ULTRA REFINED VEGETABLE OIL AND ITS USE IN PERSONAL CARE AND COSMETIC APPLICATIONS

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application ' claims the benefit of Brazilian Provisional Patent Application Serial No. 102016023137.0, filed 04 October 2016, entitled "EXTRA REFINED OIL SOURCE NO MINERAL OIL OR SYNTHETIC, IT IS USED FOR, COMPOSITION FOR PERSONAL CARE, COSMETICS, FOOD COMPOSITION, PHARMACEUTICAL COMPOSITION, COMPOSITION FOR ANIMAL CARE PRODUCTS AND PREPARATIONS FOR HOME CARE UNDERSTANDING SAID OIL AND ORIGIN OF UNDERSTANDING TOLD EXTRA REFINED OIL PRODUCT NO MINERAL OR SYNTHETIC" which application is hereby incorporated by reference herein in its entirety.

Technical field

[0002] The present invention relates to an ultra-refined oil which is derived from a vegetable source and exhibits high antioxidant stability. Such an oil has the potential of being a substitute for the mineral or synthetic oils that are currently used in personal care and cosmetic applications.

Background

[0003] Vegetable oils are the most common and affordable oils used as substitutes for mineral or synthetic oils. Vegetable oils have various applications, ranging from the food area, through cosmetic, and household applications, and are even used in the pharmaceutical area. Oils are part of the family of lipids, and are comprised mainly of triglycerides. These triglycerides can be oils, which are liquid at room temperature, and fats, which are solid at room temperature. Vegetable oils are extracted from various raw materials, and each source generates oils with particular properties that are derived from the profile of fatty acids present in their composition.

[0004] A key benefit of vegetable oils is their natural source. They are generally not harmful to the environment and more closely mimic the lipid composition of the skin and hair making them easy to absorb. They promote protection of the skin against excessive loss of water and nutrients, without interfering with the natural functions of the skin, and help in moisturizing and structuring of the underlying tissues.

[0005] Despite these desirable characteristics, natural vegetable oils have a significant inherent limitation. Unlike mineral oils they are susceptible to oxidation and can become rancid over time. The shelf life of natural oils must be carefully managed if they are to be utilized in specific applications.

[0006] The process of extracting and purifying a standard food-grade oil, that is, an oil with acceptable characteristics for application in foods that, is well known in the art The standard extraction purification process has been chosen almost exclusively based upon cost effectiveness. This process is not sufficient to completely remove trace impurities that act as catalysts for the oxidation of these oils. Trace impurities include sterols, metals, aldehydes, ketones and peroxides, the latter being formed by natural degradation of the oil during the processes mentioned.

[0007] It is important to point out that "food grade" oil means the oil whose composition comprises only substances that are recognizably safe for food use below the maximum percentages established for the composition.

[0008] Products that use vegetable oils usually have a short shelf life (1 year, on average, including their performance on the final application) resulting in problems such as loss of functional properties, phase separation, and poor organoleptic properties. These changes dramatically compromise the quality of the corresponding products. Therefore, the use of traditional vegetable oils is restricted to products with short shelf-life (e.g., food products that inherently have a shorter shelf-life), or they need addition of large amounts of antioxidants to improve its stabilization, which may not be acceptable or desirable in some applications. In addition, antioxidants have a limited lifetime in themselves, after which they begin to degrade and lose their capability of capturing electrons, thus losing their effect. The degradation products of antioxidants are often undesirable, since they alter the functional properties and organoleptic characteristics, such as texture, color and odor.

[0009] In cosmetics and body care applications, there is a strong desire to use natural oils and accordingly food-grade vegetable oils are most commonly used. However, the use of vegetable oil is limited by the points mentioned above particularly when used in more complexe formulations. Oxidation of the vegetable oil, together with degradation of the antioxidants, end up causing the product to acquire undesirable characteristics, and even to lose its effect after a relatively short shelf life.

[0010] For this reason, industries at present prefer to use mineral, non-polar, silicon and synthetic esters oils, since these oils have longer shelf life, preserving the desirable characteristics of the product for a longer time. However, industry is concerned about the use of these non-natural oils. Mineral oils in products for human or animal application, may degrade when exposed to high temperatures, of about 80°C, and generate byproducts that are harmful. In addition, mineral oil is viewed as a comedogenic product The comedogenicity scale measures the capability of an ingredient to obstruct pores and ranges from 0 to 5. So, the lower the comedogenicity value of an oil (as well as of any other substance) the more easily it is absorbed by the skin and less comedogenic it is, that is, less possibility of causing acne and blackheads on the skin.

[0011] Mineral oil does not have any nutritional value, is not absorbed by the skin and hair and does not promote moisturizing. In fact, it only lubricates the dermis on the surface, prevents loss of water and gives the false feeling of moisturizing. Since mineral oil is inert and does not dissolve in water or alcohol, it accumulates on the skin and hairs, and this accumulation causes the face to lose lushness, and hair becomes heavy, without swinging, besides making it difficult to absorb other substances that are essential to the health of the skin and hair.

[0012] A few references that mention the harmful effects of mineral oil include: "AOEC (Association of Occupational and Environmental Clinics). 2009. "AEOC exposures codes and asthmagen designation", "EC (Environment Canada). 2008. Domestic Substances List Categorization. Canadian Environmental Protection Act (CEPA) Environmental Registry", "FDA (U.S. Food and Drug Administration). 2008. EAFUS [Everything Added to Food]: A Food Additive Database. FDA Office of Food Safety and Applied Nutrition" and "NLM (National Library of Medicine). 2006. HazMap — Occupational Exposure to Hazardous Agents".

[0013] Another important factor refers to ecotoxicity and biodegradability. Oils of mineral origin are not biodegradable, potentially "pollute" the environment, and come from a non-renewable source. For this reason, the need to develop natural replacements remains, that is, products that do not use only raw materials from renewable natural sources.

[0014] The present invention further brings the advantage that the ultra-refined vegetable oil has the same fatty acid composition as the food-grade vegetable oil source, thus facilitating its substitution at the industrial plant, given the need for major adaptations of the process. Additionally, this fact also facilitates the regulation of the products by the regulatory agencies, since these oils can be considered equivalent

Description of the invention

[0015] It is a first objective of the present invention to provide an oil with high stability, as a substitute for the food-grade mineral oil or oil that is presently used in various applications.

[0016] It is a second objective of the present invention to provide use of the oil in preparing body-care, cosmetic, pharmaceutical, household-care compositions.

[0017] It is a third objective of the present invention to provide a body-care and cosmetic composition.

[0018] It is a forth objective of the present invention to provide a household-care composition.

[0019] Finally, it is a fifth objective of the present invention to provide a product containing said oil.

Brief description of the invention

[0020] The first objective of the present invention is achieved by means of an ultra- refined vegetable oil that exhibits a maximum dissipation factor of 0.20% at 25°C, 3.60% at 90°C, and 4.0% at 100 ^e C.

[0021] The second objective of the present invention is achieved by means of the ultra-refined vegetable oil, as defined herein, for preparing a body-care, cosmetic, household-care, or pharmaceutical, composition. [0022] The third objective of the present invention is achieved by means of a body- care, cosmetic composition comprising said ultra-refined vegetable oil and a cosmetically acceptable carrier.

[0023] The forth objective of the present invention is achieved by means of a pharmaceutical composition comprising said ultra-refined vegetable oil and one or more pharmaceutically acceptable excipients selected from water, alcohols, oils, glycerin, natural and synthetic esters, maltodextrin, polyols, glucose, glycose, propyleneglycol, native and modified starches, anionic, cationic, non-ionic surfactants, emulsifiers of all kinds, and natural and synthetic or polymeric HLBs, thickeners and texturizers of natural (hydrocolloids) or synthetic origin, sunscreen actives (physical or chemical sunscreens), dermatologic actives (anti-aging, bleaching, rejuvenating agents, cationic polymers, reducing or hair-oxidizing agents).

Detailed description of the invention

[0024] The present invention relates to an ultra-refined vegetable oil, hereinafter called also oil of the invention.

[0025] The term "vegetable oil" means a predominately triglyceride containing oil from plants that is either liquid or solid at room temperature, regardless of its extraction method.

[0026] The vegetable oils used in the present invention are preferably, but not restricted to any oil derived from plant, including fats, butters and/or any lipid compositions containing their combination, comprising, among others, of soybean oil, sunflower-seed oil, canola oil, cotton-seed oil, palm oil and derivatives thereof, flaxseed, corn, sesame, babassu, cocoa, or chia,

[0027] For some applications, it is necessary to add high concentrations of antioxidants, which ends up generating additional costs and undesired effects, especially considering that this is a base product for various compositions, and the latter often need addition of other antioxidants, thus being always very close to the maximum allowed by legislations. [0028] The oils are subjected to refining or purifying processes, so that they can reach the standards required for their acceptance in pharmaceutical, cosmetic and food use. At present, the most widely produced oil is the food-grade one.

[0029] The traditional refining process may take place by chemical or physical means, presented hereinafter.

[0030] The chemical refining process relies essentially upon 4 steps: (a) degumming; (b) neutralizing; (c) clarifying; and (d) deodorizing. Each step is responsible for partial removal of "impurities". At the end of the deodorizing process, we have the food-grade refined oil.

[0031] On the other hand, the physical process has 3 steps: (a) degumming; (b) clarifying; and (c) vapor refining. In the same way, at the end of the vapor refining step, we have the good-grade oil.

[0032] As a person skilled in the art knows, each step has the objective of extracting determined substances present in the oil. More specifically, the degumming step removes phosphatides and solids; the neutralizing step removes free fatty acids, metals (Ca+2, Mg+2, Fe+2, Cu+2, etc.), and pigments; the clarifying step removes pigments, soaps, metals and contaminants; the winterizing step removes waxes, steroids and saturated fatty acids and, finally, the deodorizing step removes pigments, free fatty acids, pesticides and tocopherols.

[0033] The typical food grade oil refining processes end at the above steps. On the other hand, the present invention goes beyond the traditional process.

[0034] After obtaining the refined or food-grade oil, the present invention makes use of an additional refining process, in which super adsorbent particles are applied, for example, filtration earth or synthetic hydrated magnesium silicate, which adsorbs the "impurities" that are removed by simple filtration, thus being responsible for removing said "impurities" from the oil.

[0035] By "impurities" one means all substances that are not a fatty acid and acts as a possible electron conductor, especially sterols, metals, phospholipids and peroxides, which are catalysts of the oil oxidation process. These impurities are intrinsic substances of oils or have been added, either directly or directly, by the extracting and purifying processes.

[0036] Alternatively, the extra refining may also be carried out by methods that are capable of separating impurities present in the oil, for example, chromatography or extra- filtration processes.

[0037] The use of super adsorbent particles is preferred because it is economically more viable on industrial scale. The other additional refining methods generate excessive expenditures in the production process and so they would end up raising the cost of the final product.

[0038] Since the additional refining is a physical process without using high temperatures or pressures, it has the characteristic of keeping the concentration of fatty acids in the oil unchanged, conserving the intrinsic characteristics of the oil, and this process may be replaced directly without the need for relevant adjustments in the production line.

[0039] Additionally, this fact also facilitates the regulation of the products at the regulating agencies, since oils can be considered structurally identical with respect to the contents of fatty acids.

[0040] The oil obtained by the above process can be characterized by its dissipation factor or potency factor. Traditional methods, like quantification of acidity or peroxides by rancimat, are not sufficient to differentiate a fresh oil of the invention from a fresh food-grade oil, since the composition of fatty acids is identical.

[0041] The rancimat test itself has the ability to generate peroxides through the equipment utilized, which may alter the results achieved and, given the need for high precision, rancimat is not suggested for differentiating the oil of the present invention from food grade oil.

[0042] The preferred method for evaluating the oil of the invention is, as mentioned above, by measuring its dissipation factor, or complementarily, analyzing it by differential scanning calorimetry (DSC). [0043] The methodology of analysis by DSC can be divided into 2 main methods, namely: oxidation induction time (OIT) and oxidation onset temperature (OOT).

[0044] In the OIT method, the samples are heated under protected condition, be it an inert gas or pressure, in the present case it is pressure, up to a constant temperature for a few minutes, until balance is established. Subsequently, the samples are exposed to oxygen or air. The measured time is that between contacting the sample with oxygen or air and oxidation onset.

[0045] On the other hand, the OOT method is a dynamic method, where the samples are heated up to a constant temperature and in oxidant conditions until oxidation onset.

[0046] Thus, the ultra-refined oil of the present invention has, as a peculiar characteristic, a maximum dissipation factor of, at most, 0.20% at 25°C, 3.60% at 90°C and 4.0% at 100°C, measured under the standard methodology of ABNT NBR 12133.

(0047] Once the catalysts of the oil oxidation process have been removed, the oil acquires much greater stability, even without addition of antioxidants.

[0048] Thus, the ultra refined oil of the present invention can be successfully utilized in applications that typically encounter great difficulty in employing normal food grade oil as a substitute for mineral oil, due to the problems of rapid oxidation and the consequent loss of functionality.

[0049] Especially, one has observed that the oil of the invention can be applied in products of the following areas: body-care, cosmetic, pharmaceutic, substituting for the mineral oil or food-grade oil, which at present represent the great majority of applications.

[0050] Thus, the present invention further relates to the use of the oil as defined herein for preparing a composition, preferably a body-care, cosmetic, and pharmaceutical, composition.

[0051] Said body-care, cosmetic composition, additionally comprises at least one cosmetically acceptable carrier and, optionally, a natural or synthetic antioxidant agent and/or combinations thereof.

[0052] Said cosmetically acceptable carrier is preferably at least one selected from the group comprising water, alcohols, oils, glycerin, natural and synthetic esters, maltodextrin, polyols, glucose, glycose, propyleneglycol, native and modified starches, anionic-cationic, non-ionic surfactants, emulsifiers of all kinds, natural and synthetic hydrophilic/lipophilic balance (HLBs), thickeners and texturizers of natural (hydrocolloids) or synthetic origin, sunscreen actives (physical and chemical sunscreens), dermatologic actives (anti-aging, bleaching, rejuvenating agents, cationic polymers, reducing agents, hair oxidizing agents, oxygenated water, organic and inorganic acids).

[0053] Said antioxidant is preferably selected from the group comprising natural and/or synthetic antioxidant molecules or combinations thereof, including butylated hydroxytoluene (BHT), butylated hydroxyanisol (BHA), tertiary hydrochinone (TBHQ), derivatives thereof and triazines, for example, Tinogard TL.

[0054] Said pharmaceutical composition additionally comprises one or more pharmaceutically acceptable excipients selected from water, alcohols, oils, glycerin, natural and synthetic esters, maltodextrin, polyols, glucose, porpyleneglycol, native and modified starches, anionic, cationic, non-ionic surfactants, emulsifiers of all kinds and natural and synthetic or polymeric HLBs, thickeners and texturizers of natural (hydrocolloids) or synthetic origin, actives for sunscreen (physical and chemical sunscreens), dermatologic actives (anti-aging, bleaching, rejuvenating agents, cationic polymers, reducing agents or hair-oxidizing agents).

[0055] Finally, the present invention further relates to a product comprising said oil, said product being, in a preferred embodiment, a body-care, cosmetic, food, pharmaceutical, animal-care or household-care composition.

Examples

[0056] It is important to point out that the examples below were conducted by using soybean oil, but are equally applicable to any vegetable oil or mixtures of vegetable oils. The choice of the vegetable oil to be used is made by a person skilled in the art on the basis of the contents of fatty acids characteristic of each oil, who is more capable of predicting the best field for application thereof.

Composition of ultra-refined soybean oil - Methodology AS I ^' M D924 [0057] Crude soybean oil (SBO) was purified by the conventional method, as already described, and subjected to the steps of (a) degumming step; (b) neutralizing step; (c) clarifying step; and (d) deodorizing step to obtain the food-grade oil.

[0058] The food-grade oil was then subjected to additional refining by adding an adsorbent, more specifically synthetic hydrated magnesium silicate particles, to remove the remaining impurities. The food grade oil can be treated with a 1-10% dose of magnesium silicate at ambient or elevated temperatures. The treated oil can simply be stirred and filtered to yield the oil of the invention. Alternatively, the oil may be passed through a column of magnesium silicate to affect the same purification. Those of skill in the art will appreciate the variety of standard ways in which an adsorbent can be utilized.

[0059] Gas chromatography was used to verify whether the ultra refining process would in any way modify the fatty acid composition of the soybean oil. The chromatography was carried out by using the methodology Cc7-25 AOCS.

[0060] Soybean oil has, as chief constituents, palmitic, oleic and linoleic acids. The results are presented in table 1 below.

Table 1 -Concentration of the main fatty acids of the samples of natural and ultra-refined soybean oil

[0061] As can be observed, the concentration of the main fatty acids that compose and characterize soybean oil, palmitic acid, oleic acid and linoleic acid, have not been significantly modified. Although they have not been pointed out, there was no significant change in the concentration of the other fatty acids that compose the soybean oil.

[0062] Thus, a great advantage of the invention is that the ultra refined oil, besides the great stability acquired, keeps the composition of fatty acids unchanged, preserving the properties of the oil. Oxidation induction time (ΟΓΓ)

[0063] In order to test the stability of the ultra-refined soybean oil of the present invention, evaluation of oxidation induction time (OIT) by means of the equipment DSC2920 - TA instruments - of Differential scanning calorimetry - DSC, was utilized. In this test, one determines the time in which each sample of oil begins to oxidize at a constant temperature, in this case at 130° C. The methodology used was the European standard test for OIT analysis of oils, EN 14112.

[0064] It is important to point out that the DSC was particularly chosen because the traditional technique for evaluating oxidation via rancimat is subject to interference of the free radicals formed by the method itself and, therefore, it does not have sufficient sensitivity for the purposes of the present invention.

[0065] The evaluation was designed to compare an example of the ultra-refined oil of the present invention (Ultra-oil— UT) with two types of traditional food grade vegetable oils. The first was standard refined vegetable oil and the second was previously refined oil that had been stored for 3 months and was considered to be past its "use-by" date (Aged). Standard mineral oil was also included as a control. The samples were further tested with addition of antioxidant, in this case butylated hydroxytoluene (BUT) at the concentration of 100 ppm.

[0066] A number of samples were further subjected to stress conditions to simulate the effects of a longer shelf life. Such accelerated aging evaluations are well known in the industry and in this case consists of heating a sample up to 250°C, waiting for the sample to cool down to 100°C, and heating to 250°C a second time. This methodology is often employed in the cosmetic area, so as to evaluate the behavior of the oils in their final formulations.

[0067] The data obtained are illustrated in figure 1 and in the table below.

Table 2 - OIT results of triplicate evaluations are represented as the average below.

[0068] As can be observed, there is a significant difference between the oxidation onset time of the aged oil in comparison with the oil of the present invention. More precisely, the onset of the aged SBO was only of 21.61 minutes, whereas the control UT SBO the present invention and the UT SBO of the invention with antioxidant after stress have onset of 27.71 and 26.48 minutes, respectively.

[0069] In addition, it is further possible to observe that, even after simulation of 1 year's shelf life (stress procedure), UT SBO kept an onset very close to the fresh oil, thus demonstrating its high stability, by virtue of its resistance to oxidation.

Oxidation Onset Temperature - OPT

[0070] In addition to the test above, it is possible to evaluate oils based on oxidation onset temperature in DSC. The methodology used was the European standard for OOT analysis of oils, EN 14112 (European Rule). Unlike the OIT test, where the temperature is held constant, in this test, the temperature is gradually raised to determine at what temperature the samples begin to oxidize.

[0071] Samples 4, 13, 12, and 15 from above were evaluated and the results are set out in the table below.

Table 3 -OOT Results of samples of oil

[0072] As expected, the stressed oil is the one that exhibits shorter onset time and onset oxidation temperature, 18.12 min and 94.83°C, respectively. It is further possible to observe that the samples of UT SBO of the invention (samples 12 and 13) have significantly longer onsets as compared to the oil with past use-by date, being closer to the mineral oil (sample 15).

Amount of peroxides

[0073] Finally, in order to ensure that the stability of the oil of the invention is associated to its capability of preventing the generation of free radicals responsible for its oxidation, generation of peroxides can be measured. Samples of (1) control oil (food- grade oil), (2) control oil with antioxidant, (3) oil of the invention, and (4) oil of the invention with oxidant BHT at the concentration of 100 ppm. The methodology used followed the protocol AOCS Cb 9b-90.

[0074] The results achieved corroborate the other results, demonstrating that the control oil without antioxidant is the one that has highest production of peroxides, and the oil of the invention with addition of antioxidants has the lowest production.

[0075] It is still important to note that the oil of the invention without antioxidants has a result that is statistically identical to the control oil with addition of antioxidants. In other words, the oil of the invention, even without addition of antioxidants, achieves the same effects of the control oil with antioxidants, thus demonstrating its stability.

Tests on final products

[0076] With a view to verify whether the properties of best stability of the oil of the present invention would be reflected on finished products that make use of it, tests were made by incorporating the oil of the present invention into a body lotion and into a hair conditioner, as demonstrated hereinafter.

[0077] Further, although the DSC is routinely used only for evaluation of raw materials, rather for final formulations that include various components, the use of the same methodology and of the same equipment enabled a comparison of results between the oils and the products in which they were applied.

Test on body lotion— skin-care compositions

[0078] Non-ionic body-lotion formulations were prepared by using different samples ofUT SBO oils.

[0079] AH the body-lotion formulations followed the composition of: 0.10% ethylenediamino tetraacetic acid (EDTA), 5.00% Olivem® 1000, 1.00% PEHG (phenoxyethanol and ethylexylglycerin), 10.00% oil and deionized water q.s.p. 100.

[0080] The oils used were: sample 4 (Stressed SBO) as negative control, sample 13 (UT with BHT— Antioxidant) to represent the present invention, and sample 15 (mineral oil) as positive control.

[0081] The compositions are illustrated in table 4 below.

Table 4—Body-lotion formulations tested

[0082] In a first OIT test carried out with the samples F, H and J above, none of the samples exhibited degradation until the time of 40 minutes so an accelerated test was performed.

[0083] The accelerated test consists of mixing the formulations F to J, at a ratio of 1 : 1 with the oil used. For example, in sample F, 2.5 g of formulation F were mixed for 3 minutes with 2.5g of Stressed SBO and then the mixture was left to stand for 12 hours.

[0084] The same process was carried out for formulations H and J, giving rise to samples K, L and M, according to table 5 below.

Table 5— Body-lotion formulations with accelerated oxidation

[0085] OIT test was then carried out for samples K, L and M. The results obtained are shown in table 6 below.

Table 6 - Result of the OIT test for samples K, L and M

[0086] As expected, the OIT test of samples K, L and M revealed a longer onset time for the sample referring to the present invention, thus proving its stability in the final product, as compared to the traditional vegetable oil.

[0087| Further, the comparison of the organoleptic characteristics between formulations K and L showed that formulation K exhibited phase migration, as well as yellowing and appearance of odor, in a more prominent manner when compared with formulation L.

Test on hair conditioner— hair-care compositions

[0088] One prepared hair-conditioner formulations by using different samples of vegetable oils.

[0089] AH the body- lotion formulations followed the composition of: 0.10% EDTA, 5.00% Olivem 1000, 1.00% Preserving agent PEHG, 2.00% cationic surfactant Benzalkonium chloride (BZC), 10.00% oil and deionized water q.s.p. 100.

[0090] The oils used were: sample 4 (stressed SBO) as negative control, sample 13 (UT SBO with BHT) to represent the present invention and sample 15 (mineral oil) as positive control.

[0091] The compositions are shown in table 7 below.

Table 7— Hair-conditioner formulations tested

[0092] In a first OIT test carried with samples O. P and Q above, none of the samples exhibited degradation until the time of 40 minutes so once again an accelerated oxidation test was performed as above.

[0093] Said test consists in mixing formulations at a ratio of 1 : 1 with the oil used. For example, in sample O, 2.5g of formulation O were mixed for 3 minutes with 2.5g of Stressed SBO and then the mixture was left to stand for 12 hours.

[0094] The same process was carried out for formulations P and Q, giving rise to samples R, S and T, as shown in table 8 below. Table 8 - Hair-conditioner formulations with accelerated oxidation

[0095] Table 10 - Result of the OIT test for samples R, S and T

[0096] The comparison of the organoleptic characteristics between formulations R and S showed that formulation R exhibited phase migration, yellowing and appearance of color, in a more prominent way when compared with formulation S.

[0097] Additionally, solutions containing only the oil and benzalkonium chloride (BZC) at the ratio of 2:1 were evaluated and the results shown in table 9 below.

Table 9— Formulations of vegetable oil and BZC

Table 1 1 - Result of OIT test for samples U, V and X

[0098] As expected, the OIT test of the above samples revealed a longer onset time for the sample referring to the present invention, thus proving its better stability in the final product, in comparison with the traditional SBO oil.

Determination of the dissipation factor

[0099] The determination of the dissipation factor was carried out according to the standard procedure ABNT NBR 12133, by means of the equipment DTL C. As parameters, the temperatures of 25, 90 and 100°C; the voltage of 500 VCA; and a frequency of 60 Hz were used.

[0100] The UT SBO, exhibits a dissipation factor of: 0.20% at 25°C, 3.60% at 90°C and 4.0% at 100°C.

[0101] Preferred examples of embodiments having been described, it should be understood that the scope of the present invention embraces other possible variations, being limited only by the contents of the accompanying claims, which include the possible equivalents.