Biodegradable polyester for a water-resistant oil sun care formulation

Abstract

To provide polymers that impart high static and water-resistant SPF to oil-in-water sunscreen formulations.SOLUTION: The present disclosure generally relates to a waterproofing polymer that is a substantially non-sequential reaction product of the following components: (i) at least one polyglycerol; (ii) at least one dimer acid; and (iii) at least one fatty acid having 8-30 carbon atoms, where (iii) and (i) are in a molar ratio of less than 2:1. The components are charged to a reaction vessel and subsequently reacted to produce a polyester polymer having excellent waterproofing properties.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure generally relates to new biodegradable polyesters, methods for preparing them, and their use in water-resistant oil-in-water sun care formulations.

Background Art

[0002] Sun screen formulations are important for consumer use where a large amount of sunlight exposure should be managed without experiencing severe erythema (sunburn) during long periods of sunlight exposure, with or without movement, whether the movement involves immersion in water or not. Sunscreens are rigorously controlled and measured using standard sun protection factor (SPF) tests. Each product introduced to the market must label the lesser of two SPF measurements. The static SPF measurement is denoted as "SPF" and involves applying a specific amount of sunscreen formulation to the skin, drying it for a certain period, typically 15 - 30 minutes, and then testing for SPF without further activity, measuring immediately afterwards. The water-resistant SPF measurement, or "WR SPF", is measured on the same test subject after immersion for a specific period. "High water-resistant" SPF is measured after immersion in water maintained at 40°C for 80 minutes and is the focused measurement value hereinafter referred to as "WR SPF". Sunscreen formulations contain so-called active materials that absorb or scatter UV light of specific wavelengths. However, these active substances do not exhibit the film-forming or water-resistant properties necessary to provide the applied sunscreen formulation with currently noted WR SPF values in the range of WR SPF 30, 50, 70, 90, or 100. Instead, a class of materials, typically polymers, are used to provide film-forming and water-resistant properties, which is the object of the present disclosure.

[0003] Screen film-forming agents for water resistance have long been known. Synthetic polymers containing PVP / olefin copolymers and acrylate copolymers that impart water resistance according to their dosages have been developed (both SPF and WR SPF are in the range of SPF15 to SPF50 or higher). These materials can have molecular weights ranging from about 50,000 Da to over 1,000,000 daltons. These synthetic polymers provide high SPF and WR SPF of 50 or higher with the addition of about 2 wt% polymer in the emulsion, but they are also non-biodegradable and thus not desirable for the environment. Currently, all such "microplastics" that are released into water during use such as swimming and snorkeling and do not decompose in the environment are under strict scrutiny.

[0004] As additives to cosmetics, more biodegradable hydrophilic and hydrophobic polyesters have been developed, and some of them have been recommended for sunscreens. However, those polyesters seem to be suitable only for low WR SPF formulations (i.e., those having a relatively low level of water resistance and a WR SPF rating of 15 or perhaps 30). When tested with the standard SPF50 formulation used herein, these materials do not provide an evaluable WR SPF (in some cases, an SPF of about 2 is measured for a 2 wt% polymer addition).

[0005] Therefore, manufacturers of high SPF and WR SPF sports sunscreens are still under pressure from the market and regulatory authorities to provide more natural products with zero microplastic content. Ganex™ polymers [e.g., Ganex™ V-220 polymer (INCI: VP / eicosene copolymer)] are currently very commonly used and can provide sunscreen formulations with high SPF values of 50 or higher, and at the same time can also provide WR SPF values of 50 or higher, i.e., water resistance and abrasion resistance, but these polymers are also not biodegradable.

[0006] Gruning et al., U.S. Patent No. 6,242,499, describes a polyester obtained by esterifying a polyglycerol mixture with a saturated or unsaturated straight-chain or branched fatty acid having 12 to 22 carbon atoms, and a polyfunctional carboxylic acid having 4 to 54 carbon atoms and an average functionality of 2 to 2.4, wherein the degree of esterification of the polyglycerol mixture is between 30 and 75%. The slightly described preparation procedure involves esterifying the polyglycerol with the fatty acid in a first step and, after most or all of the fatty acid has reacted, adding the polyfunctional carboxylic acid in a second step and continuing the esterification reaction. The resulting polyester is described as useful as an oil-in-water emulsifier in the preparation of cosmetic or pharmaceutical preparations including sun protection creams, but there is no teaching or suggestion that the polyester is useful as a sunscreen film-forming agent with respect to water resistance. In fact, the resulting polyester is biodegradable but is characterized by a low WR SPF value.

[0007] O’Lenick, U.S. Patent No. 8,465,730, describes a sunscreen formulation characterized by a "synergistic effect between a sunscreen active and a water-repellent polyester" prepared by reacting a mixture of polyglycerol, a diacid, and a mixture of at least two different fatty acids. The data supporting the improvement is very limited. In some cases, a polyester (Example 35) prepared by reacting polyglyceryl, stearic acid, isostearic acid, and hydrogenated C34 dimer acid provided a static SPF of 42. In other cases, a polyester (Example 68) prepared by reacting polyglyceryl, oleic acid, stearic acid, and azelaic acid provided a static SPF of 39. These values were somewhat higher than those obtained using polymers prepared according to prior art patents, but were focused only on static SPF and were not tested according to the standard immersion protocol that is required by the FDA and other agencies to be classified as water-resistant or highly water-resistant WR SPF. These polymers do not provide the values expected by those skilled in the art for water resistance in suncare formulations, such as those provided by synthetic Ganex™ polymers.

Prior Art Documents

Patent Documents

[0008]

Patent Document 1

Patent Document 2

Patent Document 3

Non-Patent Documents

[0009]

Non-Patent Document 1

[0010] Therefore, in addition to the essential static SPF performance (SPF), there is still a need in the art for a bio-based biodegradable polymer having excellent sensory, water-resistant and water-resistant sun protection factor (WR SPF) performance, which is natural, biodegradable, and resistant to dilution and removal of UV absorbers by water after application, and which exhibits strong performance in sports emulsion sunscreens. These and other objects are met by the present disclosure. [Means for Solving the Problems]

[0011] The present disclosure generally relates to, in one embodiment, a reaction product of the following components: (i) at least one polyglycerol, (ii) at least one dimer acid, and (iii) at least one fatty acid having 8 to 30 carbon atoms, wherein the molar ratio of (iii) to (i) is less than 2:1, which is a waterproof polymer.

[0012] The present disclosure generally relates to, in another embodiment, a method for preparing the disclosed waterproof polymer, comprising: (a) introducing components (i) to (iii) into a reaction vessel; and (b) polymerizing the components.

[0013] The present disclosure generally relates to, in another embodiment, a composition comprising the disclosed waterproof polymer and an organic solvent.

[0014] The present disclosure generally relates to, in another embodiment, a method for preparing the composition, comprising combining the disclosed waterproof polymer and an organic solvent.

[0015] The present disclosure generally relates to, in another embodiment, an oil-in-water formulation comprising the disclosed waterproof polymer.

[0016] The present disclosure generally relates to, in another embodiment, an oil-in-water sunscreen formulation comprising the following individual components: (a) at least one sunscreen active agent, and (b) at least one waterproof polymer disclosed herein.

[0017] "Individual components" means that one component does not satisfy two or more of the listed components. For example, consider a composition comprising individual components (a), (b), and (c). In such an example, at least three components combined to satisfy (a), (b), and (c) must be present, where a first component satisfies (a), a second component different from the first component satisfies (b), and a third component different from the first and second components satisfies (c).

[0018] The present disclosure generally, and in yet another embodiment, relates to a method of protecting a user exposed to sunlight or already exposed from the damaging effects of exposure to sunlight, the method comprising applying to the skin of the user an effective amount of an oil-in-water sunscreen formulation disclosed herein for that purpose.

[0019] The present disclosure generally, and in a further embodiment, relates to a method for making an oil-in-water sunscreen formulation containing at least one sunscreen active agent waterproof, the method comprising incorporating into the sunscreen formulation a waterproofing amount of at least one waterproof polymer disclosed herein.

[0020] The present disclosure will now be described in more detail with reference to the following figures.

Brief Description of the Drawings

[0021]

Figure 1

Figure 2

Modes for Carrying Out the Invention

[0022] The present disclosure generally relates to waterproof polymers that can impart high static and water-resistant SPF to oil-in-water sunscreen formulations.

[0023] A very important benefit of the present disclosure described is a bio-based biodegradable polymer that is natural, biodegradable, and exhibits strong performance in sports emulsion sunscreens that resist dilution and removal of the UV absorber by water after application, having excellent sensory, water-resistant, and excellent water-resistant sun protection factor (WR SPF) performance. The target for the acceptable high WR SPF is considered to be SPF50, SPF30 in some applications, and even SPF60 or higher in still other applications.

[0024] In one embodiment, the disclosed water-resistant polymer is a substantially non-sequential reaction product of the following components: (i) at least one polyglycerol, (ii) at least one dimer acid, and (iii) at least one fatty acid having 8 to 30 carbon atoms, and the reacting components are in a molar ratio of 1 mole of polyglycerol, 0.5 to 1 mol of hydrogenated dimer acid, and 0.1 mol to less than 2.0 moles of fatty acid.

[0025] In one embodiment, the disclosed water-resistant polymer is a substantially non-sequential reaction product of the following components: (i) at least one polyglycerol, (ii) at least one dimer acid, and (iii) at least one fatty acid having 8 to 30 carbon atoms, and the reacting components are in a molar ratio of 1 mole of polyglycerol, 0.5 to 1 mol of hydrogenated dimer acid, and 0.2 to 1.7 moles of fatty acid.

[0026] "Substantially non-sequential reaction product" means that the product is produced by the substantially non-sequential reaction of the reactive components (i) to (iii). The substantially non-sequential reaction of the reactive components (i) to (iii) means that substantially all of the respective contents of the reactants (i) to (iii) to be reacted are added to the reaction vessel before the reaction is initiated. This process is different from the process described in U.S. Patent No. 6,242,499, for example, in which polyglycerol is esterified with a fatty acid in a first step, and after most or all of the fatty acid has reacted, a polyfunctional carboxylic acid is added in a second step and the esterification reaction is continued. In one embodiment of the present disclosure, the entire content of each of the reactants (i) to (iii) to be reacted is added to the reaction vessel before the reaction is initiated, i.e., the reaction is completely non-sequential and the polymer is a completely non-sequential reaction product of the components (i) to (iii). In other embodiments, at least 60 to 100%, or 75 to 100%, or 80 to 100%, or 85 to 100%, or 90 to 100%, or 95 to 100%, or 97 to 100% of each of the reactants (i) to (iii) is added to the reaction vessel before the reaction is initiated.

[0027] While not being bound by theory, the inventors believe that the preparation procedure described in U.S. Patent No. 6,242,499, which reacts polyglycerol with monofunctional fatty acids in the first step, results in undesirable insufficient chain termination or “end capping”. The reaction with monofunctional fatty acids not only reduces the number of free hydroxyl sites available for reaction with polyfunctional carboxylic acids in the second step, but also the fatty acid ester functional groups generated in the first step are substantially inert and thus unavailable for participation in chain extension or branching. This has a significant effect on the properties of the polymer thus produced. As described herein, by introducing substantially all or all of the contents of components (i)-(iii) into the reaction vessel at the time of and / or prior to the occurrence of the polymer reaction, the inhibition by fatty acids on the ability of polyfunctional carboxylic acids to react with polyglycerol is minimized, resulting in longer polymer chains and a wider range of polymer chain crosslinking, higher polymer molecular weight, and higher viscosity.

[0028] With the foregoing in mind, it may be possible to sequentially produce the disclosed polymers, for example, by adding a small or large portion but not all of the monofunctional fatty acids to the polyglycerol in the first step, adding the remainder together with dimer acid in the second step, or even adding it after dimer acid in a third step. Any order is possible as long as the process is carefully designed and monitored so as to avoid insufficient end capping.

[0029] Polyglycerol may be any oligocondensation product of glycerol. In one embodiment, polyglycerol has the formula (I): H[-O-Gly-]n-OH (I) [wherein each Gly is independently the residue of a glycerol molecule after removal of two hydroxy groups, and n is from 2 to 10 (average)] having.

[0030] Generally, most of the Gly groups have the formula: -CH2-CHOH-CH2-, but residues containing etherification at secondary or even tertiary hydroxy groups are considered to be within the scope of "Gly" and can thus also be present. Examples of oligoglycerols include diglycerol, triglycerol, tetraglycerol, pentaglycerol, hexaglycerol, heptaglycerol, octaglycerol, nonaglycerol, decaglycerol, and mixtures thereof. Particularly useful polyglycerols are polyglycerols of formula (I) where n is, in particular, from 2 to 7, more particularly from 2 to 5, especially 2, 3 or 4, or mixtures of oligoglycerols within these ranges.

[0031] Particularly suitable polyglycerols include mixtures of oligoglycerols having the following oligomer distributions: Glycerol: 0 to 30% by weight, preferably 0 to 20% by weight, most preferably 0 to 15% by weight Diglycerol: 10 to 40% by weight, preferably 15 to 35% by weight, most preferably 20 to 32% by weight Triglycerol: 10 to 65% by weight, preferably 15 to 60% by weight, most preferably 18 to 55% by weight Tetraglycerol: 2 to 25% by weight, preferably 5 to 20% by weight, most preferably 8 to 20% by weight Pentaglycerol: 0 to 15% by weight, preferably 0 to 10% by weight, most preferably 0 to 5% by weight Hexaglycerol: 0 to 15% by weight, preferably 0 to 10% by weight, most preferably 0 to 5% by weight Heptaglycerol: 0 to 10% by weight, preferably 0 to 5% by weight, most preferably 0 to 3% by weight Octaglycerol: 0 to 10% by weight, preferably 0 to 5% by weight, most preferably 0 to 3% by weight Nonaglycerol: 0 to 5% by weight, preferably 0 to 3% by weight, most preferably 0 to 2% by weight Decaglycerol: 0 to 5% by weight, preferably 0 to 3% by weight, most preferably 0 to 2% by weight (All weight percentages are based on the total content of polyglycerol).

[0032] In one embodiment, the polyglycerol comprises the following oligomer distribution: Glycerol: 0 - 30 wt% Diglycerol: 15 - 40 wt% Triglycerol: 10 - 55 wt% Tetraglycerol: 2 - 25 wt% Pentaglycerol and higher order components: 0 - 15 wt% (All weight percentages are based on the total content of polyglycerol).

[0033] In one embodiment, the polyglycerol is composed of a combination of at least 40 wt%, or at least 45 wt%, or at least 50 wt% of diglycerol and triglycerol, based on the total weight of the polyglycerol.

[0034] In one embodiment, the polyglycerol is composed of at least 20 wt% or at least 25 wt% of diglycerol, at least 15 wt% or at least 18 wt% of triglycerol, and at least 10 wt% or at least 12 wt% of tetraglycerol, and all weight percentages are based on the total content of the polyglycerol.

[0035] Particularly preferred polyglycerol contains at least 25 wt% of diglycerol, at least 45 wt% of triglycerol, and at least 10 wt% of tetraglycerol.

[0036] Analysis of such any polyglycerol composition can be performed to determine its median, average, or "average" number of polyglycerol. Examples of the above oligoglycerols having both narrow and broad distributions can be equally designated as polyglycerol - 3, because this number is the integer closest to the average and / or median.

[0037] The dimer acid can be any dicarboxylic acid having at least 4 carbon atoms. The dimer acid can be linear or branched, for example, dimers prepared from malonic acid, succinic acid, fumaric acid, dimethylglutaric acid or trimethyladipic acid, and their anhydrides.

[0038] Dimer fatty acids are particularly useful. As is known, these are mixtures of acyclic and cyclic dicarboxylic acids obtained by a catalytic dimerization reaction of unsaturated fatty acids having 12 to 22 carbon atoms.

[0039] For the preparation and use of dimer acids, as well as their physical and chemical properties, reference is made to the paper "The Dimer Acids: The chemical and physical properties, reactions and applications", Ed. E. C. Leonard; Humko Sheffield Chemical, 1975, Memphis, Tenn.

[0040] The dicarboxylic acid can also contain trifunctional and polyfunctional carboxylic acids, although to a relatively low degree. The functionality of the mixture should not exceed an average value of 2.4 moles.

[0041] The inventors have found that the use of higher molecular weight dimer acids provides a beneficial combination of significant hydrophobic characteristics for enhancing waterproofing and significant hydrophilic characteristics for providing some compatibility with the aqueous phase. Dimer acids typically derived from triglycerides rich in C18 ester groups, which can produce C18 unsaturated monocarboxylic fatty acids upon hydrolysis, are preferred. The raw materials can be derived from tall oil and rapeseed oil, but other natural sources including flax, soy, pumpkin, and walnut can be used. The target monocarboxylic acids used in the reaction are rich in oleic and linoleic acid forms as listed in the following list of fatty acids contained. Dimerization mainly results in dimerization of unsaturated fatty acids, but trimers are also formed. After the reaction, the product can be maintained as a mixture of reaction products or further distilled or separated into molecular weight fractions by other means. In one embodiment, the dimerization reaction produces mostly (at least 60 wt%, more preferably at least 75 wt%) dimer acid (C36 diacid), but also produces C54 trimer acid (less than 30 wt%, more preferably less than 25%), with the remainder containing C18 acid and C27 1.5-mers (C27 1 1 / 2-mers).

[0042] In some cases, the commercially available standard dimer acid Pripol 1025 from Croda, containing a total of 7 wt% C18 monomer and C27 1.5-mer, 72 wt% dimer, and 19 wt% trimer acid, is used. In other cases, the hydrogenated standard dimer acid Radiacid 0960 from Oleon, containing 3 wt% C18 monomer and C27 1.5-mer, 87 wt% dimer, and 10 wt% trimer acid, is used. In both cases, the polymers described are characterized by higher molecular weight, higher hydrophobic characteristics, and higher viscosity than those that can be provided by pure lower molecular weight diacids. The presence of trimer acid further enhances the molecular weight and performance of these polymers.

[0043] The inventors have surprisingly discovered that the hydrogenation of dimer acid is a very important factor that affects important properties of the polymers disclosed by the inventors. In particular, the use of hydrogenated dimer acid for preparing the disclosed polymers dramatically increases the water resistance and SPF performance of the resulting sun care formulations and cosmetic formulations.

[0044] Accordingly, in one embodiment, the present disclosure relates to a waterproof polymer prepared from at least one hydrogenated dimer acid.

[0045] In another embodiment, the waterproof polymer is prepared from a hydrogenated dimer acid comprising a hydrogenated dimerized C18 fatty acid, which hydrogenated dimer acid is obtained by dimerization of an unsaturated C18 fatty acid and subsequent hydrogenation.

[0046] The inventors have found that it is beneficial when the hydrogenated dimer acid contains a certain content of trimer acid, as this increases branching and polymer molecular weight.

[0047] In one embodiment, the hydrogenated dimer acid contains a trimer acid content in the range of about 5 - 25 wt% based on the total weight of the hydrogenated dimer acid.

[0048] In another embodiment, the hydrogenated dimer acid contains mostly (at least 60 wt%, more preferably at least 75 wt% but 95 wt% or less, or better yet 90 wt% or less, or even better yet 85 wt% or less) hydrogenated dimer acid (C36 diacid), also contains C54 hydrogenated trimer acid (less than 30 wt%, more preferably less than 25 wt% but more than 5 wt%, more preferably more than 10 wt%), and contains the remaining C18 hydrogenated acid and C27 hydrogenated 1.5 mer.

[0049] The fatty monoacid desirably acts as a terminal cap for the polymerization reaction, provides an adjustable hydrophobic content, and contributes to the polymer properties. All monoacids having 8 to 30 carbon atoms, particularly monoacids having 12 to 30 carbon atoms, can be used, but the inventors prefer C18 or higher monoacids to provide a greater hydrophobic content for water repellency. These can include naturally occurring or purified fatty acids such as hydrolyzed rapeseed oil, sunflower oil, etc., which contain both lower MW chains and higher MW chains.

[0050] Useful fatty monoacids can be straight-chain, branched, saturated, unsaturated, and aromatic materials having an acidity provided by the carboxylic acid moiety. Useful acids include caprylic acid (C8), pelargonic acid (C9), capric acid (C10), undecylic acid (C11), lauric acid (C12), tridecylic acid (C13), myristic acid (C14), pentadecylic acid (C15), palmitic acid (C16), margaric acid (C17), stearic acid (C18), isostearic acid (C18), nonadecylic acid (C19), arachidic acid (C20), behenic acid (C22), and lignoceric acid (C24). Lower molecular weight organic acids including butyric acid (C4), valeric acid (C5), caproic acid (C6), and enanthic acid (C7) could also be used in place of the fatty monoacids.

[0051] Comparing stearic acid and isostearic acid, branching results in a lower melting point and lower viscosity for isostearic acid at room temperature, while stearic acid results in a solid material. This lower viscosity can assist in the handling of the raw material and can also help the esters made with this acid retain liquid properties. Branched-chain fatty acids often contain a single methyl branch along the straight carbon chain and are produced naturally by microbial action. Isostearic acid is available as a reaction byproduct in the production of the aforementioned dimer acid.

[0052] Another route to obtain the liquid product is to use unsaturated straight-chain and branched fatty monocarboxylic acids. These unsaturated acids can include palmitoleic acid (C16:1), vaccenic acid (C18:1), oleic acid (C18:1), elaidic acid (C18:1), linoleic acid (C18:2), linoleelaidic acid (C18:2), α-linolenic acid (C18:3), γ-linolenic acid (C18:3), stearidonic acid (C18:4), paullinic acid (C20:1), gondoic acid (C20:1), dihomo-γ-linolenic acid (C20:3), mead acid (C20:3), arachidonic acid (C20:4), eicosapentaenoic acid (C20:5), erucic acid (C22:1), docosatetraenoic acid (C22:4), cervonic acid (C22:6), and nervonic acid (C24:1). As is well known to those skilled in the art, the designation "CX:Y" means that the carbon chain has X carbon atoms and there are Y double bonds in the chain.

[0053] All of these acids and their mixtures provide hydrophobicity when esterified with polyglycerol. Saturated fatty acids also provide fewer manufacturing side reactions and longer long-term storage of the final product due to the oxidation of the unsaturated bonds that may cause discoloration and other by-products.

[0054] In one embodiment, the fatty acid is stearic acid, a straight-chain saturated C18 fatty acid, or oleic acid which is a monounsaturated C18. However, the unsaturation point may result in subsequent oxidative instability, and a straight-chain C18 fatty acid can cause crystallization of the polymer.

[0055] For this reason, the inventors prefer isostearic acid which provides long-term stability and inhibits crystallization and phase separation of both the raw material components and the final polymer.

[0056] In a particularly preferred embodiment, the waterproof polymer is composed of the following components: (i) at least one polyglycerol containing at least 25 wt% of diglycerol, at least 45 wt% of triglycerol, and at least 10 wt% of tetraglycerol (in each case based on the total weight of the polyglycerol), (ii) at least one hydrogenated dimer acid containing at least 60 wt% of hydrogenated C36 diacid and 5 - 25 wt% of hydrogenated C54 triacid (in each case based on the total weight of the hydrogenated acid), and (iii) isostearic acid, which is a substantially or completely non-sequential reaction product.

[0057] In one embodiment, the waterproof polymer is prepared by a one-step process in which all reactants are introduced into a reaction vessel and then a completely statistical addition of dimer acid and isostearic acid to the polyglycerol is induced.

[0058] The inventors have found that the highest waterproof properties of the polymer are obtained when the polyglycerol contains an excess of OH groups compared to the acid groups added by the combination of isostearic acid and dimer acid materials. As described above, a variety of polyglycerols are used in blended form and exhibit the unique performance imparted by this material.

[0059] As described above, the sequential process utilized in U.S. Patent No. 6,242,499 resulted in inadequate end capping, but the inventors have discovered that this alone is not a problem that prevents the realization of the beneficial properties described herein in its prior art. This situation was exacerbated by a high ratio of monofunctional fatty acids to polyglycerol. The inventors have found that when the molar ratio of fatty acid to polyglycerol is reduced to less than 2:1, an increase in waterproofness, as well as higher static SPF and WR SPF, can be achieved.

[0060] In one embodiment, the reacting components are in a molar ratio of 1 mole of polyglycerol, 0.5 - 1 mol of dimer acid, and 0.2 - 1.7 moles of fatty acid.

[0061] In another embodiment, the reacting components are in a molar ratio of 1 mole of polyglycerol, 0.5 to 0.75 mol of dimer acid, and 0.4 to 1.35 mol of isostearic acid.

[0062] In another embodiment, the reacting components are in a molar ratio of 1 mole of polyglycerol, 0.5 to 0.7 mol of dimer acid, and 0.65 to 1 mol of isostearic acid.

[0063] In one embodiment, the reacting components are in a molar ratio of 1 mole of polyglycerol, 0.5 to 1 mol of hydrogenated dimer acid, and 0.2 to 1.7 mol of fatty acid.

[0064] In another embodiment, the reacting components are in a molar ratio of 1 mole of polyglycerol, 0.5 to 0.75 mol of hydrogenated dimer acid, and 0.4 to 1.35 mol of isostearic acid.

[0065] In another embodiment, the reacting components are in a molar ratio of 1 mole of polyglycerol, 0.5 to 0.7 mol of hydrogenated dimer acid, and 0.65 to 1 mol of isostearic acid.

[0066] In another embodiment, the reacting components are in a molar ratio of 1 mole of polyglycerol-3, 0.5 to 1 mol of hydrogenated dimer acid, and 0.2 to 1.7 mol of isostearic acid.

[0067] In another embodiment, the reacting components are in a molar ratio of 1 mole of polyglycerol-3, 0.5 to 0.75 mol of hydrogenated dimer acid, and 0.4 to 1.35 mol of isostearic acid.

[0068] In another embodiment, the reacting components are in a molar ratio of 1 mole of polyglycerol-3, 0.5 to 0.7 mol of hydrogenated dimer acid, and 0.65 to 1 mol of isostearic acid.

[0069] In the most preferred embodiment, the reacting components are in a molar ratio of 1 mole of polyglycerol-3, 0.5 moles of hydrogenated dimer acid, and 1 mole of isostearic acid.

[0070] In another most preferred embodiment, the reacting components are in a molar ratio of 1 mole of polyglycerol-3, 0.67 moles of hydrogenated dimer acid, and 0.67 moles of isostearic acid.

[0071] It is also possible to control the degree of extension and end-capping of dimer acid A-polyglycerol by adjusting the molar ratio of the fatty acid end-caps and balancing the amounts of polyglycerol and dimer acid, and thus, for example, through cross-linking via trimer acid, the viscosity becomes considerably higher.

[0072] The target viscosity of the pure polymer should be >50,000 cP and <5,000,000 cP at 25°C.

[0073] In a preferred embodiment, the target viscosity is >75,000 cP and <2,500,000 cP at 25°C.

[0074] In another preferred embodiment, the target viscosity is >100,000 cP and <2,000,000 cP at 25°C.

[0075] In the most preferred embodiment, the target viscosity is >1,000,000 cP and <2,000,000 cP at 25°C, thereby further improving water resistance.

[0076] The disclosed polymers are characterized by a weight average molecular weight > 2500 Da and < 1,000,000 Da as measured using standard linear polystyrene with GPC. The GPC columns used for these tests consisted of Phenolgel, 300 × 4.6 mm, used a continuous phase of tetrahydrofuran (THF), were injected at 0.35 mL / min, the column oven was held at 40 °C, had a 50 μL injection, and used a Wyatt refractive index Ri detector. The calibration standards used were linear polystyrenes prepared to be monodisperse. The narrow range of polystyrene GPC calibration standards were prepared in the mobile phase and had peak molecular weights of 1,290,000 Da, 560,000 Da, 65,500 Da, 28,500 Da, 10,100 Da, 1,680 Da, 580 Da and 208 Da. From the standard method, the weight average and number average molecular weights are automatically calculated by the standard GPC software. Here the inventors focus on the determination of the weight average molecular weight, which the inventors herein abbreviate as “M w ”. M w can in most cases be very important information, but it is known that the radius of gyration of a fully dissolved cross-linked polymer is smaller than that of a dissolved ideal linear polymer of the same molecular weight and monomer composition. This size decrease for similar actual molecular weights is characterized as the “polymer contraction coefficient”. See the literature such as the contraction coefficient of Zimm-Stockmayer. The scale of the contraction coefficient varies depending on monomer selection, percentage of trimers, and percentage of conversion, and the aforementioned substantially non-sequential reaction conditions. The inventors, in their analytical tests, compare the low molecular weight fraction (less than 1000 Da) with both the GPC data and measurements of the remaining monomers of the materials used in the polymerization examples, e.g., polyglycerol-3, hydrogenated dimer acid, and isostearic acid. In this way, for the polyester polymers of the present disclosure, the contraction coefficient was determined to be about 3. To be consistent with the standard GPC method, the determined value of its molecular weight is reported as “measured” M w determinations compared to linear polystyrene reported without correction for the contraction coefficient. Instead the inventors use Mw Report a novel combination of (for linear polystyrene) with the viscosity of the same polymer, where a higher viscosity can be directly measured, and for branched polymers, the viscosity can increase significantly and can have a shrinkage coefficient of 3 or higher, for example.

[0077] In a preferred embodiment, the disclosed polymers have a weight average molecular weight > 4000 Da and < 250,000 Da as measured using standard linear polystyrene with GPC.

[0078] In the most preferred embodiment, the disclosed polymers have a weight average molecular weight > 5000 Da and < 150,000 Da as measured using standard linear polystyrene with GPC.

[0079] As described above, U.S. Patent No. 6,242,499 proposes esterifying polyglycerol with fatty acids in a first step, and after reacting most or all of the fatty acids, adding a polyfunctional carboxylic acid in a second step and continuing the esterification reaction. This limits the development of the molecular weight and reduces the viscosity of the polymer, and the polymer could not provide good waterproof behavior.

[0080] The inventors have found that excellent waterproof properties are provided by a specific combination of M w and viscosity obtained by the one-step process described herein. The polyester polymers of the present disclosure were measured using an MCR302 Rheometer manufactured by Anton Paar Inc. Two plates with a diameter of 50 mm, one rough and one flat, were used, coated with the polymer sample, adjusted to a gap of 0.5 - 1 mm, and both temperature and shear rate sweeps were performed. The polymers of the present disclosure exhibit Newtonian behavior and thus have a constant viscosity over a wide range of shear rates. Also, the polymers of the present disclosure demonstrated a decrease in viscosity with temperature. Therefore, the measured viscosity values were at accurately controlled temperatures and typically 1 second -1is reported at a shear rate. The value is reported in units of centipoise (cP). 1000 cP is equivalent to 1 Pascal-second (Pa-s). As described above, the measured viscosity is related to the M of the polymer measured by GPC using standard linear polystyrene w The combination with is one important parameter for defining the waterproof polymer of the present disclosure.

[0081] In one embodiment, the waterproof polymer has an M measured using standard linear polystyrene with GPC w > 2500 Da and < 1,000,000 Da, and at 25 °C has a viscosity combination of > 50,000 cP and < 5,000,000 cP for the neat polymer.

[0082] In another embodiment, the waterproof polymer has an M measured using standard linear polystyrene with GPC w > 4000 Da and < 250,000 Da, and at 25 °C has a viscosity combination of > 75,000 cP and < 2,500,000 cP for the neat polymer.

[0083] In yet another embodiment, the waterproof polymer has an M measured using standard linear polystyrene with GPC w > 5000 Da and < 150,000 Da, and at 25 °C has a viscosity combination of > 100,000 cP and < 2,000,000 cP for the neat polymer.

[0084] In a preferred embodiment, the waterproof polymer comprises the following components: (i) at least one polyglycerol containing at least 25 wt% diglycerol, at least 45 wt% triglycerol, and at least 10 wt% tetraglycerol (in each case based on the total weight of the polyglycerol), (ii) at least one hydrogenated dimer acid containing at least 60 wt% hydrogenated C36 diacid and 5 - 25 wt% hydrogenated C54 triacid (in each case based on the total weight of the hydrogenated acid), and (iii) substantially or completely non - sequential reaction products of isostearic acid, and the waterproof polymer shows a combination of viscosities of the neat polymer of M w >5000 Da and <150,000 Da, and at 25 °C >100,000 cP and <2,000,000 cP.

[0085] As described extensively above, the reaction sequence and non-sequential reactions, and the ratio of polyglycerol to dimer acid and monoacid are very important to achieve a favorable combination of viscosity and molecular weight. By definition, these ratios of polyol to monoacid and polyacid define the so-called degree of esterification when the reaction is driven to completion. Polycondensation reactions, such as those based on the polyester polymers of the present disclosure, typically involve either an excess of polyol moiety or polyacid moiety. Monoacids, by definition, cannot polymerize and rather act only as end caps. With five hydroxy groups present in polyglycerol-3, the polyol monomers of the present disclosure and their hydroxyl moieties serve as the ideal sole candidates to be retained in excess. If one were to attempt to react all the hydroxy groups with the large fatty acid groups disclosed, such reaction would result in both prohibitively high MW and gelation, rendering the product difficult to handle and unsuitable for use as a cosmetic ingredient. Thus, the inventors have calculated from the preferred molar ratios, a total esterification (total esterification) of the hydroxyl moieties of the available polyglycerol, which the inventors prefer, of 24% to 74%, and an esterification of the hydroxyl moieties of the available polyglycerol with dimer acid alone (esterification with dimer acid) of 20% to 40%. Most importantly, the degree of esterification with end cap units (esterification with monoacid) is also described in the present disclosure, and it is important to maintain the esterification with monoacid between 4% and 40%.

[0086] The inventors more preferably state that the total esterification is between 28% and 57%, of which the esterification with dimer acid is between 20% and 30% and the esterification with monoacid is between 8% and 27%.

[0087] The inventors even more preferably state that the total esterification is between 33% and 48%, of which the esterification with dimer acid is between 20% and 28% and the esterification with monoacid is between 13% and 20%.

[0088] The inventors further prefer that the total esterification is between 24% and 74%, among which the esterification using hydrogenated dimer acid is between 20% and 40% and the esterification using monoacid is between 4% and 40%.

[0089] The inventors further prefer that the total esterification is between 28% and 57%, among which the esterification using hydrogenated dimer acid is between 20% and 30% and the esterification using monoacid is between 8% and 27%.

[0090] The inventors most prefer that the total esterification is about 40%, among which the esterification using hydrogenated dimer acid is about 20% and the esterification using monoacid is about 20%.

[0091] The inventors also most prefer that the total esterification is about 40%, among which the esterification using hydrogenated dimer acid is about 27% and the esterification using monoacid is about 13%.

[0092] In a preferred embodiment, the waterproof polymer comprises the following components: (i) at least one polyglycerol containing at least 25 wt% of diglycerol, at least 45 wt% of triglycerol, and at least 10 wt% of tetraglycerol (in each case based on the total weight of the polyglycerol), (ii) at least one hydrogenated dimer acid containing at least 60 wt% of hydrogenated C36 diacid and 5 - 25 wt% of hydrogenated C54 triacid (in each case based on the total weight of the hydrogenated acid), and (iii) isostearic acid, which is a substantially or completely non-sequential reaction product, and the waterproof polymer shows a combination of the viscosity of the neat polymer with M w > 5000 Da and < 150,000 Da as measured using standard linear polystyrene with GPC, and > 100,000 cP and < 2,000,000 cP at 25°C, and the waterproof polymer is also characterized by the fact that the total esterification is about 40%, among which the esterification using hydrogenated dimer acid is about 27% and the esterification using monoacid is about 13%.

[0093] In fact, since the raw material components contain various polyglycerol units as well as various dimer and trimer acid contents, the aforementioned numbers can be adjusted using the actual (and non-theoretical) hydroxyl moieties and carboxylic acid moieties as determined by standard methods such as mass spectrometry, NMR, and liquid chromatography. The previous esterification ranges are based on the ideal structures of polyglycerol-3 and C36-dimer acid. Therefore, the actual ranges may vary slightly from the values shown previously and can be calculated based on these analytical analyses.

[0094] It is most practical to define the degree of polymerization by the final acid value (AV). The initial acid value can be reliably calculated using the actual acid value determined by the raw material components used in light of the distribution of the polyglycerol, monoacid, and polyacid moieties present.

[0095] In one example, the initial total acid value (generally defined as "AV" in mg(KOH) / g(total reactants)) is 135 AV. This includes 68 AV for the dimer acid and 67 AV for the isostearic acid in a preferred embodiment containing 1 mole of polyglycerol-3, 0.5 moles of hydrogenated C36 dimer acid, and 1 mole of isostearic acid. All of the aforementioned preferred ratio embodiments have corresponding initial AVs that can be calculated. When the AV unit is reduced during the polymerization reaction process, this ratio gives the percent conversion of the reaction from the total initial reactive acid moieties to the final remaining acid moieties. Therefore, the completion of the reaction is 1 minus the ratio of the final AV to the initial AV.

[0096] In one embodiment, the polymer of the present disclosure has a final acid value of 0.1 to <25 mg(KOH) / g (polymer).

[0097] In a preferred embodiment, the polymer has a final acid value of 0.1 to <10 mg(KOH) / g (polymer).

[0098] In the most preferred embodiment, the polymer has a final acid value of 0.1 to <5 mg(KOH) / g(polymer).

[0099] When the completion of the reaction is expressed as 1 - final AV / initial AV, the completion of the reaction from such a reactor mixture to the final polymer is >80%.

[0100] In a preferred embodiment, the completion of the reaction from such a reactor mixture to the final polymer is >90%.

[0101] In the most preferred embodiment, the completion of the reaction from such a reactor mixture to the final polymer is >95%.

[0102] In particular, in order to facilitate the transport of the polymer, the polymer can be combined with an organic solvent.

[0103] In one embodiment, the solvent is selected from the group consisting of, but not limited to, volatile solvents such as methanol, ethanol, isopropanol, glycerol, propanediol, etc., which are preferably easily removable.

[0104] If necessary, the polymer can also be diluted with various emollients as needed to reduce the viscosity of the blend at room temperature. Emollients can include any suitable oil, solvent, ester, triglyceride, ether, silicone, hydrocarbon, etc. suitable for the end-use application. Typical emollients for sun care emulsions and products include triheptanoin, isopropyl palmitate, isopropyl myristate, triheptanoin (and) C13 - C16 isoparaffin, heptyl undecylenate, caprylic / capric triglyceride, diisooctyl succinate, C13 - C16 isoparaffin (and) heptyl undecylenate, C12 - C15 alkyl benzoate, caprylic / capric triglyceride, and other suitable esters. When diluted with an emollient, the addition is carried out while mixing at about 80°C to 100°C while maintaining the final product. Next, the combination is discharged from the reactor and further cooled to 50 - 70°C for placement in a storage tank.

[0105] In one embodiment, the polymer is diluted to a polymer with a final concentration of 10 wt% to 99 wt%, and the diluent is an emollient suitable for skin and personal care applications consisting of an ester or triglyceride.

[0106] In another embodiment, the polymer is diluted to a polymer with a final concentration of 30 wt% to 90 wt%, and the diluent is an emollient suitable for skin and personal care applications consisting of an ester or triglyceride from the list described above.

[0107] In yet another embodiment, the polymer is diluted to a polymer with a final concentration of 50 wt% to 80 wt%, and the diluent is an emollient suitable for skin and personal care applications consisting of an ester or triglyceride.

[0108] The polymer can be incorporated into the formulation to impart waterproof properties to an oil-in-water formulation.

[0109] In one embodiment, the water - resistant polymer is incorporated into the water - in - oil formulation in an amount of 0.1 to 10 wt% based on the total weight of the formulation.

[0110] In another embodiment, the water - resistant polymer is incorporated into the water - in - oil formulation in an amount of 0.5 to 5 wt% based on the total weight of the formulation.

[0111] In yet another embodiment, the water - resistant polymer is incorporated into the water - in - oil formulation in an amount of 1 to 3 wt% based on the total weight of the formulation.

[0112] At these amounts, when the water - in - oil formulation is a sunscreen formulation and the water - resistant polymer is prepared from hydrogenated dimer acid, the inventors have surprisingly discovered that the sunscreen formulation is characterized by an enhancement of the SPF. The enhancement of the SPF was confirmed in both static SPF tests, particularly in the water - resistant SPF (WR SPF) test.

[0113] Sunscreen formulations typically contain at least one sunscreen active agent. For the purposes of this disclosure, a "sunscreen active agent" is a material that is used alone or in combination with other such materials that are considered to be acceptable for use as an active sunscreen component based on its ability to absorb UV radiation. Such compounds are generally described by their ability to act as UV active agents and their performance in different spectral regions described as UV-A, UV-B or UV-A / UV-B. In order for a formulation containing an active agent to be intended for use on humans, approval by regulatory authorities is required. Active agents that have been approved or are currently approved for sunscreen use in the United States include, but are not limited to, para-aminobenzoic acid, avobenzone, cinoxate, dioxybenzone, homosalate, menthyl anthranilate, octyl salicylate, oxybenzone, padimate O, phenylbenzimidazole sulfonic acid, sulisobenzone, trolamine salicylate, titanium dioxide, zinc oxide, diethanolamine methoxycinnamate, digalloyl trioleate, ethyl dihydroxypropyl PABA, glyceryl aminobenzoate, Lawson's with dihydroxyacetone, and organic and inorganic substances including petrolatum red.Examples of additional sunscreen active substances that are not yet approved in the United States but are allowed in formulations sold outside the United States include ethylhexyl triazone, dioctyl butamidotriazone, benzylidene malonate polysiloxane, terephthalylidene dicamphor sulfonic acid, disodium phenyl dibenzimidazole tetrasulfonate, diethylamino hydroxybenzoyl hexyl benzoate, bis - diethylamino hydroxybenzoyl benzoate, bis - benzoxazoyl phenyl (benzoxazoylphenyl) ethylhexyl iminotriazine, droxmetrizole trisiloxane, methylene bis - benzotriazolyl tetramethylbutylphenol, and bis - ethylhexyl oxy phenol methoxyphenyl triazine, 4 - methylbenzylidene camphor, homosalate, butyl methoxydibenzoylmethane, octocrylene, octyl salicylate, bemotrizinol, and isopentyl 4 - methoxycinnamate. However, since the list of approved sunscreens is currently expanding, those skilled in the art will recognize that the present disclosure is not limited to sunscreen active agents currently approved for human use and can be readily applied to sunscreen active agents that may be approved in the future.

[0114] Approved in Europe and thus useful sunscreen activators according to the present disclosure include, but are not limited to, benzophenones such as benzophenone-3 (BP3) and benzophenone-4 (BP4); salicylates such as homosalate (HMS) and 2-ethylhexyl salicylate (EHS); p-aminobenzoic acid and derivatives such as ethylhexyl dimethyl PABA (OD-PABA) and 4-p-aminobenzoic acid (PABA); benzimidazole derivatives such as phenylbenzimidazole sulfonic acid (PMDSA) and disodium phenyl dibenzimidazole tetrasulfonate (bisdisrizole disodium); triazines such as ethylhexyl triazone (OT), diethylhexyl butamidotriazone (DBT) and bis-ethylhexyloxyphenol methoxyphenyl triazine (EMT); benzotriazoles such as droxmetrizole trisiloxane (DRT) and methylene bis-benzotriazolyl tetramethylbutylphenol (MBP, biscotrizole); dibenzoylmethane derivatives such as 4-tert-butyl-4'-methoxydibenzoylmethane (BM-DBM, avobenzone); cinnamic acid esters such as ethylhexyl methoxycinnamate (OMC) and isoamyl p-methoxycinnamate (IMC, amyloxate); and camphor derivatives such as terephthalylidene dicamphor sulfonic acid (PDSA), 3-benzylidene camphor (3BC), benzylidene camphor sulfonic acid (BCSA), 4-methyl benzylidene camphor (4-MBC), polyacrylamide methyl benzylidene camphor (PBC) and camphor benzalkonium metosulfate (CBM).

[0115] In one embodiment of the present disclosure, the sunscreen activator comprises particulate matter of at least one inorganic pigment or nanopigment in a photoprotective effective amount, non-limiting examples of which include titanium dioxide, zinc oxide, iron oxide, zirconium oxide, cerium oxide, or a mixture thereof.

[0116] Generally, a sunscreen active agent is present in a sunscreen formulation in an amount well known in the art to be effective to protect a user who is or has been exposed to sunlight from the damaging effects of exposure to sunlight. Typically, these amounts range from 1 to 25% by weight, preferably 3 to 25% by weight, based on the total weight of the sunscreen formulation.

[0117] The disclosed sunscreen formulations, referred to herein as "cosmetic ingredients", can contain a wide variety of additional ingredients as needed, which can generally also include ingredients known as pharmaceutically active agents. CTFA Cosmetic Ingredient Handbook, Seventh Edition, 1997 and the Eighth Edition, 2000, which are hereby incorporated by reference in their entirety, describe a wide variety of cosmetic and pharmaceutical ingredients suitable for use in the compositions of the present disclosure, generally used in skin care compositions. Examples of these functional classes disclosed in this reference include absorbents, abrasives, anti-caking agents, anti-foaming agents, antioxidants, binders, biological additives, buffers, bulking agents, chelating agents, chemical additives, colorants, cosmetic astringents, cosmetic biocides, denaturants, pharmaceutical astringents, topical analgesics, film formers, fragrance components, humectants, opacifiers, pH adjusters, plasticizers, reducing agents, skin bleaching agents, skin conditioning agents (emollients, humectants, various, and occlusives), skin protectants, solvents, foam boosters, hydrotropes, solubilizers, suspending agents (non-surfactants), sunscreen agents, ultraviolet absorbers, SPF boosters, water repellents, and thickeners (aqueous and non-aqueous).

[0118] In one embodiment, the present disclosure relates to an oil-in-water sunscreen formulation comprising the following individual components: (a) at least one sunscreen active agent, and (b) at least one water-repellent polymer disclosed herein, and (c) at least one oil-in-water emulsifier.

[0119] Suitable water-in-oil emulsifiers are all well-known in the art. The materials described in U.S. Patent Application Publication No. 2018 / 0320096, the entire content of which is incorporated herein by reference, and the amounts of such materials are particularly preferred.

[0120] The disclosed water-in-oil sunscreen formulations are applied by rubbing them into the skin as a liquid, but they can also be applied as a spray. However, the disclosed water-in-oil formulations can take other forms, for example, as lipsticks, makeup, lip balms, eyeshadows, hair dyes and conditioners, or as any application where sun protection may be considered beneficial.

[0121] The present disclosure will now be described in more detail with reference to the following non-limiting examples.

Examples

[0122] Examples of Compounds A. General Procedure The inventors prefer the use of reactions in which all monomers are added in a single addition, with or without any acid or base catalyst, with the reaction vessel placed under vacuum or nitrogen sparge, or under a combination of vacuum and nitrogen sparge. The reaction mixture is heated with stirring over 10 minutes to 10 hours at a constant gradient or a stepwise gradient to a temperature of 160°C to 250°C and held at a temperature of 160°C to 250°C for 2 to 10 hours.

[0123] The inventors more preferably linearly or stepwise gradient to 200°C over 20 minutes to 8 hours and hold it at a temperature of 180°C to 210°C for 2 to 6 hours.

[0124] The inventors most preferably linearly or stepwise gradient to 200°C over 2 hours to 5 hours and hold it at a temperature of 195°C to 205°C for 3 to 5 hours.

[0125] For example, a useful waterproof polymer was prepared as follows. A mixture of 24.0 g of polyglycerol-3, 28.2 g of dimer acid, 28.4 g of isostearic acid (CAS#30399-84-9), and 0.24 g of sodium hydroxide was added to a reaction vessel under a downward distillation setting. The mixture was stirred, heated to 180 °C, and held at 180 °C for 30 minutes. Next, the temperature of the mixture was raised to 190 °C for 30 minutes and continued to 200 °C. The mixture was held at 200 °C to 205 °C for about 2 to 4 hours until the final acid value reached less than 3.0 meq(KOH) / ml by titration. Dew condensation during the reaction process was removed by the distillation setting. After cooling the final product to about 100 °C to 120 °C, it was decanted with 100% active substance.

[0126] B. Water-resistant polymer Following the general procedure outlined above, the polymers in Table 1 below were produced.

[0127]

Table 1

[0128] In the previous table, PG-3 "Type A" is a self-made polyglycerol composed of 17.62 wt% glycerol, 25.4 wt% diglycerol, 18.46 wt% triglycerol, 12.15 wt% tetraglycerol, 8.09 wt% pentaglycerol, 5.48 wt% hexaglycerol, 3.69 wt% heptaglycerol, 2.43 wt% octaglycerol, 1.46 wt% nonaglycerol, 0.83 wt% decaglycerol, 0.37 wt% undecaglycerol, and 0.16 wt% dodecaglycerol.

[0129] The PG-3 "Type B" available from Inovyn has a narrower oligoglycerol distribution and is composed of 30.6 wt% diglycerol, 49.41 wt% triglycerol, 14.78 wt% tetraglycerol, 3.86 wt% pentaglycerol, 1.10 wt% hexaglycerol, 0.28 wt% heptaglycerol, and 0.07 wt% octaglycerol.

[0130] C. Comparison with Industry Standards (WR SPF) The water-resistant SPF of the prepared polymers was compared with the controls and certain industry standards shown in Table 2 below.

[0131]

Table 2

[0132] Ganex™ V216 is a vinyl pyrrolidone and hexadecene copolymer (INCI: VP / hexadecene) and is available from Ashland Corporation. This is a synthetic polymer that exhibits performance in making sunscreen formulations waterproof but does not exhibit biodegradability performance and is liquid at 25°C.

[0133] Ganex™ V220 is a blend of polyvinyl pyrrolidone (PVP), and a copolymer of vinyl pyrrolidone and eicosane (INCI: PVP (and) VP / eicosene) and is available from Ashland Corporation. This is a synthetic polymer that exhibits performance in making sunscreen formulations waterproof but does not exhibit biodegradability performance and is solid at 25°C.

[0134] Schercemol™ PDD is a non-performing different polymer consisting of PG-3, DA, and ISA available from Lubrizol.

[0135] Isolan (trademark) PDI is a non-performing different polymer consisting of PG-3, DA, and ISA, available from Evonik Corporation.

[0136] As is standard in the art, to measure and determine the effectiveness of new biodegradable polyesters for use in water-resistant suncare formulations, the inventors make water-in-oil (O / W) sunscreen formulations using the polyesters of the present disclosure, as well as all comparative polymers and polyesters, and a control.

[0137] In the present disclosure of biodegradable polyesters for use in water-resistant O / W suncare formulations, the inventors use the following formulation procedure. Specifically, the inventors select known UV-absorbing oils used for sunscreen formulations that can be adjusted to provide SPF50 performance or higher. Specifically, as is known in the art, the inventors use commercial data to devise a cocktail of UV-absorbing oils that provide appropriate UV absorption and protection across the desired spectrum. This wavelength range is 350 nm to 400 nm. For comparison purposes, and unless otherwise noted, each emulsion was made using 2 wt% film-forming polymer. Additionally, depending on the degree of water resistance required for a given suncare application, the polymer can be used at additions of 0.1 wt% to 10 wt%. The inventors prefer the use of polymer additions of 0.1 wt% to 10 wt%. The inventors more prefer the use of polymer additions of 0.5 wt% to 5 wt% to obtain SPF performance in the range of 30 to 70 SPF or higher, and the inventors most prefer the use of polymer additions of 1 wt% to 3 wt%.

[0138] The purpose of the polymer is to provide a water-resistant, friction-resistant sunscreen after being properly applied to the skin in a standard manner and allowed to dry. Since the SPF depends on UV absorption in the desired spectral region, the inventors strictly applied the application of a film of repeatable standard thickness in all tests involving UV absorption measurements.

[0139] It is widely known that about 2 wt% of the polymer in the W / O sunscreen emulsion provides sufficient water resistance to pass the so-called 80-minute water resistance test. Here, the formulations used for all polymer tests are shown below. However, this is not a fixed manufacturing method, and other similar emulsions were also prepared and tested.

[0140] The emulsion formulation procedure mainly consists of preparing an aqueous phase solution containing hydrophilic materials, separately preparing an oil phase containing hydrophobic materials, and then emulsifying the heated oil phase mixture in the aqueous phase mixture. As long as an appropriate amount of oil is slowly added to the aqueous phase under continuous high-shear dispersion, the oil droplets decrease in size and ultimately form small oil droplets in the so-called continuous aqueous phase.

[0141] The aqueous phase was prepared by placing an overhead mixer equipped with a propeller blade and a 1000 mL beaker, filling it with deionized water, and mixing while vigorously vortexing at approximately 500 rpm. Pemulen TR-2 is an acrylic acid containing emulsifiers and thickeners mainly to bring about the emulsification of oil. It was slowly added while stirring in this way and mixed until completely dispersed (about 10 minutes). After dissolution, while maintaining stirring, the remaining aqueous phase components including disodium EDTA (chelating agent), propylene glycol (conditioning agent), phenoxyethanol and ethylhexylglycerin (preservative) were added in 1 - 2 minutes per single addition. After dissolution, the beaker was then transferred to a high-shear Silverson homogenizer set at 1200 rpm, heated, and maintained at 75 - 80 °C.

[0142] The oil phase was mixed in a separate 250 mL beaker equipped with a magnetic stirrer, thereby mixing all the oil phase components and heating them at 75 - 80 °C until dissolved. A UV absorber containing avobenzone, ethylhexyl salicylate, homosalate, and octocrylene was added. Next, the oil emulsifier ARLACEL 165 and the emollient Finsolv TN were added. Once the oil phase was melted, it was slowly added to the aqueous phase at 1200 rpm using a high-shear homogenizer, the speed was increased to 4000 rpm, and it was emulsified at 4000 rpm for 10 minutes while continuously maintaining the heat at 75 - 80 °C.

[0143] The resulting O / W emulsion was adjusted to a homogenizer speed of 3000 rpm and slow cooling to 65 °C was initiated. In a separate 30 mL beaker equipped with a magnetic stirrer, the TEA neutralizer and water were mixed until dissolved (about 1 - 2 minutes). At 65 °C, the homogenization was adjusted back to 4000 rpm, the TEA / water premix was added, and it was homogenized for 5 minutes. Finally, the homogenization was reduced to 3000 rpm and the solution was cooled to 45 °C using a room temperature water bath. At 45 °C, the significantly thickened emulsion was then transferred to a beaker and placed on an overhead mixer equipped with a jiffy paddle and mixed at 20 rpm in a water bath until the emulsion temperature reached 25 °C. Finally, the pH was adjusted to 6.00 - 6.50 using a 50% citric acid solution. After stirring at 20 - 22 °C for 18 hours, the viscosity measured at 20 rpm using a Brookfield rheometer equipped with a Heliopath Spindle C was 8000 - 12,000 cP, typically about 10,000 cP.

[0144] For each of Examples 1 - 13 in Tables 1 and 2, such O / W type SPF50 sunscreen emulsions were prepared using the method described above. These sunscreen formulations are shown as Examples 14 - 26 respectively. Each example was prepared at a total weight of 500 g, and the addition levels used and the specific components are shown in Table 3.

[0145]

Table 3 - 1

[0146]

Table 3-2

[0147] To demonstrate the effectiveness of examples of sunscreen formulations made using the polyester of the present disclosure or the lack of effectiveness of formulations made using comparative products, a series of tests were conducted on each of the formulations produced to quantify the so-called sun protection factor (SPF) and demonstrate their effectiveness in producing a demonstrable water-resistant suncare formulation. Due to the importance of the SPF test for the labeling of consumer suncare products, regulatory agencies regulate the labeling of these products and require testing of the products on human panels using specific statistical criteria. The SPF measures the ratio of the time it takes for skin protected with sunscreen to begin to show erythema compared to areas of the same human panel's skin not protected with sunscreen. The measurement of WR SPF is likewise done after standard immersion of the skin in water at 40 °C. Using statistical criteria, such as the following data, a test panel of five was tested to determine both SPF and WR SPF. The tests were conducted by Florida Suncare Testing, Inc., Bunnell, Florida, USA, in accordance with FDA, 21 CFR Sec. 201.327, subpart (i) SPF Test Procedure, Suncreen Drug Products for Over-the-Counter Human Use, Final Monograph, Federal Register, Vol. 76, No. 117, June 17, 2011. For so-called high water resistance criteria, the suncare product is simply dried on the skin and measured after immersing the skin in water maintained at 40 °C for 80 minutes to demonstrate SPF and WR SPF protection above the desired level that can be reported. In these standard tests, the skin area of the human panel was 2 mg / cm 2It is coated with a uniform layer of the sunscreen formulation having a wet weight. The results are reported and described as in vivo SPF and in vivo WR SPF.

[0148] Furthermore, for laboratory measurements of SPF and WR SPF, a series of in vitro measurements can also be performed. In Europe, the Colipa test method is used. In the United States, the FDA 21 CFR Section 201 and 320 tests are used. In these measurements, a plastic film or substrate is used to simulate the roughness and other properties of human skin. In this case, various devices can be used to perform SPF measurements using the substrate. The inventors used a Labsphere UV-1000 spectrophotometer. Vitro Skin™ manufactured by Florida Suncare, Inc. (formerly IMS Inc.), an artificial skin made of a partially hydrophilic acrylic polymer material, was used according to the manufacturer's instructions. The membrane was coated with 20 × 5 mg droplets of the emulsion and carefully and uniformly distributed over a membrane area of 100 cm 2 and 2 mg / cm 2Coat again. Using a UV spectrophotometer, the absorption (or transmission) of both UVA radiation (320 - 400 nm) and UVB radiation (290 - 320 nm) was measured. From these values, the in vitro SPF could be measured for the skin with and without the application of the sun care product to the artificial skin. These results are reported as in vitro SPF and in vitro WR SPF, where the former is also the measured value after the standard drying time has elapsed, and the latter is the measured value on the same film after immersion in water maintained at 40 °C for 80 minutes. These in vitro measurements are consistent with the in vivo data in the tests of the present inventors. Other data such as the UVA and UVB ratios can also be determined and used to quantify the protection provided by the sunscreen formulation. Alternatively, in the Colipa Tech method, Helioplate HD6 embossed PMMA plates are available from Helio Labs Inc. These PPMA plates have a surface roughness of 6 micrometers root mean square and are used without hydration. Due to the depth of the roughness, the same 2 mg / cm 2 dosage of the sunscreen emulsion, when coated on the plate and dried, has "peaks" of surface roughness covered with an oil that is relatively low in UV absorbance. Therefore, the absorbance and the calculated SPF may be somewhat reduced compared to in vivo and other in vitro measurement techniques. However, both in vitro substrates provide reproducible results and can be compared using appropriate correction factors.

[0149] Therefore, as is standard in the art, a spectrophotometer is used to measure the UV absorption through a plastic film coated with a UV-absorbing sun care formulation to mimic human skin and provide a measured value of the sun protection factor (SPF). The SPF is simply the ratio of the initial light to the light transmitted through the UV-absorbing film. If 100% is reduced to 10%, the SPF is 10. If 100% is reduced to 1%, the SPF is 100. An SPF of 50 corresponds to 2% of the UV light passing through the skin.

[0150] In each case, a UV-absorbing film having a surface area of 100 cm 2 was coated with 20 × 5 mg droplets of an emulsion containing the test polymer and exposed to UV light in the range of 290 - 400 nm to provide a so-called "static" SPF measurement.

[0151] In vitro water-resistant SPF (WR SPF) measurements were performed on the same film after placing the film in a water bath heated to 40 °C and gently stirring. The sample after removal was gently dried under reproducible conditions and measured again for light transmission, at which point WR SPF data was obtained.

[0152] The results are illustrated in Figure 1 and numerically shown in Table 4 below. Again, this formulation was designed to provide SPF50 as the target for in vitro SPF and WR SPF testing. It should be noted that the data shows that the polymers of the present disclosure are at least as good as, and in many cases better than, some biodegradable polyesters that are somewhat similar but have significantly inferior SPF performance (compare Examples 17 - 24 with Comparative Examples 25 and 26). Further, when the water-resistant polymer is prepared from a hydrogenated dimer, its WR SPF is even better than the absolute standard in the industry (compare Examples 20 - 24 with Comparative Examples 15 and 16). It should be noted that all in vitro SPF values were measured to be at or above the target value of SPF50 for a non-immersed sunscreen formulation dried on artificial skin. Thus, the polyester polymers of the present disclosure were tested at low levels since they were effective at 2 wt% addition in the formulation examples. Performance was seen in the range of 0.5 wt% - 2 wt%. Further, Comparative Polymer Examples 12 and 13 did not perform at 2 wt%, so they were tested up to 5 wt% in further examples. These comparative examples, although not listed here, continued to show in vitro WR SPF values significantly below 50 and thus significantly below the performance of the polymers of the present disclosure even at dosages 2.5 - 5 times higher. Thus, the comparative examples do not demonstrate practicality in a very important requirement of water resistance in the sun care formulations of the present disclosure.

[0153]

Table 4

[0154] Among the waterproof polymers of the present disclosure, the effect of hydrogenation and the difference in the weight average molecular weight of the polymers shown in Table 4 are further illustrated in FIG. 2. The use of hydrogenated dimer acid can clearly significantly increase the WR SPF. Further benefits can be realized by producing a waterproof polymer with a higher weight average molecular weight. In FIG. 2, the MW on the horizontal axis is described as "high" indicating the polymers of Examples 5 and 7 and "low" indicating the MW of the polymers of Examples 4 and 6 as shown in the above table. Note again that all of the high MW and low MW examples shown have viscosities 50 to 100 times higher than Comparative Examples 12 and 13 of Table 1 at 25°C.

[0155] D. Use of compositional analysis to demonstrate the criticality of the molar ratio Further analysis by hydrolysis and LC analysis was performed to further demonstrate the importance of the preferred molar ratios of the polymers of the present disclosure. This method essentially involves breaking down and then using it to quantitatively measure the molar ratios of each component in the relevant examples. Samples were analyzed by LC / ELSD to quantify the amounts of starting materials present, such as isostearic acid and dimer acid, with respect to unreacted polyglycerol. Samples were prepared by dissolving approximately 30.0 mg of the sample in 1 ml of methanol and 0.5 ml of THF. The solution was warmed to dissolve completely and then cooled and centrifuged to precipitate any insoluble portion. 1 μl of the sample solution was injected and analyzed by LC / ELSD or LC / MS. In particular, in the following table, for all polymers measured in the present invention, the molar ratios are described as measured (measurement). Also, for example, from prior art patents, the molar ratios are described as calculated (calculation), but they deviate significantly from the purposes of the present disclosure and do not teach the purposes of the present disclosure. Refer to Table 5 below for a comparison of Example 8 of the present disclosure with two comparative samples that do not provide WR SPF performance and two past US patents that do not teach the present disclosure either.

[0156]

Table 5

[0157] E. Use of Emollients and Biodegradability of Polymers The biodegradability of the waterproof polymers was assessed as shown in the following table, either alone or in combination with emollients.

[0158] The Organization for Economic Co-operation and Development (OECD) promotes sustainable development, among other goals, by including new biodegradable and non-toxic materials to replace non-compliant materials.

[0159] Some examples of the present disclosure were tested by OECD methods 301D, 201, and 202, the details of which are readily available. These are tests for biodegradability, algal toxicity, and daphnia toxicity, the latter two being sensitivities to small aquatic plants and crustaceans, respectively. The test results are classified into three evaluations demonstrating safety in the environment. The 301D evaluation includes "readily biodegradable," which means 60% - 100% biodegradation in 28 days or less. "Essentially biodegradable" means 20% - 60% biodegradation in 28 days, and "non - biodegradable" means less than 20% biodegradation in 28 days. These results are shown in Table 6 below.

[0160] Similarly, the toxicity of algae and daphnia refers to the evaluation of toxicity. In this case, the lack of toxicity to these living species is tested at various levels. If no toxicity is observed at 100 mg per liter of water for the species, they are listed as non - toxic. These results are shown in Table 7 below.

[0161]

Table 6

[0162]

Table 7

[0163] The waterproof polymers of the present disclosure were non - toxic to algae and daphnia and were also biodegradable. This demonstrates the extremely beneficial environmental profile shown by the waterproof polymers of the present disclosure.

[0164] Referring to the previous description of in - vivo SPF and WR SPF tests used to guarantee commercially available sunscreen formulations, different examples were created and tested to exemplify water - in - oil (O / W) formulations. Based on the previous formulations, Examples 17 - 24 were created with Polymers 4 - 11 of the present disclosure. These formulations are representative of a more complete range of product forms available on the market for sun care.

[0165]

Table 8

[0166] Example 45 was an O / W formulation prepared by making an aqueous phase and emulsifying an oil phase. The aqueous phase was prepared as detailed in Examples 14 - 26 of Table 3. For 500 g of the O / W sunscreen formulation, a 1000 mL beaker was filled with 273 g of deionized water and mixed at 500 rpm using an overhead mixer. To this, 2 g of Acrylates / Alkyl Acrylate (C10 - 30) Crosspolymer (Pemulen EZ - 4, Lubrizol Corp.) was slowly added and dissolved. Next, the following components were added and mixed: 0.5 g of Disodium EDTA (Nouryon Dissolvine NA2 - S), 5 g of Phenoxyethanol (and) Ethylhexylglycerin (Euxyl PE 9010, Schulke & Mayr GmbH), and 10 g of Propylene Glycol (Sigma - Aldrich Inc.). The solution was transferred to a high - shear homogenizer at 1200 rpm, heated, and held at 75 - 80 °C. In a separate 250 mL beaker equipped with a magnetic stirrer, 16.65 g of Example 28 (consisting of 60% Polymer Example 10 and 40% Caprylic / Capric Triglyceride), 15 g of Avobenzone (Neo Heliopan 357, Symrise), 65 g of Homosalate (Neo Heliopan® HMS, Symrise), 25 g of Ethylhexyl Salicylate (Neo Heliopan® OS, Symrise), 40 g of Octocrylene (Neo Heliopan® 303, Symrise), 5 g of Dimethicone (DOW CORNING® 200 Fluid, Dow Corning), 17.5 g of Glyceryl Stearate (and) PEG - 100 Stearate (Arlacel™ 165, Croda, Inc.) were added, mixed, and dissolved while heating to 75 - 80 °C. The molten oil phase was slowly added to the aqueous phase at 1200 rpm, raised to 4000 rpm, and emulsified at 75 - 80 °C for 10 minutes. The resulting O / W emulsion was slowly cooled to 65 °C, neutralized at 65 °C using 4 g of Triethanolamine (Dow Chemical) in 20 g of water, and finally homogenized and cooled to 45 °C for slow mixing and adjustment.The final pH was adjusted to 6.00 - 6.50 using 50% citric acid solution.

[0167] Comparative Example 46 was an O / W formulation prepared by creating an aqueous phase and emulsifying an oil phase. This example was prepared using Comparative Polymer Example 1, but in this case, no water - resistant polymer was used. Otherwise, it followed the same method as Example 45.

[0168] As shown in Table 8, all of these formulations were tested either by an in - vitro SPF test, an in - vivo SPF test, or both. In the in - vitro SPF and WR SPF tests, Example 45 of a suncare formulation consisting of 60% Polymer Example 10 and 40% caprylic - capric triglyceride, prepared using the method described above and Polymer - Emollient Example 28 of the present disclosure, showed an excellent WR SPF of 73. In contrast, the O / W formulation of Comparative Example 46 dramatically failed with a WR SPF of 5, showing a very large benefit affected by the polyester polymer of the present disclosure. Similarly in Table 8, the in - vivo SPF and WR SPF measured using the FDA protocol by Florida Suncare Testing, Inc. showed that Example 45 of a suncare formulation using the polyester of the present disclosure produced a very effective suncare formulation with an in - vivo WR SPF evaluation of 57. Again, in contrast, in Comparative Example 46 with a WR SPF, numerous "technical deficiencies" were reported and only a WR SPF of about 37 - 43 could be assigned.

[0169] Although the present disclosure has been described with the foregoing specific embodiments, many alternative, modified, and other variations will be apparent to those skilled in the art. All such alternatives, modifications, and variations are intended to be included within the spirit and scope of the present disclosure. The present specification includes the following aspects. Item 1. A waterproof polymer which is a reaction product of the following components: (i) at least one polyglycerol, (ii) at least one dimer acid, and (iii) at least one fatty acid having 8 to 30 carbon atoms, wherein the molar ratio of (iii) to (i) is less than 2:1. Item 2. The polymer according to item 1, which is a completely non-sequential reaction product. Item 3. The polymer according to item 1 or 2, which is produced from a polyglycerol composed of a combination of at least 40% by weight of diglycerol and triglycerol based on the total weight of the polyglycerol. Item 4. The polymer according to any one of items 1 to 3, which is produced from at least one hydrogenated dimer acid. Item 5. The polymer according to item 4, which is produced from a hydrogenated dimer acid obtained by dimerization of an unsaturated C18 fatty acid and subsequent hydrogenation. Item 6. The polymer according to item 5, which contains a trimer acid content in the range of about 5 to 25 wt% based on the total weight of the hydrogenated dimer acid. Item 7. The polymer according to any one of items 1 to 6, which is produced from at least one fatty acid selected from the group consisting of caprylic acid (C8), pelargonic acid (C9), capric acid (C10), undecylic acid (C11), lauric acid (C12), tridecylic acid (C13), myristic acid (C14), pentadecylic acid (C15), palmitic acid (C16), margaric acid (C17), stearic acid (C18), isostearic acid (C18), nonadecylic acid (C19), arachidic acid (C20), behenic acid (C22), and lignoceric acid (C24). Item 8. The polymer according to item 7, which is produced from isostearic acid. Item 9. (i) A polyglycerol composed of a combination of at least 40% by weight of diglycerol and triglycerol based on the total weight of the polyglycerol, (ii) a C18 hydrogenated dimer acid having a trimer acid content in the range of about 5 to 25 wt% based on the total weight of the hydrogenated dimer acid, and (iii) produced from isostearic acid, the polymer according to any one of items 1 to 8. Item 10. The polymer according to any one of items 1 to 9, showing a combination of viscosities of a neat polymer with Mw > 2500 Da and < 1,000,000 Da and > 50,000 cP and < 5,000,000 cP at 25 °C, measured using standard linear polystyrene with GPC. Item 11. A method for preparing a waterproof polymer according to any one of items 1 to 10, comprising (a) a step of introducing the components (i) to (iii) into a reaction vessel, and (b) a step of sequentially polymerizing the said components. Item 12. A composition comprising a waterproof polymer according to any one of items 1 to 10 and an organic solvent. Item 13. The composition according to item 12, wherein the solvent is selected from the group consisting of one or more emollients selected from the group consisting of triheptanoin, isopropyl palmitate, isopropyl myristate, triheptanoin (and) C13 - C16 isoparaffin, heptyl undecylenate, caprylic / capric triglyceride, diisooctyl succinate, C13 - C16 isoparaffin (and) heptyl undecylenate, C12 - C15 alkyl benzoate. Item 14. A method for preparing the composition according to item 12, comprising a step of combining the waterproof polymer with the solvent. Item 15. An oil-in-water formulation comprising a waterproof polymer according to any one of items 1 to 10. Item 16. An oil-in-water sunscreen formulation comprising the following individual components: (a) at least one sunscreen active agent, and (b) at least one waterproof polymer according to any one of items 1 to 10. Item 17. The sunscreen formulation according to item 16, further comprising at least one oil-in-water emulsifier. Item 18. The sunscreen active agent includes para - aminobenzoic acid, avobenzone, cinoxate, dioxybenzone, homosalate, menthyl anthranilate, octyl salicylate, oxybenzone, padimate O, phenylbenzimidazole sulfonic acid, sulisobenzone, trolamine salicylate, titanium dioxide, zinc oxide, diethanolamine methoxycinnamate, digalloyl trioleate, ethyl dihydroxypropyl PABA, glyceryl aminobenzoate, Lawson's with dihydroxyacetone, petrolatum, ethylhexyl triazone, dioctyl butamide triazone, benzylidene malonate polysiloxane, terephthalylidene dicamphor sulfonic acid, disodium phenyl dibenzimidazole tetrasulfonate, diethylamino hydroxybenzoyl hexyl benzoate, bis - diethylamino hydroxybenzoyl benzoate, bis - benzoxazolyl phenyl ethylhexyl iminotriazine, droxmetrizole trisiloxane, methylene bis - benzotriazolyl tetramethylbutylphenol, bis - ethylhexyl oxy - phenol methoxy phenyl triazine, 4 - methylbenzylidene camphor, homosalate, butyl methoxydibenzoylmethane, octocrylene, octyl salicylate, bemotrizinol and isopentyl 4 - methoxycinnamate, benzophenone - 3 (BP3), benzophenone - 4 (BP4), homosalate (HMS), 2 - ethylhexyl salicylate (EHS), ethylhexyl dimethyl PABA (OD - PABA), 4 - p - aminobenzoic acid (PABA), phenylbenzimidazole sulfonic acid (PMDSA), disodium phenyl dibenzimidazole tetrasulfonate (bis - disrizole disodium), ethylhexyl triazone (OT), diethylhexyl butamide triazone (DBT), bis - ethylhexyl oxy - phenol methoxy phenyl triazine (EMT), droxmetrizole trisiloxane (DRT), methylene bis - benzotriazolyl tetramethylbutylphenol (MBP, bis - cotrizole), 4 - tert - butyl - 4'- methoxydibenzoylmethane (BM - DBM, avobenzone), ethylhexyl methoxycinnamate (OMC), isoamyl p - methoxycinnamate (IMC, amiloxate),The sunscreen formulation according to claim 17, which is at least one member selected from the group consisting of terephthalylidene dicamphor sulfonic acid (PDSA), 3-benzylidene camphor (3BC), benzylidene camphor sulfonic acid (BCSA), 4-methylbenzylidene camphor (4-MBC), polyacrylamide methylbenzylidene camphor (PBC), camphor benzalkonium metosulfate (CBM), titanium dioxide, zinc oxide, iron oxide, zirconium oxide, cerium oxide, and mixtures thereof. Claim 19. A method for protecting a user who is exposed to sunlight or has already been exposed from the damaging effects of sunlight exposure, the method comprising the step of applying to the skin of the user an effective amount of the sunscreen formulation according to any one of claims 16 to 18 for that purpose. Claim 20. A method for making a water-in-oil sunscreen formulation containing at least one sunscreen active agent waterproof, the method comprising the step of incorporating into the sunscreen formulation a waterproof amount of at least one waterproof polymer according to any one of claims 1 to 10.

Claims

1. A water - repellent polymer which is a reaction product of the following components: (i) at least one polyglycerol, (ii) at least one dimer acid, and (iii) at least one fatty acid having 8 to 30 carbon atoms, wherein the molar ratio of (iii) to (i) is less than 2:1, wherein the at least one polyglycerol comprises a mixture of oligoglycerols having the following oligomer distribution, (a) 0 to 30% by weight of glycerol; (b) 10 to 40% by weight of diglycerol; (c) 10 to 65% by weight of triglycerol; (d) 2 to 25% by weight of tetraglycerol; (e) 0 to 15% by weight of pentaglycerol; (f) 0 to 15% by weight of hexaglycerol; (g) 0 to 10% by weight of heptaglycerol; (h) 0 to 10% by weight of octaglycerol; (i) 0 to 5% by weight of nonaglycerol; and (j) 0 to 5% by weight of decaglycerol; wherein all percentages by weight are based on 100% by weight of the at least one polyglycerol. A water - repellent polymer.

2. The polymer according to claim 1, produced from a polyglycerol composed of a combination of at least 40% by weight of diglycerol and triglycerol, based on the total weight of the polyglycerol.

3. The polymer according to claim 1 or 2, produced from at least one hydrogenated dimer acid.

4. The polymer according to claim 3, produced from a hydrogenated dimer acid obtained by dimerization of an unsaturated C18 fatty acid and subsequent hydrogenation.

5. The polymer according to claim 4, containing a trimer acid content in the range of about 5 - 25 wt% based on the total weight of the hydrogenated dimer acid.

6. The polymer according to any one of claims 1 to 5, produced from at least one fatty acid selected from the group consisting of caprylic acid (C8), pelargonic acid (C9), capric acid (C10), undecylic acid (C11), lauric acid (C12), tridecylic acid (C13), myristic acid (C14), pentadecylic acid (C15), palmitic acid (C16), margaric acid (C17), stearic acid (C18), isostearic acid (C18), nonadecylic acid (C19), arachidic acid (C20), behenic acid (C22), and lignoceric acid (C24).

7. The polymer according to claim 6, produced from isostearic acid.

8. (i)A polyglycerol composed of a combination of at least 40% by weight of diglycerol and triglycerol based on the total weight of the polyglycerol, (ii) a C18 hydrogenated dimer acid having a trimer acid content in the range of about 5 to 25 wt% based on the total weight of the hydrogenated dimer acid, and (iii) produced from isostearic acid, the polymer according to any one of claims 1 to 7.

9. The polymer according to any one of claims 1 to 8, showing a combination of viscosities of a neat polymer measured using GPC with standard linear polystyrene such that Mw > 2500 Da and < 1,000,000 Da, and > 50,000 cP and < 5,000,000 cP at 25°C.

10. A method for preparing a waterproof polymer according to any one of claims 1 to 9, comprising (a) introducing the constituents (i) to (iii) into a reaction vessel, and (b) sequentially polymerizing the said constituents.

11. A composition comprising a waterproof polymer according to any one of claims 1 to 9 and an organic solvent.

12. The composition according to claim 11, wherein the organic solvent is selected from the group consisting of one or more emollients selected from the group consisting of triheptanoin, isopropyl palmitate, isopropyl myristate, triheptanoin (and) C13 - C16 isoparaffin, heptyl undecylenate, caprylic / capric triglyceride, diisooctyl succinate, C13 - C16 isoparaffin (and) heptyl undecylenate, C12 - C15 alkyl benzoate.

13. A method for preparing the composition according to claim 11, comprising combining the waterproof polymer with the organic solvent.

14. An oil-in-water formulation comprising a waterproof polymer according to any one of claims 1 to 9.

15. An oil-in-water sunscreen formulation comprising the following individual components: (a) at least one sunscreen active agent, and (b) at least one waterproof polymer according to any one of claims 1 to 9.

16. The sunscreen formulation according to claim 15, further comprising at least one oil-in-water emulsifier.

17. The sunscreen active agent includes para - aminobenzoic acid, avobenzone, cinoxate, dioxybenzone, homosalate, menthyl anthranilate, octyl salicylate, oxybenzone, padimate O, phenylbenzimidazole sulfonic acid, sulisobenzone, trolamine salicylate, titanium dioxide, zinc oxide, diethanolamine methoxycinnamate, digalloyl trioleate, ethyl dihydroxypropyl PABA, glyceryl aminobenzoate, Lawson's with dihydroxyacetone, petrolatum, ethylhexyl triazone, dioctyl butamide triazone, benzylidene malonate polysiloxane, terephthalylidene dicamphor sulfonic acid, disodium phenyl dibenzimidazole tetrasulfonate, diethylamino hydroxybenzoyl hexyl benzoate, bis - diethylamino hydroxybenzoyl benzoate, bis - benzoxazolyl phenyl ethylhexyl iminotriazine, droxmetrizole trisiloxane, methylene bis - benzotriazolyl tetramethylbutylphenol, bis - ethylhexyl oxy - phenol methoxy phenyl triazine, 4 - methylbenzylidene camphor, homosalate, butyl methoxydibenzoylmethane, octocrylene, octyl salicylate, bemotrizinol and isopentyl 4 - methoxycinnamate, benzophenone - 3 (BP3), benzophenone - 4 (BP4), homosalate (HMS), 2 - ethylhexyl salicylate (EHS), ethylhexyl dimethyl PABA (OD - PABA), 4 - p - aminobenzoic acid (PABA), phenylbenzimidazole sulfonic acid (PMDSA), disodium phenyl dibenzimidazole tetrasulfonate (bis - disrizole disodium), ethylhexyl triazone (OT), diethylhexyl butamide triazone (DBT), bis - ethylhexyl oxy - phenol methoxy phenyl triazine (EMT), droxmetrizole trisiloxane (DRT), methylene bis - benzotriazolyl tetramethylbutylphenol (MBP, bis - cotrizole), 4 - tert - butyl - 4'-methoxydibenzoylmethane (BM - DBM, avobenzone), ethylhexyl methoxycinnamate (OMC), isoamyl p - methoxycinnamate (IMC, amyloxate),The sunscreen formulation according to claim 16, which is at least one member selected from the group consisting of terephthalylidene dicamphor sulfonic acid (PDSA), 3-benzylidene camphor (3BC), benzylidene camphor sulfonic acid (BCSA), 4-methylbenzylidene camphor (4-MBC), polyacrylamide methylbenzylidene camphor (PBC), camphor benzalkonium metosulfate (CBM), titanium dioxide, zinc oxide, iron oxide, zirconium oxide, cerium oxide, and mixtures thereof.

18. A method for protecting a user who is exposed to sunlight or has already been exposed from the damaging effects of sunlight exposure, the method comprising the step of applying to the skin of the user an effective amount of the sunscreen formulation according to any one of claims 15 to 17 for that purpose. [

19. ] A method for making a water-in-oil sunscreen formulation containing at least one sunscreen active agent waterproof, the method comprising the step of incorporating into the sunscreen formulation a waterproof amount of at least one waterproof polymer according to any one of claims 1 to 9.

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