.

[0101] Figure 7 shows Comparative candle 5.

[0102] Figure 8 shows Comparative candle 6.

[0103] As shown in Figure 1 , Invention candle 1 has an even surface and an aesthetically pleasing appearance. The surface of the candle was not oily or tacky to touch and no phase separation was observed. No cracks were observed in the candle.

[0104] As shown in Figure 2, Invention candle 2 also has an even surface and an aesthetically pleasing “feathering effect” upon the surface. The surface of the candle was not oily or tacky to touch and no phase separation was observed. No cracks were observed in the candle.

[0105] As shown in Figure 3, Comparative candle 1 has a very uneven surface. The surface was also oily and tacky to the touch indicating phase separation. The candle was aesthetically unacceptable.

[0106] As shown in Figures 4 and 5, Comparative candles 2 and 3 also have unacceptable and uneven surfaces. The surfaces were also oily and tacky to the touch indicating phase separation.

[0107] As shown in Figures 6 and 7, Comparative candles 4 and 5 have uneven surfaces and are not a desirable cylindrical shape. The candles are not aesthetically acceptable.

[0108] As shown in Figure 8, Comparative candle 6 is not cylindrical which is undesirable. Whilst the candle has even surfaces, there is a very large crack in the top surface which is unacceptable.

[0109] It can be concluded that the candles of the invention are acceptable in that they have even aesthetically acceptable shapes and surfaces. There are no cracks in the candles. Furthermore, the surfaces of the candles are not oily or tacky as no phase separation has occurred. In contrast, each of comparative candles 1 to 6 suffers has associated therewith one or more defects such as cracks present in the candles, tacky or oily surfaces indicating phase separation, uneven surfaces, and / or an uneven asymmetric shape.

Claims

CLAIMS1. A candle comprising a wax composition, wherein the wax composition comprises from 85% to 98% by weight of stearic acid (C18:0) and from 2% to 15% by weight of palmitic acid (C16:0); and wherein the wax composition comprises at least 75% by weight of free fatty acids; wherein said percentages of fatty acid residues refers to free fatty acids and fatty acids bound as acyl groups in esters in the wax composition and being based on the total weight of C4 to C24 fatty acid residues bound as acyl groups and present as free fatty acids present in the wax composition.

2. A candle according to Claim 1 , wherein the wax composition comprises from 85% to 95% by weight of stearic acid (C18:0).

3. A candle according to Claim 1 or Claim 2, wherein the wax composition comprises from 88% to 95% by weight of stearic acid (C18:0).

4. A candle according to any preceding claim, wherein the wax composition comprises from 90% to 95% by weight of stearic acid (C18:0).

5. A candle according to any preceding claim, wherein the wax composition comprises from 5% to 15% by weight of palmitic acid (C16:0).

6. A candle according to any preceding claim, wherein the wax composition comprises from 5% to 12% by weight of palmitic acid (C16:0).

7. A candle according to any preceding claim, wherein the wax composition comprises from 5% to 10% by weight of palmitic acid (C16:0).

8. A candle according to any preceding claim, wherein the wax composition comprises from 5% to 10% by weight of palmitic acid (C16:0) and from 90% to 95% by weight of stearic acid (C18:0).

9. A candle according to any preceding claim, wherein the wax composition further comprises oleic acid (C18:1).

10. A candle according to Claim 9, wherein the oleic acid (C18: 1 ) is present in the wax composition in an amount of from 0.1% to 12% by weight.

11. A candle according to Claim 9 or Claim 10, wherein the oleic acid (C18: 1 ) is present in the wax composition in an amount of from 0.1% to 8% by weight.

12. A candle according to any one of Claims 9 to 11 , wherein the oleic acid (C18:1) is present in the wax composition in an amount of from 0.1% to 5% by weight.

13. A candle according to any preceding claim, where the wax composition further comprises one or more fatty acid residues having 20 or more carbons.

14. A candle according to Claim 13, wherein the one or more fatty acid residues having 20 or more carbon atoms are present in the wax composition in a total amount of from 0.2% to 5% by weight.

15. A candle according to Claim 13 or Claim 14, wherein the one or more fatty acid residues having 20 or more carbon atoms are present in the wax composition in a total amount of from 0.5% to 4% by weight.

16. A candle according to any one of Claims 13 to 15, wherein the one or more fatty acid residues having 20 or more carbon atoms are present in the wax composition in a total amount of from 0.75% to 3% by weight.

17. A candle according to any preceding claim, wherein the wax composition further comprises arachidic acid (C20:0).

18. A candle according to Claim 17, wherein the arachidic acid (C20:0) is present in the wax composition in a total amount of from 0.2% to 5% by weight.

19. A candle according to Claim 17 or Claim 18, wherein the arachidic acid (C20:0) is present in the wax composition in a total amount of from 0.5% to 4% by weight.

20. A candle according to any one of Claims 17 to 19, wherein the arachidic acid (C20:0) is present in the wax composition in a total amount of from 0.75% to 3% by weight.

21. A candle according to any preceding claim, wherein the wax composition comprises at least 80% by weight of free fatty acids; preferably at least 85% by weight of free fatty acids.

22. A candle according to any preceding claim, wherein the wax composition comprises at least 90% by weight of free fatty acids; preferably at least 95% by weight of free fatty acids.

23. A candle according to any preceding claim, wherein the wax composition comprises less than 10% by weight of trans fatty acids; preferably less than 5% by weight of trans fatty acids; and more preferably less than 2% by weight of trans fatty acids.

24. A candle according to any preceding claim, wherein the wax composition comprises less than 1 % by weight of trans fatty acids.

25. A candle according to any preceding claim, wherein the wax composition has an iodine value of less than 30; preferably less than 20; and more preferably less than 10.

26. A candle according to any preceding claim, wherein the wax composition has an iodine value of less than 5; preferably less than 2; and more preferably less than 1.

27. A candle according to any preceding claim, wherein the wax composition has a melting point of from 45°C to 75°C; preferably from 55°C to 70°C.

28. A candle according to any preceding claim, wherein the wax composition has a melting point of from 60°C to 70°C; preferably from 65°C to 70°C.

29. A candle according to any preceding claim, wherein the wax composition has a solid fat content at 40°C of 75 % to 100 %; preferably 85 % to 100 %; and more preferably 95 % to 100 %.

30. A candle according to any preceding claim, wherein the wax composition has a solid fat content at 35°C of 75 % to 100 %; preferably 85 % to 100 %; and more preferably 95 % to 100 %.

31. A candle according to any preceding claim, wherein the wax composition has a solid fat content at 30°C of 75 % to 100 %; preferably 85 % to 100 %; and more preferably 95 % to 100 %.

32. A candle according to any preceding claim, wherein the wax composition has a solid fat content at 25°C of 75 % to 100 %; preferably 85 % to 100 %; and more preferably 95 % to 100 %.

33. A candle according to any preceding claim, wherein the wax composition has a solid fat content at 20°C of 75 % to 100 %; preferably 85 % to 100 %; and more preferably 95 % to 100 %.

34. A candle according to any preceding claim, wherein the wax composition has a solid fat content at 10°C of 75 % to 100 %; preferably 85 % to 100 %; and more preferably 95 % to 100 %.

35. A candle according to any preceding claim, wherein the wax composition has:(i) a solid fat content at 40°C of from 85 % to 100 %;(ii) a solid fat content at 35°C of 85 % to 100 %;(iii) a solid fat content at 30°C of 85 % to 100 %;(iv) a solid fat content at 25°C of 85 % to 100 %;(v) a solid fat content at 20°C of 85 % to 100 %; and(vi) a solid fat content at 10°C of 95 % to 100 %.

36. A candle according to any preceding claim, wherein the wax composition has:(i) a solid fat content at 40°C of from 95 % to 100 %;(ii) a solid fat content at 35°C of 95 % to 100 %;(iii) a solid fat content at 30°C of 95 % to 100 %;(iv) a solid fat content at 25°C of 95 % to 100 %;(v) a solid fat content at 20°C of 95 % to 100 %; and(vi) a solid fat content at 10°C of 95 % to 100 %.

37. A candle according to any preceding claim, wherein the wax composition comprises free fatty acids derived from shea butter, cotton oil, rice bran oil, palm oil, canola oil, rapeseed oil, coconut oil, com oil, cottonseed oil, olive oil, peanut oil, safflower oil, sesame oil, soybean oil, sunflower oil, linseed oil, palm kernel oil, tung oil, jatropha oil, mustard oil, camelina oil, pennycress oil, castor oil, any faction thereof, or any combination thereof.

38. A candle according to any preceding claim, wherein the wax composition comprises free fatty acids derived from shea butter or a fraction thereof.

39. A candle according to any preceding claim, wherein the wax composition comprises free fatty acids derived from shea olein.

40. A candle according to any preceding claim, wherein the wax composition comprises palm oil and palm oil derived products in an amount of less than 15% by weight; preferably less than 10% by weight; and more preferably less than 5% by weight.

41. A candle according to any one of Claims 1 to 40, wherein the wax composition is free of palm oil and any palm oil derived products.

42. A candle according to any preceding claim, wherein the wax composition comprises animal derived products in an amount of less than 15% by weight; preferably less than 10% by weight; and more preferably less than 5% by weight.

43. A candle according to any one or more of Claims 1 to 42, wherein the wax composition is free of animal-derived products.

44. A candle according to any preceding claim, wherein the wax composition comprises petrochemicals and petrochemical derived products in an amount of less than 15% by weight; preferably less than 10% by weight; and more preferably less than 5% by weight.

45. A candle according to any one or more of Claims 1 to 44, wherein the wax composition is free of petrochemicals and petrochemical derived products.

46. A candle according to any preceding claim, wherein the wax composition comprises one or more additives.

47. A candle according to Claim 46, wherein the one or more additives comprise one or more perfumes, one or more colourants, or a combination thereof.

48. A candle according to Claim 47, wherein the one or more perfumes are present in the wax composition in an amount of from 0.1 % to 15% by weight of the wax composition.

49. A candle according to Claim 47 or Claim 48, wherein the one or more colourants are present in the wax composition in an amount of from 0.1 % to 5% by weight of the wax composition.

50. A candle according to any preceding claim, wherein the candle comprises at least 80% by weight of a wax composition as defined in any one or more of Claims 1 to 49; preferably at least 90% by weight of a wax composition as defined in any one or more of Claims 1 to 49; and more preferably at least 95% by weight of a wax composition as defined in any one or more of Claims 1 to 49.

51. A candle according to any preceding claim, wherein the candle is a container candle; a pillar candle; a crown candle; a tapered candle; or a molded candle; preferably wherein the candle is a pillar candle; a crown candle; a tapered candle; or a molded candle.

52. Use of a wax composition as defined in any one or more of Claims 1 to 49 in a candle; preferably wherein the candle is according to any preceding claim.

53. Use according to Claim 52, wherein the use comprises using the wax composition to improve the stability of the candle towards oxidation.

54. Use according to Claim 52 or Claim 53, wherein the use comprises using the wax composition to reduce cracking or breakage of the candle during and / or after manufacture.

55. Use according to any one or more of Claims 52 to 54, wherein the use comprises using the wax composition to reduce oiling out and / or phase separation of the candle.

56. Use according to any one or more of Claims 52 to 55, wherein the use comprises using the wax composition to improve the visual appearance of the candle after manufacture; such as a reduced white spot (frosting) formation, a reduction in uneven surfaces, or a combination thereof.

57. Use according to any one or more of Claims 52 to 56, wherein the use comprises using the wax composition to reduce adhesion of the candle to surfaces of molds and / or containers used in manufacture of the candle.

58. A process for producing a candle according to any one or more of Claims 1 to 51 , the process comprising providing a wax composition as defined in any one or more of Claims 1 to 49; and producing a candle therefrom.

59. A process according to Claim 58, wherein the candle is a pillar candle, and wherein the process comprises applying pressure to flakes or a powder of the wax composition.

60. A process according to Claim 59, wherein the candle is a crown candle or a molded candle, and wherein the process comprises heating the wax composition to a temperature above its melting point so as to form a melted wax composition; providing the melted wax composition in a mold; and cooling the melted wax composition in the mold so as to form the candle.

61. A process according to Claim 60, wherein the candle is a tapered candle, and wherein the process comprises dipping a wick into a melted wax composition as defined in any one or more of Claims 1 to 49 and allowing the melted wax composition to solidify around the wick.

Images