Low viscosity non-water-based metal oxide particle dispersions and methods of making same

Abstract

The present invention relates to a non-aqueous based composition for dispersing metal oxide particles. The non-aqueous based composition comprises a dispersion medium comprising an ester having a branched or unsaturated alkyl chain, preferably synthesized from 100% bio-based carbon, and a polyester dispersant comprising terminal carboxylic acid functional groups. The ester dispersion medium includes a liquid ester selected from the group consisting of Formulae (I), (II), (III) and combinations thereof. The present invention also relates to a non-aqueous based dispersion comprising the above non-aqueous based composition and metal oxide particles dispersed therein. The metal oxide particles may include zinc oxide, titanium oxide, or a combination thereof. Formulations using the compositions and dispersions and methods of making the same are also disclosed.

Description

[0001] Cross - reference to related applications

[0002] This application claims priority to U.S. Provisional Application No. 63 / 422,063, filed on November 3, 2022, and U.S. Provisional Application No. 63 / 422,057, filed on November 3, 2022, which are hereby incorporated by reference in their entirety. Technical field

[0003] The present invention relates to compositions, dispersions, and formulations comprising a non - aqueous ester dispersion medium and a polyester dispersant (optionally in combination with metal oxide particles), methods for preparing the compositions, methods for using the compositions to prepare dispersions and formulations, and their applications, including personal care applications such as sunscreen formulations. Background art

[0004] Inorganic metal oxides, such as zinc oxide (ZnO) and titanium dioxide (TiO2), are important sunscreen ingredients because they can absorb and / or scatter UVB and UVA radiation, thus providing protection against sunburn and photo - damage (which may lead to premature aging and / or skin cancer). These metal oxides are most desirably supplied as sub - micron - sized particles that do not scatter visible light wavelengths on the skin and thus do not cause skin whitening. Metal oxide particles ("MOP") are typically prepared and supplied in the form of free - flowing powders.

[0005] To effectively prepare sunscreen formulations containing ZnO and / or TiO2 MOP to provide sufficient sun protection factor ("SPF") values and not cause skin whitening, a stable and non - caking MOP dispersion needs to be created.

[0006] The formation of a dispersion requires high - shear mixing or grinding to mechanically break up the powdered and / or any agglomerated MOP and disperse it into a liquid medium (i.e., the dispersion medium). The nature of the dispersion medium can be water - based or non - aqueous. Wetting of the MOP by the dispersion medium to form a dispersed and homogeneous state typically requires a dispersant to prevent re - agglomeration of the MOP. [See, e.g., C. Agbo et al., A Review on the Mechanism of Pigment Dispersion, J. Disp. Sci. Tech., 2018, 39(6), 874 - 889.]

[0007] MOP is preferably dispersed in a non-aqueous fluid that is easy to apply to the skin and has a consumer-acceptable skin feel. Non-aqueous dispersion media for MOP (such as ZnO and TiO2) include various cosmetically acceptable fluids that are commonly used as emollients in cosmetics and personal care products. Examples of such fluids include aliphatic hydrocarbons, triglycerides, benzoates, aliphatic esters, or combinations thereof, and silicones (such as cyclomethicone and dimethicone).

[0008] Given the increasing consumer preference for more natural and sustainable products, the non-aqueous dispersion medium is preferably derived from sustainable, renewable plant-based raw materials. An example of a dispersion medium of natural origin is caprylic / capric triglyceride, which is a triglyceride synthesized by the complete esterification of plant glycerol with a mixture of C8 (caprylic acid) and C 10 (capric acid) fatty acids from coconut or palm kernel oil. Other examples of plant-derived bio-based non-aqueous dispersion media include plant-derived oils, such as jojoba oil or sunflower oil; fermentation-derived hydrocarbons, such as hydrogenated farnesene; hydrocarbons derived from triglyceride oils (by hydrolysis to fatty acids, reduction to fatty alcohols, and dehydration / hydrogenation to hydrocarbons), such as coconut alkane; and esters derived from plant-derived saturated fatty acids and saturated fatty alcohols, such as coco-caprylate / caprate derived from the esterification of hydrogenated coconut fatty alcohol with C8 / C 10 fatty acids.

[0009] Obtaining a stable MOP dispersion in a non-aqueous medium typically requires surface modification of the particles to make the hydrophilic inorganic surface hydrophobic and thus compatible with the relatively non-polar dispersion medium, i.e., the non-aqueous dispersion can wet the MOP surface. This surface modification can be achieved by using a hydrophobic coating that adheres to the MOP surface through physical and / or covalent interactions. Examples of surface modifiers for MOP include fatty acids (such as isostearic acid), trialkoxyalkylsiloxanes (such as triethoxyoctylsilane), or silicones (such as methylsilicone or dimethicone). Surface modification of MOP typically requires additional process steps and / or unit operations to properly apply the surface treatment, see, for example, U.S. Patent No. 9,254,398 B2. Therefore, developing a dispersion system that can use un-surface-treated (i.e., uncoated) MOP is more efficient and economical.

[0010] Ideally, a flowable, low-viscosity particulate dispersion with a high MOP loading is produced, which can minimize the carry-over of excess dispersion medium into subsequent formulations (where a specific MOP dispersion is added). However, when formulated at MOP loadings with a solid particle volume fraction greater than about 50%, conventional triglyceride dispersion media (such as caprylic / capric triglyceride and triheptanoin) typically produce MOP dispersions with undesirably high viscosities. See, e.g., D.A. Brune et al., Model for the Viscosity of Particle Dispersions; Journal of Macromolecular Science - Rev. Macromol. Chem. Phys., C39(4), 561 - 642 (1999). Thus, to obtain a stable and pourable MOP dispersion containing these triglycerides, unfortunately, the particle loading must be reduced.

[0011] In addition, a dispersant is needed to provide steric stability to prevent particle agglomeration in the non-aqueous dispersion medium. Polymer dispersants are common, and polyhydroxystearic acid is a well-known dispersant for ZnO and TiO2 MOPs. [See, e.g., B.J. Naden et al., Adsorption of poly(hydroxystearic acid) to TiO2 nanoparticles, studied using gel permeation chromatography, Coll. Surf. A: Physicochem. Eng. Aspects, 2015, 478, 36 - 44.]

[0012] Such non-aqueous dispersions preferably have a low viscosity (i.e., less than about 1000 cP) for ease of preparation and handling in subsequent formulation steps, and the dispersed solid particles must remain stable in the dispersion for an extended period. Low-viscosity dispersions are also desirable when formulated into sunscreen products as they make the product easier for consumers to dispense and apply.

[0013] Accordingly, there is a need for stable, low-viscosity, high-solid-content MOP dispersions. Due to the market demand for more sustainable ingredients and the greater consumer appeal for so-called "natural" ingredients derived from renewable bio-based feedstocks, non-aqueous compositions should preferably be based on renewable carbon sources, i.e., plant-based carbon. Specifically, there is a need for non-aqueous compositions comprising one or more dispersants prepared from renewable bio-based carbon (more preferably 100% bio-based carbon). Summary of the Invention

[0014] The non-aqueous compositions described and claimed herein meet these long-standing needs and comprise an ester dispersion medium (EDM) and a carboxylic acid-terminated polyester, to which MOP can be added to provide a uniform MOP dispersion.

[0015] Applicants have surprisingly found that a dispersion medium comprising a branched or unsaturated ester (preferably synthesized from 100% biobased carbon as described herein) can provide a stable MOP dispersion with extremely low viscosity at relatively high particle loadings. Thus, a stable, low-viscosity, high-solids-content MOP dispersion can be achieved using a dispersion medium and a dispersant based on 100% natural and renewable carbon. And the ester can be used in combination with an easily obtainable polyester dispersant (PEDA), the applicability of which does not depend on the molecular weight distribution, i.e., both low molecular weight and high molecular weight polyesters work well with the branched or unsaturated esters described herein.

[0016] In some embodiments, the present invention relates to a non-aqueous composition. The non-aqueous composition comprises an ester and a polyester having terminal carboxylic acid functional groups. The ester is selected from the group consisting of the following (i)-(iv):

[0017] (i) A liquid ester of Formula I:

[0018]

[0019] wherein R and R1 are each a linear, branched or cyclic alkyl group; a linear, branched or cyclic alkenyl group; or a linear, branched or cyclic alkynyl group; provided that if one of R and R1 is a linear alkyl group, the other of R and R1 is a branched or cyclic alkyl group; a linear, branched or cyclic alkenyl group; or a linear, branched or cyclic alkynyl group;

[0020] (ii) A liquid ester of Formula II:

[0021]

[0022] wherein R2 is a branched alkyl group, a linear or branched alkenyl group, or a linear or branched alkynyl group, R3 is a linear or branched alkyl group, a linear or branched alkenyl group, or a linear or branched alkynyl group, and R4 is a linear or branched alkyl group, a linear or branched alkenyl group, or a linear or branched alkynyl group;

[0023] (iii) A liquid ester of Formula III:

[0024]

[0025] wherein R5 is a branched alkyl group, a linear or branched alkene, or a linear or branched alkyne, R6 is a linear or branched alkyl group, a linear or branched alkene, or a linear or branched alkyne, and R7 is a linear or branched alkyl group, a linear or branched alkene, or a linear or branched alkyne; and

[0026] (iv) Combinations of the above esters.

[0027] The esters of the non-aqueous base composition in the preceding paragraph may have the formula I, and R is C5-C 17 branched or cyclic alkyl, linear, branched or cyclic alkenyl, or linear, branched or cyclic alkynyl; and R1 is C3-C 18 linear, branched or cyclic alkyl, linear, branched or cyclic alkenyl, or linear, branched or cyclic alkynyl. The esters of formula I may include esters in which R and R1 are different.

[0028] The esters of the non-aqueous base composition described in any of the preceding paragraphs may have the formula II, and R2 is C3-C 18 branched alkyl, linear or branched alkenyl, or linear or branched alkynyl; R3 is C2-C8 linear or branched alkyl, linear or branched alkenyl, or linear or branched alkynyl; and R4 is C3-C 18 linear or branched alkyl, linear or branched alkenyl, or linear or branched alkynyl. The esters of formula II may include esters in which R2 and R4 are the same.

[0029] The esters of the non-aqueous base composition described in any of the preceding paragraphs may have the formula III, and R5 is C3-C 18 branched alkyl, linear or branched olefin, or linear or branched alkyne, R6 is C2-C8 linear or branched alkyl, linear or branched olefin, or linear or branched alkyne, and R7 is C3-C 18 linear or branched alkyl, linear or branched olefin, or linear or branched alkyne. The esters of formula III may include esters in which R5 and R7 are the same.

[0030] The esters of the non-aqueous base composition described in any of the preceding paragraphs may be liquid at 25 °C. The esters may be 100% biobased.

[0031] The polyesters of the non-aqueous base composition described in any of the preceding paragraphs may contain a single terminal carboxylic acid functional group. The polyesters may contain two terminal carboxylic acid functional groups.

[0032] The polyesters of the non-aqueous base composition described in any of the preceding paragraphs may include homopolymers derived from AB hydroxycarboxylic acid monomers. The polyesters may include copolymers derived from AA diol and BB diacid or diester monomers.

[0033] The polyesters of the non-aqueous base composition described in any of the preceding paragraphs may have a number average molecular weight (Mn) of less than about 10,000 g / mol. The polyesters may have an acid value of at least 15 mg KOH / g.

[0034] The polyesters of the non-aqueous compositions described in any preceding paragraph are selected from the group consisting of: polyhydroxystearic acid, polyhydroxystearic acid stearate, polyhydroxystearyl succinate, polyhydroxystearyl sebacate, and combinations thereof. The carbon present in the polyester can be 100% biobased.

[0035] In certain embodiments, the present invention relates to a non-aqueous composition consisting essentially of an ester and a polyester having a terminal carboxylic acid functional group, wherein the ester is selected from the group consisting of the following (i)-(iv):

[0036] (i) A liquid ester of Formula I:

[0037]

[0038] wherein R and R1 are each a linear, branched, or cyclic alkyl group; a linear, branched, or cyclic alkenyl group; or a linear, branched, or cyclic alkynyl group; provided that if one of R and R1 is a linear alkyl group, the other of R and R1 is a branched or cyclic alkyl group; a linear, branched, or cyclic alkenyl group; or a linear, branched, or cyclic alkynyl group;

[0039] (ii) A liquid ester of Formula II:

[0040]

[0041] wherein R2 is a branched alkyl group, a linear or branched alkenyl group, or a linear or branched alkynyl group, R3 is a linear or branched alkyl group, a linear or branched alkenyl group, or a linear or branched alkynyl group, and R4 is a linear or branched alkyl group, a linear or branched alkenyl group, or a linear or branched alkynyl group;

[0042] (iii) A liquid ester of Formula III:

[0043]

[0044] wherein R5 is a branched alkyl group, a linear or branched alkene, or a linear or branched alkyne, R6 is a linear or branched alkyl group, a linear or branched alkene, or a linear or branched alkyne, and R7 is a linear or branched alkyl group, a linear or branched alkene, or a linear or branched alkyne; and

[0045] (iv) Combinations of the above esters.

[0046] In other certain embodiments, the present invention relates to a non-aqueous composition consisting of an ester and a polyester having a terminal carboxylic acid functional group, wherein the ester is selected from the group consisting of the following (i)-(iv):

[0047] (i) A liquid ester of Formula I:

[0048]

[0049] wherein each of R and R1 is a linear, branched or cyclic alkyl group; a linear, branched or cyclic alkenyl group; or a linear, branched or cyclic alkynyl group; provided that if one of R and R1 is a linear alkyl group, the other of R and R1 is a branched or cyclic alkyl group; a linear, branched or cyclic alkenyl group; or a linear, branched or cyclic alkynyl group;

[0050] (ii) a liquid ester of formula II:

[0051]

[0052] wherein R2 is a branched alkyl group, a linear or branched alkenyl group, or a linear or branched alkynyl group, R3 is a linear or branched alkyl group, a linear or branched alkenyl group, or a linear or branched alkynyl group, and R4 is a linear or branched alkyl group, a linear or branched alkenyl group, or a linear or branched alkynyl group;

[0053] (iii) a liquid ester of formula III:

[0054]

[0055] wherein R5 is a branched alkyl group, a linear or branched alkene, or a linear or branched alkyne, R6 is a linear or branched alkyl group, a linear or branched alkene, or a linear or branched alkyne, and R7 is a linear or branched alkyl group, a linear or branched alkene, or a linear or branched alkyne; and

[0056] (iv) a combination of the above esters.

[0057] In other embodiments, the present invention relates to a non-aqueous dispersion comprising a non-aqueous composition and a metal oxide particle powder. The non-aqueous composition of the non-aqueous dispersion can be the non-aqueous composition according to any of the preceding paragraphs.

[0058] The metal oxide particles of the non-aqueous dispersion in the preceding paragraph can include un-surface-modified metal oxide particles, e.g., un-surface-modified particles.

[0059] The metal oxide particles of the non-aqueous dispersion according to any of the preceding paragraphs can include zinc oxide, titanium oxide, or a combination thereof.

[0060] The non-aqueous dispersion according to any of the preceding paragraphs can have a viscosity of less than about 1000 cP. The metal oxide particles can account for about 15 wt% to about 75 wt% of the non-aqueous dispersion, with the balance being the non-aqueous composition according to any of the preceding paragraphs. In some embodiments, the metal oxide particles account for about 40 wt% to about 60 wt% of the non-aqueous dispersion. Based on the total weight of the dispersion, the amount of polyester present can be about 3 wt% to about 5 wt%. The non-aqueous dispersion can be substantially free of silicone.

[0061] In certain embodiments, the present invention relates to a non-aqueous dispersion comprising a composition and a plurality of metal oxide particles dispersed in the composition, the composition comprising an ester and a polyester having terminal carboxylic acid functional groups, wherein the ester is selected from the group consisting of the following (i)-(iv):

[0062] (i) A liquid ester of formula I:

[0063]

[0064] wherein each of R and R1 is a linear, branched or cyclic alkyl group; a linear, branched or cyclic alkenyl group; or a linear, branched or cyclic alkynyl group; provided that if one of R and R1 is a linear alkyl group, the other of R and R1 is a branched or cyclic alkyl group; a linear, branched or cyclic alkenyl group; or a linear, branched or cyclic alkynyl group;

[0065] (ii) A liquid ester of formula II:

[0066]

[0067] wherein R2 is a branched alkyl group, a linear or branched alkenyl group, or a linear or branched alkynyl group, R3 is a linear or branched alkyl group, a linear or branched alkenyl group, or a linear or branched alkynyl group, and R4 is a linear or branched alkyl group, a linear or branched alkenyl group, or a linear or branched alkynyl group;

[0068] (iii) A liquid ester of formula III:

[0069]

[0070] wherein R5 is a branched alkyl group, a linear or branched alkene, or a linear or branched alkyne, R6 is a linear or branched alkyl group, a linear or branched alkene, or a linear or branched alkyne, and R7 is a linear or branched alkyl group, a linear or branched alkene, or a linear or branched alkyne; and

[0071] (iv) A combination of the above esters.

[0072] In still other embodiments, the present invention relates to a formulation comprising the non-aqueous composition or non-aqueous dispersion described in any of the preceding paragraphs. The formulation may be a personal care product selected from the following or may be a component of a personal care product selected from the following: cosmetics, hair, nail, skin or textile softeners, shampoos, hair styling products, oils or waxes for grooming beards, perming solutions, hair dyes, facial cleansers or body washes, makeup removers, cleansing lotions, emollient lotions or creams, bar soaps, liquid soaps, shaving creams, foams or gels, sunscreen, gels, lotions or creams for treating sunburn, deodorants or antiperspirants, moisturizing gels, shaving foams, facial powders, foundations, lipsticks, blushes, eyeliners, anti-wrinkle creams or anti-aging creams, eyeshadows, eyebrow pencils, mascaras, mouthwashes, toothpastes, oral care products, skin cleansing products, textile cleansing products, dishwashing products, hair or fur cleansing products, and skin care lotions or moisturizing creams. The formulation may be a sunscreen or a component of a sunscreen. The formulation may be an oil-in-water (O / W) emulsion or a water-in-oil (W / O) emulsion. The formulation may also comprise at least one additional ingredient selected from film-forming polymers, rheology-modifying polymers, waxes, emulsifiers, emollients, humectants, and combinations thereof.

[0073] The present invention also relates to a method for preparing a non-aqueous composition for dispersing metal oxide particle powders. The method comprises mixing an ester and a polyester having a terminal carboxylic acid functional group to form a homogeneous solution, wherein the ester is selected from the group consisting of the following (i)-(iv):

[0074] (i) A liquid ester of formula I:

[0075]

[0076] wherein R and R1 are each a linear, branched or cyclic alkyl group; a linear, branched or cyclic alkenyl group; or a linear, branched or cyclic alkynyl group; provided that if one of R and R1 is a linear alkyl group, the other of R and R1 is a branched or cyclic alkyl group; a linear, branched or cyclic alkenyl group; or a linear, branched or cyclic alkynyl group;

[0077] (ii) A liquid ester of formula II:

[0078]

[0079] wherein R2 is a branched alkyl group, a linear or branched alkenyl group, or a linear or branched alkynyl group, R3 is a linear or branched alkyl group, a linear or branched alkenyl group, or a linear or branched alkynyl group, and R4 is a linear or branched alkyl group, a linear or branched alkenyl group, or a linear or branched alkynyl group;

[0080] (iii) A liquid ester of formula III:

[0081]

[0082] wherein R5 is a branched alkyl, linear or branched olefin, or linear or branched alkyne, R6 is a linear or branched alkyl, linear or branched olefin, or linear or branched alkyne, and R7 is a linear or branched alkyl, linear or branched olefin, or linear or branched alkyne; and

[0083] (iv) combinations of the above esters.

[0084] The method may include the esters described in any of the previous paragraphs, for example, the esters of Formula I, Formula II, Formula III, and combinations thereof. The method may include the polyesters described in any of the previous paragraphs.

[0085] The mixing process to form a homogeneous solution may include heating. The mixing process may include high-shear mixing.

[0086] The method may further include dispersing metal oxide particles in the homogeneous solution to form a non-aqueous dispersion. The metal oxide particles of the method may include the metal oxide particles described in any of the previous paragraphs.

[0087] The method may further include adding at least one additional ingredient thereto to form a formulation. The at least one additional ingredient may be selected from film-forming polymers, rheology-modifying polymers, waxes, emulsifiers, emollients, humectants, and combinations thereof. The formulation of the method may be a sunscreen. BRIEF DESCRIPTION OF THE DRAWINGS

[0088] Figure 1 Shows the variation of the dispersion viscosity with the polyester concentration for Examples E1 - E2 and Comparative Examples CE1 - CE2 according to the embodiments herein. DETAILED DESCRIPTION

[0089] Before describing the compounds, compositions, methods, etc. of the present invention, it should be understood that the present invention is not limited to the specific processes, compositions, or methods described, as these may vary. It should also be understood that the terms used in the specification are only for describing a particular version or embodiment and are not intended to limit the scope of the present invention, which is limited only by the appended claims. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. Although any methods and materials similar or equivalent to those described herein may be used to practice or test the embodiments of the present invention, the preferred methods, devices, and materials are now described. All publications mentioned herein are incorporated herein by reference in their entirety. Nothing herein should be construed as an admission that the present invention is not entitled to antedate such disclosure by virtue of prior invention.

[0090] It must also be noted that, as used herein and in the appended claims, the singular forms "a", "an", and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "a cell" refers to one or more cells and equivalents thereof known to those skilled in the art, and so forth.

[0091] Unless otherwise indicated, "%" may refer to weight percent or volume percent.

[0092] Unless otherwise indicated, room temperature may refer to about 25 °C, or 25 °C, or a range from 22.5 °C to 27.5 °C, or a range from 20 °C to 30 °C.

[0093] In applicable cases, symbols such as C x -C y represent a range of carbon atom numbers, including C x and C y and all groups therebetween. For example, C5-C9 includes each of pentyl, hexyl, heptyl, octyl, and nonyl groups.

[0094] "Cosmetically acceptable" means suitable for use in contact with the skin and without undue toxicity, incompatibility, instability, irritation, allergic response, and the like.

[0095] In applicable cases, chemicals will be designated by their INCI names in accordance with the guidelines of the International Nomenclature of Cosmetic Ingredients. Further information (including suppliers and trade names) can be found under the corresponding INCI monograph in the 16th Edition of the International Cosmetic Ingredient Dictionary and Handbook published by the Personal Care Products Council (Washington, D.C.), and also online at the Personal Care Products Council INCIpedia (https: / / incipedia.personalcarecouncil.org / ).

[0096] In numerous embodiments, the present invention includes biobased compositions. Biobased compositions must be produced using biobased or "natural" feedstocks. Examples of biobased compositions are compositions prepared from bioderived feedstocks (e.g., from current and sustainable agricultural activities such as fermentation, algae, plant, or vegetable derived; e.g., from plant sources, preferably using non-genetically modified organisms or biomass, and which are not petrochemically derived (e.g., from sustainable tree and plant farms active in the 21st century rather than fossil sources such as oil, gas, or coal)). Such feedstocks are referred to herein as "natural" and "renewable" (i.e., "sustainable") and are known in the art as non-petroleum-derived feedstocks. In addition, such materials are formed from "new" carbon rather than from petroleum or other fossil fuel sources ("old" carbon). Such products are referred to herein as "natural" products and are known in the art as non-petrochemically derived or "biological" products. As used herein, the term "sustainable" refers to starting materials, reaction products, compositions, and / or formulations derived from renewable sources. Thus, "sustainable" is contrasted with "non-sustainable" starting materials, reaction products, compositions, and / or formulations, which contain carbon from finite natural resources such as fossil fuels (e.g., oil or coal), natural gas, etc. Thus, natural or biological products are not petrochemically derived and / or made from non-petrochemically derived sources, but are sustainable and renewable. True natural products (biocompounds) are formed using biomass (e.g., materials stored in the carbon cycle process in living plants, roots, etc., or materials released through animal respiration or feces or through decomposition). When carbon decomposes and degrades under pressure over millions of years, it produces fossil fuels (sources of petrochemically derived carbon). Biocompounds herein are intended to include materials derived from carbon of recently existing and / or sustainable plant sources / biomass and expressly exclude materials derived from fossil fuels.

[0097] To distinguish petro-based products from true natural and / or sustainable products, it is necessary to test their authenticity using mature and reliable test methods. Current methods employ mass spectrometry for detailed analysis of stable isotopes and assessment of the carbon-12 / carbon-13 and / or hydrogen-1 / hydrogen-2 ratios. Such tests are available through multiple analytical service testing institutions and are faster, more cost-effective, and provide more detailed information compared to radiocarbon testing methods.

[0098] Stable isotope analysis is based on the principle of kinetic isotope effects. The latter effect is well known to experts in the field of chemical kinetics. Broadly speaking, the heavy isotopes of a particular element react more slowly than their lighter isotopes (e.g., carbon-12 compared to carbon-13). Thus, when a plant incorporates carbon dioxide into its biomass, the ratio of carbon-12 to carbon-13 will vary depending on the type of chemistry the plant uses to make biomass (e.g., whether the plant undergoes the C3 or C4 photosynthetic pathway). This is typically reported as the δ 13 C / 12 C ratio (i.e., δ 13 C), and referenced to the current carbon dioxide standard. Additionally, a similar isotopic kinetic effect is observed when water is incorporated into new biomass, which is measured as the δ 2 H / 1 H ratio (i.e., δ 2 H). Using a combination of the δ 13 C and δ 2 H ratios, those familiar with the relevant field can readily distinguish and verify the nature of the raw materials used to prepare the product being analyzed (i.e., whether it is from petrochemicals or from recently living or living algae, plants, or similar biogenic sources).

[0099] The compositions and / or formulations of the present invention can be identified and distinguished from those of the prior art by their biobased carbon content. In some embodiments, the biobased carbon content can be measured by radiocarbon dating to determine the relative age of materials composed of organic (i.e., carbon-containing) substances. Radiocarbon is an unstable isotope of carbon, called carbon-14 (i.e., “ 14 C”). 14 14 C is an unstable isotope that emits radiation energy in the form of β particles at a very consistent rate (i.e., the half-life of radiocarbon is 5730 years) and ultimately decays to the more stable nitrogen-14 ( 14 N). Since petro-based (i.e., petrochemically derived) raw materials are derived from plants and animals buried millions of years ago, the radiocarbon (i.e., 14 14The C content is known, and thus the percentage of carbon from renewable sources can be estimated by total organic carbon analysis, which provides the data needed to determine whether a compound is truly derived from a "natural" and / or "sustainable" ("renewable") source of raw materials or instead from "old" sequestered compounds (i.e., petrochemical or petroleum-based sources). It is generally considered that the use of petroleum-based (also known as "fossil-based") raw materials is not sustainable, i.e., old carbon is not sustainable, not a renewable raw material, and is not considered "natural" and / or "sustainable" in the art.

[0100] In some embodiments, the formulations and / or compositions of the present invention comprise bio-based carbon as substantially all of the carbon present in the mixture of compounds, which may refer to a bio-based carbon content of at least 90%, at least 95% or at least 98%.

[0101] In some embodiments, the compositions of the present invention comprise 14 a C content that is substantially equal to the 14 C content in the current atmosphere, as determined by ASTM D6866. In some embodiments, the compositions of the present invention comprise 14 a C content that is at least about 90%, at least about 95%, at least about 98% or at least about 99% of the 14 C content in the current atmosphere, as determined by ASTM D6866. In some embodiments, the compositions of the present invention comprise at least about 0.8 12 C atoms per 10 14 carbon atoms present in the composition, at least about 1.0 12 C atoms per 10 14 carbon atoms present in the composition, or at least about 1.2 12 C atoms per 10 14 carbon atoms present in the composition, as determined by ASTM D6866.

[0102] By "sustainable" the applicant herein means materials from renewable sources. In contrast, "unsustainable" means materials from finite natural resources, such as fossil fuels (e.g., petroleum, natural gas, coal, etc.).

[0103] Introduction

[0104] The present invention relates to non-aqueous compositions comprising an ester dispersion medium (EDM) and a carboxylic acid-terminated polyester, to which MOP can be added to provide a uniform MOP dispersion. The ester can be the EDM and the polyester can be a polyester dispersant (PEDA). As described above, the use of a dispersion medium and a dispersant based on 100% natural and renewable carbon enables the formation of a stable, low-viscosity, high-solids-loading MOP dispersion. The applicant has surprisingly found that, as described herein, a dispersion medium comprising an ester having a branched or unsaturated alkyl chain (preferably synthesized from 100% biobased carbon) can provide a stable dispersion with extremely low viscosity at relatively high particle loadings. The ester is not a completely saturated linear ester, i.e., compounds comprising only saturated linear esters are not included herein.

[0105] Non-aqueous dispersion

[0106] The non-aqueous composition of the present invention comprises an EDM (including esters containing branched or unsaturated alkyl groups) and a carboxylic acid-terminated PEDA. Metal oxide particles are added to the non-aqueous composition of the present invention to form a uniform non-aqueous dispersion.

[0107] The non-aqueous composition of the present invention provides a "ready-to-use" dispersion system that is capable of forming low-viscosity dispersions with a wide range of metal oxide particles. In particular, users of non-aqueous dispersions do not require specialized mixing equipment or experience in manufacturing stable non-aqueous dispersions.

[0108] In some embodiments, the non-aqueous composition of the present invention consists essentially of (i) one or more liquid esters having branched or unsaturated alkyl groups and (ii) a carboxylic acid-terminated polyester polymer. The basic and novel properties of such compositions of the present invention include the ability to form stable, low-viscosity non-aqueous dispersions with a variety of metal oxide particles. In addition, the non-aqueous compositions described herein exhibit ease of processing, which is at least in part due to the achievement of low viscosity.

[0109] Metal oxide particles

[0110] Some embodiments of the present disclosure relate to dispersion compositions comprising metal oxide particles. The MOPs are preferably solid, white (or colorless), and odorless metal oxide particles. The MOPs herein may include zinc oxide (ZnO) and / or titanium dioxide (TiO2) particles. These are particularly useful in formulations such as sunscreen formulations. Some of the dispersions and / or formulations herein may additionally or alternatively comprise metal oxides including one or more of iron, copper, manganese, magnesium, cerium, vanadium, zirconium, aluminum, silicon, such as FeO, Fe2O3, Fe3O4, CeO2, V2O5, ZrO2, MnO2, MgO, Al2O3, SiO2, CaO, or combinations thereof, and other cosmetically acceptable metal oxides. Suitable metal oxides also include doped metal oxides (e.g., doped with any of the above metals and metal oxides). Other suitable metal oxide particles include coated particles (e.g., coated with any of the above metals and metal oxides). The MOPs have high purity, e.g., greater than 95%, greater than 96%, greater than 97%, greater than 98%, or greater than 99%.

[0111] In some embodiments, the surface of the metal oxide particles can be modified. Such surface modification, especially in the case of TiO2, can inhibit photocatalytic activity in subsequent formulations. Inorganic coatings such as alumina or silica are preferably used for any surface modification.

[0112] Alternatively, organic surface modification, while less preferred, is also acceptable. Surface modification with organic or hybrid organic-inorganic coatings derived from fossil-based carbon is not desirable due to poor sustainability and low consumer acceptance. Specifically, surface modification with silicone or siloxane is less preferred. For example, trialkoxyalkylsilanes (e.g., triethoxyoctylsilane) or silicones (e.g., methyl silicone or dimethyl silicone) are less preferred because of their negative environmental impact and / or negative consumer perception.

[0113] Any coating or surface modification of the particles as described above is included as part of the mass or weight of the particles herein (e.g., MOPs).

[0114] Unsurface-modified MOPs can also be used in the compositions and formulations described herein. In some embodiments, uncoated metal oxide particles are preferred. In certain embodiments, MOPs comprising uncoated ZnO are used in the compositions and formulations described herein.

[0115] The average particle size of the MOP is not limited, however, the average particle size of the MOP can preferably be in the submicron diameter range. For example, the metal oxide particles can be present in the composition with an average particle size of from 10 nm to 500 nm, such as from 10 nm to 400 nm, from 20 nm to 300 nm or from 30 nm to 150 nm. In terms of the upper limit, the average particle size of the MOP can be less than 500 nm, such as less than 400 nm, less than 300 nm or less than 150 nm. In terms of the lower limit, the average particle size of the MOP can be greater than 10 nm, such as greater than 20 nm or greater than 30 nm. In a preferred embodiment, the average particle size of the MOP is less than about 200 nm. These ranges and limitations can also apply to the formulations containing these compositions.

[0116] The MOP used in the compositions, dispersions and formulations described herein can exhibit a wide range of average particle size distributions. The average particle size distribution can be, for example, in the range of about 10 nm to about 500 nm, such as in the range of 10 nm to 400 nm, 20 nm to 300 nm or 30 nm to 150 nm. In a preferred embodiment, the average particle size distribution is in the range of about 30 nm to about 150 nm. The particles can be present in the form of clusters or aggregates. The MOP can exhibit a particle shape selected from spherical, rod-shaped, star-shaped, equiaxed, spherical, plate-shaped, flake or combinations thereof. In some preferred embodiments, the MOP (e.g., ZnO particles) is characterized as having a variety of shapes. [See, e.g., Zinc oxide (nano form); What are the properties of ZnO nanoparticles?, https: / / ec.europa.eu / health / scientific_committees / opinions_layman / zinc-Oxide / de / l-3 / 3.ht m#.]

[0117] In some or other embodiments, the MOP can be added to a non-aqueous composition to form a dispersion. In other words, a non-aqueous composition containing the ester dispersion medium and the carboxylic acid-terminated polyester dispersant described herein is provided directly, or the MOP is subsequently added to form its dispersion and / or formulation.

[0118] Ester dispersion medium

[0119] The non-aqueous compositions for dispersing metal oxide particles, and the dispersions and formulations herein, comprise a non-aqueous ester dispersion medium (EDM). The "ester dispersion medium" or simply "ester", which can be used interchangeably herein, is an ester having physical properties suitable for use as a dispersion medium. For example, the ester is a liquid (at room temperature, e.g., 25 °C) and / or the viscosity of the ester at 25 °C is less than about 100 cSt. Esters suitable for use as an ester dispersion medium include branched esters or unsaturated esters as described below.

[0120] In aspects herein, the ester comprises one or more selected R groups such that the ester is a liquid at 25 °C.

[0121] As described herein, the compositions, dispersions, and formulations of the present invention may contain other esters (not the EDM as defined herein) in addition to the ester dispersion medium. Non-EDM esters that may be present include wax esters for constructing formulations and films, enhancing water repellency, etc. Examples of non-EDM esters include, but are not limited to, hydrogenated rapeseed oil, jojoba esters, hydrogenated jojoba oil, synthetic beeswax.

[0122] The inventors surprisingly found that a dispersion medium comprising a branched or unsaturated ester is suitable for non-aqueous compositions of MOP dispersions because, in combination with a polyester dispersant (PEDA as described below), it can reduce the viscosity of the composition.

[0123] Preferably, the non-aqueous composition comprises an ester having a branched alkyl or unsaturated alkyl group. For the purposes herein, the branching point can be defined relative to any carbon or heteroatom in the molecule, or it can also refer to a stereocenter. For example, in certain embodiments, the methyl branching is at the 1-position, e.g., the methyl branching is on the carbon atom bearing the hydroxyl group of the alcohol, e.g., 1-methylheptanol, as shown below:

[0124]

[0125] In some embodiments, the non-aqueous composition for dispersing metal oxide particles comprises a liquid ester of Formula I:

[0126]

[0127] wherein R and R1 are each a linear, branched, or cyclic alkyl group; a linear, branched, or cyclic alkenyl group; or a linear, branched, or cyclic alkynyl group; provided that if one of R and R1 is a linear alkyl group, the other of R and R1 is a branched or cyclic alkyl group; a linear, branched, or cyclic alkenyl group; or a linear, branched, or cyclic alkynyl group. In some embodiments, R is a C5-C 17 branched or cyclic alkyl, linear, branched, or cyclic alkenyl, or linear, branched, or cyclic alkynyl; and R1 is a C3-C 18Linear, branched or cyclic alkyl, linear, branched or cyclic alkenyl, or linear, branched or cyclic alkynyl. In some embodiments, the ester has the formula I and R and R1 are different. In some embodiments, R is preferably C 10 Unsaturated. R is even more preferably C 10 Terminal unsaturated. In some embodiments, R1 is preferably C6-C 12 Linearly saturated. R1 is even more preferably C7-C8 linearly saturated.

[0128] Examples of esters according to formula (I) include heptyl undecylenate according to structure (I-i) ( Natural, INOLEX Inc.)

[0129]

[0130] In addition to heptyl undecylenate as described above, other examples of esters include octyl undecylenate and / or decyl undecylenate.

[0131] In other embodiments, the non-aqueous composition for dispersing metal oxide particles comprises a liquid ester of formula (II):

[0132]

[0133] Wherein R2 is a branched alkyl, linear or branched alkenyl, or linear or branched alkynyl, R3 is a linear or branched alkyl, linear or branched alkenyl, or linear or branched alkynyl, and R4 is a linear or branched alkyl, linear or branched alkenyl, or linear or branched alkynyl. In some embodiments, R2 is C3-C 18 Branched alkyl, linear or branched alkenyl, or linear or branched alkynyl, R3 is C2-C8 linear or branched alkyl, linear or branched alkenyl, or linear or branched alkynyl; and R4 is C3-C 18 Linear or branched alkyl, linear or branched alkenyl, or linear or branched alkynyl. In some embodiments, the ester has the formula II and R2 and R4 are the same. In some embodiments, R2 and R4 are preferably branched C4-C 18 , more preferably branched C5-C 18 , even more preferably branched C6-C 12 . In some embodiments, R3 is preferably linear C2-C8.

[0134] Examples of esters according to formula (II) include diisooctyl succinate according to structure (II-i) (SustOleo TM DCS, INOLEX Inc.)

[0135]

[0136] In other embodiments, the non-aqueous composition for dispersing metal oxide particles comprises a liquid ester of formula (III):

[0137]

[0138] wherein R5 is a branched alkyl, linear or branched alkene, or linear or branched alkyne, R6 is a linear or branched alkyl, linear or branched alkene, or linear or branched alkyne, and R7 is a linear or branched alkyl, linear or branched alkene, or linear or branched alkyne. In some embodiments, R5 is a C3-C 18 branched alkyl, linear or branched alkene, or linear or branched alkyne, R6 is a C2-C8 linear or branched alkyl, linear or branched alkene, or linear or branched alkyne, and R7 is a C3-C 18 linear or branched alkyl, linear or branched alkene, or linear or branched alkyne. In some embodiments, the ester has formula III and R5 and R7 are the same.

[0139] Examples of esters according to formula (III) include propylene glycol diisostearate and propylene glycol undecylenate.

[0140] The non-aqueous compositions herein for dispersing metal oxide particles may comprise esters selected from the group consisting of: (i) esters of formula I, (ii) esters of formula II, (iii) esters of formula III, and combinations thereof. In some embodiments, the dispersion and / or formulation comprises esters of formula I, formula II, formula III, and combinations thereof. In some embodiments, the dispersion and / or formulation comprises liquid esters of formula I, formula II, formula III, and combinations thereof. The esters of formula I, formula II, formula III, and combinations thereof may have a viscosity at 25 °C of less than about 100 cSt. The ester dispersion media herein include the esters as described above.

[0141] Other ester dispersion media or esters contemplated include non-aqueous esters, including triglyceride compounds, such as a triglyceride compound of formula (IV):

[0142]

[0143] wherein R8, R9, and R 10 are each independently selected from linear, branched, saturated, or unsaturated alkyl groups containing 5 to 18 carbon atoms (C5-C 18 ). In some embodiments, two or more of R8, R9, and R 10 are the same. In some particular embodiments, R8, R9, and R 10 are unsaturated, branched, or have double bonds, or one of R8, R9, and R 10 can be removed to form a diester.

[0144] However, these triglyceride esters (Formula IV) having R8, R9, and R 10 (all linear) are comparative examples as described herein and include saturated triglycerides such as triheptanoin and / or caprylic / capric triglyceride.

[0145] One comparative example of an ester according to Formula (IV) includes triheptanoin (SustOleo TM MCT, INOLEX Inc.) according to Structure (IV-i), which is non-palm, 100% natural medium-chain triglyceride:

[0146]

[0147] According to the present invention, since these triglyceride esters have a high dispersion viscosity when combined with PEDA (as detailed in Table 2 below and Figure 1 described in detail), they are not suitable for use in the non-aqueous compositions herein.

[0148] In some embodiments, the esters of the non-aqueous dispersions herein have a viscosity of less than about 100 cSt at 25°C. In preferred embodiments, the esters have a viscosity of less than about 50 cSt at 25°C. More preferably, the esters have a viscosity of less than 25 cSt at 25°C.

[0149] As described above, the carbon present in the esters can be 100% bio-based carbon. In embodiments herein, the carbon atoms of the esters contain greater than about 50% bio-based carbon, such as greater than 70%, greater than 80%, greater than 90%, greater than 95%, or greater than 99% (as determined by 14 the C radiocarbon dating method described above or other methods known to those skilled in the art). In some embodiments, the esters contain 100% bio-based carbon. In some embodiments, substantially all of the carbon present in the compounds of Formulas (I), (II), (III), (IV) or combinations thereof is bio-based. Preferred embodiments herein include that the ester dispersion medium contains 100% bio-based carbon.

[0150] The non-aqueous EDM may also optionally contain one or more other non-aqueous organic fluids that can be mixed with the main ester component and can be used for cosmetic purposes. Examples of suitable non-aqueous organic fluids include hydrocarbons, cyclic alkyl carbonates, dialkyl carbonates, dialkyl ketones, etc.

[0151] Describing a composition and / or dispersion as "non-aqueous" herein means that the composition (and / or dispersion) is substantially free of added water, preferably containing less than about 3 wt% water, more preferably less than about 1 wt% water, even more preferably less than about 0.5 wt% water, and most preferably less than about 0.1 wt% water. The non-aqueous composition (and / or dispersion) may contain a small amount of accidental water (e.g., from absorbing environmental humidity) or processing conditions (e.g., incomplete drying after washing).

[0152] Polyester dispersant

[0153] The non-aqueous compositions for dispersing metal oxide particles and the dispersions and formulations herein may contain polyester dispersants. As used herein, "polyester dispersant" and "polyester" are used interchangeably, where the polyester dispersant (PEDA) herein is a polyester having terminal carboxylic acid functional groups and performs specific functions as described below.

[0154] As described herein, the compositions of the present invention may contain other polyesters (not PEDA as defined herein) in addition to PEDA. Other non-PEDA polyesters may include, for example, polyester film formers for improving water resistance, etc.

[0155] The non-aqueous composition contains an aliphatic polyester insoluble in water. In some embodiments, the polyester is carboxyl-functional, in other words, one or more chain ends are capped with carboxylic acid structural moieties. The polyesters herein have terminal carboxylic acid functional groups. Thus, the polyesters described herein are carboxylic acid-capped polyester dispersants. For example, the polyester may contain a single terminal carboxylic acid functional group or two terminal carboxylic acid functional groups.

[0156] PEDA can be characterized by an acid value (measured by the AOCS official method Te 2a-64). In some embodiments, PEDA has an acid value of at least 15 mg KOH / g. The acid value of PEDA can be, for example, from about 15 mg KOH / g to about 100 mg KOH / g, such as 20 mg KOH / g to 90 mg KOH / g, 25 mg KOH / g to 80 mg KOH / g, or 30 mg KOH / g to 75 mg KOH / g. The acid value of PEDA (in terms of the lower limit) can be greater than about 15 mg KOH, such as greater than 20 mg KOH, greater than 25 mg KOH / g, or greater than 30 mg KOH / g. The acid value of PEDA (in terms of the upper limit) can be less than about 100 mg KOH, such as less than 90 mg KOH, less than 80 mg KOH / g, or less than 75 mg KOH / g.

[0157] In some embodiments, the non-aqueous composition for dispersing MOP in the dispersions and / or formulations herein contains a polyester homopolymer derived from the polycondensation of hydroxyalkanoic acids of formula (V):

[0158]

[0159] wherein R is selected from linear, branched, saturated or unsaturated alkyl groups having 5 to 23 carbon atoms (C5-C 23 ); and R' is selected from H or linear, branched, cyclic, saturated or unsaturated alkyl or acyl groups having 1 to 22 carbon atoms (C1-C 22 ).

[0160] Examples of polyesters according to formula (V) include polyhydroxystearic acid (the structure is shown in (V-i) below), polyhydroxystearic acid stearate (polyhydroxystearic acid, where some or all of the hydroxyl groups react with stearic acid to form stearate), polyhydroxystearyl succinate (polyhydroxystearic acid, where some or all of the hydroxyl groups react with succinic acid to form succinic acid monoester and / or diester), polyhydroxystearyl sebacate (polyhydroxystearic acid, where some or all of the hydroxyl groups react with sebacic acid to form sebacic acid monoester and / or diester), polyricinoleic acid, and carboxyl-terminated lactone (estolide) derivatives from oleic acid, such as coconut oil fatty acid lactone. The monoesters of polyhydroxystearyl succinate and polyhydroxystearyl sebacate are shown in Figures V-ii and V-iii, respectively. The copolymers of the diesters polyhydroxystearyl succinate and polyhydroxystearyl sebacate are shown in Figure V-iv, where R 10 = succinyl [C(O)(CH2)2C(O)] or sebacoyl [C(O)(CH2)8C(O)] and R 11 = C 17 H 34 .

[0161]

[0162]

[0163] In some embodiments, the polyester can be a polyester copolymer derived from the polycondensation of two or more difunctional monomers (such as diols and diacids or diesters (such as methyl esters)) according to structure (VI):

[0164]

[0165] wherein R is selected from linear, branched, cyclic, saturated or unsaturated alkyl groups having 2 to 34 carbon atoms (C2-C 34 ); R' is selected from linear, branched, saturated or unsaturated alkyl groups having 2 to 34 carbon atoms (C2-C 34 ); and R'' is selected from H or linear, branched, saturated or unsaturated alkyl groups having 1 to 22 carbon atoms (C1-C 22) linear, branched, cyclic, saturated or unsaturated alkyl or acyl groups. The acid-functional monomers must be present in excess to ensure that most of the polyester copolymer chain ends are carboxyl-functional. One end of the polyester copolymer may be capped with an ester group, but at least one chain end includes a carboxylic acid functional group. Alternatively, the hydroxyl-functional polyester may be COOH-capped, for example, by a post-polymerization reaction with an acid anhydride (such as succinic anhydride).

[0166] For example, 1,2-pentanediol (pentanediol, R' = 1,2-substituted n-pentyl) can be copolymerized with a slightly molar excess of sebacic acid to produce carboxyl-terminated telechelic (functionally terminated at both ends) poly(1,2-pentanediol sebacate). Examples of polyesters according to formula (VI) include the pentanediol / sebacic acid copolymer according to structure (VI-i):

[0167]

[0168] wherein R is an 1,8-substituted n-octyl and R' is a 1,2-substituted n-pentyl.

[0169] In some embodiments, the carboxylic acid-terminated polyester dispersant comprises a linear polyester terminated with one carboxylic acid group. In other embodiments, the carboxylic acid-terminated polyester dispersant comprises a linear polyester terminated with two carboxylic acid groups, or a telechelic linear polyester terminated with carboxylic acid groups at both chain ends. In other embodiments, the carboxylic acid-terminated polyester dispersant comprises a homopolymer derived from an AB hydroxycarboxylic acid monomer. In other embodiments, the carboxylic acid-terminated polyester dispersant comprises a copolymer derived from an AA diol and a BB diacid or diester monomer. In a preferred embodiment, PEDA does not contain an unsaturated structural moiety in the polymer backbone or as a side chain group, i.e., PEDA does not contain a C═C double bond susceptible to oxidative degradation.

[0170] The carboxylic acid-terminated polyester dispersant may be selected from polyhydroxystearic acid, polyhydroxystearic acid stearate, polyhydroxystearyl succinate, polyhydroxystearyl sebacate, and combinations thereof.

[0171] The polyester dispersant as described above contains bio-based carbon. In the embodiments herein, the carbon atoms of the polyester contain greater than about 90%, such as greater than 95%, greater than 96%, greater than 97%, greater than 98% or greater than 99% bio-based carbon (as determined by 14 14C radiocarbon dating or other methods known to those skilled in the art as described above). In some embodiments, the polyester contains 100% bio-based carbon. In some embodiments, substantially all of the carbon present in the compounds of formula (V), (VI) or combinations thereof is bio-based. The polyester is preferably composed of renewable bio-based carbon. In a preferred embodiment, the carboxylic acid-terminated polyester dispersant contains 100% bio-based carbon.

[0172] Preparation / method of the dispersion

[0173] The non-aqueous dispersions of the present invention may advantageously contain a high loading of metal oxide particles. The weight fraction of metal oxide particles contained in the non-aqueous dispersion ranges from about 15 wt% to about 75 wt%, based on the total weight of the non-aqueous dispersion. For example, 25 wt% to 75 wt%, 30 wt% to 75 wt%, 35 wt% to 75 wt%, 40 wt% to 75 wt%, 45 wt% to 75 wt%, 50 wt% to 75 wt% or 40 wt% to 60 wt%. As for the lower limit, the dispersion may contain a weight fraction of metal oxide particles greater than 15 wt%, greater than 25 wt%, greater than 30 wt%, greater than 35 wt%, greater than 40 wt%, greater than 45 wt% or greater than 50 wt%. In a preferred embodiment, the MOP fraction in the dispersion is greater than 40 wt% or greater than 45 wt%.

[0174] The non-aqueous dispersions of the present invention desirably contain a high loading of metal oxide particles, and this is also true in terms of volume fraction. The solid particle volume fraction of metal oxide particles contained in the non-aqueous dispersion ranges from about 20 vol% to about 80 vol% based on the total volume of the non-aqueous dispersion. For example, 25 vol% to 75 vol%, 30 vol% to 70 vol%, 35 vol% to 70 vol%, 40 vol% to 70 vol%, 45 vol% to 65 vol%, or 50 vol% to 65 vol%. As for the lower limit, the dispersion may contain a volume fraction of metal oxide particles greater than 20 vol%, greater than 25 vol%, greater than 30 vol%, greater than 35 vol%, greater than 40 vol%, greater than 45 vol%, or greater than 50 vol%. In a preferred embodiment, the MOP fraction in the dispersion is greater than 50 vol%, greater than 60 vol%, or greater than 70 vol%.

[0175] The amount (or concentration) of polyester in the dispersion is selected to produce the lowest possible dispersion viscosity range. These dispersions contain from about 1.00 wt% to about 10.00 wt% polyester (based on the total weight of the dispersion (EDM + PEDA + MOP)), such as 1.00 wt% to 7.00 wt%, 2.00 wt% to 6.00 wt%, 2.50 wt% to 5.50 wt% or 3.00 wt% to 5.00 wt%. In a preferred embodiment, the dispersion composition contains from 3.00 wt% to 5.00 wt% polyester. The amount of polyester required to achieve a stable, low-viscosity dispersion generally increases as the MOP loading in the dispersion increases. The preferred amount of polyester is 3.00 wt% to 5.00 wt%, with the MOP loading being 50.05 wt% based on the total weight of the dispersion, plus the amount of EDM present in the dispersion, for a total of 100 wt%.

[0176] The methods herein include preparing a non-aqueous based composition for dispersing metal oxide particles. In some embodiments, the method includes adding one or more components to the non-aqueous based composition to form a non-aqueous based dispersion and / or formulation.

[0177] The dispersion can be prepared according to any technique familiar to those skilled in the art of pigment dispersions. The dispersion is preferably prepared by first preparing a non-aqueous based composition. The non-aqueous based composition can be prepared by dissolving polyester in an ester, thereby dissolving PEDA in EDM to form a homogeneous solution.

[0178] Subsequently, the method includes adding MOP to the homogeneous solution (or mixture), mixing and shearing sufficiently to ensure a homogeneous non-aqueous based dispersion. Heating can be used to improve the dissolution of the polyester in the ester. In addition to or in place of heating, high-shear mixing can be performed using a rotor-stator homogenizer, a Cowles blade, a colloid mill or other high-shear devices to ensure optimal dispersion and stabilization of the MOP.

[0179] In some embodiments, the method includes mixing EDM with a polyester (PEDA) having terminal carboxylic acid functional groups to form a homogeneous solution (or mixture). EDM is selected from the group consisting of: (i) a liquid ester of formula I, (ii) a liquid ester of formula II, (iii) a liquid ester of formula III and combinations thereof. The esters have been described in detail above. The method can include an ester having a viscosity of less than about 100 cSt at 25°C. 100% of the carbon present in the ester is bio-based.

[0180] The polyester can contain a single terminal carboxylic acid functional group. In other embodiments, the method includes the polyester containing two terminal carboxylic acid functional groups.

[0181] The method may include that the polyester has a number average molecular weight (Mn) of less than about 10,000 g / mol. The polyester may have an acid value of at least 15 mg KOH / g. The method may include that the polyester is selected from polyhydroxystearic acid, polyhydroxystearic acid stearate, polyhydroxystearyl succinate, polyhydroxystearyl sebacate, and combinations thereof. The carbon present in the polyester is 100% biobased.

[0182] The non-aqueous dispersions described herein preferably have a low viscosity for easy processing (such as mixing, pumping, etc.), handling, and application. In some embodiments, the method includes that the viscosity of the non-aqueous dispersion is less than about 1000 cP. The viscosity of the dispersion composition (in terms of the upper limit) is less than about 1000 cP, such as less than 1000 cP, less than 900 cP, less than 750 cP, less than 500 cP, less than 300 cP, or less than 200 cP. These viscosities of the non-aqueous dispersion include MOP.

[0183] The weight ratio of inorganic solid particles, metal oxide particles to the ester-polyester mixture (homogeneous solution) of the non-aqueous composition in these low-viscosity non-aqueous metal oxide particle dispersions ranges from about 1 to 0.33 (1:0.33) to about 1 to 5 (1:5). In a preferred embodiment, the weight ratio of inorganic particles to the ester-polyester mixture in the non-aqueous dispersion is about 1 to about 0.67 (1:0.67). In a more preferred embodiment, the weight ratio of inorganic particles to the ester-polyester mixture in the non-aqueous dispersion is about 1 to about 1 (1:1). The ester-polyester mixture is a non-aqueous composition containing EDM and PEDA.

[0184] The non-aqueous dispersions described herein do not contain silicone. For example, the low-viscosity non-aqueous metal oxide particle dispersions are substantially free of silicone.

[0185] The non-aqueous dispersion should exhibit stability during preparation, which means that sedimentation, separation, or a sharp change in viscosity should not occur from the time of preparation to use. This generally means that the dispersion remains stable for several days to weeks after preparation. The ability to easily redisperse the settled solids by stirring the settled dispersion (such as using a stirrer or oscillator) is also a favorable indicator of the dispersion stability, for example, in cases where a lower solid loading is required and the colloidal filling and / or yield value is insufficient to prevent sedimentation.

[0186] The method may include pre-preparing a homogeneous solution for subsequent addition of MOP, that is, the MOP component can be considered optional and added later to form a non-aqueous dispersion. Therefore, the method may also include dispersing metal oxide particles in the mixture to form a non-aqueous dispersion. The metal oxide particles may include zinc oxide, titanium oxide, combinations thereof, and other metal oxides listed above.

[0187] Non-aqueous dispersions and formulations containing non-aqueous dispersions can be free or substantially free of silicones, such as methyl silicone, dimethyl silicone, cyclopentasiloxane, etc. "Silicone-free" compositions and formulations contain less than about 1 wt%, preferably less than about 0.5 wt%, more preferably less than about 0.1 wt% of silicone components, or most preferably do not contain a measurable concentration or amount of silicone.

[0188] The non-aqueous dispersion composition can be used directly or for formulating a final product. For example, the dispersion can be formulated into various product forms, such as oil-in-water (O / W) emulsions, water-in-oil (W / O) emulsions, creams, lotions, pastes, sprays, sticks, etc.

[0189] The method can also include adding at least one additional ingredient therein to form a formulation. The at least one additional ingredient is selected from film-forming polymers (such as polyester-7, polyester-10, trimethylpentanediol / adipic acid / glycerol cross-linked polymer, adipic acid / diethylene glycol cross-linked polymer, ethyl cellulose, acrylate copolymer (such as Avalure TM AC series of Lubrizol, polyurethane-62, PPG-17 / IPDI / DMPA copolymer), rheology-modifying polymers (such as acrylate copolymer, carbomer, acrylate / C 10-30 alkyl acrylate cross-linked polymer, acrylate / polyoxyethylene-25 behenyl methacrylate copolymer, sodium acrylate / sodium acryloyldimethyltaurate copolymer, acrylate / vinyl neodecanoate cross-linked polymer, hydroxypropyl methylcellulose, hydroxyethyl cellulose, polyurethane-79), waxes (such as Cera Alba (beeswax), candelilla wax, carnauba wax, microcrystalline wax), emulsifiers (such as cetearyl alcohol polyoxyethylene-12 ether, PEG-100 stearate, glyceryl stearate, rapeseed glyceride, rapeseed alcohol, lauryl polyoxyethylene-4 ether, potassium cetyl phosphate), emollients (such as petrolatum, mineral oil, sunflower oil, squalene, almond oil), humectants (such as glycerol, urea, betaine), pH regulators, antioxidants, fragrances, multifunctional ingredients, preservation techniques, and combinations thereof. In some embodiments, the formulation is a sunscreen.

[0190] Other components may be provided, including those known in the field of sun care formulations or components for personal care compositions (such as cosmetics). The composition may optionally contain, for example, surfactants, buffers, fragrances, colorants, dyes, viscosity regulators, water, oils, emulsifiers, preservatives, antioxidants, emollients, thickeners, gelling agents, vitamins, humectants, alcohols, plant extracts, and powders. Other suitable additives or components may include one or more oils in the product, such as almond oil, castor oil, coconut oil, corn oil, cottonseed oil, rapeseed oil, flaxseed oil, nut oil, olive oil, palm oil, peanut oil, safflower oil, sesame oil, soybean oil, sunflower oil, jojoba oil, or combinations of these oils.

[0191] Surfactants may be included in the personal care composition, such as anionic surfactants, zwitterionic surfactants, cationic surfactants, nonionic surfactants, or combinations thereof. Other exemplary components or additives may include, but are not limited to, lipids, additional alcohols, waxes, pigments, vitamins, fragrances, bleaching agents, antibacterial agents, anti-inflammatory agents, antifungal agents, thickeners, gums, starches, chitosan, polymeric materials, cellulosic materials, glycerin, proteins, amino acids, keratin fibers, fatty acids, siloxanes, plant extracts, abrasives, and / or exfoliants (chemical or mechanical), anti-caking agents, antioxidants, binders, biologic additives, buffers, swelling agents, chelating agents, chemical additives, denaturing agents, topical analgesics, film formers, humectants, opacifiers, pH regulators, preservatives, propellants, reducing agents, sunscreens, skin tanning agents, essential oils, skin sensates, or combinations thereof.

[0192] The personal care composition of the present invention may also contain one or more optical brighteners, as described in U.S. Patent Publication No. 2011 / 0104078A1, which is incorporated herein by reference, and also includes, for example, triazine-stilbene (disulfonated, tetrasulfonated, or hexasulfonated), coumarin, imidazoline, oxadiazole, triazole, benzoxazoline, and diphenylstilbene.

[0193] The scope of the present invention also includes a method of protecting the skin, hair, and / or nails of a mammal from damage caused by exposure to UV wavelength light by applying the composition as described above to the skin, hair, or nails. "Skin" includes the outer skin of living mammals, reptiles, amphibians, birds, and other animals, as well as processed skin, such as leather or suede. "Hair" includes the hair, fur, wool, and other filamentous keratinized structures of mammals and other animals. Similarly, "nails" includes the claws, hooves, and similar structures of mammals and other animals.

[0194] The scope of the present invention also includes a method for improving the aesthetics of a light protection preparation by using the composition to avoid an oily and / or greasy feel and to prevent significant loss or separation of the components when the skin is wet, moistened or otherwise wetted.

[0195] Formulation

[0196] In some embodiments, the present invention relates to a dispersion composition comprising metal oxide particles, which can be used in formulations for various applications. The dispersion composition or formulation is a personal care product, a household care product, a textile care product, an institutional care product, a pharmaceutical product, a veterinary product, a food or an industrial product or can be a component of these products. In some embodiments, the composition can be used in a formulation or can be a component of a personal care product. Personal care products include cosmetics, hair, nail, skin or textile conditioners, shampoos, hair styling products, oils or waxes for grooming beards, perming solutions, hair dyes, facial cleansers or body washes, makeup removers, cleansing milks, emollient lotions or creams, bar soaps, liquid soaps, shaving creams, foams or gels, sunscreen products, gels, lotions or creams for treating sunburn, deodorants or antiperspirants, moisturizing gels, shaving foams, face powders, foundations, lipsticks, blushes, eyeliners, anti-wrinkle creams or anti-aging creams, eyeshadows, eyebrow pencils, mascaras, mouthwashes, toothpastes, oral care products, skin cleansing products, textile cleansing products, dishwashing products, hair or fur cleansing products, and skin care lotions or moisturizers. In a preferred embodiment, the formulation is a sunscreen product.

[0197] The formulations of the present invention can be used, for example, as skin creams, facial moisturizers, sunscreen lotions, nourishing creams, day creams or night creams. Typical embodiments are creams, gels, such as but not limited to hydrogels, water-dispersed gels, oil gels; emulsions, alcohols and water / alcohol solutions, various forms of emulsions, such as but not limited to oil-in-water (O / W), water-in-oil (W / O), mixed emulsions, PIT emulsions, Pickering emulsions, microemulsions, nanoemulsions; aerosol foams, non-aerosol foams, aerosol sprays, non-aerosol sprays, pump sprays, serums, roll-ons, pastes, balms or stick formulations. These compositions may also contain mild surfactants, co-emulsifiers, superfatting agents, pearlescent waxes, thickening agents, thickeners, polymers, silicone compounds, fats, waxes, stabilizers, bioactive ingredients, deodorant active ingredients, antidandruff agents, film formers, swelling agents, hydrotropes, preservatives, insect repellents, tanning agents, artificial self-tanning agents (such as dihydroxyacetone), stabilizers, aromatic oils, dyes, antibacterial agents, water-based and non-water-based plant extracts, etc. as further auxiliaries and additives. A person skilled in the art can determine the amounts of cosmetic or dermatological auxiliaries and carrier substances as well as fragrances that can be used in each case based on the nature of the product under discussion. In a preferred embodiment according to the present invention, the composition is a sunscreen preparation or sunscreen with an SPF of 30 or higher. The SPF is determined according to the standard ISO 24444:2019 "In Vivo Determination of the Sun Protection Factor (SPF)" and in accordance with the provisions in "Over-the-counter sunscreen drug products; required labeling based on effectiveness testing", Food and Drug Administration, Code of Federal Regulations, Title 21, §201.327.

[0198] In some embodiments, the sunscreen active agent and / or metal oxide are present in the formulation in an amount effective to provide sun protection consistent with the desired SPF of the composition, and can account for about 0.5 wt% to about 75 wt% of the composition, preferably about 5 wt% to about 70 wt% of the composition, and most preferably about 10 wt% to about 40 wt% of the composition, although this amount can be adjusted according to the desired final effect and based on the selected active ingredients known in the art.

[0199] In some cases, the disclosed compositions may expressly exclude one or more of the above ingredients in this section, for example, by claim language. For example, the claim language can be modified to state that the disclosed compositions, formulations, methods, etc. do not use or do not contain one or more of the above optional ingredients.

[0200] These detailed descriptions are used to illustrate the above general descriptions and embodiments that form part of the present invention. These detailed descriptions are for illustrative purposes only and are not intended to limit the scope of the present invention.

[0201] Examples

[0202] Dispersion preparation. The MOP dispersion examples and comparative examples were prepared according to the following procedure. Load the ester dispersion medium and polyester dispersant into a glass beaker of appropriate size, and gently mix and heat until the polyester liquefies (about 50 - 60 °C). Use a Silverson L5M-A high-shear rotor / stator laboratory mixer to mix the ester and polyester at 2000 - 2500 rpm for about one minute, or until a clear (transparent) and homogeneous solution is obtained. Add MOP to this ester-polyester mixture and mix at 5000 - 5500 rpm for five minutes to obtain a homogeneous dispersion. Generally, adjust the mixing speed as needed according to the dispersion viscosity. Note to ensure that all MOP is uniformly incorporated into the dispersion and that there is no undispersed MOP.

[0203] Brookfield viscosity determination. The viscosity of the dispersion was measured using a Brookfield DV1 type digital viscometer. Select the spindle and rotation speed to ensure that the viscosity reading is obtained within a torque window of 10 - 80% of the maximum torque range. For most dispersions, use the RV spindle 3 to record the viscosity at a rotation speed of 10 - 100 rpm.

[0204] Kinematic viscosity determination. The kinematic viscosity (unit: cSt (centistokes)) was measured using an Anton Paar Stabinger viscometer (model: SVM 3001) that meets the requirements of ASTM method D7042.

[0205] Rheological parameters. Rheological parameters G' 平台 , G” 频率 , yield stress and at 0.1 s -1 and 1 s -1 and the viscosity at. The yield stress value was determined by the modulus crossover method through an amplitude sweep test (at 1 rad / s), where where % strain 交叉 and G' 交叉 is the value at which G' and G” cross each other, i.e., G'交叉 = G” 交叉 。[See, for example, Utracki LA, Schlund B (1987) Linear low density polyethylenes and their blends. Part 2. Shear flow of LLDPE’s. Polym Eng Sci 27:367-379; and Vega JF, -Escalona A, Santamaría A, ME, Lafuente P (1996) Comparison of the rheological properties of metallocene-catalyzed and conventional high-density polyethylenes. Macromolecules 29:960-965.] The plateau value G' of the storage modulus G' was also determined by amplitude sweep testing 平台 and the amplitude range with linear response (required for frequency sweep testing). The frequency dependence (flow and relaxation kinetics) was determined by measuring the storage modulus (G') and the loss modulus (G”) by frequency sweep testing (% strain in the linear range, 0.03% strain to 0.1% strain for the compositions measured). G” 频率 was determined based on the measurement results at a frequency of 1 rad / s. Viscosity and shear thinning behavior were determined by flow curve measurement, i.e., viscosity vs shear rate (s -1 ).

[0206] In vitro UV transmittance measurement. The UV transmittance values of compositions containing metal oxide particles (MOP) were measured for wavelengths of 250 - 450 nm using a Labsphere UV-2000 ultraviolet transmittance analyzer; the protocol applied conformed to the broad spectrum and UV1 / UV determination of the US FDA method (2011). Specifically, 18.75 mg (milligrams) of the composition was uniformly applied on a 5 x 5 cm 2 polymethyl methacrylate (PMMA) plate. Before transmittance measurement, the treated plate was placed in a dark place and allowed to stand for 15 minutes. The transmittance was measured at five positions on each of the three treated PMMA plates for each composition (using an untreated PMMA plate as a reference), and the average of these 15 measurements was used to determine the in vitro UV transmittance of the composition at a wavelength of 340 nm.

[0207] Dispersion composition. Table 1 shows Examples E1 and E2 of the dispersion composition prepared according to the above method and the indicated amounts, as well as Comparative Examples CE1 and CE2. Table 1 provides a comparison of unsaturated and branched esters vs saturated triglyceride esters.

[0208] Examples E1, E2 and Comparative Examples CE1, CE2

[0209] Unsaturated and branched esters (E1, E2) vs saturated triglyceride esters (CE1, CE2).

[0210]

[0211] The MOP used in the dispersed metal oxide composition in Table 1 is zinc oxide, 10 (EverCare). The polyester is polyhydroxystearic acid Dispersun DSP-OL300 (Innospec), and the amounts are 2.00 wt%, 3.00 wt%, 4.00 wt%, 5.00 wt% and 6.00 wt%. The weight ratio of MOP to ester in all compositions ranges from about 25:1 to about 8:1. These components are the same in Examples E1 and E2 and Comparative Examples CE1 and CE2, while the esters are different.

[0212] The dispersion composition of Example E1 is prepared with the unsaturated ester - heptyl undecylenate LexFeel TM Natural (INOLEX, Inc.). The dispersion composition of Example E2 is prepared with the branched ester - diisooctyl succinate SustOleo TM DCS (INOLEX, Inc.). The comparative dispersion composition of Example CE1 is prepared with the saturated triglyceride ester - triheptanoin SustOleo TM MCT (INOLEX, Inc.). The comparative dispersion composition of Example CE2 is prepared with the saturated triglyceride ester - triglyceride caprylate / caprate GT - 865 (INOLEX, Inc.).

[0213] Table 2 lists the dispersion viscosities of Examples E1 and E2 and Comparative Examples CE1 and CE2, where the amounts of polyester are 2.00 wt%, 3.00 wt%, 4.00 wt%, 5.00 wt% and 6.00 wt% respectively. Figure 1 The data shown as a function of polyester concentration.

[0214] For (E1, E2) vs (CE1, CE2), the relationship between dispersion viscosity and polyester concentration.

[0215]

[0216] As Figure 1 shown in Table 2, within the entire polyester concentration range tested, the viscosity values of Examples E1 and E2 are significantly lower than those of Comparative Examples CE1 and CE2. Within the optimal polyester range of 3.00 to 5.00 wt%, the dispersion viscosities of Examples E1 and E2 are significantly lower than those of Comparative Examples CE1 and CE2, and the lowest viscosity value is obtained at a MOP loading of 50.05 wt%.

[0217] These results demonstrate that using unsaturated or branched esters to prepare low-viscosity MOP dispersions has surprising benefits compared to saturated triglyceride esters conventionally used for such dispersions.

[0218] The data of the ester dispersion medium at the time of supply are shown in Table 3 below.

[0219]

[0220] Examples E3 - E5 are detailed in Tables 4 - 6 respectively. Examples E3 - E5 use an ester dispersion medium (i.e., heptyl undecylenate the same as in E1 for E3, and diisooctyl succinate the same as in E2 for E4 and E5) in combination with polyhydroxystearic acid (4 wt%) as a polyester dispersant, as described in the dispersion compositions and property data in Tables 1 and 2 above. Comparative Example CE3 uses the same ester dispersion medium as in CE2 (glyceryl caprylate / caprate), and Comparative Examples CE4 and CE5 use the same ester dispersion medium as in CE1 (glyceryl triheptanoate). E3 and CE3 are made into water-in-oil (W / O) emulsions; E4 and CE4 are made into oil-in-water (O / W) emulsions, and E5 and CE5 are made into water-in-oil (W / O) emulsions.

[0221] The preparation of the sunscreen formulation examples is as follows. Zinc oxide is dispersed into a mixture of polyester (PHSA) and the selected ester, homogenized at 1000 rpm for 1 minute and then at 2500 rpm for 2 minutes (Silverson L5M - A, General Purpose Head) according to the formulations detailed herein. Then the remaining oil phase components are added and heated to 70 - 75 °C while mixing at 100 rpm with a propeller mixer. In a separate container, the main batch components are mixed and heated to 70 - 75 °C while mixing at 100 rpm with a propeller mixer. Then the main batch components are added to the oil phase and homogenized at 2500 rpm for 5 minutes. Then the formulation is transferred for propeller mixing at 250 rpm, cooled, and the remaining components are added at 40 °C and mixing is continued for 5 minutes. Mixing is continued until the temperature reaches ≤30 °C.

[0222]

[0223]

[0224]

[0225]

[0226] To demonstrate the benefits of the present invention, the finished formulation viscosities and in vitro UV transmittance values of sunscreen formulations generated using different MOP dispersions according to Table 4 - 6 were analyzed. Importantly, compared to Comparative Examples CE3 - CE5, Examples E3 - E5 of the present invention exhibited lower viscosities and lower in vitro UV transmittance. By achieving a high level of well - dispersed ZnO particles in the formulation while providing improved sensory, tactile, and spreading behavior (e.g., reduced viscosity, storage modulus, loss modulus, and yield stress values), a sunscreen formulation with sufficient sun protection performance (e.g., low UV transmittance) can be created.

[0227] As described above, two types of sunscreen formulations were prepared, oil - in - water emulsions (such as E4) and water - in - oil emulsions (such as E3 and E5).

[0228] Table 7 shows the data of Examples (E3 to E5) and Comparative Examples (CE3 to CE5) of the present invention (using the same PHSA) to study the effect of different esters on the rheological properties of finished sunscreen formulations using ZnO particle dispersions. The in vitro UV transmittance values were also measured and are listed in Table 7.

[0229]

[0230]

[0231] The rheological parameters listed in Table 7 indicate that the viscosities, storage moduli, loss moduli (G', G”), and yield stress values of the examples of the present invention are lower than those of the corresponding comparative examples, i.e., the value of E3 is lower than CE3, the value of E4 is lower than CE4, and the value of E5 is lower than CE5. Rheological parameters characterize the feel, touch, and spreading behavior of materials. Sunscreen formulations are usually very thick, greasy, and difficult to spread, i.e., they exhibit high viscosities, storage moduli, loss moduli, and yield stress values. It is desirable to manufacture sunscreen formulations with sufficient sun protection performance but with improved feel, touch, and spreading behavior. The examples of the present invention in Table 7 exhibit this improved behavior compared to the corresponding comparative examples listed in the same table. Specifically, the G' of the examples of the present invention 平台 is 3 to 9 times lower than that of the comparative example, G” 频率 is 2 to 6 times lower, the yield stress is 3 to 7 times lower, the viscosity at 0.1 s -1 is 1.5 to 3 times lower, and the viscosity at 1 s -117% to 60% lower in viscosity. The quality of the MOP dispersion is very important for achieving good sun protection and SPF values at a given MOP usage level. The in vitro UV transmittance values of the examples of the present invention are 22% to 55% lower than those of the comparative examples. Table 8 lists the % reduction in rheological and UV transmittance parameters of Examples E3 to E5 of the present invention compared to their corresponding Comparative Examples CE3 to CE5, where x is the parameter value of an example or a comparative example of the present invention from Table 7 above.

[0232]

[0233] Table 8 shows that, compared to linear saturated esters, the % reduction in G' 平台 using the branched or unsaturated esters of the present invention is on average 81%; the % reduction in G'' 频率 is on average 65%; the % reduction in yield stress is on average 78%; the % reduction in viscosity at 0.1 s -1 is on average 53%; the % reduction in viscosity at 1 s -1 is on average 30%; the % reduction in UV transmittance is on average 34%. The sunscreen formulations according to the examples herein provide reduced UV transmittance (e.g., high SPF factor) while having increased spreadability.

[0234] Embodiments

[0235] Among other embodiments, the following embodiments are disclosed.

[0236] Clause 1. A non-aqueous composition for dispersing metal oxide particles, the composition comprising an ester selected from the group consisting of the following (i)-(iv) and a polyester having a terminal carboxylic acid functional group:

[0237] (i) A liquid ester of Formula I: wherein R and R1 are each a linear, branched or cyclic alkyl group; a linear, branched or cyclic alkenyl group; or a linear, branched or cyclic alkynyl group; provided that if one of R and R1 is a linear alkyl group, the other of R and R1 is a branched or cyclic alkyl group; a linear, branched or cyclic alkenyl group; or a linear, branched or cyclic alkynyl group;

[0238] (ii) A liquid ester of Formula II: wherein R2 is a branched alkyl group, a linear or branched alkenyl group, or a linear or branched alkynyl group, R3 is a linear or branched alkyl group, a linear or branched alkenyl group, or a linear or branched alkynyl group, and R4 is a linear or branched alkyl group, a linear or branched alkenyl group, or a linear or branched alkynyl group;

[0239] (iii) A liquid ester of Formula III: wherein R5 is a branched alkyl, linear or branched alkene, or linear or branched alkyne, R6 is a linear or branched alkyl, linear or branched alkene, or linear or branched alkyne, and R7 is a linear or branched alkyl, linear or branched alkene, or linear or branched alkyne; and (iv) combinations of the above esters.

[0240] Clause 2. The non-aqueous composition according to Clause 1, wherein the ester has Formula I and R is C5-C 17 branched or cyclic alkyl, linear, branched or cyclic alkenyl, or linear, branched or cyclic alkynyl; and R1 is C3-C 18 linear, branched or cyclic alkyl, linear, branched or cyclic alkenyl, or linear, branched or cyclic alkynyl.

[0241] Clause 3. The non-aqueous composition according to Clause 1, wherein the ester has Formula I and R and R1 are different.

[0242] Clause 4. The non-aqueous composition according to Clause 1, wherein the ester has Formula II and R2 is C3-C 18 branched alkyl, linear or branched alkenyl, or linear or branched alkyne; R3 is C2-C8 linear or branched alkyl, linear or branched alkenyl, or linear or branched alkyne; and R4 is C3-C 18 linear or branched alkyl, linear or branched alkenyl, or linear or branched alkyne.

[0243] Clause 5. The non-aqueous composition according to Clause 1, wherein the ester has Formula II and R2 and R4 are the same.

[0244] Clause 6. The non-aqueous composition according to Clause 1, wherein the ester has Formula III and R5 is C3-C 18 branched alkyl, linear or branched alkene, or linear or branched alkyne, R6 is C2-C8 linear or branched alkyl, linear or branched alkene, or linear or branched alkyne, and R7 is C3-C 18 linear or branched alkyl, linear or branched alkene, or linear or branched alkyne.

[0245] Clause 7. The non-aqueous composition according to Clause 1, wherein the ester has Formula III and R5 and R7 are the same.

[0246] Clause 8. The non-aqueous composition according to Clause 1, wherein the ester is liquid at 25 °C.

[0247] Clause 9. The non-aqueous composition according to Clause 1, wherein the viscosity of the ester at 25 °C is less than about 100 cSt.

[0248] Clause 10. The non-aqueous composition according to Clause 1, wherein the carbon present in the ester is 100% bio-based.

[0249] Clause 11. The non-aqueous composition according to Clause 1, wherein the polyester comprises a terminal single carboxylic acid functional group.

[0250] Clause 12. The non-aqueous composition according to Clause 1, wherein the polyester comprises two terminal carboxylic acid functional groups.

[0251] Clause 13. The non-aqueous composition according to Clause 1, wherein the polyester comprises a homopolymer derived from an AB hydroxycarboxylic acid monomer.

[0252] Clause 14. The non-aqueous composition according to Clause 1, wherein the polyester comprises a copolymer derived from an AA diol and a BB diacid or diester monomer.

[0253] Clause 15. The non-aqueous composition according to Clause 1, wherein the polyester has a number average molecular weight (Mn) of less than about 10,000 g / mol.

[0254] Clause 16. The non-aqueous composition according to Clause 1, wherein the polyester has an acid value of at least 15 mg KOH / g.

[0255] Clause 17. The non-aqueous composition according to Clause 1, wherein the polyester is selected from the group consisting of polyhydroxystearic acid, polyhydroxystearic acid stearate, polyhydroxystearyl succinate, polyhydroxystearyl sebacate, and combinations thereof.

[0256] Clause 18. The non-aqueous composition according to Clause 1, wherein the carbon present in the polyester is 100% bio-based.

[0257] Clause 19. A non-aqueous composition for dispersing metal oxide particles, the composition consisting essentially of an ester selected from the group consisting of (i)-(iv) below and a polyester having a terminal carboxylic acid functional group:

[0258] (i) A liquid ester of Formula I: wherein R and R1 are each a linear, branched, or cyclic alkyl group; a linear, branched, or cyclic alkenyl group; or a linear, branched, or cyclic alkynyl group; provided that if one of R and R1 is a linear alkyl group, the other of R and R1 is a branched or cyclic alkyl group; a linear, branched, or cyclic alkenyl group; or a linear, branched, or cyclic alkynyl group;

[0259] (ii) A liquid ester of Formula II: wherein R2 is a branched alkyl group, a linear or branched alkenyl group, or a linear or branched alkynyl group, R3 is a linear or branched alkyl group, a linear or branched alkenyl group, or a linear or branched alkynyl group, and R4 is a linear or branched alkyl group, a linear or branched alkenyl group, or a linear or branched alkynyl group;

[0260] (iii) a liquid ester of formula III: wherein R5 is a branched alkyl group, a linear or branched alkene, or a linear or branched alkyne, R6 is a linear or branched alkyl group, a linear or branched alkene, or a linear or branched alkyne, and R7 is a linear or branched alkyl group, a linear or branched alkene, or a linear or branched alkyne; and (iv) a combination of the above esters.

[0261] Clause 20. A non-aqueous composition for dispersing metal oxide particles, the composition comprising an ester selected from the group consisting of the following (i)-(iv) and a polyester having a terminal carboxylic acid functional group:

[0262] (i) a liquid ester of formula I: wherein each of R and R1 is a linear, branched or cyclic alkyl group; a linear, branched or cyclic alkenyl group; or a linear, branched or cyclic alkynyl group; provided that if one of R and R1 is a linear alkyl group, the other of R and R1 is a branched or cyclic alkyl group; a linear, branched or cyclic alkenyl group; or a linear, branched or cyclic alkynyl group;

[0263] (ii) a liquid ester of formula II: wherein R2 is a branched alkyl group, a linear or branched alkenyl group, or a linear or branched alkynyl group, R3 is a linear or branched alkyl group, a linear or branched alkenyl group, or a linear or branched alkynyl group, and R4 is a linear or branched alkyl group, a linear or branched alkenyl group, or a linear or branched alkynyl group;

[0264] (iii) a liquid ester of formula III: wherein R5 is a branched alkyl group, a linear or branched alkene, or a linear or branched alkyne, R6 is a linear or branched alkyl group, a linear or branched alkene, or a linear or branched alkyne, and R7 is a linear or branched alkyl group, a linear or branched alkene, or a linear or branched alkyne; and (iv) a combination of the above esters.

[0265] Clause 21. A non-aqueous dispersion comprising the non-aqueous composition according to Clause 1 and metal oxide particles dispersed therein.

[0266] Clause 22. The non-aqueous dispersion according to Clause 21, wherein the metal oxide particles are not surface-modified.

[0267] Clause 23. The non-aqueous dispersion according to Clause 21, wherein the metal oxide particles comprise zinc oxide, titanium oxide, or a combination thereof.

[0268] Clause 24. The non-aqueous dispersion according to Clause 21 has a viscosity of less than about 1000 cP.

[0269] Clause 25. The non-aqueous dispersion according to Clause 21, wherein the metal oxide particles account for about 15 wt% to about 75 wt% of the non-aqueous dispersion.

[0270] Clause 26. The non-aqueous dispersion according to Clause 21, wherein the weight balance of the non-aqueous dispersion consists of the non-aqueous composition as claimed in Claim 1.

[0271] Clause 27. The non-aqueous dispersion according to Clause 21, wherein the metal oxide particles account for about 40 wt% to about 60 wt% of the non-aqueous dispersion.

[0272] Clause 28. The non-aqueous dispersion according to Clause 21, wherein, based on the total weight of the dispersion, the amount of polyester present is about 3 wt% to about 5 wt%.

[0273] Clause 29. The non-aqueous dispersion according to Clause 21, wherein the non-aqueous dispersion is substantially free of silicone.

[0274] Clause 30. A non-aqueous dispersion comprising a composition and a plurality of metal oxide particles dispersed in the composition, the composition comprising esters selected from the group consisting of (i)-(iv) below and a polyester having terminal carboxylic acid functional groups: (i) a liquid ester of Formula I: wherein R and R1 are each a linear, branched or cyclic alkyl group; a linear, branched or cyclic alkenyl group; or a linear, branched or cyclic alkynyl group; provided that if one of R and R1 is a linear alkyl group, the other of R and R1 is a branched or cyclic alkyl group; a linear, branched or cyclic alkenyl group; or a linear, branched or cyclic alkynyl group;

[0275] (ii) a liquid ester of Formula II: wherein R2 is a branched alkyl group, a linear or branched alkenyl group, or a linear or branched alkynyl group, R3 is a linear or branched alkyl group, a linear or branched alkenyl group, or a linear or branched alkynyl group, and R4 is a linear or branched alkyl group, a linear or branched alkenyl group, or a linear or branched alkynyl group;

[0276] (iii) a liquid ester of Formula III: wherein R5 is a branched alkyl group, a linear or branched olefin, or a linear or branched alkyne, R6 is a linear or branched alkyl group, a linear or branched olefin, or a linear or branched alkyne, and R7 is a linear or branched alkyl group, a linear or branched olefin, or a linear or branched alkyne; and (iv) a combination of the above esters.

[0277] Clause 31. A preparation comprising the dispersion according to any one of Clauses 21 or 30, wherein the preparation is a personal care product or a component thereof, and the personal care product is selected from the group consisting of: cosmetics, softeners for hair, nails, skin or textiles, shampoos, hair styling products, oils or waxes for grooming beards, perming liquids, hair dyes, facial cleansers or body washes, makeup removers, cleansing lotions, emollient lotions or creams, bar soaps, liquid soaps, shaving creams, foams or gels, sunscreen products, gels, lotions or creams for treating sunburns, deodorants or antiperspirants, moisturizing gels, shaving foams, face powders, foundations, lipsticks, blushes, eyeliner pastes, anti-wrinkle creams or anti-aging creams, eyeshadows, eyebrow pencils, mascaras, mouthwashes, toothpastes, oral care products, skin cleansing products, textile cleansing products, tableware cleansing products, hair or fur cleansing products, and skin care lotions or moisturizing creams.

[0278] Clause 32. The preparation according to Clause 31, wherein the preparation is a sunscreen product or a component of a sunscreen product.

[0279] Clause 33. The preparation according to Clause 31, wherein the preparation is an oil-in-water (O / W) emulsion or a water-in-oil (W / O) emulsion.

[0280] Clause 34. The preparation according to Clause 31, further comprising at least one additional ingredient selected from the group consisting of film-forming polymers, rheology-modifying polymers, waxes, emulsifiers, emollients, humectants, pH regulators, antioxidants, fragrances, multifunctional ingredients, preservation technologies, and combinations thereof.

[0281] Clause 35. A method for preparing a non-aqueous composition for dispersing metal oxide particles, the method comprising: mixing: an ester selected from the group consisting of (i)-(iv) below and a polyester having a terminal carboxylic acid functional group to form a homogeneous solution: (i) a liquid ester of Formula I: wherein R and R1 are each a linear, branched or cyclic alkyl group; a linear, branched or cyclic alkenyl group; or a linear, branched or cyclic alkynyl group; provided that if one of R and R1 is a linear alkyl group, the other of R and R1 is a branched or cyclic alkyl group; a linear, branched or cyclic alkenyl group; or a linear, branched or cyclic alkynyl group;

[0282] (ii) a liquid ester of Formula II: wherein R2 is a branched alkyl group, a linear or branched alkenyl group, or a linear or branched alkynyl group, R3 is a linear or branched alkyl group, a linear or branched alkenyl group, or a linear or branched alkynyl group, and R4 is a linear or branched alkyl group, a linear or branched alkenyl group, or a linear or branched alkynyl group;

[0283] (iii) a liquid ester of Formula III: wherein R5 is a branched alkyl, linear or branched alkene, or linear or branched alkyne, R6 is a linear or branched alkyl, linear or branched alkene, or linear or branched alkyne, and R7 is a linear or branched alkyl, linear or branched alkene, or linear or branched alkyne; and (iv) a combination of the above esters.

[0284] Clause 36. The method according to Clause 35, wherein the ester has the formula I and R is C5-C 17 branched or cyclic alkyl, linear, branched or cyclic alkenyl, or linear, branched or cyclic alkynyl; and R1 is C3-C 18 linear, branched or cyclic alkyl, linear, branched or cyclic alkenyl, or linear, branched or cyclic alkynyl.

[0285] Clause 37. The method according to Clause 35, wherein the ester has the formula I and R and R1 are different.

[0286] Clause 38. The method according to Clause 35, wherein the ester has the formula II, and R2 is C3-C 18 branched alkyl, linear or branched alkenyl, or linear or branched alkynyl, R3 is C2-C8 linear or branched alkyl, linear or branched alkenyl, or linear or branched alkynyl; and R4 is C3-C 18 linear or branched alkyl, linear or branched alkenyl, or linear or branched alkynyl.

[0287] Clause 39. The method according to Clause 35, wherein the ester has the formula II and R2 and R4 are the same.

[0288] Clause 40. The method according to Clause 35, wherein the ester has the formula III, and R5 is C3-C 18 branched alkyl, linear or branched alkene, or linear or branched alkyne, R6 is C2-C8 linear or branched alkyl, linear or branched alkene, or linear or branched alkyne, and R7 is C3-C 18 linear or branched alkyl, linear or branched alkene, or linear or branched alkyne.

[0289] Clause 41. The method according to Clause 35, wherein the ester has the formula III and R5 and R7 are the same.

[0290] Clause 42. The method according to Clause 35, wherein the viscosity of the ester at 25 °C is less than about 100 cSt.

[0291] Clause 43. The method according to Clause 35, wherein the carbon present in the ester is 100% biobased.

[0292] Clause 44. The method according to Clause 35, wherein the polyester contains a terminal single carboxylic acid functional group.

[0293] Clause 45. The method according to Clause 35, wherein the polyester contains two terminal carboxylic acid functional groups.

[0294] Clause 46. The method according to Clause 35, wherein the polyester has a number average molecular weight (Mn) of less than about 10,000 g / mol.

[0295] Clause 47. The method according to Clause 35, wherein the polyester has an acid value of at least 15 mg KOH / g.

[0296] Clause 48. The method according to Clause 35, wherein the polyester is selected from the group consisting of polyhydroxystearic acid, polyhydroxystearic acid stearate, polyhydroxystearyl succinate, polyhydroxystearyl sebacate, and combinations thereof.

[0297] Clause 49. The method according to Clause 35, wherein the carbon present in the polyester is 100% biobased.

[0298] Clause 50. The method according to Clause 35, wherein mixing to form a homogeneous solution includes heating.

[0299] Clause 51. The method according to Clause 35, wherein mixing to form a homogeneous solution includes high-shear mixing.

[0300] Clause 52. The method according to Clause 35, which further comprises dispersing metal oxide particles in the homogeneous solution to form a non-aqueous dispersion.

[0301] Clause 53. The method according to Clause 52, wherein the metal oxide particles include zinc oxide, titanium oxide, or a combination thereof.

[0302] Clause 54. The method according to Clause 52, wherein the viscosity of the non-aqueous dispersion is less than about 1000 cP.

[0303] Clause 55. The method according to Clause 52, wherein the metal oxide particles account for about 15 wt% to about 75 wt% of the non-aqueous dispersion.

[0304] Clause 56. The method according to Clause 52, wherein the metal oxide particles account for about 40 wt% to about 60 wt% of the non-aqueous dispersion.

[0305] Clause 57. The method according to Clause 52, wherein the non-aqueous dispersion is substantially free of silicone.

[0306] Clause 58. The method according to Clause 52, which further comprises adding at least one additional ingredient thereto to form a formulation.

[0307] Clause 59. The method according to Clause 52, wherein the at least one additional ingredient is selected from the group consisting of film-forming polymers, rheology-modifying polymers, waxes, emulsifiers, emollients, humectants, pH regulators, antioxidants, fragrances, multi-functional ingredients, preservation techniques, and combinations thereof.

[0308] Clause 60. The method according to Clause 52, wherein the formulation is a sunscreen.

[0309] The scope of the present invention is not limited by the specific embodiments described herein. In fact, those skilled in the art can clearly see from the above description and drawings that there are various variations of the present invention in addition to those described herein. These variations should all fall within the scope of the appended claims.

[0310] It should also be understood that all values are approximate values and are only for description. All references cited and discussed in this specification are hereby incorporated by reference in their entirety, to the same extent as if each reference were individually incorporated herein.

[0311] References:

[0312] - C. Agbo et al., A Review on the Mechanism of Pigment Dispersion, J. Disp. Sci. Tech., 2018, 39(6), 874 - 889

[0313] - D. A. Brune et al., Model for the Viscosity of Particle Dispersions; Journal of Macromolecular Science - Rev. Macromol. Chem. Phys., C39(4), 561 - 642(1999).

[0314] - B. J. Naden et al. Adsorption of poly(hydroxystearic acid) to TiO2 nanoparticles, studied using gel permeation chromatography, Coll. Surf. A.: Physicochem. Eng. Aspects, 2015, 478, 36 - 44.

[0315] - Zinc oxide (nano form); What are the properties of ZnO nanoparticles?,

[0316] https: / / ec.europa.eu / health / scientific_committees / opinions_layman / zinc-oxide / de / l-3 / 3.htm#.

[0317] -Utracki LA, Schlund B(1987)Linear low density polyethylenes and their blends.Part 2.Shear flow of LLDPE’s.Polym Eng Sci 27:367-379.

[0318] -Vega JF, -Escalona A, Santamaría A, ME, Lafuente P(1996)Comparison of the rheological properties of metallocene-catalyzed and conventional high-density polyethylenes.Macromolecules 29:960-965.

[0319] -U.S. Patent No.9,254,398B2.

[0320] -U.S. Patent Publication No.2011 / 0104078 A1.

Claims

1. A non-aqueous composition for dispersing metal oxide particles, the non-aqueous composition comprising an ester selected from the group consisting of the following (i)-(iv) and a polyester having a terminal carboxylic acid functional group: (i) A liquid ester of Formula I: wherein R and R1 are each a linear, branched or cyclic alkyl group; a linear, branched or cyclic alkenyl group; or a linear, branched or cyclic alkynyl group; provided that if one of R and R1 is a linear alkyl group, the other of R and R1 is a branched or cyclic alkyl group; a linear, branched or cyclic alkenyl group; or a linear, branched or cyclic alkynyl group; (ii) A liquid ester of Formula II: wherein R2 is a branched alkyl group, a linear or branched alkenyl group, or a linear or branched alkynyl group, R3 is a linear or branched alkyl group, a linear or branched alkenyl group, or a linear or branched alkynyl group, and R4 is a linear or branched alkyl group, a linear or branched alkenyl group, or a linear or branched alkynyl group; (iii) A liquid ester of Formula III: wherein R5 is a branched alkyl group, a linear or branched alkene, or a linear or branched alkyne, R6 is a linear or branched alkyl group, a linear or branched alkene, or a linear or branched alkyne, and R7 is a linear or branched alkyl group, a linear or branched alkene, or a linear or branched alkyne; and (iv) A combination of the above esters.

2. A non-aqueous dispersion comprising a composition and a plurality of metal oxide particles dispersed in the composition, the composition comprising an ester selected from the group consisting of the following (i)-(iv) and a polyester having a terminal carboxylic acid functional group: (i) A liquid ester of Formula I: wherein R is a branched or cyclic alkyl group, a linear, branched or cyclic alkenyl group, or a linear, branched or cyclic alkynyl group, and R1 is a linear, branched or cyclic alkyl group, a linear, branched or cyclic alkenyl group, or a linear, branched or cyclic alkynyl group; (ii) A liquid ester of Formula II: wherein R2 is a branched alkyl group, a linear or branched alkenyl group, or a linear or branched alkynyl group, R3 is a linear or branched alkyl group, a linear or branched alkenyl group, or a linear or branched alkynyl group, and R4 is a linear or branched alkyl group, a linear or branched alkenyl group, or a linear or branched alkynyl group; (iii) A liquid ester of Formula III: wherein R5 is a branched alkyl group, a linear or branched alkene, or a linear or branched alkyne, R6 is a linear or branched alkyl group, a linear or branched alkene, or a linear or branched alkyne, and R7 is a linear or branched alkyl group, a linear or branched alkene, or a linear or branched alkyne; and (iv) A combination of the above esters.

3. The non-aqueous composition according to claim 1 or the non-aqueous dispersion according to claim 2, wherein, The ester is selected from the group consisting of: Formula I and R is C5-C 17 branched or cyclic alkyl, linear, branched or cyclic alkenyl, or linear, branched or cyclic alkynyl; and R1 is C3-C 18 linear, branched or cyclic alkyl, linear, branched or cyclic alkenyl, or linear, branched or cyclic alkynyl; Formula II and R2 is C3-C 18 branched alkyl, linear or branched alkenyl, or linear or branched alkynyl; R3 is C2-C8 linear or branched alkyl, linear or branched alkenyl, or linear or branched alkynyl; and R4 is C3-C 18 linear or branched alkyl, linear or branched alkenyl, or linear or branched alkynyl; Formula III and R5 is C3-C 18 branched alkyl, linear or branched alkene, or linear or branched alkyne, R6 is C2-C8 linear or branched alkyl, linear or branched alkene, or linear or branched alkyne, and R7 is C3-C 18 linear or branched alkyl, linear or branched alkene, or linear or branched alkyne; and combinations of the above esters.

4. The non-aqueous composition according to claim 1 or the non-aqueous dispersion according to claim 2, wherein The ester is liquid at 25 °C.

5. The non-aqueous composition according to claim 1, wherein The ester has a viscosity less than about 100 cSt at 25 °C.

6. The non-aqueous dispersion according to claim 2, wherein, The non-aqueous dispersion has a viscosity less than about 1000 cP.

7. The non-aqueous composition according to claim 1 or the non-aqueous dispersion according to claim 2, wherein, The polyester comprises: a single terminal carboxylic acid functional group; two terminal carboxylic acid functional groups; a homopolymer derived from an AB hydroxycarboxylic acid monomer; a copolymer derived from an AA diol and a BB diacid or diester monomer, or a combination thereof.

8. The non-aqueous composition according to claim 1 or the non-aqueous dispersion according to claim 2, wherein, The polyester has a number average molecular weight (Mn) less than about 10,000 g / mol, or wherein the acid value of the polyester is at least 15 mg KOH / g.

9. The non-aqueous composition according to claim 1 or the non-aqueous dispersion according to claim 2, wherein, The polyester is selected from the group consisting of polyhydroxystearic acid, polyhydroxystearic acid stearate, polyhydroxystearyl succinate, polyhydroxystearyl sebacate, and combinations thereof.

10. The non-aqueous composition according to claim 1 or the non-aqueous dispersion according to claim 2, wherein, The carbon present in the ester is 100% biobased, the carbon present in the polyester is 100% biobased, or both.

11. The non-aqueous dispersion according to claim 2, wherein, The plurality of metal oxide particles are not surface modified, or wherein the plurality of metal oxide particles include zinc oxide, titanium oxide, or a combination thereof.

12. The non-aqueous dispersion according to claim 2, wherein, The plurality of metal oxide particles account for about 15 wt% to about 75 wt% of the non-aqueous dispersion, or wherein the plurality of metal oxide particles account for about 40 wt% to about 60 wt% of the non-aqueous dispersion.

13. A formulation comprising the non-aqueous composition of claim 1 or the non-aqueous dispersion of claim 2, wherein the formulation is a personal care product or a component of a personal care product, and the personal care product is selected from the group consisting of: cosmetics, softeners for hair, nails, skin, or textiles, shampoos, hair styling products, oils or waxes for grooming beards, permanent wave solutions, hair dyes, facial cleansers or body washes, makeup removers, cleansing lotions, emollient lotions or creams, bar soaps, liquid soaps, shaving creams, foams or gels, sunscreens, gels, lotions or creams for treating sunburn, deodorants or antiperspirants, moisturizing gels, shaving foams, face powders, foundations, lipsticks, blushes, eyeliner creams, anti-wrinkle creams or anti-aging creams, eyeshadows, eyebrow pencils, mascaras, mouthwashes, toothpastes, oral care products, skin cleansing products, textile cleansing products, tableware cleansing products, hair or fur cleansing products, and skin care lotions or moisturizing creams, or wherein the formulation is a sunscreen or a component of a sunscreen, or wherein the formulation is an oil-in-water (O / W) emulsion or a water-in-oil (W / O) emulsion.

14. A method for preparing a non-aqueous composition for dispersing metal oxide particles, the method comprising: Mixing an ester selected from the group consisting of (i)-(iv) below and a polyester having a terminal carboxylic acid functional group to form a homogeneous solution: (i) A liquid ester of Formula I: wherein R and R1 are each a linear, branched, or cyclic alkyl group; a linear, branched, or cyclic alkenyl group; or a linear, branched, or cyclic alkynyl group; provided that if one of R and R1 is a linear alkyl group, the other of R and R1 is a branched or cyclic alkyl group; a linear, branched, or cyclic alkenyl group; or a linear, branched, or cyclic alkynyl group; (ii) A liquid ester of Formula II: wherein R2 is a branched alkyl group, a linear or branched alkenyl group, or a linear or branched alkynyl group, R3 is a linear or branched alkyl group, a linear or branched alkenyl group, or a linear or branched alkynyl group, and R4 is a linear or branched alkyl group, a linear or branched alkenyl group, or a linear or branched alkynyl group; (iii) A liquid ester of Formula III: wherein R5 is a branched alkyl group, a linear or branched alkene, or a linear or branched alkyne, R6 is a linear or branched alkyl group, a linear or branched alkene, or a linear or branched alkyne, and R7 is a linear or branched alkyl group, a linear or branched alkene, or a linear or branched; and (iv) A combination of the above esters; Mixing to form a homogeneous solution optionally includes heating, high-shear mixing, or both.

15. The method according to claim 14, further comprising dispersing metal oxide particles in the homogeneous solution to form a non-aqueous dispersion, wherein the metal oxide particles include zinc oxide, titanium oxide, or a combination thereof.

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