Oil-in-water wax emulsion composition

Abstract

The present invention relates to a composition in the form of an oil-in-water emulsion, preferably comprising an aqueous phase, a natural wax, at least two surfactants, and a neutralizing agent.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Application No. 63 / 142564, filed January 28, 2021, which is incorporated by reference herein. Priority to U.S. Provisional Application No. 63 / 142564, filed January 28, 2021, is hereby claimed.

[0002] 1. Field of the invention The present invention relates to a composition in the form of an oil-in-water natural wax emulsion. [Background technology]

[0003] 2. General Background of the Invention Oil-in-water wax emulsions have been used in a variety of applications and industries, including, but not limited to, paper coatings, textiles, gunpowder, fruit and vegetable coatings, medicines, candles, moldings, electrical insulation, textile and leather sizing, waterproofing, carbon paper, typewriter ribbons, printing inks, lubricants, crayons, adhesives, chewing gum, and cosmetics. Typically, these types of emulsions are used either as stand-alone or as active ingredients in formulations in the aforementioned applications. Looking at these oil-in-water emulsions, there are many different types of waxes that can be considered, and many different problems associated with the various formulations.

[0004] Waxes are substances consisting of hydrocarbons or fatty acid esters that are insoluble in water and soluble in non-polar organic solvents.

[0005] Wax emulsions are used in a variety of applications and are preferred in certain application formulations due to their aqueous phase and ease of formulation. The present invention addresses the challenge of creating high solids oil-in-water emulsions that have certain physical attributes, are commercially preferred, and can be phase stable, meeting certain regulatory compliances. The present invention is capable of achieving higher solids oil-in-water emulsions that are stable at both room temperature and elevated temperatures (e.g., 50° C.), pH 7-10 (typically pH 8-8.5), viscosity range 1-10,000 centipoise (cps) (with solids affecting viscosity, approximately 200-5000 cps), good hand shear, contact angle with water greater than 90° without smudging, and sebum contact angle greater than 90° without smudging.

[0006] Waxes from a wide variety of sources are contemplated for formulating oil-in-water emulsions. The present invention focuses on natural waxes (examples include white beeswax, yellow beeswax, cetyl palmitate, carnauba wax, and rice bran wax), and more specifically, rice bran wax (RBX). Rice bran wax is extracted from rice bran oil, where the main components are fatty acids and higher alcohol esters. The fatty acids consist of palmitic acid (C16), behenic acid (C22), lignoceric acid (C24), and other higher wax acids, and the higher alcohol esters consist primarily of cetyl alcohol (C26) and melissyl alcohol (C30). Rice bran wax also contains constituents such as free fatty acids (palmitic acid), squalene, and phospholipids. Natural waxes typically have a melting point of 77°C to 86°C and are off-white to subdued orange / brown in color.

[0007] Rice bran wax can be used in many applications, and is important for use in waterproofing materials, emollients, and as a skin exfoliant material. In addition, rice bran wax can produce hard coatings. These properties are particularly useful and desirable in personal care applications and in the construction and building industries. The main obstacle to using rice bran wax in oil-in-water emulsions is the difficulty of being able to incorporate a high percentage of rice bran wax into the oil-in-water emulsion composition. Oil-in-water emulsions need to be fluid, and the tendency of rice bran wax can make the emulsion significantly thicker and solidify the emulsion. An additional obstacle to using rice bran wax in oil-in-water emulsions is the inability to create stable emulsions at high concentrations due to the hydrophobic nature of rice bran wax, and to produce stable droplets or stable micelles.

[0008] US Patent No. 9,283,173 discloses the use of oil-in-water emulsions containing beeswax, lanolin wax, Chinese insect wax, rice wax, carnauba wax, candelilla wax, ouricle wax, esparto wax, cork fiber wax, sugarcane wax, Japan wax, haze wax, montan wax, microcrystalline wax, paraffin wax, and ozokerite; polyethylene waxes, and Fischer-Tropsch waxes emulsified with fatty acids. US Patent No. 9,283,173 provides the following background information about wax-containing emulsions and emulsifiers:

[0009] A wide variety of wax-containing emulsions and emulsifiers have been proposed, many targeted to specific cosmetic applications. For example, US Patent No. 4,507,279 discloses an oil-in-water cosmetic composition comprising an oily substance without free carboxyl groups (such as beeswax and carnauba wax, among others), water, and an emulsifier composed of either a combination of basic polypeptides and higher fatty acids, or salts (soaps) formed from these compounds.

[0010] US Patent No. 6,264,965 discloses a creamy composition in the form of an oil-in-water emulsion, comprising an oily phase dispersed in an aqueous phase, characterized in that it contains at least one anionic emulsifier that is liquid at room temperature and at least 5% by weight of one or more waxes relative to the total weight of the composition, and that the oily phase is in the form of a soft paste at room temperature.The anionic emulsifier is preferably a surfactant containing a phosphoric acid group, such as octyldecyl phosphoric acid.A method for preparing this composition, characterized in that at least one step of the method is carried out using a mixer-extruder, and the use of this composition in cosmetics and dermatology are also disclosed.

[0011] Compact powders for use in cosmetic, pharmaceutical or food compositions are typically anhydrous compositions that may consist mainly of solid particles formed by compression and a fatty binder. The use of derivatives of basic amino acids such as lysine has been proposed to modify the surface of inorganic substances present in such compositions and to increase the dispersibility of the compositions (e.g., U.S. Pat. No. 4,640,943; U.S. Pat. No. 5,688,527; U.S. Pat. No. 5,688,527).

[0012] US Patent Application Publication No. 2008 / 0124292, published after the priority date of the present application, discloses a composition useful for coating eyelashes, which addresses the problem of uniform dispersion of pigments and waxes in mascara compositions. The composition of this application contains an aqueous phase and an emulsifying system including at least one specific amino acid compound, including basic amino acids, glutamic acid, sarcosine, and glycine.

[0013] Humans typically suffer from a variety of skin disorders that can result from environmental factors, age, injury, and exposure to chemicals, as well as from inflammatory and allergic responses of the skin.

[0014] Many attempts have been made to treat these skin conditions, and a multi-billion dollar industry, including hundreds of international companies, manufactures and distributes thousands of different creams, salves, soothes, ointments, and medicines to heal the skin.

[0015] Below are some examples of ointments for treating the skin: US Patent No. 4,355,046 discloses a skin moisturizing treatment with a cream containing specially formulated petrolatum, siloxane solvents, and microcrystalline waxes; US Patent No. 4,880,627 discloses a skin treatment mixture that includes a natural ingredient - an extract of the Eupatorium plant - in combination with the chemical ingredients sulfathiazole, petrolatum, and zinc oxide.

[0016] US Patent No. 6,375,942 discloses a skin healing ointment comprising a base containing petrolatum, beeswax, or other wax, and an antibacterial component. These base components can be combined with zinc oxide and an anti-itch component to make the ointment universally applicable and effective in treating various skin disorders.

[0017] Some attempts have been directed to the use of stimulators or certain inhibitors, as one example, collagen stimulation has been used for skin treatment (Schiltz, John et al., J Invest Dermatol 87:663-667).

[0018] No. 6,419,936 relates to a topical skin ointment for application to the skin of individuals suffering from minor dermatitis such as dry chapped skin, minor wounds, abrasions, and peeling skin, which contains ingredients intended to relieve the discomfort associated with these types of dermatitis, as well as ingredients intended to promote natural healing, such as vitamins and zinc oxide.

[0019] Since higher solids emulsions result in better consistency, it would be desirable and advantageous to continually develop new and improved solutions for creating oil-in-water emulsions.

[0020] Soleimanian et al. provide an overview of wax-based delivery systems and provide some background information on wax delivery systems and the use of wax-based emulsions with water-in-oil emulsions. Yasamin Soleimanian, Sayed Amir Hossein Goli, Atefe Shirvani, Ameneh Elmizadeh, Alejandro G. Marangoni, August 29, 2020, "Wax based delivery systems: Preparation, characterization, and food applications," Comprehensive Reviews in Food Science and Food Safety, Volume 19, Issue 6 (available at https: / / doi.org / 10.1111 / 1541-4337.12614).

[0021] Wijamprecha et al. describe the use of rice bran wax (RBX), an oleogel, and glycerol monostearate (GMS) to stabilize water-in-oil emulsions. Khakhanang Wijamprecha, Auke de Vries, Pravit Santiwattana, Sopark Sonwai, Derick Rousseau, "Microstructure and rheology of oleogel-stabilized water-in-oil emulsions containing crystal-stabilized droplets as active fillers", LWT, Vol. 115, 2019, p. 108058, ISSN 0023-6438 (available at https: / / doi.org / 10.1016 / j.lwt.2019.04.059). Water inhibits the stability of oil-in-water emulsions. Unlike the present invention, Wijamprecha et al. solve this problem by using water as a filler, rather than as a vehicle phase. However, this completely changes the rheological properties and microstructure by moving towards a water-in-oil emulsion.

[0022] Conversely, Khakhanang Wijamprecha, Auke de Vries, Pravit Santiwattana, Sopark Sonwai, Derick Rousseau, "Rheology and structure of oleogelled water-in-oil emulsions containing dispersed aqueous droplets as inactive fillers", LWT, Vol. 115, 2019, p. 108067, ISSN0023-6438, https: / / doi.org / 10.1016 / j.lwt.2019.04.068, describes a similar water-in-oil emulsion using water as a filler rather than as a medium, highlighting the stability challenge of rice bran wax emulsions in oil-in-water emulsions as the emulsion moves towards water-in-oil.

[0023] US 2016 / 0000665 describes an oil-in-water emulsion in a continuous aqueous phase with an oily phase dispersed with at least one hydrocarbon-based oil, comprising 1% to 10% wax having a melting point greater than 45°C (113°F), one or more C40-C70 ester compounds that are not C20-C39 ester compounds, a non-ionic surfactant having 16 carbon atoms that is not a fatty alcohol, a fatty alcohol containing at least 16 carbon atoms, a water-soluble polysaccharide, and a hydrocarbon-based oil. The emulsifier package and wax range used in the present invention differ from those disclosed in US 2016 / 0000665 in that it has an even higher percentage of wax (25-60% wax vs. 1-10% wax). Additionally, the primary surfactants used in the '665 document are non-ionic water-soluble polysaccharides containing 16 carbon atoms, and a hydrocarbon-based oil. In contrast, the present invention emulsifies using a non-ionic surfactant having 80-84 carbons (or 39-41 moles of epoxylation), a linear epoxylated surfactant, and polyethylene glycol. Additionally, the present invention does not use hydrocarbon-based oils; the only oil in the present invention is derived from the rice bran wax itself.

[0024] U.S. Patent No. 9,828,504 describes the use of oil-in-water emulsions containing waxes containing paraffin, montan, carnauba, sunflower, rice, tallow, or organic acids or esters emulsified with either polyethylene glycol, methoxypolyethylene glycol, or polyvinyl alcohol in joint compounds for water resistance.

[0025] The following U.S. patents and publications are incorporated by reference herein: 9283173; 9828504; 2016 / 0000665. [Prior art documents] [Patent documents]

[0026] [Patent Document 1] U.S. Patent No. 9,283,173 [Patent Document 2] U.S. Patent No. 4,507,279 [Patent Document 3] U.S. Patent No. 6,264,965 [Patent Document 4] U.S. Patent No. 4,640,943 [Patent Document 5] U.S. Patent No. 5,688,527 [Patent Document 6] US Patent Application Publication No. 2008 / 0124292 [Patent Document 7] U.S. Patent No. 4,355,046 [Patent Document 8] U.S. Patent No. 4,880,627 [Patent Document 9] U.S. Patent No. 6,375,942 [Patent Document 10] U.S. Patent No. 6,419,936 [Patent Document 11] US Patent Application Publication No. 2016 / 0000665 [Patent Document 12] U.S. Patent No. 9,828,504 [Patent Document 13] U.S. Patent No. 9,283,173 [Non-patent literature]

[0027] [Non-Patent Document 1] Schiltz, John et al., J Invest Dermatol 87:663-667. [Non-Patent Document 2] Yasamin Soleimanian, Sayed Amir Hossein Goli, Atefe Shirvani, Ameneh Elmizadeh, Alejandro G. Marangoni, August 29, 2020, "Wax based delivery systems: Preparation, characterization, and food applications", Comprehensive Reviews in Food Science and Food Safety, Volume 19, Issue 6 (https: / / doi.org / 10.1111 / 1541-4337.12614) [Non-Patent Document 3] Khakhanang Wijamprecha, Auke de Vries, Pravit Santiwattana, Sopark Sonwai, Derick Rousseau, “Microstructure and rheology of oleogel-stabilized water-in-oil emulsions containing crystal-stabilized droplets as active fillers”, LWT, Volume 115, 2019, Page 108058, ISSN0023-6438(https: / / doi.org / 10.1016 / j.lwt.2019.04.059) [Non-Patent Document 4] Khakhanang Wijamprecha, Auke de Vries, Pravit Santiwattana, Sopark Sonwai, Derick Rousseau, “Rheology and structure of oleogelled water-in-oil emulsions containing dispersed aqueous droplets as inactive fillers”, LWT, Volume 115, 2019, Page 108067, ISSN0023-6438, https: / / doi.org / 10.1016 / j.lwt.2019.04.068 [Non-Patent Document 5] https: / / www.sciencedirect.com / topics / engineering / saponification-value [Non-Patent Document 6] https: / / www.sciencedirect.com / topics / chemistry / acid- number#:~:text=The%20acid%20number%20is%20defined,and%20for%20phenol%2D modified%20resins Summary of the Invention [Means for solving the problem]

[0028] The present invention relates to a composition in the form of an oil-in-water emulsion, comprising a solids portion, an aqueous phase, a wax, and an emulsification package. Preferably, the composition further comprises a neutralizing agent. Preferably, the wax is a natural wax, most preferably rice bran wax (Oryza Sativa bran wax). Preferably, the emulsification package comprises an alcohol ether surfactant or polyethylene glycol of ethylene oxide propylene oxide, secondary alcohol ethoxylate, preferably with a molecular weight of up to 10,000 Daltons, more preferably 50-10,000 Daltons, even more preferably 100-5,000 Daltons, most preferably 150-500 Daltons, and an average of 300 Daltons, and an alkalizing agent or neutralizing agent.

[0029] Preferably, the aqueous phase is a continuous aqueous phase that is opaque, and the solids portion preferably constitutes 30% to 65% by weight of the oil-in-water emulsion.

[0030] Preferably, the wax has a melting point greater than 45° C. (113° F.). Preferably, the wax is a natural wax that is a long-chain ester containing phospholipids and free fatty acids and alcohols. Preferably, the wax is present in an amount of 25 to 65% by weight of the oil-in-water emulsion.

[0031] In a more preferred embodiment, the emulsion of the present invention comprises a wax of natural origin from renewable resources, with a melting point between 49 and 100°C. Preferably, the wax has an iodine value (IV) of less than 20 g / 100 g, a maximum acid value of 13 KOH / g, and a saponification value of more than 20 mg KOH / g. More preferably, the saponification value is between 70 and 120 mg KOH / g. The saponification value or saponification index represents the amount of milligrams of KOH that reacts with 1 gram of wax at high temperature and indicates the amount of material, free carboxylic acids plus any esters, that can be saponified. The saponification value value and acidity index described provide an indication of the free carboxylic acid and ester content of the wax. See https: / / www.sciencedirect.com / topics / engineering / saponification-value. The acidity index is defined as the number of grams of KOH required to neutralize 1 gram of resin (wax) under certain conditions. See https: / / www.sciencedirect.com / topics / chemistry / acid-number#:~:text=The%20acid%20number%20is%20defined,and%20for%20phenol%2D modified%20resins).

[0032] In one or more embodiments, the emulsification package includes at least two nonionic surfactants.

[0033] Preferably, one of the at least two surfactants is an alcohol ether surfactant of ethylene oxide propylene oxide containing a saturated C8 to C18 carbon chain with several moles of ethoxylated and propoxylated chains.

[0034] Preferably, one of the at least two surfactants is an alcohol ether surfactant of ethylene oxide propylene oxide containing a saturated C8-C10 carbon chain with several moles of ethoxylated and propoxylated chains.

[0035] Preferably, the ethylene oxide propylene oxide alcohol ether surfactant comprises 0.5% to 5.0% by weight of the oil-in-water emulsion.

[0036] Preferably, the secondary alcohol ethoxylate has a secondary chain length of approximately 30 to 60 moles of ethylene oxide. More preferably, the secondary alcohol ethoxylate has a secondary chain length of approximately 40 moles of ethylene oxide. Preferably, the secondary alcohol ethoxylate comprises 0.5% to 5% by weight of the oil-in-water emulsion.

[0037] The neutralizing agent is any agent for neutralizing free fatty acids and alcohols. Preferably, sufficient neutralizing agent is used to achieve a pH range of 7-10.5. In a preferred embodiment, the neutralizing agent may be a base, including one or more from the following group: potassium hydroxide, sodium hydroxide, and amines, such as ammonia, ethylamine, ethanolamine, isopropylamine, and other amine derivatives. Preferably, the neutralizing agent of the composition is 0.25% to 5% by weight of the oil-in-water emulsion. Preferably, the neutralizing agent is ammonium hydroxide (30% ammonium hydroxide) at 0.1% to 10%, more preferably 2.0 to 4.0% by weight of the oil-in-water emulsion. Any alkaline agent that may be effective to achieve a pH range of 7-10.5 may be used as the neutralizing agent. Preferably, the alkaline agent is added in an amount sufficient to provide a pH of 7-10.5.

[0038] The oil-in-water emulsion process is a multi-stage process. Water, emulsifier package, and neutralizing agent are mixed and heated to between 180°F and 210°F (82°C and 100°C), or at least 5-10°C (9-18°F) above the melting point of the wax. The wax is blended with the heated pre-emulsion. The mixture is maintained at the desired temperature until completely blended and dispersed as a blended aqueous mixture. In a preferred embodiment, the mixture is homogenized in a homogenizer, preferably at 1000-3000 pounds per square inch (psi) (6.9-20.7 megapascals (MPa)).

[0039] In a preferred embodiment, a method of preparing any of the aforementioned compositions is provided.

[0040] In a preferred embodiment, the method for preparing an oil-in-water composition comprises the following steps: (a) mixing a solids component, an aqueous phase, an emulsifier package, and a neutralizing agent; (b) heating the mixture of step (a) to a temperature above the melting point of the wax of step (c); (c) blending the heated mixture of step (b) with the wax and pre-emulsion to form a new mixture; (d) maintaining the temperature of the mixture of step (c) until the mixture is completely blended and dispersed as a blended aqueous mixture. Includes.

[0041] In one or more embodiments, the method further comprises homogenizing the blended aqueous mixture of step (d), which can be carried out in a homogenizer at 1000-3000 psi (6.9-20.7 MPa).

[0042] In one or more embodiments, the wax is a natural wax.

[0043] In one or more embodiments, the wax is of natural origin. Preferably, the wax is from a renewable resource. Preferably, the wax has a melting point between 49-100° C. and a saponification value of more than 20 mg KOH / g.

[0044] In one or more embodiments, the wax has a saponification number of 70 to 120 mg KOH / g.

[0045] In one or more embodiments, the wax is Oryza sativa bran wax (rice bran wax).

[0046] In one or more embodiments, the emulsification package includes at least two nonionic surfactants. The emulsification package can include an alcohol ether, a polyethylene glycol (PEG), and a secondary alcohol ethoxylate. The alcohol ether can be an ethylene oxide propylene oxide alcohol ether surfactant. The PEG can have a molecular weight of 50-10,000 daltons, preferably 100-5,000 daltons, most preferably 150-500 daltons, and an average molecular weight of 300 daltons.

[0047] In one or more embodiments, the aqueous phase is a continuous aqueous phase that is opaque.

[0048] In one or more embodiments, the solids constitute 30% to 65% by weight of the oil-in-water emulsion.

[0049] In one or more embodiments, the wax has a melting point greater than 45°C.

[0050] In one or more embodiments, the wax has a melting point between 49°C and 100°C.

[0051] In one or more embodiments, the waxes are natural waxes that are long chain esters containing phospholipids and free fatty acids and alcohols.

[0052] In one or more embodiments, the wax is present in an amount of 40 to 60% by mass relative to the oil-in-water emulsion.

[0053] In one or more embodiments, one of the two surfactants is an alcohol ether surfactant of ethylene oxide propylene oxide containing a saturated C8 to C18 carbon chain with several moles of ethoxylated and propoxylated chains.

[0054] In one or more embodiments, one of the two surfactants is an alcohol ether surfactant of ethylene oxide propylene oxide that contains a saturated C8-C10 carbon chain with several moles of ethoxylated and propoxylated chains.

[0055] In one or more embodiments, the ethylene oxide propylene oxide alcohol ether surfactant comprises 0.5% to 5.0% by weight of the oil-in-water emulsion.

[0056] In one or more embodiments, the secondary alcohol ethoxylates have secondary chains that are approximately 3 to 60 moles of ethylene oxide in length.

[0057] In one or more embodiments, the secondary alcohol ethoxylate has a secondary chain that is approximately 40 moles of ethylene oxide in length.

[0058] In one or more embodiments, the secondary alcohol ethoxylate comprises from 0.5% to 5% by weight of the oil-in-water emulsion.

[0059] In one or more embodiments, the wax comprises free fatty acids and alcohols, and the neutralizing agent is any agent for neutralizing the free fatty acids and alcohols.

[0060] In one or more embodiments, the neutralizing agent comprises ammonium hydroxide at a mass ratio of 0.1 to 10% of the oil-in-water emulsion.

[0061] In one or more embodiments, the neutralizing agent comprises 30% ammonium hydroxide comprising 0.1-10% by weight of the oil-in-water emulsion.

[0062] In one or more embodiments, the neutralizing agent is an alkaline agent.

[0063] In one or more embodiments, the alkaline agent is added in an amount sufficient to provide a pH of 7 to 10.5.

[0064] In one or more embodiments, in step (b) above, the mixture is heated to a temperature 5° C. to 10° C. (9° F. to 18° F.) above the melting temperature of the wax in step (c).

[0065] In one or more embodiments, in step (b) above, the mixture is heated to 180°F to 210°F (82°C to 99°C). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0066] Wax emulsions are used in a variety of applications and are preferred in certain application formulations due to their aqueous phase and ease of formulation. The present invention addresses the continuing challenge of creating high solids oil-in-water emulsions that can be phase stable while retaining desirable physical attributes and maintaining regulatory compliance. Desirable physical attributes may include water resistance, viscosity in the range of 1-10,000 centipoise (cps), sebum resistance, pH range of 7-10, smooth coating, and shear stability. In addition, the present invention can meet compliance requirements in indirect and direct food contact, board coating applications, and personal care regulations in several countries, which may include U.S. Code of Federal Regulations (CFR) compliance, China Guo Bio (GB) compliance, European Union REACH regulations, and other regulatory regulations known to those skilled in the art.

[0067] Preferred compositions can be found in the following table (Table 1):

[0068] [Table 1]

[0069] The emulsion is preferably formulated by blending the water and emulsifier package and then heating the solution to 190°F (88°C). Ammonium hydroxide is then added while heating the formulation in a hood. When the formulation is at approximately 190°F (88°C), the rice bran wax is added. The formulation is preferably mixed between 190°F and 200°F (88°C and 94°C) for approximately 1 hour to melt and emulsify the rice bran wax. After 1 hour when the formulation is completely blended and in a homogenous phase, the formulation is homogenized in a homogenizer at 2000 psi (13.8 Mpa). After homogenization, the emulsion is cooled to room temperature and filtered through a 300 micron filter.

[0070] The emulsifier package preferably comprises PEG and an ethoxylated surfactant or an alcohol surfactant. In a preferred embodiment, the alcohol surfactant is a Pareth surfactant, of which Pareth-40 is preferred. In a more preferred embodiment, the emulsifier package further comprises an ethoxylated propoxylated surfactant. Although other known emulsifier packages suitable for use with higher wax solids may be used, such as those comprising fatty alcohols, linear surfactants, and polysaccharides, the emulsifier package of the present invention exhibits enhanced stability of higher wax emulsions.

[0071] In some preferred embodiments, a secondary surfactant of an alcohol ether of ethylene oxide is not required, hi some preferred embodiments, a primary alcohol can be used in place of the secondary alcohol.

[0072] The polyethylene glycol in the final formulation is preferably of molecular weight 300 Daltons.

[0073] The present invention is capable of realizing high solids oil-in-water emulsions with stability at both room temperature and elevated temperatures (e.g., approximately 40-60°C, preferably approximately 50°C), pH 7-10.5 (preferably pH 8-10), viscosity range 1-10000 cps (preferably 200-5000 cps, preferably including solids that affect viscosity), good manual shearability, contact angle with water of greater than 90° without staining, and sebum contact angle of greater than 90° without staining.

[0074] A preferred composition formulation includes a natural wax, a polyethylene glycol (PEG), an alcohol, at least one surfactant, and a neutralizing agent.

[0075] Preferably, the natural wax is rice bran wax (RBX). However, other natural waxes, petroleum waxes, and synthetic waxes, such as white beeswax, yellow beeswax, cetyl palmitate, carnauba wax, beeswax, lanolin wax, Chinese insect wax, rice wax, candelilla wax, ouricle wax, esparto wax, cork fiber wax, sugarcane wax, Japan wax, haze wax, montan wax, microcrystalline wax, paraffin wax, and ozokerite, polyethylene wax, as well as waxes obtained by the Fischer-Tropsch process, can also be used. Preferably, the composition of the present invention is 20-60% natural wax; more preferably, the composition of the present invention is 40-55% natural wax; most preferably, the composition of the present invention is 40-55% rice bran wax.

[0076] Preferably, the PEG has a molecular average weight of up to 10,000 Daltons. More preferably, the PEG has an average molecular weight of 50-10,000 Daltons. Most preferably, the PEG has an average molecular weight of 300 Daltons. Preferably, the composition of the present invention is 0.1-10% PEG. More preferably, the composition of the present invention is 3% PEG.

[0077] Preferably, the composition of the present invention has 0.1-10% alcohol, more preferably 1% alcohol.

[0078] Preferably, the composition of the present invention comprises at least one surfactant. Preferably, the composition of the present invention comprises 0.1-10% of a surfactant, more preferably 3% of a surfactant. More preferably, the composition of the present invention comprises at least two surfactants. Preferably, these two surfactants are a C12-C14 Pareth-40 surfactant and a C8-C10 ethoxylated propoxylated surfactant.

[0079] Preferably, the present invention contains 0.1 to 10% of a neutralizing agent. More preferably, the present invention contains 0.25 to 1.0% of a neutralizing agent. Preferably, the neutralizing agent is an alkaline agent. More preferably, the neutralizing agent is ammonium hydroxide.

[0080] Preferably, the balance of the composition is water.

[0081] In some preferred embodiments, the water and emulsifier package (PEG and both surfactants) are blended and then the solution is preferably heated to 180°F-210°F (82°C-99°C). More preferably, the solution is heated to 190°F (88°C). A neutralizing or alkaline agent is then preferably added while the formulation is heated, preferably in a hood. The natural wax is preferably added once the formulation has reached the desired temperature. The formulation is preferably mixed for 30 to 120 minutes at a temperature of 190°F-210°F (82°C-99°C) to melt and emulsify the natural wax.

[0082] In some preferred embodiments, after the formulation is thoroughly blended and in a homogenous phase, the formulation is preferably homogenized in a homogenizer, preferably at 1000-3000 psi (6.9-20.7 Mpa), more preferably at 2000 psi (13.8 Mpa). This additional step is not essential to the stability of the composition, but results in a more consistent range of particle sizes. After homogenization, the emulsion is preferably cooled to room temperature and preferably filtered through a 100-300 micron filter. The product has been tested for stability at ambient temperature and at 50° C. for one year with no change in its characteristics. The inventors believe that continued testing at these temperatures indicates continued stability.

[0083] All measurements disclosed herein are at standard temperature and Earth's sea level pressure unless otherwise indicated. All materials used or that may be used in humans are biocompatible unless otherwise indicated.

[0084] The foregoing embodiments are presented by way of example only, and the scope of the present invention is limited only by the following claims.

Claims

1. 1. An oil-in-water emulsion composition comprising a solids portion and an aqueous phase, the solids portion comprises a wax and the aqueous phase comprises an emulsification package and a neutralizing agent; the wax is a natural wax and is present in the oil-in-water emulsion composition in an amount of 20 to 60% by mass; The wax is of natural origin, a renewable resource, has a melting point between 49 and 100° C., and a saponification value of greater than 20 mg KOH / g; A composition wherein the emulsification package comprises polyethylene glycol (PEG) having a molecular weight of 150 to 500 daltons.

2. 2. The composition of claim 1, wherein the wax is rice bran wax.

3. The composition of claim 1 , wherein the emulsification package comprises at least two nonionic surfactants.

4. 4. The composition of claim 3, wherein one of the at least two surfactants is an ethylene oxide propylene oxide alcohol ether surfactant comprising a saturated C8 to C10 carbon chain with several moles of ethoxylated and propoxylated chains.

5. 10. The composition of claim 1, wherein the wax comprises free fatty acids and alcohols, and the neutralizing agent is any agent for neutralizing the free fatty acids and alcohols.

6. 2. The composition of claim 1, wherein the neutralizing agent comprises 0.25 to 5% by weight of the oil-in-water emulsion composition of a base including potassium hydroxide, sodium hydroxide, and / or an amine, such as ammonia, ethylamine, ethanolamine, isopropylamine, and other amine derivatives.

7. The emulsion package comprising an alcohol ether, a polyethylene glycol (PEG), and a secondary alcohol ethoxylate, 2. The composition of claim 1, wherein the secondary alcohol ethoxylate has a secondary chain length of 41 moles of ethylene oxide.

8. A method for preparing the composition of claim 1, comprising the steps of: (a) mixing said emulsifier package and an aqueous phase containing said neutralizing agent; (b) heating the mixture of step (a) to a temperature above the melting point of the wax of step (c); (c) blending the heated mixture of step (b) with a wax to form a new mixture; (d) maintaining the temperature of the mixture of step (c) until the mixture is completely blended and dispersed as a blended aqueous mixture. A method comprising:

9. After step (d): (e) homogenizing the blended aqueous mixture of step (d). The method of claim 8, further comprising:

10. 9. The method of claim 8, wherein the emulsification package comprises an alcohol ether, a polyethylene glycol (PEG), and a secondary alcohol ethoxylate.

11. 11. The method of claim 10, wherein the alcohol ether is an ethylene oxide propylene oxide alcohol ether surfactant.

12. 11. The method of claim 10, wherein the secondary alcohol ethoxylate has a secondary chain length of 30 to 60 moles of ethylene oxide.

13. 9. The method of claim 8, wherein the aqueous phase is a continuous aqueous phase that is opaque.

14. 9. The method of claim 8, wherein the wax comprises free fatty acids and alcohols, and the neutralizing agent is any agent for neutralizing free fatty acids and alcohols.

15. 15. The method of claim 14, wherein the neutralizing agent is comprised of 30% ammonium hydroxide in an amount of 0.1-10% by weight of the oil-in-water emulsion.