Ski wax compositions

Abstract

The invention provides ski wax compositions comprising a lipid component which is a cholesterol or a cholesterol derivative, a fatty acid or salt of a fatty acid, a diglyceride, or a combination thereof. It further provides ski wax compositions comprising squalene or a squalene derivative. The ski wax compositions according to the invention can be used as a glide wax or grip wax and may be applied directly to the base of a ski or to a ski skin.

Description

[0001] SKI WAX COMPOSITIONS

[0002] Technical field

[0003] The present invention relates to ski wax compositions for use on sports or recreational equipment used on snow.

[0004] In particular, the invention relates to a ski wax composition for application to snow ski or snowboard bases to improve glide capabilities and prevent the accumulation of snow and ice in a range of snow and weather conditions. The ski wax composition contains no per- or polyfluoroalkyl substances (PFAS) and thus presents no threat to human health or to the environment.

[0005] The invention further relates to a ski wax composition for application to snow ski or snowboard bases to improve grip capabilities and provide traction in a range of snow and weather conditions.

[0006] Background of the invention

[0007] Ski wax is a material applied to snow runners, such as skis, snowboards and toboggans to adjust their coefficient of friction performance on snow and ice. Ski wax can also prevent ice-accumulation and ice-adhesion (known as “snow clubbing”) which is an issue in many winter sports, particularly in cross-country skiing.

[0008] The two main types of ski wax are glide waxes and grip waxes. Glide wax minimizes kinetic or “sliding” friction and is used for both alpine (i.e. down-hill) skiing where the boot is attached to the ski from toe to heel and Nordic (i.e. cross-country) skiing where the toe of the ski boot is fixed to the binding in a way that allows the heel to rise off the ski. Grip wax (also known as “kick wax”) minimizes static friction and thus provides traction on snow for cross-country skiers as they transfer their bodyweight to the ski and kick toward the rear to propel themselves forward. Grip on the snow also keeps the skier from backsliding when going uphill. Both types of waxes can be matched to weather and snow conditions, including the ice crystal type and size, and the moisture content of the snow which varies depending on the temperature. The different wax formulations are intended to perform best in different snow conditions.

[0009] Ski skins offer additional grip on snow. These are strips which attach to the bottom of skis and which have unidirectional textures, such as microscale hairs, which are designed to allow the ski to slide forward but not backward. They are typically made from nylon or mohair, or a combination thereof. To ensure that ski skins provide a good glide, glide wax can also be applied. Where improved grip on the snow is required, for example when going uphill, a grip wax may alternatively be applied.

[0010] Modern skis have bases made from polymer materials such as ultra-high molecular weight polyethylene (LIHMWPE) and have excellent gliding properties on snow.

[0011] The polymer bases may be produced by extrusion or sintering. Extruded bases are made of a single impermeable sheet of polyethylene. Sintered bases are produced by compression of polyethylene pellets which gives rise to a surface structure which is porous.

[0012] Conventional ski waxes can be divided into hydrocarbon-based and fluorocarbon- based waxes and are available in a variety of different types, including block wax, liquid wax, paste wax, powder wax and spray wax. The specific composition of the wax varies depending on the different snow conditions, humidity levels and weather conditions for which they are designed.

[0013] Typically, a ski wax is applied by “hot-waxing” in which a solid bar of wax (a “block wax”) is melted against a ski-iron and the resulting liquid wax is dripped over the ski base from tip to tail. The wax is then smoothed out over the base using the iron and fills any pores in the surface structure, for example in the porous surface of a sintered base. Once hardened, most of the wax is then brushed or scraped away, and the remaining thin layer of wax is buffed with a rag or cork. When carried out on a large scale, the process is the same but is automated. Ski skins pre-warmed using a waxing iron set to 100-110°C may also be waxed using the same wax products by rubbing of the wax into the fur both with, and against, the fur direction. Hydrocarbon-based waxes are made from hydrocarbons such as paraffin waxes and microcrystalline waxes. Whereas most recreational skiers use hydrocarbonbased waxes, fluorocarbon-based waxes have been favoured by competitive skiers and serious amateurs due to their high water repellency and better performance, i.e. improved glide, compared to hydrocarbon-based waxes. Fluorocarbon-based ski waxes include per- and polyfluoroalkyl substances (PFAS), such as perfluorooctanoic acid (PFOA), to promote glide in wet snow conditions.

[0014] Substitution of some of the hydrogen atoms in the hydrocarbons with fluorine atoms achieves a lower coefficient of friction and has a greater ability to repel water than pure hydrocarbon waxes. However, the presence of PFAS in ski waxes has been shown to cause unwanted environmental effects. As the wax is worn from the base of the ski during skiing it is deposited on the snow and accumulates in the ground once the snow melts. It then passes into a variety of ecosystems, for example via groundwater, and tends to persist and bioaccumulate in the food chain where it affects life negatively. PFAS can also cause adverse effects on human health during the application of the ski wax, particularly when this process is carried out manually. For these reasons, fluorocarbon-based ski waxes have recently been banned worldwide.

[0015] A need thus exists for alternative ski wax compositions, in particular such compositions which include performance additives that can effectively replace PFAS. The present invention addresses this need.

[0016] Summary of the invention

[0017] The anti-icing properties of polar bear fur has been investigated and it has now been found that the low ice adhesion is mainly caused by the layer of hair grease (i.e. sebum) present on the surface of the fur.

[0018] Sebum is an oily substance produced by the sebaceous glands of mammals and secreted along hairs. Previous studies of sebum including its lipid analysis have generally focused on humans and biomedically relevant laboratory animals, such as mice and rats. It has been intensively researched for human health and well-being issues, notably its potential role in skin conditions such as acne, and in the production of cosmetics which are to be applied to the skin. Sebum is recognised as an important part of an animal fur’s ability to repel water and pathogens, but has so far not been investigated for its anti-icing properties. It is believed that no previous studies have been carried out on any bear sebum.

[0019] As described herein, lipid analyses of the sebum obtained from polar bear fur have been performed and reveal a large fraction of di- and tri-acyl glycerol, cholesterol, and branched fatty acids compared to other animal’s sebum. Density functional theory (DFT) simulations of adsorption energies of relevant lipids on an ice surface indicate that several lipid components present in the sebum aid ice shedding by providing low ice adhesion strengths. Inspired by these findings, alternative ski wax formulations are proposed herein for application to the base of a ski, or other kinds of runners to be used on snow or ice, and which contain one or more lipids analogous, or similar, to those found in polar bear sebum. Although not wishing to be bound by theory, the cholesterol, fatty acid and diglyceride lipids proposed for use in the invention are expected to possess low ice adhesion strengths and thus effective anti-icing properties, for example when measured by DFT or direct experimentation, which makes them suitable for use as additives to ski waxes which not only improve glide performance but which also reduce or prevent the accumulation and adhesion of ice. In view of these properties, it is proposed that these lipids are a suitable replacement for PFAS in fluorocarbon-based ski waxes.

[0020] Lipid analysis of the sebum obtained from polar bear fur also revealed the absence of squalene. Squalene is a triterpene and biochemical precursor to steroids. It is found in human hair sebum and in the sebum of mammals that are native to damp or aquatic environments such as the sea otter, beaver and sea lion. The absence of squalene in the sebum of the polar bear is unexpected given the polar bear’s aquatic lifestyle. DFT simulations on squalene indicate that it has high ice adhesion strength. This leads to the proposal to use squalene or derivatives of squalene as an additive to ski waxes to improve grip performance on ice.

[0021] Detailed description of the invention

[0022] In one aspect, the invention provides a ski wax composition comprising a lipid component selected from the group consisting of a cholesterol or a cholesterol derivative, a fatty acid or salt of a fatty acid, a diglyceride, and any combination thereof. This composition finds use as a glide wax and is also referred to herein as a “glide wax”.

[0023] The ski wax composition may be provided in any conventional form, for example as a solid bar (“block wax”), liquid wax, paste wax, powder wax or spray wax.

[0024] The ski wax composition comprises a base material which contains a wax or combination of waxes, but which may also contain other components such as those herein described and which are used in conventional hydrocarbon-based ski waxes either to provide the wax in the desired form (i.e. solid, liquid, paste, powder or spray) or to improve the properties of the composition in accordance with conventional practice in the art. The base material incorporates one or more of the cholesterol, fatty acid or diglyceride lipid components herein described as an anti- icing additive, i.e. as an additive which enhances the anti-icing performance of the ski wax composition and thus improves glide on snow and reduces “snow clubbing”.

[0025] Typically, the main component of the ski wax composition according to the invention will be the wax or combination of waxes. The amount of wax will vary depending on the form of the composition, i.e. whether it is a solid wax, liquid wax, paste wax, powder wax or spray wax, and appropriate amounts can readily be determined by those skilled in the art. The wax component may be present in an amount of at least 30% by weight, or at least 40% by weight, or at least 50% by weight, for example it may be present in an amount of from 50 to 90% by weight (based on the total weight of the composition). In some embodiments, the wax component may be present in an amount of from 50 to 85% by weight, from 60 to 80% by weight, or from 65 to 75% by weight (based on the total weight of the composition).

[0026] Waxes are lipophilic organic compounds that are malleable solids at ambient temperature, but which melt to give low viscosity liquids. Waxes are insoluble in water but soluble in non-polar solvents. Natural waxes are produced by plants and animals, but waxes can also be derived from petroleum or synthesised from oils of plant or mineral origin. Wax materials suitable for use in the ski wax composition of the invention include synthetic waxes and natural wax products such as those produced by plants, insects and animals. Waxes that are known for use in conventional ski wax products are particularly suitable.

[0027] Waxes generally consist of long aliphatic alkyl chains, but may also contain aromatic compounds. Natural waxes may contain unsaturated bonds and include various functional groups such as fatty acids, primary and secondary alcohols, ketones, aldehydes and fatty acid esters. Waxes of animal origin typically consist of wax esters. Waxes of plants are mixtures of substituted long-chain aliphatic hydrocarbons containing alkanes, alkyl esters, fatty acids, primary and secondary alcohols, diols, ketones and aldehydes. Waxes suitable for use in the invention include petroleum derived waxes, synthetic waxes, plant and animal waxes and modified plant and animal waxes which have been subjected to chemical modifications to enhance their properties.

[0028] In one embodiment, the base material may comprise a petroleum-based wax such as a paraffin wax or microcrystalline wax. Paraffin waxes are mixtures of saturated n- and iso-alkanes, naphthenes, and alkyl- and naphthene-substituted aromatic compounds. The degree of branching of the alkanes influences the properties of the wax. Paraffin waxes are soft, candle-like waxes which typically contain hydrocarbon compounds having 25-30 carbon atoms. In contrast to paraffin wax which contains mainly unbranched alkanes, microcrystalline waxes contain a higher percentage of isoparaffinic (branched) hydrocarbons and naphthenic hydrocarbons. They are characterised by the fineness of their crystals in comparison to the large crystals of paraffin wax. Microcrystalline waxes generally consist of higher molecular weight saturated aliphatic hydrocarbons. They contain hydrocarbon compounds having 25-50 carbon atoms and have a higher coefficient of friction than paraffin wax.

[0029] In one embodiment, the base material may comprise a synthetic wax. Synthetic waxes are hydrocarbon waxes obtained by synthesis. These are more durable and more wear resistant than paraffin waxes. Synthetic waxes typically consist of branched hydrocarbons that may contain about 50-60 carbon atoms. Examples of synthetic waxes include polyethylene and polypropylene waxes. In one embodiment, the base material may comprise a plant-based wax. Plantbased waxes may be derived from the leaves or seeds of plants including, for example, the carnauba palm, the Candelilla shrub, sunflower seeds, soy, sugar cane bagasse, or they may be extracted from the bran oil of rice. In other embodiments, the base material may comprise a natural wax derived from an animal or produced by an insect, for example beeswax.

[0030] In one embodiment, the base material comprises a combination of different waxes. The relative proportions of different waxes can be varied to produce a wax composition with different properties for different snow and weather conditions. The selection of different waxes and their relative amounts is well within the knowledge and capability of those skilled in the art.

[0031] The ski wax composition may contain other non-wax components such as those present in modern ski waxes. Such components may include resins, rosins, natural rubber, synthetic rubbers (e.g. polyisobutylene), graphite, nanocarbon materials, surfactants (e.g. sodium dodecyl sulfate), organic solvents or mixtures of organic solvents, and any combination thereof. Resins, rosins, natural rubber or synthetic rubbers may improve properties of the ski wax composition such as fine-tuning of optimal snow temperature range, durability of the ski wax after application, provide grip on snow surfaces, or improve mechanical properties when the wax is spread on ski or ski skins and subsequently abraded against snow and ice. Graphite or nanocarbon materials may be added to enhance the performance of the wax by reducing the static build up in the wax. A surfactant will enhance the miscibility of the wax and other components of the composition. An organic solvent or mixture of such solvents will be employed when producing a liquid, paste or spray wax formulation in which the wax and other components of the composition must be dissolved or dispersed. Suitable surfactants, organic solvents and mixtures of organic solvents can readily be selected by those skilled in the art according to need.

[0032] The amount of any additional components may be varied depending on the type of wax or waxes that are present, the form of the wax composition, and the snow and weather conditions for which it is designed, for example whether the wax composition is an all temperature wax or cold temperature wax. Appropriate amounts of each additional component may readily be determined by those skilled in the art but will typically these may each be present in an amount in the range of from 1 to 40% by weight, preferably 5 to 20% by weight, e.g. about 10% by weight (based on the total weight of the ski wax composition).

[0033] In one embodiment, the ski wax may contain up to 30% by weight natural or synthetic rubbers, for example 10 to 30% by weight or 15 to 25% by weight natural or synthetic rubbers (based on the total weight of the ski wax composition).

[0034] Where any resin is present, this may be provided in an amount of up to 30% by weight, for example 10 to 30% by weight or 15 to 25% by weight (based on the total weight of the ski wax composition).

[0035] Where any rosin is present, this may be provided in an amount of up to 10% by weight, for example 1 to 10% by weight or 2 to 5% by weight (based on the total weight of the ski wax composition).

[0036] If present, any surfactant may be provided in an amount of up to 10% by weight, for example 1 to 10% by weight or 1 to 5% by weight (based on the total weight of the ski wax composition).

[0037] Any graphite or nanocarbon material may be present in an amount of up to 5% by weight, for example 1 to 5% by weight (based on the total weight of the ski wax composition).

[0038] The amount of the cholesterol, fatty acid or diglyceride lipid component present in the ski wax composition may be varied and will be dependent on factors such as the type of wax or waxes present in the base material, the nature of the lipid component(s), the form of the wax composition (i.e. whether it is a solid, a liquid, a paste, a powder or a spray), the snow and climatic conditions in which the ski wax composition will be used, etc. An appropriate amount of the lipid component may readily be determined by those skilled in the art taking account of such factors. In one embodiment, the lipid component may be present in an amount of up to 15% by weight (based on the total weight of the ski wax composition). In other embodiments, the lipid component may be present in an amount in the range from 1 to 15% by weight, from 2 to 10% by weight, or from 5 to 10% by weight (based on the total weight of the ski wax composition).

[0039] In one set of embodiments, the ski wax composition (“glide wax”) comprises a lipid component which is a cholesterol or a cholesterol derivative. The cholesterol or cholesterol derivative may be present in the composition as the only lipid component, or it may be used in combination with other lipid components, such as any of the other anti-icing lipid components as herein described. Cholesterol derivatives suitable for use in the invention include, but are not limited to, cholestanes, cholestenes and cholestadienes.

[0040] Cholesterol and cholesterol derivatives for use in the invention may be obtained from both animal and plant sources, for example from tripe, fish liver, or egg yolk. Commercial suppliers of cholesterol products include Avanti Polar Lipids, USA.

[0041] Non-limiting examples of cholesterol and cholesterol derivatives that may be used in the composition according to the invention are cholest-5-en-3p-ol, cholesta-4,6- dien-3p-ol, cholest-3,5-diene, and cholesta-3,5-dien-7-one. In one embodiment, the lipid component is cholest-5-en-3p-ol.

[0042] The amount of any cholesterol or cholesterol derivative which may be present will depend on whether it is the sole lipid component or whether other lipid components, such as those as herein described, may also be present. If it is the only lipid component present, it may be present in an amount of up to 15% by weight (based on the total weight of the ski wax composition). For example, the cholesterol or cholesterol derivative may be present in an amount in the range from 1 to 15% by weight, from 2 to 10% by weight, or from 5 to 10% by weight (based on the total weight of the ski wax composition). In cases where the cholesterol or cholesterol derivative is used in combination with other lipid components, such as any of the other anti-icing lipid components as herein described, it may be provided in a lower amount depending on the amount of the other lipid components that are present. For example, it may be present in an amount of from 0.5 to 5% by weight, or from 1 to 4% by weight, or from 2 to 3% by weight (based on the total weight of the ski wax composition). In another set of embodiments, the ski wax composition (“glide wax”) comprises a lipid component which is a fatty acid or a salt of a fatty acid. The fatty acid may be a naturally occurring fatty acid or it may be a synthetic analogue. Salts of fatty acids are well known in the art and widely available commercially and include, but are not limited to, the lithium, sodium and potassium salts.

[0043] The fatty acid or salt thereof may be present in the composition as the only lipid component, or it may be used in combination with other lipid components, such as any of the other anti-icing lipid components as herein described.

[0044] The amount of any fatty acid or salt thereof which may be present will depend on whether it is the sole lipid component or whether other lipid components, such as those as herein described, are also present. If it is the only lipid component which is present, it may be provided in an amount of up to 15% by weight (based on the total weight of the ski wax composition). For example, the fatty acid or salt thereof may be present in an amount in the range from 1 to 15% by weight, from 2 to 10% by weight, or from 5 to 10% by weight (based on the total weight of the ski wax composition). If the fatty acid or salt thereof is used in combination with other lipid components, such as any of the other anti-icing lipid components as herein described, it may be provided in a lower amount depending on the amount of the other lipid components that are present. For example, it may be present in an amount of from 0.5 to 5% by weight, or from 1 to 4% by weight, or from 2 to 3% by weight (based on the total weight of the ski wax composition).

[0045] In another set of embodiments, the ski wax composition (“glide wax”) comprises a diglyceride as the lipid component. Diglycerides (also known as “diacylglycerols”) are esters derived from glycerol and two fatty acids. The diglyceride may be a naturally occurring diglyceride or it may be a synthetic analogue. Diglycerides may be 1,2-diacylglycerols or 1,3-diacylglycerols. In one embodiment, the diglyceride for use in the invention is a 1,2-diacylglycerol.

[0046] In another embodiment, the diglyceride for use in the invention is a 1 ,3- diacylglycerol. For example, the 1,3-diacylglycerol may be glyceryl 1 ,3-dipalmitin (also known as glyceryl 1,3-dipalmitate, 1 ,3-dipalmitin or 1 ,3-dipalmitoylglycerol). The diglyceride may be present in the composition as the only lipid component, or it may be used in combination with other lipid components, such as any of the other anti-icing lipid components as herein described.

[0047] The amount of any diglyceride which may be present will depend on whether it is the sole lipid component or whether other lipid components, such as those as herein described, are also present. If it is the only lipid present, it may be present in an amount of up to 15% by weight (based on the total weight of the ski wax composition). For example, the diglyceride may be present in an amount in the range from 1 to 15% by weight, from 2 to 10% by weight, or from 5 to 10% by weight (based on the total weight of the ski wax composition). If the diglyceride is used in combination with other lipid components, such as any of the other anti-icing lipid components as herein described, it may be provided in a lower amount depending on the amount of the other lipid components that are present. For example, it may be present in an amount of from 0.5 to 5% by weight, or from 1 to 4% by weight, or from 2 to 3% by weight (based on the total weight of the ski wax composition).

[0048] As used herein, the term “fatty acid” refers to an un-branched or branched hydrocarbon chain having a carboxylic acid (-COOH) group at one end, conventionally denoted the a (alpha) end. The hydrocarbon chain may be saturated or (mono- or poly-) unsaturated. By convention, the numbering of the carbon atoms starts from the a-end such that the carbon atom of the carboxylic acid group is carbon atom number 1. The other end, which is usually a methyl (-CH3) group, is conventionally denoted co (omega) such that the terminal carbon atom is the co-carbon. Any double bonds present may be cis- or trans- in configuration. The nomenclature “co-x” is used to signify that a double bond is located on the xth carbon-carbon bond, counting from the terminal carbon (i.e. the co-carbon) towards the carbonyl carbon.

[0049] The hydrocarbon chain of any of the fatty acids herein described, either in the context of a free fatty acid or its salt, or a fatty acid moiety in a diglyceride, may be saturated or unsaturated, and it may be un-branched or branched. Fatty acids differ in their chain length and may be categorized as “short”, “medium”, “long”, or “very long” chain fatty acids. Those having a hydrocarbon chain of 5 or fewer carbons are referred to as “short-chain fatty acids”; those with a hydrocarbon chain of 6 to 12 carbon atoms are referred to as “medium-chain fatty acids”; those with a hydrocarbon chain of 13 to 21 carbons are referred to as “long-chain fatty acids”; and those with a hydrocarbon chain of 22 carbons or more are referred to as “very long-chain fatty acids”. Any of these fatty acids may be used in the invention. In one set of embodiments, the fatty acid may have a hydrocarbon chain of 12 to 34 carbon atoms, preferably 14 to 30 carbon atoms, more preferably 16 to 26 carbon atoms, e.g. 16 to 22 carbon atoms. Long-chain and very long-chain fatty acids are generally preferred for use in the invention.

[0050] Unsaturated fatty acids are those in which the carbon chain contains one or more carbon-carbon double bonds. The double bonds may be in the cis- or transconfiguration, or any combination thereof where more than one double bond is present. In naturally occurring fatty acids, the carbon-carbon double bonds adopt a cis-configuration, whereas trans-configurations are more common in processed fatty acids. Mono-unsaturated fatty acids contain one carbon-carbon double bond, whereas poly-unsaturated fatty acids contain more than one carbon-carbon double bond. Mono- and poly-unsaturated fatty acids and their salts are well known and available in the art and any of these may find use in the invention. Such fatty acids typically will contain 12 to 26 carbons, more typically 16 to 22 carbons, and may have a mono- or poly-unsaturated hydrocarbon chain. In one set of embodiments, the fatty acid may be a long-chain or very long-chain unsaturated fatty acid.

[0051] In one embodiment, the free fatty acid or salt thereof for use in the invention is an unsaturated fatty acid or salt of an unsaturated fatty acid. The unsaturated fatty acid may be branched or un-branched, but preferably it will be un-branched. It may contain from 12 to 34 carbon atoms, preferably 14 to 30 carbon atoms, more preferably 16 to 26 carbon atoms, e.g. 18 to 22 carbon atoms. For example, the unsaturated fatty acid may be an omega-6 fatty acid or salt thereof, such as arachidonic acid or a salt thereof.

[0052] In one embodiment, the free fatty acid or salt thereof for use in the invention is a saturated fatty acid which contains no carbon-carbon double bonds, or a salt of a saturated fatty acid. The saturated fatty acid may be branched or un-branched, but preferably will be branched. In one embodiment, the saturated fatty acid may contain from 12 to 34 carbon atoms, preferably from 14 to 30 carbon atoms, more preferably from 16 to 26 carbon atoms, for example from 20 to 22 carbon atoms. The saturated fatty acids are preferably branched, for example they may be isobranched or anteiso-branched. Iso-branched fatty acids have the branch point on the penultimate carbon (w-1, second carbon from the terminal end), while anteiso- branched fatty acids have the branch point on the ante-penultimate carbon atom (co-2, third carbon from the terminal end). Saturated fatty acids which comprise a carbon chain having one or more methyl branches, for example one methyl branch, are particularly preferred. In one set of embodiments, the carbon chain of the saturated fatty acid may include one methyl branch in the anteiso position.

[0053] Saturated free fatty acids or salts thereof having longer hydrocarbon chains are generally preferred for use in the invention. Preferably, the saturated fatty acid will thus be either a long-chain or very long-chain fatty acid or salt thereof. More preferably, the saturated fatty acid may be a long-chain or very long-chain fatty acid or salt thereof which is iso-branched or anteiso-branched, for example methyl isobranched or methyl anteiso-branched.

[0054] Examples of saturated free fatty acids for use in the invention include eicosanoic acid (also known as arachic acid, arachidic acid, or icosanoic acid) having 20 carbon atoms and no double bonds, and docosanoic acid (also known as behenic acid) having 22 carbon atoms and no double bonds. Optionally, these saturated fatty acids may be modified to include one or more methyl branches, for example a methyl branch in the iso- or anteiso-position. Salts of eicosanoic acid, docosanoic acid or any such modified eicosanoic or docosanoic acid may also be used in the invention.

[0055] Non-limiting examples of saturated anteiso fatty acids that may be used in the invention include 18-methyleicosanoic acid (18-MEA) and 20-methyldocosanoic acid (20-MDA).

[0056] Any of the free fatty acids or their salts for use in the invention may be naturally occurring or they may be synthetically produced. Sources of primarily saturated fatty acids include natural oils, such as coconut oil and palm oil, as well as industrially hydrogenated oils. Sources of fatty acids with higher degrees of unsaturation include oils obtained from olives, canola seeds, flaxseed, and peanuts, as well as fish livers and marine microorganisms. Oils from other plants, algae, or microorganism sources can also be used. Commercial providers of fatty acids that may be used in the invention include Emami Agrotech Limited, Gulab Oil and Foods Pvt. Ltd., Mahesh Edible Oil Industries, and Marico Limited.

[0057] The fatty acid components of the diglyceride for use in the invention may be the same or different and may include any of the fatty acids herein described.

[0058] In one embodiment, the fatty acids of the diglyceride may be of different chain lengths. The fatty acid chains present in the diglyceride may contain from 12 to 34 carbon atoms, preferably 14 to 30 carbon atoms, more preferably 16 to 26 carbon atoms, e.g. 16 to 22 carbon atoms. The fatty acid chains may be saturated or unsaturated and may be un-branched or branched. In one set of embodiments, the fatty acids of the diglyceride may be selected from long-chain and very long-chain fatty acids.

[0059] The fatty acid chains of the diglyceride may be saturated or unsaturated, but preferably they will be unsaturated, i.e. in which the hydrocarbon chain contains one or more carbon-carbon double bonds.

[0060] In one embodiment, the fatty acid chains of the diglyceride are mono- or polyunsaturated. In one embodiment, the fatty acid chains are mono-unsaturated. In another embodiment, the fatty acid chains are poly-unsaturated. For example, the fatty acid chains of the diglyceride may contain up to 4 carbon-carbon double bonds, for example two, three or four carbon-carbon double bonds. The precise position of the double bonds in the fatty acid chains may vary, but in one set of embodiments the fatty acid is an co-3 fatty acid, i.e. the final double bond is found in the o-3 position.

[0061] In one embodiment, the fatty acid chains of the diglyceride may be the same or different and may each comprise 14, 16 or 18 carbon atoms and up to 4 carboncarbon double bonds, for example two, three or four carbon-carbon double bonds. In one embodiment, the fatty acid chains of the diglyceride, which may be the same or different, are selected from 14:4 (which denotes a hydrocarbon chain having 14 carbon atoms and four carbon-carbon double bonds) and 16:4 (a hydrocarbon chain having 16 carbon atoms and four carbon-carbon double bonds). In one embodiment, the fatty acids, which may be the same or different, are 14:4 or 16:4 in which the final carbon-carbon double-bond occurs in the co-3 position.

[0062] In one embodiment, the fatty acid chains of the diglyceride, which may be the same or different, are selected from 16:0 (a hydrocarbon chain having 16 carbon atoms and no carbon-carbon double bonds) and 18:1 (a hydrocarbon chain having 18 carbon atoms and one carbon-carbon double bond). In one embodiment, the carbon-carbon double bond in the 18:1 fatty acid chain occurs in the co-3 position.

[0063] In one embodiment, the fatty acid chains of the diglyceride, which may be the same or different, are saturated. For example, the saturated fatty acid chains may contain from 12 to 26 carbon atoms, preferably from 12 to 20 carbon atoms. In one embodiment, one or more of the fatty acid chains of the diglyceride may be derived from palmitic acid.

[0064] Diglycerides for use in the invention may be naturally occurring or they may be synthetically produced using methods well known in the art. Commercial suppliers of diglycerides include Emami Agrotech Limited, Gulab Oil and Foods Pvt. Ltd., Mahesh Edible Oil Industries, and Marico Limited.

[0065] Any of the above-mentioned lipid components (i.e. cholesterol or a cholesterol derivative, a fatty acid or salt of a fatty acid, or a diglyceride) may be used individually or in combination as the anti-icing additive in the ski wax composition according to the invention.

[0066] In one set of embodiments, any of the above-mentioned lipid components may be used alone, i.e. as the sole lipid component. In another set of embodiments, two, three or more of the above-mentioned lipid components may be used in combination. Where combinations of lipid components are used, their weight ratio may be varied and suitable ratios may readily be selected by those skilled in the art. In any mixture of lipid components, the weight ratios of any two lipid components may be in the range from 0.1 to 10, for example. In one embodiment, the different lipid components may be used in roughly equivalent amounts by weight, i.e. in a 1 :1 weight ratio. For example, where two lipid components are used, these may be employed in a weight ratio of about 1:1. Where three lipid components are used, these may be employed in a weight ratio of about 1 :1 :1. However, other weight ratios may be selected other than equivalent weight ratios. For example, the weight ratio of any two of the lipid components, either in a two-component or three- component combination of lipids, may vary from 1:10 to 10:1 , for example 1 :5 to 5:1, 1 :4 to 4:1 , 1 :3 to 3:1 or 1:2 to 2:1.

[0067] In one embodiment, two different anti-icing lipid components as herein described may be provided in the ski wax composition according to the invention. For example, the lipid component may comprise a combination of a fatty acid or salt of a fatty acid and a diglyceride. Examples of such lipid combinations include, but are not limited to, eicosanoic acid with methyl branching at the anteiso position and 1- palmitoyl-2-oleoyl-sn-glycerol (a diacylglycerol with 16:0 and 18:1 fatty acid moieties). For example, the lipid component may comprise 4% by weight eicosanoic acid with methyl branching at the anteiso position and 4% by weight 1- palmitoyl-2-oleoyl-sn-glycerol (based on the total weight of the ski wax composition). Preferably, the lipid component may comprise 2% by weight eicosanoic acid with methyl branching at the anteiso position and 4% by weight 1- palmitoyl-2-oleoyl-sn-glycerol (based on the total weight of the ski wax composition).

[0068] Alternatively, the lipid component may comprise a combination of a fatty acid or a salt of a fatty acid and a cholesterol or a cholesterol derivative. Examples of such lipid combinations include, but are not limited to, eicosanoic acid with methyl branching at the anteiso position and a cholesterol or cholesterol derivative which is cholest-5-en-3p-ol, cholesta-4,6-dien-3p-ol, cholest-3,5-diene, or cholesta-3,5-dien- 7-one, preferably cholest-5-en-3p-ol. For example, the lipid component may comprise 4% by weight eicosanoic acid with methyl branching at the anteiso position and 4% by weight cholest-5-en-3p-ol, cholesta-4,6-dien-3p-ol, cholest-3,5- diene or cholesta-3,5-dien-7-one, preferably 4% by weight cholest-5-en-3p-ol (based on the total weight of the ski wax composition). Preferably, the lipid component may comprise 2% by weight eicosanoic acid with methyl branching at the anteiso position and 4% by weight cholest-5-en-3p-ol, cholesta-4,6-dien-3p-ol, cholest-3,5-diene or cholesta-3,5-dien-7-one, preferably 4% by weight cholest-5-en- 3p-ol (based on the total weight of the ski wax composition).

[0069] Alternatively, the lipid component may comprise a combination of a cholesterol or a cholesterol derivative and a diglyceride. Examples of such lipid combinations include, but are not limited to a cholesterol or cholesterol derivative which is cholest-5-en-3p-ol, cholesta-4,6-dien-3p-ol, cholest-3,5-diene, or cholesta-3,5-dien- 7-one, and 1-palmitoyl-2-oleoyl-sn-glycerol (a diacylglycerol with 16:0 and 18:1 fatty acid moieties). For example, the lipid component may comprise 4% by weight cholest-5-en-3p-ol, cholesta-4,6-dien-3p-ol, cholest-3,5-diene, or cholesta-3,5-dien- 7-one, preferably 4% by weight cholest-5-en-3p-ol, and 4% by weight 1-palmitoyl-2- oleoyl-sn-glycerol (based on the total weight of the ski wax composition).

[0070] In one embodiment, three anti-icing lipid components as herein described may be provided in the ski wax composition according to the invention. For example, the lipid component may comprise a cholesterol or cholesterol derivative, a fatty acid or salt of a fatty acid, and a diglyceride. Examples of such lipid combinations include, but are not limited to, cholest-5-en-3p-ol, eicosanoic acid with methyl branching at the anteiso position, and 1-palmitoyl-2-oleoyl-sn-glycerol (a diacylglycerol with 16:0 and 18:1 fatty acid moieties). For example, the lipid combination may comprise 4% by weight cholest-5-en-3p-ol, 4% by weight eicosanoic acid with methyl branching at the anteiso position, and 4% by weight 1-palmitoyl-2-oleoyl-sn-glycerol (based on the total weight of the ski wax composition). Preferably, the lipid combination may comprise 4% by weight cholest-5-en-3p-ol, 2% by weight eicosanoic acid with methyl branching at the anteiso position, and 4% by weight 1-palmitoyl-2-oleoyl-sn- glycerol (based on the total weight of the ski wax composition).

[0071] It is intended that the lipid components herein described will effectively replace PFAS which are conventionally added to ski wax formulations to enhance performance. In one set of embodiments, the composition herein described is thus substantially free from any PFAS. By “substantially free” it is intended that the composition should include less than 0.01 wt.% PFAS. For example, it may be entirely free from PFAS. The ski wax compositions according to the invention may be prepared using methods analogous to those used in the art in the production of ski waxes. The method of preparation will be dependent on the type of ski wax, for example whether it is a solid, liquid, paste or powder wax. Such methods are well known to those skilled in the art.

[0072] For the production of a solid ski wax, for example, the various components may be separately heated to a temperature above their melting points to produce liquids that are subsequently mixed with rapid stirring to produce a substantially homogenous mixture. This mixture is then poured into a mold and cooled rapidly to form a solid bar (a “block wax”). To produce any liquid wax formulation, the wax, the lipid, and other components as herein described may be dissolved in an organic solvent, or solvent mixture. This solvent mixture must be capable of dissolving the components at relatively high (e.g. 10% by weight) concentrations, satisfy HSE requirements for ski preparation products, and be relatively volatile so that the liquid components evaporate after the composition has been applied to the ski base or ski skin. Citric oils, terpenes, and short chain alcohols, such as methanol, are examples of solvents which may satisfy these criteria and which are thus suitable for use in the production of any liquid ski wax composition.

[0073] Any of the methods herein described for preparation of the ski wax compositions form a further aspect of the invention.

[0074] The ski wax compositions herein described (“glide wax”) may be applied to any snow runner to adjust their coefficient of friction performance on snow and ice, or to prevent ice-accumulation and ice-adhesion. The compositions are not limited to use on skis, but also find use on other snow runners such as snowboards, toboggans, etc., or any other sports or recreational equipment that is used on snow or ice.

[0075] The wax compositions may be applied to the base of a ski using any method conventionally known for use in the application of a ski wax. The precise method will depend on the form of the wax, for example whether it is a solid wax, liquid wax, paste wax, powder wax or spray wax. A solid wax (or “block wax”) may be applied using traditional methods such as “hot-waxing”. In such methods, a solid bar of the wax composition is melted against a ski-iron and the liquid wax is dripped over the ski base. The wax is then smoothed out over the base using the iron and may be arranged over the entire area of the base of the ski or over a predetermined zone, left to dry and solidify. Once hardened, excess wax is removed by brushing and / or scrapping, and the remaining thin layer of wax is buffed.

[0076] For application to ski skins, the ski skins will typically be pre-warmed using a ski iron set to about 110°C. The wax is then rubbed into the hairs of the skins at least twice, once with the direction of the hairs, and once against the direction of the hairs. If necessary, a solid wax can be gently pre-heated as well, to allow for more easy distribution on the hairs. Liquid wax formulations can be directly applied to ski skins without pre-heating, massaged into the hairs, and then left to dry.

[0077] In a further aspect the invention provides the use of a ski wax composition as herein described as a ski wax coating or as a ski skin coating. Due to the anti-icing properties of the above-mentioned lipid components, it is proposed that the ski wax composition is applied to the base of skis or to a ski skin to improve glide performance, i.e. the ski wax composition is primarily intended for use as a glide wax.

[0078] As evidenced herein, it has also been found that squalene has high ice adhesion strength. This leads to the proposal to use squalene and derivatives thereof as an additive to a ski wax composition to improve grip performance on snow and ice. In a further aspect, the invention thus provides a ski wax composition comprising squalene or a squalene derivative. This composition finds use as a grip wax and is also referred to herein as a “grip wax”.

[0079] Any disclosure herein relating to the form and base materials of the glide wax formulations are equally applicable to this other aspect of the invention in which the ski wax composition comprises squalene or a squalene derivative.

[0080] For example, the ski wax composition comprising squalene or a squalene derivative may be provided in any conventional form, for example as a solid bar (“block wax”), liquid wax, paste wax, powder wax or spray wax. The ski wax composition comprising squalene or a squalene derivative additionally comprises a base material, which contains a wax or combination of waxes, but which may also contain other components such as those herein described and which are used in conventional hydrocarbon-based ski waxes either to provide the wax in the desired form (i.e. solid, liquid, paste, powder or spray) or to improve the properties of the composition in accordance with conventional practice in the art. The base material incorporates squalene or a squalene derivative as herein described as an additive which enhances the performance of the ski wax composition as a grip wax and thus improves grip on snow and ice. The wax component may be present in an amount as herein described in respect of the glide wax and may be selected from any of the waxes herein described.

[0081] The ski wax composition (“grip wax”) may contain other non-wax components such as those present in modern ski waxes. Such components include any of those described herein in respect of the glide wax. The amount of any additional components may be varied according to need and as described herein in respect of the glide wax.

[0082] Squalene derivatives suitable for use in the invention include, but are not limited to, squalane, malabaricane, oleanane and lanostane.

[0083] Squalene and squalene derivatives may be obtained from both animal, plant and fungi sources. Commercial suppliers of such products include Avanti Polar Lipids, USA.

[0084] The amount of squalene or squalene derivative which may be present in the grip wax composition will depend on whether it is the sole grip component or whether other grip components may also be present. If it is the only grip component present, it may be present in an amount of up to 15% by weight (based on the total weight of the ski wax composition). For example, the squalene or squalene derivative may be present in an amount in the range from 1 to 15% by weight, from 2 to 10% by weight, or from 5 to 10% by weight (based on the total weight of the ski wax composition). In cases where the squalene or squalene derivative is used in combination with other known grip components, it may be provided in a lower amount depending on the amount of the other grip components that are present. For example, it may be present in an amount of from 0.5 to 5% by weight, or from 1 to 4% by weight, or from 2 to 3% by weight (based on the total weight of the ski wax composition).

[0085] The ski wax compositions herein described (“grip wax”) may be applied to the base of skis of ski skins to adjust their coefficient of friction performance on snow and ice, in particular to enhance grip when the full weight of the skier is on the middle of the ski. The ski wax composition may be applied using methods analogous to those herein described in respect of the glide waxes.

[0086] In a further aspect the invention provides the use of a ski wax composition comprising squalene or a squalene derivative as a ski wax coating or as a ski skin coating. Due to the high ice adhesion strength of the squalene or squalene derivative, it is proposed that this ski wax composition is applied to the base of a ski or to a ski skin to improve grip performance, i.e. the ski wax composition is primarily intended for use as a grip wax.

[0087] The invention is illustrated further by way of the following non-limiting Examples and the accompanying figures, in which:

[0088] Figure 1 : Ice adhesion measurements of unwashed (PB) and washed (WPB) polar bear fur compared with unwashed (HH) and washed human hair (WHH) and racing (RSS) and non-racing (NRSS) ski skins. Both racing and non-racing ski skin hairs are fluorocarbon treated. Error bars represent the standard deviation of measurements for each sample type. Raw measurements are shown as grey diamonds on the plots.

[0089] Figure 2: Box plots of lipid quantification of sebum by (a) GC-MS in pgram of fatty acids (FA) per gram of hair and (b) NMR in pmol per gram of hair. Acylglycerols represent the sum of mono-, di-, and tri- acylglycerols, whereby 1,2-diacylglycerols are the dominant class. The central line indicates the median, and the whiskers extend to the most extreme data points that are not considered outliers. Outliers are plotted individually.

[0090] Figure 3: Schematic of the fully-saturated structures of (a) triglyceride (TG), (b) diglyceride (DG), (c) cholest-5-en-3p-ol, (d) wax, (e) PFAS, (f) eicosanoic acid and (g) squalene adsorbed on ice. These are among the most relevant molecular species in sebum analysis and their adsorption energy is plotted in

[0091] (h). The star index ”*” denotes the presence of a methyl group in the anteiso position of the respective carbon chain.

[0092] Figure 4: (a) Variation of energy as a function of the distance between triglyceride (TG) and the ice surface, (b) Adsorption energy values of the triglyceride (TG) and diglyceride (DG) as a function of the number of unsaturations in the structure, (c) Adsorption energy values for the non-branched and branched saturated TG and eicosanoic acid. The star index ”*” indicates the presence of a methyl group in the anteiso position of the respective carbon chain.

[0093] Examples

[0094] Example 1 - Anti-icing properties of polar bear fur

[0095] Methods:

[0096] Polar bear fur was tested for its ice adhesion properties. For reference, experiments were also carried out on two types of fluorocarbon-treated ski skins sourced from Colltex AG. Ski skins are hairy fabrics, in this case mohair, attached to a substrate that is stuck onto the ski using an adhesive. The hairs are oriented so as to allow the skis to easily slide forward on snow, but provide increased friction in the opposite direction. Although no longer commercially available, fluorocarbon- treated ski skins were chosen as a comparison due to their known very low ice adhesion properties. Measurements of ice adhesion on human hairs were also conducted as human hair sebum is rich in squalene, similar to many mammals that are native to damp or aquatic environments such as the sea otter, beaver and sea lion. Given the similar aquatic lifestyle of the polar bear, squalene might be expected to be present in polar bear sebum. Human hair also has structural similarities to polar bear hair, making it a good candidate for comparison. The effect of polar bear hair grease (sebum) was also investigated. Ice adhesion experiments were repeated using polar bear fur that had been washed with sodium dodecyl sulphate (SDS) to remove all hair grease. Sodium dodecyl sulfate (20% SDS solution) was chosen as it is very effective at dissolving lipid membranes. Ice-adhesion measurements were performed using a purpose-built instrument. This apparatus consisted of a liquid cooled cold plate capable of reaching -40°C inside an insulated perspex box and a force gauge on a track used to apply force for ice adhesion strength measurement. Ice adhesion measurements were performed by placing a mold used to form an ice block to a desired size and area on a cooled substrate and measuring the force required to move it across the surface. For polar bear fur, the challenge is that that the fur is so well insulated that it cannot be cooled from the back (skin side). Therefore, the whole setup had to be placed in a climate chamber, which was then cooled. Furthermore, given that the fur is an uneven surface, fur samples were placed on top of the mold once it was filled with water, rather than the mold being placed on top of the samples. This prevented water from seeping out of the mold onto the sample.

[0097] Results:

[0098] Ice adhesion results are presented in Figure 1. Ice adhesion strength was measured using the maximum shear force required to remove the block of ice of known contact area from the surface and this force was then divided by the contact area to obtain an ice adhesion strength. The ice adhesion of unwashed polar bear fur was found to be similar to the racing ski skin and around 40 kPa lower than standard ski skin on average. At 50 kPa, it falls well below the typically accepted threshold of icephobicity of 100 kPa. Washed (sebum-free) fur was observed to have significantly higher ice adhesion than unwashed fur, with the ice adhesion strength of washed fur at least 100kPa greater than unwashed fur. Furthermore, in all tests it was impossible to remove the washed hair from the ice once it had stuck. The maximum force applied was used to make a conservative estimate of the ice adhesion pressure, which is shown in Figure 1 , but the actual ice adhesion force likely exceeds this value. The adhesive strength of the ice on unwashed polar bear fur was generally greater than either the shear strength of the ice or the adhesive strength of the clamp used to hold down the fur. Similarly, the human hair containing squalene displayed a strong adhesion to ice, comparable to that of the washed polar bear fur. Both the unwashed and washed human hair displayed a high ice adhesion of over 150 kPa on average. The results suggest that certain lipid components of polar bear sebum ascribe an anti-icing advantage over human sebum, whereas squalene has a strong adhesion to ice. The measurements of anti-icing properties of polar bear fur evidence the crucial role of the sebum. In the presence of sebum, the ice adhesion is comparable to fluorinated ski skins, but after the sebum is removed the ice adhesion strength increases almost four-fold.

[0099] Example 2 - Sebum analysis

[0100] Method:

[0101] In order to determine the molecular composition of polar bear sebum, fur samples from six polar bears were obtained and adapted a two-phase extraction protocol to collect lipids and other hydrophobic molecules coating the hairs of the samples. Three different methods were used to analyse the lipid isolates: gas chromatography-mass spectrometry (GC-MS), liquid chromatography-mass spectrometry (LC-MS / MS) and nuclear magnetic resonance (NMR). GC-MS involves separating unesterified core fatty acyls (for example, fatty acids, fatty alcohols and hydrocarbons), sterols and prenols by gas chromatography and detection by mass spectrometry. GC-MS provides molecular details on branching and unsaturation positions on fatty acids and when combined with fractionation of total extracts (for example, by solid phase extraction), GC-MS can provide information on the fatty acid composition of lipid classes. LC-MS / MS involves separating molecular species by liquid chromatography prior to detection by mass spectrometry. This approach can analyse complex intact lipids. Our LC-MS / MS setup matches exact molecular masses to a lipid species database and reconstructs each fraction’s molecular nature in a manner consistent with the detected signals. The advantage of this is that, for each major group of glycerolipids, waxes and other lipid species, a semi-quantitative profile of each compound’s fatty acid moieties is provided. In support of both techniques, NMR provides an at-a-glance overview of the mixture of molecules present in the samples and can also provide quantitative information.

[0102] Preparation of samples for lipid analyses:

[0103] Polar bear hair samples from six polar bears were collected from the Svalbard polar bear population by personnel from the Norwegian Polar Institute. Solvent and chemicals for lipid extraction were acquired from Millipore Sigma (St Louis, MO, USA). Dichloromethane was purchased from Thermo Fischer Scientific (Massachusetts, USA). 50 mL tubes were opened, and the hair was weighed prior to solvent extraction of lipids. The sampled hair was washed two times with 10 mL of organic extraction mixture (dichloromethane / methanol 3:1 v / v). The extraction mixture was collected and water was added to a 2:1 (organic:water) ratio. Next, isopropanol was added until the mixture was uniphasic and transferred to a separation funnel. To this, dichloromethane was added until two phases appeared. After time for equilibration, the denser organic phase containing the lipid solutes was collected. The collected solvent was removed by rotary evaporator and freeze- dried, leaving films of lipid material on the glassware.

[0104] GC-MS:

[0105] Total lipid extracts were spiked with 10 pg of both 5alpha-cholestane (Thermo Scientific Acros) and nonadecanoic acid (Merck Supelco). A 20% aliquot of lipid extracts was directly transesterified using 0.5 M methanolic HCI (Thermo Scientific Acros, reacted at 70°C for 45 min) and analysed by GC-MS. Separately, a second aliquot representing 60% of the total lipid extract was fractionated by solid phase extraction according to established protocols (Pinkart et al., J. Microbial. Methods 34(1), 9-15, 1998). Briefly, aliquots of total extracts were loaded onto a 500 mg aminopropyl SPE cartridge (Waters, USA). Neutral lipids were eluted with 5 mL chloroform and two separate more polar lipid fractions were eluted with acetone and 6:1 (v / v) methanokchloroform, respectively. Neutral lipids were further fractionated using a second 500 mg aminopropyl SPE cartridge by elution with 5 mL each of the following solvents: F1 with n-hexane, F2 with 88:10:2 (v / v) n- hexane:dichloromethane:chloroform, F3 with 5:95 (v / v) hexane:ethyl acetate, F4 with 15:85 (v / v) hexane:ethyl acetate and F5 with 2:1 (v / v) chloroform:methanol. Using this approach, hydrocarbons, wax esters and steryl esters elute in F1, triacylglycerols elute in F2 and diacylglycerols and free sterols elute in F3.

[0106] GC-MS analysis was performed using a 30 m polyethylene glycol stationary phase capillary column (DB-WAX, 30 m x 250 urn inner diameter x 0.25 urn film thickness; Agilent J&W, USA) installed in an Agilent 7890A gas chromatograph hyphenated to an Agilent 5975 mass spectrometer. GC conditions were as follows: 50°C for 1 min, 5°C min-1to 200°C, 3°C min-1to 230°C and finally hold for 25 min. MS scan ranges were 50 to 600 Da. Data analysis was performed using Chemstation (Version E02.01). Quantification of lipid classes was performed by reference to the internal standards. A 37 component FAME reference standard (Supelco CRM47885, Merck Sigma, USA) was run with each sequence to assist in identifying the position of double bonds in monounsaturated fatty acids and to monitor instrument performance.

[0107] LC-MS / MS:

[0108] LC-MS / MS was run according to previously published protocols (Jakubec et al., ACS Omega 4(25), 21596-21603, 2019). Briefly, samples for LC-MS / MS were prepared by reconstituting freeze-dried lipid material from the extraction step described above into a mixture of methanokethanol (50:50, v / v). The analytes were separated on a UPLC HSS C18 column (1.8 pm particle size, Waters, USA) at a rate of 0.4 mL / min; an injection volume of 5 pL was used. Mobile phase A consisted of 40% acetonitrile and 60% water, mobile phase B consisted of 10% acetonitrile and 90% isopropanol, and both phases were supplemented with 10 mM ammonium acetate. Data processing was done by using previously in lab writing script in Matlab 2020b with updated libraries available at Github. Targeted searches were done for TAG, DAG, free fatty acids, squalene, wax esters, cholesterol and cholesterol esters using predictive fragmentation collected from literature (Jakubec et al., ACS Omega 4(25), 21596-21603, 2019; Fitzgerald et al, J. Lipid Res. 48(5), 1231-1246, 2007; and Camera et al., J. Lipid Res. 51(11, 3377- 3388, 2010).

[0109] NMR:

[0110] Samples for NMR were prepared by reconstituting freeze-dried lipid material from the final steps in the lipid extraction process described above. These films were suspended in deuterated chloroform, with 0.03% tetramethylsilane serving as a chemical shift reference and internal standard for protons. All NMR experiments were acquired at 300K on a 600 MHz Avance NEO 600 Spectrometer fitted with a1H / 13C / 15N / 31P QCI cryogenic probe. The NMR instrument was equipped with a temperature controlled SampleJet which ensured that samples were stored at 4°C prior to and between use. The following experiments were accumulated:31P NMR experiments were acquired as described earlier (Jakubec et al., ACS Omega 4(25), 21596-21603, 2019; and Furse et al., Sci. Rep. 7(1), 8012, 2017). Briefly, protons were decoupled using inverse gating, and 2560 transients were acquired with a recycling delay of 8 seconds, and a p1 pulse duration of 40 ps. No phospholipids were detected in this manner. For proton and13C spectra 64 and 1024 scans were summed, respectively. The spectra were processed in Topspin 4.0.6 (Bruker, Berlin, Germany), using line broadening and baseline correction, and peaks were deconvoluted and peak areas assigned to glycerols, waxes and sterols used to determine amounts of these lipids in a manner analogous to the approach of Jakubec at al. (ACS Omega 4(25), 21596-21603, 2019). Peaks were assigned using literature values (Khandelwal et al., J. Lipid Res. 55(7), 1366-1374, 2014; Nieva-Echevarria et al., Food Chem. 179, 182-190, 2015; and Robosky et al., J. Lipid Res. 49(3), 686-692, 2008).

[0111] Lipid Analysis:

[0112] 1H,13C, and31P NMR spectra were acquired for all samples to provide an overview of lipid content, detect squalene, and phospholipids, respectively. The1H spectra were deconvoluted, and signals corresponding to the broad lipid groups of cholesterol, wax and acylglycerols (all acylglycerols, and diacylglycerols), were isolated by deconvolution and used to provide the quantitative data presented in Fig. 2b. The13C spectra indicated that there was no detectable squalene present, as there would be signals present in the 120-140 ppm region characteristic of squalene.

[0113] Fatty Acid Methyl Ester Analysis:

[0114] Lipids were subject to the separation and digestion scheme detailed above. The relative abundances from the fatty acid methyl ester analysis are box plots in Fig. 2a.

[0115] Results:

[0116] GC-MS, LC-MS and NMR data were in broad agreement with respect to the relative abundance of lipid classes: primarily steryl esters, wax esters, free sterols, triacylglycerols and diacylglycerols, with the data suggesting that the waxes and glycerol species constitute the bulk of the lipids. GC-MS also suggested the presence of wax diesters, given the occurrence of hexadecan-1 ,2-diol. GC-MS and LC-MS / MS provided somewhat different fatty acid lengths; for GC-MS results, they range from 9 carbons to 26, with 16:0, 18:0, 18:1(9Z) being most abundant. For LC-MS / MS, fatty acid lengths are notably detected from 10 carbons and up to 30 carbon atoms, with up to 5 sites of unsaturation. NMR estimates the total sterol molar content to be 0.3 - 1.5 pmol per gram of hair. As determined by GC-MS, cholest-5-en-3p-ol represented more than 90% of sterols detected, but cholesta- 4,6-dien-3p-ol, cholest-3,5-diene and cholesta-3,5-dien-7-one were also detected. Hydrocarbons, including squalene, were not detected by GC-MS. The absence of squalene and phospholipids was also confirmed by13C and31P NMR, respectively. The absence of squalene is surprising given the polar bear’s aquatic lifestyle. GC- MS analysis revealed the occurrence of a series of methyl-branched saturated fatty acids, with the methyl-branching occurring in the ‘anteiso’ position (co-2, third carbon from the terminal end). Anteiso fatty acids were detected as prominent fatty acids in all samples and fractions analysed, but were most abundant as triacylglycerol fatty acids (up to 53% of TAG FAME). 18-methyleicosanoic acid (18- MEA) and 20-methyldocosanoic acid (20-MDA) were the most abundant anteiso fatty acids detected.

[0117] Example 3 - Density Functional Theory Calculations

[0118] The sebum analysis revealed a very large number of lipid molecules divided among the broad classes shown in Figure 2. To gain insight into how the composition of the polar bear sebum affects ice adhesion of the fur, first-principles density functional theory (DFT) calculations were performed to evaluate the adsorption energy, Eads, with ice for the most prominent components in the polar bear sebum: triglycerides (TG), diglycerides (DG) and cholesterol as well as, for comparison, polyfluoroalkyl (PFAS) previously used extensively to increase the anti-icing performance of ski wax, and squalene, a prominent compound in human sebum. The calculated Eads are useful and well-known proxies for predicting macroscopic characteristics of materials such as friction coefficients and anti-icing qualities.

[0119] Representation of the saturated adsorbed structures is shown in Fig. 3a-g, respectively. The TG, DG, wax, ski wax and cholesterol molecules are amphipathic and their assembly on the ice surface is expected to occur with the hydrophobic part (alkyl-chain) pointing towards the surface and the hydrophilic head (polar domain) pointing away from it, forming aggregates similar to bilayers. This adsorption behaviour was prioritised in the calculations (Fig. 3a-f) except for squalene, which only contains carbon and hydrogen atoms in its structure. The molecular model of TG was constructed based on the experimental results obtained in this work in which the three ester groups are connecting 14, 16 and 18 carbon atoms chains. According to the analysis reported in previous sections, the DG have much longer carbon chains of 24 and 27 atoms. In order to allow a more direct comparison of the adsorption energy values, the DG, wax and PFAS models were assumed to have the same carbon atom length as the TG model (14 and 16). The sebum analysis evidenced the presence of the sterol variant cholest-5-en-3p-ol and this form was adopted in the calculations. For the representation of the PFAS, the hydrogen atoms were substituted for fluorine atoms in the wax structure.

[0120] The influence of the number of unsaturations present in the TG and DG structures on adsorption energy at an ice surface was analysed as shown in Fig. 4b. The sebum analysis shows that the structures of the TG and DG in the polar bear fur contain 1 and 4 double bonds, respectively and the calculated adsorption energies for the DG (14:4 / 16:4) and TG (14:1 / 16:1 / 18:1) are -28.94 kJ mol’1and -57.89 kJ mol’1, respectively. The lipid analyses also showed an abundance of fully-saturated branched structures, in which a methyl group is present in the anteiso position and hereafter is denoted as a star index ”*” in the respective carbon chain. The effect of the presence of methyl groups and the ice adhesion for the TG and eicosanoic acid was analysed and the results are shown in Fig. 4c. For the TG, the presence of a methyl group in the anteiso position of the carbon chains, TG (14:0* / 16:0* / 18:0*), slightly decreased the ice adhesion by 11% (adsorption energy became less negative) in comparison with the non-branched TG (14:0 / 16:0 / 18:0). The same was observed for eicosanoic acid, in which the presence of the methyl group in the anteiso position marginally attenuated (10%) the ice adhesion, with the Eads values for eicosanoic acid (20:0) and (20:0*) being -22.19 kJ mol’1and -20.26 kJ mol’1, respectively.

[0121] In Fig. 3h, the values of adsorption energy for the molecules present in the sebum analysis are compared. The adsorption energy of PFAS is included for comparison and also the values for the branched and non-branched variants of the fully saturated eicosanoic acid (20:0* and 20:0, respectively) and TG (14:0* / 16:0* / 18:0* and 14:1 / 16:1 / 18:1 , respectively). It is noteworthy that the branched TG considered is fully saturated, correlating with the sebum analysis. It can be observed that the PFAS and eicosanoic acid (20:0*) have the lowest ice adhesion with the latter being less attracted to the surface, with its adsorption energy being 1.92 kJ mol-1higher than PFAS. The cholest- 5-en-3p-ol, DG (14:4 / 16:4) and wax (14:0 / 16:0) have low adhesion with the ice surface, being comparable with PFAS and eicosanoic acid, evidenced by adsorption energy values of -24.12 kJ mol’1, -28.94 kJ mol’1and - 31.84 kJ mol’1. Squalene, absent in polar bear sebum but included here as a contrast to low Eads compounds, has stronger adhesion on the ice surface with an adsorption energy of -102.27 kJ mol’1.

[0122] Conclusions:

[0123] Based on the lipid analyses and guided by the computational results, it can be concluded that the low ice adhesion of the polar bear fur on the ice surfaces is related to DG, cholesterol, and branched fatty acids. The simulations support the notion that these compounds are important, as they have low Eads values towards the ice surface. In particular, the high abundances of DG with unsaturated fatty acid moieties (e.g. 14:4, 16:4, but also longer and less unsaturated species), eicosanoic acid (e.g. 20:0*), and cholest-5-en-3p-ol and other sterol variants in the sebum samples are indicated as promising ski-wax additives. Beyond individual components, the presence of unsaturations, methyl-branching and very long carbon chain lengths on FA species, as well as component ratios and the total amount of lipids, may all be important for explaining the anti-icing properties of polar bear sebum. Simulations also suggest that saturated vs. unsaturated species can contribute, although DG seems to behave differently than other fatty acid substituted species in this regard. It is possible that branching and saturation effects can be additive and dependent on exact positioning of these modifications in a way that would strongly favour de-icing.

[0124] The absence of squalene in polar bear sebum is notable as the simulations suggest that this compound is a poor anti-icing compound. Based on these results, squalene and squalene derivatives can be expected to demonstrate high grip capabilities and thus provide traction in a range of snow and weather conditions.

[0125] Example 4 - Ski wax formulation (“glide wax”)

[0126] Composition:

[0127] 20 wt.% poly-iso-butylene 20 wt.% resins

[0128] 50 wt.% paraffin- and Fischer-Tropsch waxes

[0129] 2 wt.% palmitoyl-2-oleoyl-sn-glycerol

[0130] 2 wt.% cholest-5-en-3p-ol

[0131] 2 wt.% eicosanoic acid

[0132] 2 wt.% rosins

[0133] 1 wt.% graphite

[0134] 1 wt.% sodium dodecyl sulfate

[0135] Preparation:

[0136] A ski wax composition is prepared according to the following steps:

[0137] (i) co-melt the wax components;

[0138] (ii) heat the melt to 120-150°C;

[0139] (iii) add the rosins, poly-iso-butylene, and sodium dodecyl sulfate under stirring;

[0140] (iv) add graphite in portions with stirring; and

[0141] (iv) pour into pre-cooled molds and cool the composition rapidly.

[0142] Example 5 - Ski wax formulation (“grip wax”)

[0143] Composition:

[0144] 20 wt.% poly-iso-butylene

[0145] 20 wt.% resins

[0146] 50 wt.% paraffin- and Fischer-Tropsch waxes

[0147] 6 wt.% squalene

[0148] 2 wt.% rosins

[0149] 1 wt.% graphite

[0150] 1 wt.% sodium dodecyl sulfate

[0151] Preparation:

[0152] A ski wax composition is prepared according to Example 4.

Claims

Claims:

1. A ski wax composition comprising a lipid component selected from the group consisting of a cholesterol or a cholesterol derivative, a fatty acid or salt of a fatty acid, a diglyceride, and any combination thereof.

2. A ski wax composition as claimed in claim 1 , wherein said lipid component is cholesterol or a cholesterol derivative.

3. A ski wax composition as claimed in claim 1 , wherein said lipid component is a fatty acid or salt of a fatty acid.

4. A ski wax composition as claimed in claim 1 , wherein said lipid component is a diglyceride.

5. A ski wax composition as claimed in claim 1 , wherein said lipid component is a combination of a fatty acid or salt of a fatty acid, and a diglyceride.

6. A ski wax composition as claimed in claim 1, wherein said lipid component is a combination of a fatty acid or a salt of a fatty acid, and a cholesterol or a cholesterol derivative.

7. A ski wax composition as claimed in claim 1 , wherein said lipid component is a combination of a cholesterol or a cholesterol derivative, and a diglyceride.

8. A ski wax composition as claimed in claim 1, wherein said lipid component is a combination of a cholesterol or a cholesterol derivative, a fatty acid or salt of a fatty acid, and a diglyceride.

9. A ski wax composition as claimed in any one of the preceding claims, wherein the lipid component is present in an amount in the range from 1 to 15% by weight, based on the total weight of the composition.

10. A ski wax composition as claimed in any one of claims 1 , 2 and 6-9, wherein the cholesterol derivative is a cholestane, a cholestene or a cholestadiene.

11. A ski wax composition as claimed in any one of claims 1 , 2 and 6-10, wherein the cholesterol or cholesterol derivative is cholest-5-en-3p-ol, cholesta-4,6- dien-3p-ol, cholest-3,5-diene, or cholesta-3,5-dien-7-one.

12. A ski wax composition as claimed in claim 11 , wherein the cholesterol is cholest-5-en-3p-ol.

13. A ski wax composition as claimed in any one of claims 1 , 3, 5, 6 and 8-12, wherein the fatty acid has a hydrocarbon chain of 12 to 34 carbon atoms.

14. A ski wax composition as claimed in claim 13, wherein the fatty acid has a hydrocarbon chain of 16 to 26 carbon atoms.

15. A ski wax composition as claimed in claim 13, wherein the fatty acid has a hydrocarbon chain of 16 to 22 carbon atoms.

16. A ski wax composition as claimed in any one of claims 1 , 3, 5, 6 and 8-15, wherein the fatty acid is saturated.

17. A ski wax composition as claimed in any one of claims 1 , 3, 5, 6 and 8-16, wherein the fatty acid is branched.

18. A ski wax composition as claimed in claim 17, wherein the fatty acid comprises a carbon chain having one or more methyl branches.

19. A ski wax composition as claimed in claim 17 or claim 18, wherein the fatty acid is iso-branched or anteiso-branched.

20. A ski wax composition as claimed in claim 19, wherein the fatty acid comprises a carbon chain having one methyl branch in the anteiso position.

21. A ski wax composition as claimed in claim 20, wherein the fatty acid is 18- methyleicosanoic acid or 20-methyldocosanoic acid.

22. A ski wax composition as claimed in any one of claims 1 and 4-21 , wherein the diglyceride is a 1,2-diacylglycerol.

23. A ski wax composition as claimed in any one of claims 1 and 4-22, wherein the fatty acid chains of the diglyceride contain from 12 to 34 carbon atoms.

24. A ski wax composition as claimed in claim 23, wherein the fatty acid chains of the diglyceride contain from 16 to 26 carbon atoms.

25. A ski wax composition as claimed in claim 23, wherein the fatty acid chains of the diglyceride contain from 16 to 22 carbon atoms.

26. A ski wax composition as claimed in any one of claims 1 , 4, 5 and 7-25, wherein the fatty acid chains of the diglyceride are saturated or mono-unsaturated.

27. A ski wax composition as claimed in claim 1, wherein the lipid component comprises eicosanoic acid with methyl branching at the anteiso position, and 1- palmitoyl-2-oleoyl-sn-glycerol.

28. A ski wax composition as claimed in claim 1 , wherein the lipid component comprises cholest-5-en-3p-ol, eicosanoic acid with methyl branching at the anteiso position, and 1-palmitoyl-2-oleoyl-sn-glycerol.

29. A ski wax composition as claimed in any one of the preceding claims which is provided in the form of a solid wax, a liquid wax, a paste wax, a powder wax or spray wax.

30. A ski wax composition as claimed in any one of the preceding claims which comprises a wax selected from a petroleum-derived wax, a synthetic wax or plant or animal wax.

31. A ski wax composition as claimed in any one of the preceding claims which further comprises one or more of the following components: resin, rosin, natural rubber, synthetic rubber, graphite, nanocarbon materials, a surfactant, an organic solvent or mixture of organic solvents.

32. A ski wax composition as claimed in any one of the preceding claims which is substantially free from per- and polyfluoroalkyl substances.

33. Use of a ski wax composition as claimed in any one of the preceding claims as a ski wax coating or as a ski skin coating.

34. Use of a ski wax composition as claimed in claim 33 as a glide wax.

35. A ski wax composition comprising squalene or a squalene derivative.

36. A ski wax composition as claimed in claim 35, wherein said squalene derivative is squalane, malabaricane, oleanane or lanostane.

37. A ski wax composition as claimed in claim 35 or claim 36, wherein the squalene or squalene derivative is present in an amount in the range from 1 to 15% by weight, based on the total weight of the composition.

38. A ski wax composition as claimed in any one of claims 35 to 37 which is provided in the form of a solid wax, a liquid wax, a paste wax, a powder wax or spray wax.

39. A ski wax composition as claimed in any one of claims 35 to 38 which comprises a wax selected from a petroleum-derived wax, a synthetic wax or plant or animal wax.

40. A ski wax composition as claimed in any one of claims 35 to 39 which further comprises one or more of the following components: resin, rosin, natural rubber, synthetic rubber, graphite, nanocarbon materials, a surfactant, an organic solvent or mixture of organic solvents.

41. A ski wax composition as claimed in any one of claims 35 to 40 which is substantially free from per- and polyfluoroalkyl substances.

42. Use of a ski wax composition as claimed in any one of claims 35 to 41 as a ski wax coating or as a ski skin coating.

43. Use of a ski wax composition as claimed in claim 42 as a grip wax.

44. A ski having a ski base provided with a wax coating comprising a ski wax composition as claimed in any one of claims 1 to 32 and 35 to 41.

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