Process for the micronization of UV filter dispersions

Abstract

The present invention relates to a process for micronization of UV filter dispersions comprising at least one micronized insoluble organic UV absorber, the method comprising: a) providing a first aqueous dispersion comprising said at least one insoluble organic UV absorber; b) grinding the first aqueous dispersion in a ball mill, preferably a stirred media mill, comprising grinding beads with a diameter in the range of 0.6 to 2.0 mm in a first milling step to obtain a second dispersion; c) grinding the second dispersion obtained in b) in a ball mill, preferably a stirred media mill, comprising grinding beads with a diameter in the range of 0.05 to 0.6 mm in a second milling step to obtain the aqueous dispersion comprising a least one micronized insoluble organic UV absorber, wherein the diameter of the grinding beads in step b) is greater than the diameter of the grinding beads in step c). Furthermore, the present invention relates to aqueous dispersions comprising at least one micronized organic insoluble UV absorber obtainable by such a process, and to compositions, such as sunscreen compositions, comprising such an aqueous dispersion.

Description

[0001] PROCESS FOR THE MICRONIZATION OF UV FILTER DISPERSIONS Field of the invention The present invention relates to a process for micronization of UV filter dispersions comprising at least one micronized insoluble organic UV absorber, the method comprising: a) providing a first aqueous dispersion comprising said at least one insoluble organic UV absorber; b) grinding the first aqueous dispersion in a ball mill, preferably a stirred media mill, comprising grinding beads with a diameter in the range of 0.6 to 2.0 mm in a first milling step to obtain a second dispersion; c) grinding the second dispersion obtained in b) in a ball mill, preferably a stirred media mill, comprising grinding beads with a diameter in the range of 0.05 to 0.6 mm in a second milling step to obtain the aqueous dispersion comprising a least one micronized insoluble organic UV absorber, wherein the diameter of the grinding beads in step b) is greater than the diameter of the grinding beads in step c). Furthermore, the present invention relates to aqueous dispersions comprising at least one micronized organic insoluble UV absorber obtainable by such a process, and to compositions, such as sunscreen compositions, comprising such an aqueous dispersion. Background of the invention State of the art micronization of UV filter dispersions often comprises one step of pre-grinding of a UV filter slurry, e.g., in a colloid mill, and, subsequently, one step of grinding of the resulting aqueous dispersion, e.g., in a stirred media mill, to obtain the final UV-filter dispersion with desired particle size, preferably Dv50 of less than 200 nm. WO 2018 / 069207 A1, for example, claims an aqueous dispersion comprising nano-sized, organic, insoluble UV-absorber, wherein the final particle size is obtained by using a single grinding step. To achieve target particle size of the UV filter dispersions, the grinding step, e.g. in a stirred media mill, is operated with very small beads (e.g.0.3 mm bead size). To provide UV filters with the required small particle sizes, the dispersion has however to be circulated over the mill several times. In addition, the required specific energy input per kg of final particles is high. Surprisingly, the inventors now found that employing an additional grinding step with larger beads (e.g., 1 mm) after pre-grinding but prior to the fine milling step down-sizes the large particle fraction in short time at low energy consumption. After this step, particle size is optimal for a second grinding / milling step with smaller beads. It has been found that the overall specific grinding energy of the micronization process using two grinding / milling steps with beads in different sizes is much lower than in the state-of-the-art process, in which only one grinding / milling step with small beads is employed, and, thus, allows higher production capacity at the same energy input level. Summary of the invention Therefore, in a first aspect, the present invention relates to a method for the preparation of an aqueous dispersion comprising at least one micronized insoluble organic UV absorber, the method comprising: a) providing a first aqueous dispersion comprising said at least one insoluble organic UV absorber; b) grinding the first aqueous dispersion of step a) in a ball mill, preferably a stirred media mill, comprising grinding beads with a diameter in the range of 0.6 to 2.0 mm in a first milling step to obtain a second dispersion; c) grinding the second dispersion obtained in b) in a ball mill, preferably a stirred media mill, comprising grinding beads with a diameter in the range of 0.05 to 0.6 mm in a second milling step to obtain the aqueous dispersion comprising a least one micronized insoluble organic UV absorber, wherein the diameter of the grinding beads in step b) is greater than the diameter of the grinding beads in step c).

[0002] In various embodiments, step a) of the inventive process includes the steps of a1) providing an aqueous slurry comprising said at least one insoluble organic UV absorber; and a2) pre-grinding the slurry in a colloid mill, preferably a toothed colloid mill, or a rotor mill to prepare the first aqueous dispersion comprising said at least one insoluble organic UV absorber.

[0003] In various embodiments, the grinding beads in step b) and / or step c) are yttrium-stabilized zirconium oxide grinding beads.

[0004] In some embodiments

[0005] (1) the grinding beads in step b) have a diameter in the range of 0.6 to 2.0 mm, preferably 0.6 to 1 .5 mm or 0.6 to 1 .3 mm, more preferably 0.6 to 0.8 mm or 1 .0 to 1 .3 mm,

[0006] (2) the grinding beads in step c) have a diameter in the range of 0.05 to 0.6 mm, preferably 0.3 to 0.6 mm, more preferably 0.3 to 0.4 mm or 0.4 to 0.6 mm; and / or

[0007] (3) the grinding beads in step b) and step c) differ in diameter by at least 0.2 mm, preferably by at least 0.3 mm.

[0008] In various further embodiments,

[0009] (1) the at least one insoluble organic UV absorber in the first aqueous dispersion in step a) has a mean particle size distribution as determined by laser diffraction of Dv90 >1 pm, preferably from 1 to 400 pm, more preferably from 20 to 200 pm, most preferably from 50 to 200 pm;

[0010] (2) the at least one insoluble organic UV absorber in the second aqueous dispersion after step b) has a mean particle size distribution as determined by laser diffraction of Dv90 >400 nm, preferably Dv50 >145 nm and Dv90 >400 nm; and / or

[0011] (3) the at least one insoluble organic UV absorber in the aqueous dispersion after step c) has a mean particle size distribution as determined by laser diffraction of Dv50 <200 nm and Dv90 <400 nm, preferably Dv50 <150 nm and Dv90 <300 nm, more preferably a Dv50 particle size in the range of from 50 to 180 nm, even more preferably 75 to 150 nm or 75 to 140 nm, most preferably 80 to 130 nm.

[0012] In further embodiments, the specific energy input to achieve a mean particle size distribution of the at least one insoluble organic UV absorber in the aqueous dispersion after step c) as determined by laser diffraction of Dv50 <150 nm and Dv90 <300 nm is less than 3 kWh / kg, preferably less than 2.5 kWh / kg, more preferably less than 2.0 kWh / kg. n some embodiments, the at least one insoluble UV absorber is selected from (1) a compound of formula (I) (I) wherein R1 and R2 independent from each other are C1-C20alkyl, C2-C20alkenyl, C3-C10cycloalkyl, C3- C10cycloalkenyl, or R1 and R2 together with the linking nitrogen atom form a 5- or 6-membered heterocyclic ring; A is -N(R3)-, -O- or a direct bond; B is a bivalent radical selected from alkylene, cycloalkylene, alkenylene or phenylene radical which is optionally substituted by a carbonyl- or carboxy group; a radical of formula -CH2-C≡C-CH2-; or the divalent radical -B- corresponds to the formula (Ia) ) wherein n1 is a number from 1 to 3; A is -N(R3)- or -O-; and R3 is hydrogen; C1-C5alkyl or hydroxy-C1-C5alkyl; (2) a compound of formula (II) II) wherein T1 is hydrogen, C1-C12alkyl, preferably iso-octyl, or C1-C4alkyl substituted by phenyl; (3) a compound of formula (III)

[0013] II) wherein R4 and R5 independently from each other are hydrogen, C1-C18alkyl, or C6-C12aryl; R6, R7 and R8 independently from each other are hydrogen or C1-C18alkyl or a radical of formula (IIIa) wherein R9, R10 and R11 independently from each other are hydrogen or C1-C18alkyl; and 4) a compound of formula (IV) wherein R12 and R13 independent from each other represent hydrogen, halogen, C1-C12alkyl, C1-C18hydroxyalkyl, C1-C18alkoxy, poly(ethoxy)-alkoxy with a C1-C4 alkyl fragment and an ethoxy number ranging from 1 to 4, C1-C4 mono- or dialkylamino; R14 represents halogen, hydroxy, amino, or phenyl, with phenyl being optionally substituted 1 to 3 times by hydroxy radical situated at least in para position, 1 to 3 times by a C1-C12alkoxy, cyano or C1-C7alkylamino group in an ortho, meta or para position, and / or 1 time a meta or para position, preferably para position. n some further embodiments, the at least one insoluble organic UV absorber is selected from tris-biphenylriazine, phenylene bis-diphenyltriazine, bis-(diethylaminohydroxybenzoyl benzoyl) piperazine and methylene bis-benzotriazolyl tetramethylbutylphenol or combinations thereof. n various embodiments, the at least one micronized insoluble organic UV absorber is comprised in the aqueous dispersion in an amount of 20 to 80 wt.-%, preferably 30 to 70 wt.-%, more preferably 35 to 65 wt.-% or 40 to 60 wt.-%, relative to the total weight of the aqueous dispersion. n other embodiments, the method further comprises the steps of (d) removing the grinding beads; and, optionally, (e) adding at least one additive to the obtained aqueous dispersion. n some embodiments, the aqueous dispersion further comprises at least one additive, preferably selectedrom the group consisting of surfactants, rheology modifiers, pH-adjusters, buffering agents, preservatives, and mixtures thereof. n various such embodiments, the at least one additive is ) at least one wetting agent, preferably (poly)propylene glycol and / or butylene glycol, optionally in an amount of 0.05 to 5 wt.-% based on the total weight of the aqueous dispersion; and / or i) at least one rheology modifier, preferably xanthan gum, gellan gum and / or carboxymethylcellulose, optionally in an amount of 0.05 to 5 wt.-% based on the total weight of the aqueous dispersion; and / orii) at least one surfactant, preferably a non-ionic surfactant, optionally in an amount of 0.5 to 25 wt.-% based on the total weight of the aqueous dispersion; and / or v) selected from the group of preservatives, buffering agents, and pH adjusting agents. n some such embodiments, the at least one surfactant is selected from alkyl(poly)glycosides, preferably alkyl polyglucosides, more preferably C8-C16alkyl polyglucosides, most preferably C8-C10alkyl polyglucosides. n some such embodiments, the surfactant is contained in the aqueous dispersion of step a) of the method. n a further aspect, the present invention relates to an aqueous dispersion comprising at least one micronized organic insoluble UV absorber obtainable by a process according to the present invention. In yet another aspect, the present invention also relates to a composition, preferably a sunscreen composition, a daily care composition, a hair care composition, or a make-up / foundation composition, comprising an aqueous dispersion according to the present invention.

[0014] These and other aspects, embodiments, features, and advantages of the invention become apparent to the person skilled in the art in the following detailed description, claims and figures. Each feature from one aspect of the invention can be used in any other aspect of the invention. Furthermore, the examples contained herein are intended to describe and illustrate the invention, but do not restrict it. In particular, the invention is not limited to these examples.

[0015] Detailed description

[0016] Before describing in detail exemplary embodiments of the present invention, definitions which are important for understanding the present invention are given.

[0017] As used in this specification and in the appended claims, the singular forms of "a" and "an" also include the respective plurals unless the context clearly dictates otherwise.

[0018] In the context of the present invention, the terms "about" and "approximately" denote an interval of accuracy that a person skilled in the art will understand to still ensure the technical effect of the feature in question. The term typically indicates a deviation from the indicated numerical value of ±20 %, preferably ±15 %, more preferably ±10 %, and even more preferably ±5 %.

[0019] It is to be understood that the term "comprising" is not limiting. For the purposes of the present invention the term "consisting of' is considered to be a preferred embodiment of the term "comprising of'. If hereinafter a group is defined to comprise at least a certain number of embodiments, this is meant to also encompass a group which preferably consists of these embodiments only.

[0020] Furthermore, the terms "first", "second", "third" or "(a)", "(b)", "(c)", "(d)" etc. and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the invention described herein are capable of operation in other sequences than described or illustrated herein. In case the terms "first", "second", "third" or "(a)", "(b)", "(c)", "(d)", "i", "ii" etc. relate to steps of a method or use or assay there is no time or time interval coherence between the steps, i.e. the steps may be carried out simultaneously or there may be time intervals of seconds, minutes, hours, days, weeks, months or even years between such steps, unless otherwise indicated in the application as set forth herein above or below.

[0021] It is to be understood that this invention is not limited to the particular methodology, protocols, reagents etc. described herein as these may vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the present invention that will be limited only by the appended claims. Unless defined otherwise, all technical and scientific terms used herein have the same meanings as commonly understood by one of ordinary skill in the art.

[0022] As used herein the term “does not comprise” or “free of’ means in the context that the composition of the present invention is free of a specific compound or group of compounds, which may be combined under a collective term, that the composition does not comprise said compound or group of compounds in an amount of more than 0.8 % by weight, based on the total weight of the composition. Furthermore, it is preferred that the composition according to the present invention does not comprise said compounds or group of compounds in an amount of more than 0.5 % by weight, preferably the composition does not comprise said compounds or group of compounds at all.

[0023] When referring to compositions and the weight percent of the therein comprised ingredients it is to be understood that according to the present invention the overall amount of ingredients does not exceed 100% (± 1% due to rounding).

[0024] According to the invention, the method for the preparation of an aqueous dispersion comprising at least one micronized insoluble organic UV absorber, the method comprising: a) providing a first aqueous dispersion comprising said at least one insoluble organic UV absorber; b) grinding the first aqueous dispersion in a ball mill, preferably a stirred media mill, comprising grinding beads with a diameter in the range of 0.6 to 2.0 mm in a first milling step to obtain a second dispersion; c) grinding the second dispersion obtained in b) in a ball mill, preferably a stirred media mill, comprising grinding beads with a diameter in the range of 0.05 to 0.6 mm in a second milling step to obtain the aqueous dispersion comprising a least one micronized insoluble organic UV absorber, wherein the diameter of the grinding beads in step b) is greater than the diameter of the grinding beads in step c).

[0025] The insoluble organic UV absorber may be subjected to pre-grinding to break lumps or agglomerates of crystals / particles or even break crystals / particles to smaller size. To this end, the insoluble organic UV absorber may be formulated into an aqueous slurry suitable for wet grinding. The slurry contains the solvent, i.e., water, and optionally compounds that are capable of wetting the at least one insoluble organic UV absorber solids in the solvent. The slurry is preferably prepared in equipment which allows the preparation of a liquid formulation, the incorporation of the at least one insoluble organic UV absorber, and the formation of a homogenous dispersion for further processing.

[0026] Thus, in some embodiments, step a) includes the steps of a1) providing an aqueous slurry comprising said at least one insoluble organic UV absorber; and a2) pre-grinding the slurry in a colloid mill, preferably a toothed colloid mill, or a rotor mill to prepare the first aqueous dispersion comprising said at least one insoluble organic UV absorber.

[0027] Thus, in preferred embodiments, the method for the preparation of an aqueous dispersion comprising at least one micronized insoluble organic UV absorber comprises the following steps: a) providing a first aqueous dispersion comprising said at least one insoluble organic UV absorber, wherein the aqueous dispersion is obtained by a1) providing an aqueous slurry comprising said at least one insoluble organic UV absorber; and a2) pre-grinding the slurry in a colloid mill, preferably a toothed colloid mill or a rotor mill, to prepare the first aqueous dispersion comprising said at least one insoluble organic UV absorber; b) grinding the first aqueous dispersion in a ball mill, preferably a stirred media mill, comprising grinding beads with a diameter in the range of 0.6 to 2.0 mm in a first milling step to obtain a second dispersion; c) grinding the second dispersion obtained in b) in a ball mill, preferably a stirred media mill, comprising grinding beads with a diameter in the range of 0.05 to 0.6 mm in a second milling step to obtain the aqueous dispersion comprising a least one micronized insoluble organic UV absorber, wherein the diameter of the grinding beads in step b) is greater than the diameter of the grinding beads in step c).

[0028] In the context of the present invention, the term “dispersion” preferably means a heterogeneous mixture of at least two substances that do not or hardly dissolve in each other or do not chemically combine with each other. In various embodiments, one or more substances are finely dispersed as a so-called dispersed phase in another continuous substance, the so-called dispersion medium or continuous phase. Preferably, according to the invention, the at least one insoluble organic UV filter is finely dispersed in water (thus forming a suspension). The dispersion may comprise further compounds or additives in either phase.

[0029] The term “slurry” preferably means a mixture of (mainly) water and solid particles, i.e., in the context of the present invention, refers to a mixture of water and at least one insoluble organic UV filter and optionally further suitable additives, as herein described below.

[0030] “Colloid mills” are well known and widely used in the art. They work on the rotor-stator (the teeth) principle, so that a high level of hydraulic stress is applied on the fluid which results in disrupting and breaking down the structure. While they are often used to increase the stability of suspensions and emulsions, they are also used to reduce the particle size of solids in suspensions. “Toothed colloid mills” are generally built as circular rows of pins sitting tooth on tooth opposite to each other. Suitable toothed colloid mills are for example available from Fryma (FrymaKoruma AG).

[0031] “Rotor mills” use a different mechanical principle. The fluid is forced through a gap which is formed by the surfaces of corrugated grinding rollers which are inclined against each other. Rotor mills are widely used for particle deagglomeration and wet milling. Suitable rotor mills are for example available from Fryma or from Siefer (e.g., Trigonal mill).

[0032] “Ball mills” and / or “stirred media mills” are well known to the person skilled in the art and are commercially available, for example, from the company Netzsch (LMZ mill), Drais, Buhler AG or Bachofen. Milling beads, as used particularly in stirred media mills may typically be selected from the list comprising glass beads, zirconium oxide, such as yttrium-stabilized zirconium oxide, or mixed ceramic grinding beads. These beads are typically essentially spherical. Suitable grinding beads that can be used in step b) and / or c) of the process can be steel grinding beads, glass grinding beads, yttrium-stabilized zirconium oxide grinding beads, cerium-stabilized zirconium oxide grinding beads or zirconium silicate grinding beads, or mixed ceramic grinding beads, such as composites made of tungsten carbide with yttrium-stabilized zirconium oxide, without being limited thereto. The various beads are offered in different sizes, for example from the company Netzsch under the tradenames STEELBEADS MICRO, STEELBEADS Q, GLASSBEADS, ZETABEADS®, ZETABEADS® PLUS, ZETABEADS® NANO, VITABEADS® NANO, CERABEADS, ZSBEADS, or from company Sigmund Lindner under the tradenames of SiLiBeads Typ S, SiLiBeads Typ ZY, SiLiBeads ZC or SiLiBeads Typ TO.

[0033] In various embodiments, the grinding beads in step b) and / or step c) are yttrium-stabilized zirconium oxide grinding beads. In various such embodiments, the grinding beads in step b) and / or step c) are yttrium- stabilized zirconium oxide having a high density and being highly spherical.

[0034] Typical yttrium-stabilized zirconium oxide grinding beads according to the present invention may have the following properties:

[0035] Chemical Composition: 95 % ZrO2, 5 % Y2O3

[0036] Specific Density: 6.1 g / cm3

[0037] Bending Strength: 1200 MPa

[0038] Hardness (Hv10): 1250

[0039] Modulus of Elasticity: 210 GPa

[0040] Fracture Toughness: 6.0 Mpam°

[0041] Such grinding beads are, e.g., commercially available from Tosho Ceramics, Japan.

[0042] In various embodiments, the slurry formation takes place by adding (purified or distilled) water to a reaction vessel and, subsequently, adding a dispersing agent and the at least on UV filter to form a slurry, and stirring the mixture for further homogenization. Equipment and process for slurry formation are typically carefully selected to achieve good dispersion of the solid material and avoid sedimentation and to prevent the formation of foam. Further compounds, such as surfactants or pH adjusting agents can be added before starting step b) of the process according to the invention.

[0043] In various embodiments, the grinding beads in step b) have a diameter in the range of 0.6 to 2.0 mm, for instance, but without limitation, a diameter of 0.6, 0.7, 0.8, 0.9, 1.0, 1.1 , 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0 mm, for example 0.6 to 1.8 mmm or 0.6 to 1.6 mm, preferably 0.6 to 1.5 mm or 0.6 to 1.3 mm, more preferably 0.6 to 1 .0 or 0.6 to 0.9 mm or 0.6 to 0.8 mm or 0.8 to 1 .3 mm, 0.9 to 1 .3 mm or 1 .0 to 1 .3 mm.

[0044] In various other embodiments, the grinding beads in step c) have a diameter in the range of 0.05 to 0.6 mm, for instance, but without limitation, a diameter of 0.05, 0.06, 0.07, 0.08, 0.09, 0.1 , 0.2, 0.3, 0.4, 0.5, or 0.6 mm, for example 0.1 to 0.6 or 0.15 to 0.6 or 0.2 to 0.6 or 0.25 to 0.6, preferably 0.3 to 0.6 mm or 0.2 to 0.5, more preferably 0.3 to 0.4 mm or 0.4 to 0.6 mm. In some embodiments, the grinding beads in step b) and step c) differ in diameter by at least 0.1 mm, such as by 0.15 mm, preferably by at least 0.2 mm, more preferably by at least 0.3 mm, for example by 0.4 mm or 0.5 mm.

[0045] In various embodiments,

[0046] (1) the grinding beads in step b) have a diameter in the range of 0.6 to 2.0 mm, preferably 0.6 to 1 .5 mm or 0.6 to 1 .3 mm, more preferably 0.6 to 0.8 mm or 1 .0 to 1 .3 mm, and / or

[0047] (2) the grinding beads in step c) have a diameter in the range of 0.05 to 0.6 mm, preferably 0.3 to 0.6 mm, more preferably 0.3 to 0.4 mm or 0.4 to 0.6 mm; and / or

[0048] (3) the grinding beads in step b) and step c) differ in (average) diameter by at least 0.2 mm, preferably by at least 0.3 mm.

[0049] In various embodiments,

[0050] (1) the grinding beads in step b) have a diameter in the range of 0.6 to 2.0 mm, preferably 0.6 to 1 .5 mm or 0.6 to 1 .3 mm, more preferably 0.6 to 0.8 mm or 1 .0 to 1 .3 mm, or

[0051] (2) the grinding beads in step c) have a diameter in the range of 0.05 to 0.6 mm, preferably 0.3 to 0.6 mm, more preferably 0.3 to 0.4 mm or 0.4 to 0.6 mm; or

[0052] (3) the grinding beads in step b) and step c) differ in (average) diameter by at least 0.2 mm, preferably by at least 0.3 mm.

[0053] In various embodiments,

[0054] (1) the grinding beads in step b) have a diameter in the range of 0.6 to 2.0 mm, preferably 0.6 to 1 .5 mm or 0.6 to 1 .3 mm, more preferably 0.6 to 0.8 mm or 1 .0 to 1 .3 mm, and

[0055] (2) the grinding beads in step c) have a diameter in the range of 0.05 to 0.6 mm, preferably 0.3 to 0.6 mm, more preferably 0.3 to 0.4 mm or 0.4 to 0.6 mm; and

[0056] (3) the grinding beads in step b) and step c) differ in (average) diameter by at least 0.2 mm, preferably by at least 0.3 mm.

[0057] “Diameter”, as used herein in relation to the grinding beads, refers to the size of the beads in their maximum dimension (in case they are not perfectly spherical). It is to be understood that such beads that are commercially obtainable for this purpose typically are of essentially uniform size, i.e., if they are indicated to have a given diameter, all beads do essentially have the given diameter. “Essentially having the given diameter”, as used in relation to the grinding beads, preferably means that each bead has a diameter equal to the given diameter with a variation of no more than ±20%, preferably no more than ±10%, more preferably no more than ±5%. In a concrete example, beads having a diameter of 0.3 mm means that all of these beads have a diameter in the range of 0.3 mm ±20%, i.e., 0.24 to 0.36 mm. If a diameter range is already given for the beads, such as 0.3 to 0.4 mm, this then means that all beads have a diameter in the given range plus the variation, i.e. in this example 0.24 to 0.48 mm, preferably 0.27 to 0.44 mm, more preferably 0.285 to 0.42 mm. The diameter of the grinding beads can be determined by any suitable means known to those skilled in the art, for example using a caliper or similar mechanical tool. In addition, the grinding beads with the given diameters are commercially available. It is further understood that if the beads used in a milling step of the inventive process are defined by a given diameter or diameter range that in said step only such beads are used, i.e., no other types or sizes of beads are purposively present or used. This may, for example, mean that the milling media in the media mill does comprise at least 95% beads of the indicated size, preferably 99 or 100%. The term “UV filter” or “ultraviolet filter” or “UV absorber” or “ultraviolet absorber”, as used interchangeably herein, refers to organic or inorganic compounds, which can absorb and may further reflect and scatter UV radiation caused by sunlight. UV-filter can be classified based on their UV protection curve as UV-A, UV- B, or broadband filters. The terms “UV filter” or “UV absorber” are used synonymously in the context of the present invention. “Organic UV absorbers” are UV absorbers that are based on or are organic molecules,.e. carbon-containing molecules. n the context of the present invention, it is to be understood that the term “insoluble UV absorber” refers to UV absorbers that are not soluble in water and cosmetic oils at 25 °C. Particularly, the term “insoluble”, as used herein, refers to an UV filter which exhibits a solubility at RT (i.e., ~ 22 °C) in common cosmetic oils such as, e.g., C12-15 alkyl benzoate, propylene glycol, mineral oil, but also in water of less than 0.01 wt.-%, preferably of less than 0.05 wt.-%, most preferably of less than 0.03 wt.-%. In the context of the presentnvention, water soluble UV absorbers have a solubility in water of at least 2 % by weight, preferably ateast 3 % by weight, more preferably at least 5 % by weight, and oil soluble UV absorbers have a solubilityn common cosmetic oils, such as C12-C15-alkyl benzoate, dibutyl adipate, diisopropyl sebacate, phenethyl benzoate, or dicaprylyl carbonate of at least 2 % by weight, preferably at least 5 % by weight, more preferably at least 7 % by weight. n various embodiments, the at least one insoluble UV absorber is selected from (1) a compound of formula (I) I) wherein R1 and R2 independent from each other are C1-C20alkyl, C2-C20alkenyl, C3-C10cycloalkyl, C3- C10cycloalkenyl, or R1 and R2 together with the linking nitrogen atom form a 5- or 6-membered heterocyclic ring; A is -N(R3)-, -O- or a direct bond; B is a bivalent radical selected from alkylene, cycloalkylene, alkenylene or phenylene radical which is optionally substituted by a carbonyl- or carboxy group; a radical of formula -CH2-C≡C-CH2-; or the divalent radical -B- corresponds to the formula (Ia) ) wherein n1 is a number from 1 to 3; A is -N(R3)- or -O-; and R3 is hydrogen; C1-C5 alkyl or hydroxy-C1-C5 alkyl; 2) a compound of formula (II) II) wherein T1 is hydrogen, C1-C12alkyl, preferably iso-octyl, or C1-C4alkyl substituted by phenyl;3) a compound of formula (III) II) wherein R4 and R5 independently from each other are hydrogen, C1-C18alkyl, or C6-C12aryl; R6, R7 and R8 independently from each other are hydrogen or C1-C18alkyl or a radical of formula (IIIa) wherein R9, R10 and R11 independently from each other are hydrogen or C1-C18alkyl; and 4) a compound of formula (IV) wherein R12 and R13 independent from each other represent hydrogen, halogen, C1-C12alkyl, C1-C18hydroxyalkyl, C1-C18alkoxy, poly(ethoxy)-alkoxy with a C1-C4 alkyl fragment and an ethoxy number ranging from 1 to 4, C1-C4 mono- or dialkylamino; R14 represents halogen, hydroxy, amino, phenyl, the phenyl being optionally substituted 1 to 3 times by a hydroxy radical situated at least in para position, 1 to 3 times by a C1-C12alkoxy, cyano or C1-C7alkylamino group in an ortho, meta or para position, and / or 1 time a meta or para position, preferably para position. C1-C20Alkyl denotes a linear or branched, unsubstituted or substituted alkyl group such as, for example, methyl, ethyl, propyl, isopropyl, n-butyl, n-hexyl, cyclohexyl, n-decyl, n-dodecyl, n-octadecyl, eicosyl, methoxyethyl, ethoxypropyl, 2-ethylhexyl, hydroxyethyl, chloropropyl, Ν,Ν-diethylaminopropyl, cyanoethyl, phenethyl, benzyl, p-tert-butylphenethyl, p-tert-octylphe- noxyethyl, 3-(2,4-di-tert-amylphenoxy)-propyl, ethoxycarbonylmethyl-2-(2-hydroxyethoxy)- ethyl or 2-furylethyl. C2-C20alkenyl is for example allyl, methallyl, isopropenyl, 2-butenyl, 3-butenyl, isobutenyl, n-penta-2,4- dienyl, 3-methyl-but-2-enyl, n-oct-2-enyl, n-dodec-2-enyl, iso-dodecenyl, n-dodec- 2-enyl or n-octadec-4- enyl. C3-C10cycloalkyl is for example cyclopropyl, cyclobutyl, cyclopentyl, cycloheptyl, cyclooctyl, cyclononyl or cyclodecyl and preferably cyclohexyl. These radicals may be substituted, for example by one or more or equal or different C1-C4alkyl radicals, preferably by methyl, and / or hydroxy. If cycloalkyl radicals are substituted by one or more radicals, they are preferably substituted by one, two or four, preferably by one or two equal or radicals. C3-C10cycloalkenyl is for example cyclopropenyl, cyclobutenyl, cyclopentenyl, cycloheptenyl, cycloocentyl, cyclononenyl or cyclodecenyl and preferably cyclohexenyl. These radicals may be substituted with one or more equal or different C1-C4alkyl radical, preferably with methyl, and / or hydroxy. If cycloalkenyl radicals are substituted with one or more radicals they are preferably substituted with one, two, three or four, preferably with one or two equal or different radicals. Hydroxy substituted C1-C5alkyl groups are for example hydroxymehtyl, hydroxyethyl, hydroxypropyl, hydroxybutyl or hydroxypentyl. An alklyene radical is preferably a C1-C12alkylene radical, like for example methylene, ethylene, propylene, butylene, hexylene or octylene. A cycloalklyene radical is preferably a cyclo-C3-C12alkylene radical, like for example cyclopropylene, cyclobutylene, cyclohexylene or cyclooctylene. The alkylene- or cycloalkylene radicals may optionally be substituted by one or more C1-C5alkyl radicals.f R1 and R2 are heterocyclic radicals, these comprise one, two, three or four equal or different ring hetero atoms. Special preference is given to heterocycles which contain one, two or three, especially one or two,dentical or different hetero atoms. The heterocycles may be mono- or poly-cyclic, for example mono-, bi- or tri-cyclic. They are preferably mono- or bi- cyclic, especially monocyclic. The rings preferably contain 5, 6 or 7 ring members. Examples of monocyclic and bicyclic heterocyclic systems from which radicals occurring in the compounds of formula (I) or (II) may be derived are, for example, pyrrole, furan, thiophene,midazole, pyrazole, 1,2,3-triazole, 1,2,4-triazole, pyridine, pyridazine, pyrimidine, pyrazine, pyran,hiopyran, 1,4-dioxane, 1,2-oxazine, 1,3-oxazine, 1,4-oxazine, indole, benzothio- phene, benzofuran, pyrrolidine, piperidine, piperazine, morpholine and thiomorpholine. n some embodiments, in the compounds of formula (I), R1and R2independently from each other are hydrogen; or C1-C20alkyl; or R1 and R2 together with the linking nitrogen atom form a 5- or 6-membered heterocyclic ring; B is an alkylene-radical which is optionally interrupted by a carbonyl- or carboxy group; or a radical oformula (Ia), in particular those where n1 is 2; A is -O-; or -N(R3)-; or the direct bond; and R3 is hydrogen; C1-C5alkyl; or hydroxy-C1-C5alkyl. n some embodiments, in the compounds of formula (I), R1 and R2 are C1-C20alkyl, preferably C1-C5alkyl; and most preferably ethyl. Preferably, Ri and R2 in formula (I) have the same definition. Most preferred are compounds of formula (I), wherein B corresponds to formula (la) with m being 2.

[0058] In various embodiments, the compound (I) corresponds to formula

[0059] (IA; bis-(diethylaminohydroxybenzoyl benzoyl) piperazine).

[0060] In some embodiments, the compound (II) corresponds to formula

[0061] (IIA; methylene bis-benzotriazolyl tetramethylbutylphenol).

[0062] In various embodiments, the compound (III) corresponds to formula

[0063] (II IA; tris-biphenyl triazine).

[0064] In various embodiments, the compound (IV) corresponds to formula

[0065] (IVA; phenylene bis-diphenyltriazine).

[0066] In some embodiments, the at least one insoluble organic UV absorber is selected from the group consisting of tris-biphenyl triazine (formula IIIA), phenylene bis-diphenyltriazine (formula IVA), bis- (diethylaminohydroxybenzoyl benzoyl) piperazine (formula IA) and methylene bis-benzotriazolyl tetramethylbutylphenol (formula HA) or combinations thereof.

[0067] According to some embodiments, the at least one insoluble organic UV absorber in the first aqueous dispersion in step a) has a mean particle size distribution as determined by laser diffraction of Dv90 >1 pm, preferably 1 to 400 pm, more preferably 20 to 200 pm, most preferably 50 to 200 pm.

[0068] In some embodiments, the at least one insoluble organic UV absorber in the second aqueous dispersion after step b) has a mean particle size distribution as determined by laser diffraction of Dv90 >400 nm, preferably Dv50 >145 nm and Dv90 >400 nm.

[0069] In some further embodiments, the at least one insoluble organic UV absorber in the aqueous dispersion after step c) has a mean particle size distribution as determined by laser diffraction of Dv50 <200 nm and Dv90 <400 nm, preferably Dv50 <150 nm and Dv90 <300 nm, more preferably a Dv50 particle size in the range of from 50 to 180 nm, even more preferably 75 to 150 nm or 75 to 140 nm, most preferably 80 to 130 nm. Accordingly, the desired at least one “micronized” insoluble organic UV absorber may have a mean particle size distribution as determined by laser diffraction of Dv50 <200 nm and Dv90 <400 nm, preferably Dv50 <150 nm and Dv90 <300 nm, more preferably a Dv50 particle size in the range of from 50 to 180 nm, even more preferably 75 to 150 nm or 75 to 140 nm, most preferably 80 to 130 nm. The term “micronized” may thus means that the mean particle size distribution is as defined above. Determination is preferably made by laser diffraction using a Mastersizer 2000 (Malvern Panalytical), with the analysis of the data preferably being carried out employing the Mie model and using the experimental values for the index of refraction of the UV filter particles in water, as disclosed herein below.

[0070] “Dv50” refers to the volume-based mean particle size and gives the value at which 50% of the total number of particles are smaller and 50% are bigger than the given value. Similarly, “Dv90” refers to a particle size threshold value at which 90% of the total number of particles are smaller than the given value and 10% are bigger than the given value. In combination Dv50 and Dv90 also provide information on the particle size distribution. The particle size can be determined in dry form, i.e. as powder or in suspension. Preferably the particle size is determined in suspension.

[0071] Preferably, mean particle size distribution is volume-based mean particle size distribution and measured by laser diffraction. Further information on this particle size characterization method can, for example, be found in “Basic principles of particle size analysis”, Dr. Alan Rawle, Malvern Instruments Limited, Enigma Business Part, Grovewood road, Malvern, Worcestershire, WR14 1XZ, UK and the “manual of Malvern particle size analyzer”. If nothing else is stated, all particle sizes of the insoluble organic UV absorber were determined by laser diffraction using a Mastersizer 2000, from Malvern Panalytical. Analysis of the data was carried out employing the Mie model and using the experimental values for the index of refraction of the UV filter particles in water.

[0072] In some embodiments,

[0073] (1) the at least one insoluble organic UV absorber in the first aqueous dispersion in step a) has a mean particle size distribution as determined by laser diffraction of Dv90 >1 pm, preferably 1 to 400 pm, more preferably 20 to 200 pm, most preferably 50 to 200 pm; and / or

[0074] (2) the at least one insoluble organic UV absorber in the second aqueous dispersion after step b) has a mean particle size distribution as determined by laser diffraction of Dv90 >400 nm, preferably Dv50 >145 nm and Dv90 >400 nm; and / or

[0075] (3) the at least one insoluble organic UV absorber in the aqueous dispersion after step c) has a mean particle size distribution as determined by laser diffraction of Dv50 <200 nm and Dv90 <400 nm, preferably Dv50 <150 nm and Dv90 <300 nm, more preferably a Dv50 particle size in the range of from 50 to 180 nm, even more preferably 75 to 150 nm or 75 to 140 nm, most preferably 80 to 130 nm.

[0076] In some embodiments,

[0077] (1) the at least one insoluble organic UV absorber in the first aqueous dispersion in step a) has a mean particle size distribution as determined by laser diffraction of Dv90 >1 pm, preferably 1 to 400 pm, more preferably 20 to 200 pm, most preferably 50 to 200 pm; or

[0078] (2) the at least one insoluble organic UV absorber in the second aqueous dispersion after step b) has a mean particle size distribution as determined by laser diffraction of Dv90 >400 nm, preferably Dv50 >145 nm and Dv90 >400 nm; or

[0079] (3) the at least one insoluble organic UV absorber in the aqueous dispersion after step c) has a mean particle size distribution as determined by laser diffraction of Dv50 <200 nm and Dv90 <400 nm, preferably Dv50 <150 nm and Dv90 <300 nm, more preferably a Dv50 particle size in the range of from 50 to 180 nm, even more preferably 75 to 150 nm or 75 to 140 nm, most preferably 80 to 130 nm.

[0080] In some other embodiments,

[0081] (1) the at least one insoluble organic UV absorber in the first aqueous dispersion in step a) has a mean particle size distribution as determined by laser diffraction of Dv90 >1 pm, preferably 1 to 400 pm, more preferably 20 to 200 pm, most preferably 50 to 200 pm; and (2) the at least one insoluble organic UV absorber in the second aqueous dispersion after step b) has a mean particle size distribution as determined by laser diffraction of Dv90 >400 nm, preferably Dv50 >145 nm and Dv90 >400 nm; and

[0082] (3) the at least one insoluble organic UV absorber in the aqueous dispersion after step c) has a mean particle size distribution as determined by laser diffraction of Dv50 <200 nm and Dv90 <400 nm, preferably Dv50 <150 nm and Dv90 <300 nm, more preferably a Dv50 particle size in the range of from 50 to 180 nm, even more preferably 75 to 150 nm or 75 to 140 nm, most preferably 80 to 130 nm.

[0083] In some embodiments, particularly, the specific energy input to achieve a mean particle size distribution of the at least one insoluble organic UV absorber in the aqueous dispersion after step c) as determined by laser diffraction of Dv50 <150 nm and Dv90 <300 nm is less than 3 kWh / kg, preferably less than 2.5 kWh / kg, more preferably less than 2.0 kWh / kg, such as 1 .9, 1 .8, 1 .7, 1 .6, 1 .5, 1 .4, 1 .3, 1.2, 1.1 , 1 .0, 0.9, 0.8, 0.7, 0.6, or 0.5 kWh / kg.

[0084] In various embodiments, the at least one micronized insoluble organic UV absorber is comprised in the aqueous dispersion in an amount of 1 to 80 wt.-%, typically 10 to 80 wt.-% or 20 to 80 wt.-%, preferably 30 to 70 wt.-%, more preferably 35 to 65 or 35 to 60 or 35 to 55 or 40 to 65, 40 to 60 or 40 to 55 or 45 to 55 wt.-%, e.g. about 40, 41 , 42, 43, 44, 45, 46, 47, 48, 49, 50, 51 , 52, 53, 54, 55, 56, 57, 58, 59 or 60 % by weight. In various such embodiments, the range may be 20 to 80 wt.-%, preferably 30 to 70 wt.-%, more preferably 35 to 65 wt.-% or 40 to 60 wt.-%, relative to the total weight of the aqueous dispersion.

[0085] In various embodiments, the method further comprises the steps of

[0086] (d) removing the grinding beads; and, optionally,

[0087] (e) adding at least one additive to the obtained aqueous dispersion.

[0088] In some such embodiments, the aqueous dispersion comprises at least one additive, preferably selected from the group consisting of surfactants, rheology modifiers, pH-adjusters, buffering agents, preservatives, and mixtures thereof. The addition of the at least one additive can occur at any step of the methods described herein, i.e., may also be carried prior to step a) or b) or after step c) or d).

[0089] In various embodiments, the at least one additive is i) at least one wetting agent, preferably (poly)propylene glycol and / or butylene glycol, optionally in an amount of 0.05 to 5 wt.-%, based on the total weight of the aqueous dispersion; and / or ii) at least one rheology modifier, preferably xanthan gum, gellan gum and / or carboxymethylcellulose, optionally in an amount of 0.05 to 5 wt.-%, based on the total weight of the aqueous dispersion; and / or iii) at least one surfactant, preferably a non-ionic surfactant, optionally in an amount of 0.5 to 25 wt.-%, based on the total weight of the aqueous dispersion; and / or iv) selected from the group of preservatives, buffering agents, and pH adjusting agents.

[0090] Rheology modifiers are optionally added to the aqueous dispersion, which help to stabilize across the time such composition. Examples for aqueous thickeners are represented by natural ingredients and their derivatives, such as gums and alginates or by synthetic / semi-synthetic ingredients such as modified starch, modified cellulose and polyacrylates. Examples of preferred rheology modifiers are xanthan gum, gellan gum, and carboxymethylcellulose. Examples of wetting agents suitable for employment in the context of the present invention encompass (poly)propylene glycol and / or butylene glycol as well as mixtures thereof. In some embodiments, the wetting agent is propylene glycol. Suitable surfactants can be selected from anionic surfactants, such as sulfates, sulfonates sulfosuccinates, phosphates, and acylamino acid and salts thereof; non-ionic surfactants, such as amine oxides; amphoteric or zwitterionic surfactants, such as acyl / dialkyl ethylenediamines; and cationic surfactants, such as alkylamines, alkyl imidazolines, and quaternary compounds. In various embodiments, the at least one surfactant is selected from non-ionic surfactants. In particular embodiments, the at least one surfactant is selected from alkyl (poly)glycosides, preferably alkyl polyglucosides. Suitable alkyl polyglucosides are for example those known under the INCI name “decyl glucoside” (CAS-68515-73-1), such as the C8-16 alkyl polyglucoside available as PlantaCare 2000 UP from BASF or the C8-10 alkyl polyglucoside commercially available as APG Green APG 0810 from Zheijang Tizhou Tu-Poly Co. Ltd. or Glucopon 225DK from BASF. The term “alkyl polyglucoside (APG)” refers to a class of non-ionic surfactants having the generic formula CnH2n+1O(C6H10O5)xH, in which n is an integer selected from the range of 2 to 22 and x refers to the mean polymerization level of the glucoside moiety (i.e., to the respective mono-, di-, tri-, oligo-, and poly- glucosides as well as mixtures thereof). Preferably, APGs may be derived from renewable raw materials, such as glucose derived from corn and plant-derived fatty alcohols. These alkyl poly-glucosides generally exhibit a mean polymerization level of the glucoside moiety ranging from 1 to 1.7, preferably from 1.2 to 1.6 such as from 1.4 to 1.6. Further advantageous mean polymerization level of the glucoside moiety range from 1.1 to 1.6, such as from 1.1 to 1.4 or from 1.1 to 1.3. Additional advantageous mean polymerization level of the glucoside moiety range from 1.2 to 1.7, respectively from 1.4 to 1.6. In various embodiments, particularly advantageous APGs consist essentially of caprylyl (C8) and capryl (C10) polyglucosides. Preferably such caprylyl (C8) and capryl (C10) poly-glucosides furthermore exhibit a ratio (% / %, wherein all % are area-% determined by HPLC-MS) of caprylyl (C8) monoglucoside to capryl (C10) monoglucoside in the range of 3: 1 to 1 :3, preferably in the range of about 2:1 to 1 :2, most preferably in the range of 1.5: 1 to 1 :1.5. Additionally, such C8-C10 alkyl polyglucoside preferably contain no more than 3 wt.-%, more preferably no more than 2 wt.-%, most preferably no more than 1.5 wt.-% of C12 alkyl mono-glucoside (as determined by HPLC-MS). It is understood that such alkyl poly-glucosides are basically free of any (i.e. contain no) higher (i.e. C14-C16) alkyl polyglucosides. These C8-C10 alkyl poly-glucosides preferably exhibit a mean polymerization level of the glucoside moiety x ranging from 1 to 1.7, preferably from 1.1 to 1.6, most preferably from 1.1 to 1.4, such as particularly in e range of 1.1 to 1.3. hus, in an advantageous embodiment, the present invention also relates to the cosmetic composition ccording to present invention wherein the C8-C10 alkyl polyglucoside contains no more than 2 % of C12 kylmonoglucoside. Preferably, the C8-C10 alkyl polyglucoside contains in addition no C14-C16 alkyl olyglucosides at all. urthermore, the C8-C10 alkyl poly-glucosides according to the invention consisting essentially of caprylylC8) and capryl (C10) poly-glucosides contain advantageously at least 60 %, preferably at least 65 %, most referably at least 70 % of the respective mono-glucosides as, e.g., determined by HPLC-MS. is furthermore preferred that the C8-C10 alkyl polyglucoside according to the present invention are ubstantially (essentially) free of any C9 alkyl polyglucosides, i.e., contain essentially no C9 alkyl olyglucosides. This means that the amount of any C9 alkyl poly-glucosides in the C8-C10 alkyl polyglucoside less than 0.1 wt.-%, preferably less than 0.05 wt.-%, most preferably less than 0.01 % such as in particular ss than 0.005 wt.-%, based on the total weight of the C8-C10 alkyl polyglucoside. A particularly dvantageous C8-C10 alkyl polyglucoside according to the present invention is made from glucose derived om corn and C8 and C10 fatty alcohols derived from coconut and palm kernel oils, which is, e.g., sold as n aqueous dispersion under the tradename Green APG 0810 by Shanghai Fine Chemical. In another mbodiment such C8-10 alkyl polyglucoside may be Glucopon 225DHK from BASF. some other embodiments, suitable alkyl polyglucosides correspond to the formula CnH2n+1O(C6H10O5)xH, which n is an integer ranging from 8 to 16, and x is the mean polymerization level of the glucoside moietyC6H10O) and ranges from 1.4 to 1.6, or an ester thereof. various other embodiments, particularly advantageous APGs consist essentially of C8-C16 alkyl olyglucosides, i.e. comprise substantial portions of C12-C16 alkyl polyglucosides. In such embodiments, e portion of C12-C16 alkyl polyglucosides may comprise at least 30 % C12-16 alkyl polyglucosides, for xample at least 50%. A typical distribution of such suitable C8-16 alkyl polyglucosides comprises 15-25 %, uch as 18-22 %, of C8 monoglucoside, 11-21 %, such as 14-18 %, of C10 monoglucoside, 36-46 %, such s 39-43 %, of C12 monoglucoside, 15-25%, such as 18-22 %, of C14 monoglucoside and up to 5 %, such s up to 3%, of C16 monoglucoside. Such APGs are commercially available from BASF under the adename Plantacare UP 2000. referred C8-C16 poly-glucosides preferably exhibit a mean polymerization level of the glucoside moiety xanging from 1 to 1.7, preferably from 1.1 to 1.6, most preferably from 1.1 to 1.4, such as particularly in theange of 1.1 to 1.3. some embodiments, the surfactant may be a C1-C12 ester of the compound of formula nH2n+1O(C6H10O5)xH, namely an ester formed by reacting a C1-C12 carboxylic acid with one or more free OH group of the glucoside moiety (C6H10O). The ester may be formed by reacting formic, acetic, propionic, butyric, sulfosuccinic, citric, or tartaric acid, with one or more free OH groups on the glucoside moiety (C6H10O). In some embodiments, the surfactant, as herein defined, is contained in the aqueous dispersion of step a) of the method, i.e. is present during the grinding steps. In applying different milling bead sizes for method steps b) and c), as herein defined and described, the method for the preparation of an aqueous dispersion comprising at least one micronized insoluble organic UV absorber according to the present invention is highly economic in terms of energy consumption compared to methods relying on only one grinding step and only one type / size of milling beads. This, in turn, results in an improvement of overall production capacity, not only of the aqueous dispersion of the present invention, but also of any downstream product formulated to comprise such an aqueous dispersion of the present invention. In a further aspect, the present invention also relates to an aqueous dispersion comprising at least one micronized organic insoluble UV absorber obtainable by a process as defined and described herein. All embodiments defined and described in the context of the method according to the present invention therefore also apply to the aqueous dispersion of the present invention, and vice versa. The aqueous dispersions of the present invention, as herein defined and described, are particularly suitable for use in cosmetic, dermatological, or pharmaceutical preparations. Non-limiting examples of such preparations include sunscreen compositions, skin care compositions, e.g., daily care compositions, hair care compositions, and make-up / foundation compositions. The term “sunscreen composition” or “sunscreen” refers to any topical product, which absorbs and which may further reflect and scatter certain parts of UV radiation. Thus, the term “sunscreen composition” is to be understood as not only including sunscreen compositions, but also any cosmetic compositions that provide UV protection. The term “topical product” refers to a product that is applied to the skin and can refer, e.g., to sprays, lotions, creams, oils, foams, powders, or gels. The term “daily care composition” refers to any topical product, which absorbs and which may further reflect and scatter certain parts of UV radiation and is used as an everyday care product for the human body, e.g., for face or body. The daily care composition may comprise one or more active agents, e.g., organic and / or inorganic UV filters, as well as other ingredients or additives, e.g., emulsifiers, emollients, viscosity regulators, stabilizers, preservatives, or fragrances. Suitable daily care composition are according to the present invention, e.g., leave-on face and body care products. Suitable leave-on products for face and body are, e.g., decorative preparations and skin care preparations. Suitable decorative preparations are, e.g., lipsticks, nail varnishes, eye shadows, mascaras, dry and moist make-up, rouge, powders, depilatory agents and suntan lotions. Suitable skin care preparations are, e.g., moisturizing, refining, and lifting preparations. The cited daily care compositions can be in the form of creams, ointments, pastes, foams, gels, lotions, powders, make-ups, sprays, sticks or aerosols. Thus, in another aspect, the present invention further relates to a composition, preferably a sunscreen composition, a daily care composition, a hair care composition, or a make-up / foundation composition, comprising an aqueous dispersion according to the present invention, as defined and described herein. In some embodiments, the aqueous dispersion, as defined and described herein, may be present in such a composition in an amount of 0.1 to 50.0 wt.-%, preferably 0.1 to 40.0 or 0.1 to 35.0 or 0.1 to 30.0 wt.-%, such as, for instance but without limitation, in an amount of (about) 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0, 9.5, 10.0, 11.0, 12.0, 13.0, 14.0, 15.0, 16.0, 17.0, 18.0, 19.0, 20.0, 21.0, 22.0, 23.0, 24.0 or 25.0 wt.-%, more preferably in an amount of 0.2 to 25.0 wt.-%, 0.3 to 22.0 wt.-%, 0.5 to 20.0 wt.-%, 0.5 to 18.0 wt.-%, 0.5 to 15.0 wt.-%, 0.5 to 12.0 wt.-%, 0.8 to 10.0 wt.-%, 1.0 to 10.0 wt.-%, or 1.5 to 8.0 wt.-%, based on the total weight of said composition. In various embodiments, the lower limit may be 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9 or 1.0 wt.-% and / or the upper limit may be 40.0, 35.0, 30.0, 28.0, 26.0, 25.0, 24.0, 22.0, 20.0, 19.0, 18.0, 17.0, 16.0, 15.0, 14.0, 13.0, 12.0, 11.0, 10.0, 9.0 or 8.0 wt.-%. The concrete amounts and ranges of suitable concentrations may depend on the concrete type of composition. As disclosed above, the aqueous dispersions may comprise the at least one insoluble UV absorber in amounts of 1 to 80 wt.-%, typically 10 to 80 wt.-% or 20 to 80 wt.-%, preferably 30 to 70 wt.-%, more preferably 35 to 65 or 35 to 60 or 35 to 55 or 40 to 65, 40 to 60 or 40 to 55 or 45 to 55 wt.-%, e.g. about 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59 or 60 % by weight. Since the amount of UV absorber in the dispersion may thus vary, the above given broad ranges for the amounts of the dispersion that may be included in the compositions similarly apply to the UV absorber(s) contained therein. In various embodiments, the UV absorber(s) contained in the aqueous dispersion may therefore be present in such a composition in an amount of 0.01 to 50 wt.-%, preferably 0.1 to 40 wt.-% or 0.1 to 35 or 0.1 to 30 wt.-%, such as, for instance but without limitation, in an amount of (about) 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0, 9.5, 10.0, 11.0, 12.0, 13.0, 14.0, 15.0, 16.0, 17.0, 18.0, 19.0, 20.0, 21.0, 22.0, 23.0, 24.0 or 25.0 wt.-%, more preferably in an amount of 0.2 to 25.0 wt.-%, 0.3 to 22.0 wt.-%, 0.5 to 20.0 wt.-%, 0.5 to 18.0 wt.-%, 0.5 to 15.0 wt.-%, 0.5 to 12.0 wt.-%, 0.8 to 10.0 wt.-%, 1.0 to 10.0 wt.-%, or 1.5 to 8.0 wt.-%, based on the total weight of said composition. In various embodiments, the lower limit may be 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 07., 0.8, 0.9 or 1.0 wt.-% and / or the upper limit may be 40.0, 35.0, 30.0, 28.0, 26.0, 25.0, 24.0, 22.0, 20.0, 19.0, 18.0, 17.0, 16.0, 15.0, 14.0, 13.0, 12.0, 11.0, 10.0, 9.0 or 8.0 wt.-%. The concrete amounts and ranges of suitable concentrations may depend on the concrete type of composition. The sunscreen composition of the present invention may be produced by physically blending the aqueous dispersion comprising at least one micronized insoluble organic UV absorber and carrier components, e.g., cosmetically compatible carrier components, by any conventional method, e.g., by simply stirring the two materials together. A sunscreen composition of the present invention may be formulated as a water-in oil or an oil-in-water dispersion, an oil or oil-alcohol lotion, a vesicular dispersion of an ionic or nonionic amphiphilic lipid, a gel, a solid stick or an aerosol formulation. When formulated as a water-in oil or an oil-in-water dispersion, the optional cosmetically acceptable carrier preferably comprises 5 to 50 % of an oil phase, 5 to 20 % of an emulsifier and 30 to 90 % of water, each by weight based on the total weight of the carrier. The oil phase may comprise any oil conventionally used in cosmetic formulations, e.g., one or more of a hydrocarbon oil, a wax, a natural oil, a silicone oil, a fatty acid ester or a fatty alcohol. Preferred mono- or polyols are ethanol, isopropanol, propylene glycol, hexylene glycol, glycerin and sorbitol. The emulsifier also may comprise any emulsifier conventionally used in cosmetic formulations, e.g., one or more of an ethoxylated ester of a natural oil derivative such as a polyethoxylated ester of hydrogenated castor oil; a silicone oil emulsifier such as a silicone polyol; an optionally ethoxylated fatty acid soap; an ethoxylated fatty alcohol; an optionally ethoxylated sorbitan ester; an ethoxylated fatty acid; or an ethoxylated glyceride. The sunscreen composition of the invention may also comprise further components which are known to perform a useful function in a sunscreen composition. Examples of such further components include, e.g., emollients, skin moisturizers, skin tanning accelerators, antioxidants, emulsion stabilizers, thickening agents such as xanthan, moisture-retention agents such as glycerin, film formers, preservatives, perfumes and colorants. The sunscreen composition according to the present invention may comprise one or more than one additional UV absorbers. It is preferred that the at least one organic or inorganic UV filter is selected from the group consisting of: UVA absorbing filters - 4-(tert.-butyl)-4’-methoxydibenzoylmethane (INCI butyl methoxydibenzoylmethane), - hexyl 2-[4-(diethylamino)-2-hydroxybenzoyl]benzoate (INCI diethylamino hydroxybenzoyl hexyl benzoate), - [(3Z)-3-[[4-[(Z)-[7,7-dimethyl-2-oxo-1-(sulfomethyl)-3- bicyclo[2.2.1]heptanylidene]methyl]phenyl]methylidene]-7,7-dimethyl-2-oxo-1- bicyclo[2.2.1]heptanyl]methanesulfonic acid (INCI terephthalylidene dicamphor sulfonic acid), - disodium phenyl dibenzimidazole tetrasulfonate, - 1,1'-(1,4-piperazinediyl)bis[1-[2-[4-(diethylamino)-2-hydroxybenzoyl]phenyl]-methanone (INCI Bis- (diethylaminohydroxybenzoyl benzoyl) piperazine), - 2-ethoxyethyl (2Z)-2-cyano-2-[3-(3-methoxypropylamino)cyclohex-2-en-1-ylidene]acetate (INCI methoxypropylamino cyclohexenylidene ethoxyethylcyanoacetate); Broad spectrum (UVA+UVB) absorbing filters - 2,4-bis-{[4-(2-ethyl-hexyloxy)-2-hydroxy]-phenyl}-6-(4-methoxyphenyl)-1,3,5 triazine (INCI bis- ethylhexyloxyphenyl methoxyphenyl triazine), - 2,2’-methylenebis[6-(2H-1,2,3-benzotriazol-2-yl)-4-(2,4,4-trimethylpentan-2-yl)phenol] (INCI methylene bis-benzotriazolyl tetramethylbutylphenol), - 2-(2H-benzotriazol-2-yl)-4-methyl-6-[2-methyl-3-[1,3,3,3-tetramethyl-1-[(trimethylsilyl)oxy]-1- disiloxanyl]propyl]phenol (INCI drometrizole trisiloxane), - phenylene bis-diphenyltriazine, - zinc oxide; UVB absorbing filters - 2-phenyl-1H-benzimidazole-5-sulfonic acid (INCI phenylbenzimidazole sulfonic acid), - Tris-biphenyl triazine, - 4,4’,4’’-(1,3,5-triazin-2,4,6-triyltriimino)tris-benzoic acid tris(2-ethylhexyl)ester (INCI ethylhexyl triazone), - (RS)-2-ethylhexyl-2-hydroxybenzoate (INCI ethylhexyl salicylate), - Dimethicone diethyl benzalmalonate (INCI Polysilicone-15), - diethylhexyl butamido triazone, - titanium dioxide, - cerium oxide; and mixtures thereof. These UV filters are commonly employed UV filters with excellent UV protection properties. The cosmetic or pharmaceutical preparations of the present invention may be, for example, creams, gels, lotions, alcoholic and aqueous / alcoholic solutions, emulsions, wax / fat compositions, stick preparations, powders or ointments. In addition to the above-mentioned UV filters, the cosmetic or pharmaceutical preparations may contain further adjuvants as described below. As water- and oil-containing emulsions (e.g. W / O, O / W, O / W / O and W / O / W emulsions or microemulsions) the preparations contain, for example, from 0.1 to 60 % by weight, preferably from 0.1 to 20 % by weight and especially from 0.5 to 10 % by weight, based on the total weight of the composition, of the aqueous dispersion according to the present invention, from 1 to 60 % by weight, especially from 5 to 50 % by weight and preferably from 10 to 35 % by weight, based on the total weight of the composition, of at least one oil component, from 0 to 30 % by weight, especially from 1 to 30 % by weight und preferably from 4 to 20 % by weight, based on the total weight of the composition, of at least one emulsifier, from 10 to 90 % by weight, especially from 30 to 90 % by weight, based on the total weight of the composition, of water, and from 0 to 88.9 % by weight, especially from 1 to 50 % by weight, of further cosmetically acceptable adjuvants. The cosmetic or pharmaceutical compositions / preparations according to the present invention may also contain one or one more additional compounds like fatty alcohols, esters of fatty acids, natural or syntheticriglycerides including glyceryl esters and derivatives, pearlescent waxes: hydrocarbon oils: silicones or siloxanes, organo-substituted super-fatting agents, surfactants consistency regulators / thickeners andheology modifiers, polymers, biogenic active ingredients, deodorizing active ingredients, anti-dandruff agents, antioxidants, hydrotropic agents, preservatives and bacteria-inhibiting agents, perfume oils, colorants, polymeric beads or hollow spheres as spa enhancers. Cosmetic or pharmaceutical formulations are contained in a wide variety of cosmetic preparations. There come into consideration, for example, especially the following preparations: skin-care preparations, e.g., skin-washing and cleansing preparationsn the form of tablet-form or liquid soaps, soap-less detergents or washing pastes, bath preparations, e.g.,iquid (foam baths, milks, shower preparations) or solid bath preparations, e.g., bath cubes and bath salts; skin-care preparations, e.g., skin emulsions, multi-emulsions or skin oils; cosmetic personal care preparations, e.g., facial make-up in the form of day creams or powder creams, face powder (loose or pressed), rouge or cream make-up, eye-care preparations, e.g. eyeshadow preparations, mascara, eyeliner, eye creams or eye-fix creams; lip-care preparations, e.g. lipsticks, lip gloss, lip contour pencils, nail-care preparations, such as nail varnish, nail varnish removers, nail hardeners or cuticle removers; foot- care preparations, e.g. foot baths, foot powders, foot creams or foot balsams, special deodorants and antiperspirants or callus-removing preparations; light-protective preparations, such as sun milks, lotions, creams or oils, sunblocks or tropicals, pre-tanning preparations or after-sun preparations; skin-tanning preparations, e.g. self-tanning creams; depigmenting preparations, e.g. preparations for bleaching the skin or skin-lightening preparations; insect-repellents, e.g. insect-repellent oils, lotions, sprays or sticks; deodorants, such as deodorant sprays, pump-action sprays, deodorant gels, sticks or roll-ons; antiperspirants, e.g., antiperspirant sticks, creams or roll-ons; preparations for cleansing and caring for blemished skin, e.g., synthetic detergents (solid or liquid), peeling or scrub preparations or peeling masks; hair-removal preparations in chemical form (depilation), e.g., hair-removing powders, liquid hair-removing preparations, cream- or paste-form hair-removing preparations, hair- removing preparations in gel form or aerosol foams; shaving preparations, e.g., shaving soap, foaming shaving creams, non-foaming shaving creams, foams and gels, preshave preparations for dry shaving, aftershaves or aftershave lotions;ragrance preparations, e.g., fragrances (eau de Cologne, eau de toilette, eau de parfum, parfum de toilette, perfume), perfume oils or perfume creams; cosmetic hair-treatment preparations, e.g., hair-washing preparations in the form of shampoos and conditioners, hair-care preparations, e.g., pre-treatment preparations, hair tonics, styling creams, styling gels, pomades, hair rinses, treatment packs, intensive hairreatments, hair-structuring preparations, e.g., hair-waving preparations for permanent waves (hot wave, mild wave, cold wave), hair-straightening preparations, liquid hair- setting preparations, hair foams, hairsprays, bleaching preparations, e.g., hydrogen peroxide solutions, lightening shampoos, bleaching creams, bleaching powders, bleaching pastes or oils, temporary, semi-permanent or permanent hair colorants, preparations containing self-oxidizing dyes, or natural hair colorants, such as henna or chamomile. The final formulations listed may exist in a wide variety of presentation forms, for example: in the form ofiquid preparations as a W / O, O / W, 0 / W / O, W / O / W or PIT emulsion and all kinds of microemulsions, in the form of a gel, in the form of an oil, a cream, milk or lotion, in the form of a powder, a lacquer, a tablet or make-up, in the form of a stick, in the form of a spray (spray with propellant gas or pump-action spray) or an aerosol, - in the form of a foam, or in the form of a paste. Of special importance as cosmetic preparations for the skin are light-protective preparations, such as sun milks, lotions, creams, oils, sun blocks or tropicals, pre-tanning preparations or after-sun preparations, also skin-tanning preparations, for example self-tanning creams. Of particular interest are sun protection creams, sun protection lotions, sun protection milk and sun protection preparations in the form of a spray. Of special importance as cosmetic preparations for the hair are the above-mentioned preparations for hair treatment, especially hair-washing preparations in the form of shampoos, hair conditioners, hair-care preparations, e.g., pre-treatment preparations, hair tonics, styling creams, styling gels, pomades, hair rinses, treatment packs, intensive hair treatments, hair- straightening preparations, liquid hair-setting preparations, hair foams and hairsprays. Of special interest are hair-washing preparations in the form of shampoos. A shampoo has, for example, the following composition: from 0.01 to 10 % or 0.1 to 10 % or 0.5 to 8 % or 1 to 5 % by weight of an aqueous dispersion comprising at least one micronized insoluble organic UV absorber according to the invention, 12.0 % by weight of sodium laureth-2-sul- fate, 4.0 % by weight of cocamidopropyl betaine, 3.0 % by weight of sodium chloride, and water ad 100%. Other typical ingredients in such formulations are preservatives, bactericides and bacteriostatic agents, perfumes, dyes, pigments, thickening agents, moisturizing agents, humectants, fats, oils, waxes or other typical ingredients of cosmetic and personal care formulations such as alcohols, poly-alcohols, polymers, electrolytes, organic solvents, silicon derivatives, emollients, emulsifiers or emulsifying surfactants, surfactants, dispersing agents, antioxidants, anti-irritants and anti-inflammatory agents etc. Examples Example 1: 2,2'-Methylenbis(6-(2H-benzotriazol-2-yl)-4-(1,1,3,3-teramethylbutyl)phenol) as UV filter Table 1: Formulation 1 w r % 5 1 35 Deion. Wasser Comparative Example 1A 2 kg of formulation 1 are mixed with water to form a slurry and degassed while being stirred slowly over night. Particle size is measured in the slurry using laser diffraction (Mastersizer 2000, from Malvern Panalytical).

[0091] Results: Dv50 = 37 pm (micrometer), Dv90 = 159 pm (micrometer)

[0092] The product is milled using an agitator ball mill (Dyno Multilab, Bachofen) and SiliBeads ZY (yttrium- stabilized zirconium oxide grinding beads) 0.3-0.4 mm. Samples are taken at regular intervals and particle sizes are determined. The results, including specific energy input into the product are indicated in Table 2 below.

[0093] Table 2: Results Comparative Example 1A

[0094] Example 1B (according to the invention)

[0095] 2 kg of formulation 1 are prepared according to Example 1A. After degassing overnight, the slurry is milled using an agitator mill (Dyno Multilab, Bachofen) and SiliBeads ZY 0.6-0.8 mm until the energy input into the product has reached 0.5 kWh. The resultant dispersion is removed from the mill, 1 .83 kg of material is obtained.

[0096] Subsequently, the dispersion is milled using an agitator mill (Dyno Multilab, Bachofen) and SiliBeads ZY 0.3-0.4 mm. Samples are taken at regular intervals and particle sizes are determined. The results, including specific energy input into the product are indicated in table 3 below.

[0097] Table 3: Results Example 1 B (according to the invention)

[0098] Micronizing in accordance with the present invention results in similar particle sizes as obtained in comparative Example 1A but requiring only 1 kWh / kg as opposed to 1.5 - 2.0 kWh / kg. The inventive process therefore requires much less energy compared to existing processes for the production of fine particles having the desired particle size.

[0099] Example 2: tris-Biphenyl triazine as UV filter

[0100] Table 4: Formulation 2

[0101] The particle size of the UV Filter used in the examples was determined by laser diffraction (Malvern Mastersizer 2000, dry measurement, spray pressure 0.5 bar, Fraunhofer analysis).

[0102] Results: Dv50 = 14.7 pm, Dv90 = 30.9 pm

[0103] Comparative Example 2A

[0104] 2 kg of formulation 2 are mixed with water to form a slurry and degassed while being stirred slowly over night.

[0105] The product is milled using an agitator ball mill (Dyno Multilab, Bachofen) and SiliBeads ZY 0.3-0.4 mm. Samples are taken at regular intervals and particle sizes are determined by laser diffraction. The results, including specific energy input into the product are indicated in table 5 below.

[0106] Table 5: Results Comparative Example 2A

[0107] Example 2B (according to the invention)

[0108] Using the same raw materials, 2 kg of formulation 2 are prepared and degassed in the same way as in example 2A. The dispersion is then milled using an agitator mill (Dyno Multilab, Bachofen) and SiliBeads ZY 1 .0-1 .2 mm until the energy input into the product has reached 0.25 kWh. The product is removed from the mill.

[0109] 1.831 kg of this product is milled using an agitator mill (Dyno Multilab, Bachofen) and SiliBeads ZY 0.3-0.4 mm. Samples are taken at regular intervals and particle sizes are determined by laser diffraction. The results, including specific energy input into the product are indicated in table 8 below.

[0110] Table 6: Results Example 2B (according to the invention)

[0111] Micronizing in accordance with the present invention results in similar particle sizes as obtained in comparative Example 2A but requiring only about 0.7 kWh / kg as opposed to 0.9 - 1.0 kWh / kg. The inventive process therefore requires much less energy compared to existing processes for the production of fine particles having the desired particle size.

[0112] Example 2C (according to the invention)

[0113] Using the same raw materials, 2 kg of formulation 2 are prepared and degassed in the same way as in example 2A. The dispersion is then milled using an agitator mill (Dyno Multilab, Bachofen) and SiliBeads ZY 1 .0-1 .2 mm until the energy input into the product has reached 1 .5 kWh. The product is removed from the mill.

[0114] 1.857 kg of this product is milled using an agitator mill (Dyno Multilab, Bachofen) and SiliBeads ZY 0.3-0.4 mm. Samples are taken at regular intervals and particle sizes are determined by laser diffraction. The results, including specific energy input into the product are indicated in table 8 below. Table 7: Results Example 2C (according to the invention)

[0115] Micronizing in accordance with the present invention is more effective than in comparative Example 2A when specific energy input is higher than about 1.4 kWh / kg. The final product has a significantly smaller particle size distribution even though less specific energy has been consumed.

Claims

Claims1. A method for the preparation of an aqueous dispersion comprising at least one micronized insoluble organic UV absorber, the method comprising: a) providing a first aqueous dispersion comprising said at least one insoluble organic UV absorber; b) grinding the first aqueous dispersion in a ball mill, preferably a stirred media mill, comprising grinding beads with a diameter in the range of 0.6 to 2.0 mm in a first milling step to obtain a second dispersion; c) grinding the second dispersion obtained in b) in a ball mill, preferably a stirred media mill, comprising grinding beads with a diameter in the range of 0.05 to 0.6 mm in a second milling step to obtain the aqueous dispersion comprising a least one micronized insoluble organic UV absorber, wherein the diameter of the grinding beads in step b) is greater than the diameter of the grinding beads in step c).

2. The method according to claim 1 , wherein step a) includes the steps of a1) providing an aqueous slurry comprising said at least one insoluble organic UV absorber; and a2) pre-grinding the slurry in a colloid mill, preferably a toothed colloid mill, or a rotor mill, to prepare the first aqueous dispersion comprising said at least one insoluble organic UV absorber.

3. The method according to claim 1 or 2, wherein the grinding beads in step b) and / or step c) are yttrium-stabilized zirconium oxide grinding beads.

4. The method of any one of claims 1 to 3, wherein(1) the grinding beads in step b) have a diameter in the range of 0.6 to 2.0 mm, preferably 0.6 to 1 .5 mm or 0.6 to 1 .3 mm, more preferably 0.6 to 0.8 mm or 1 .0 to 1 .3 mm,(2) the grinding beads in step c) have a diameter in the range of 0.05 to 0.6 mm, preferably 0.3 to 0.6 mm, more preferably 0.3 to 0.4 mm or 0.4 to 0.6 mm; and / or(3) the grinding beads in step b) and step c) differ in diameter by at least 0.2 mm, preferably by at least 0.3 mm.

5. The method of any one of claims 1 to 4, wherein(1) the at least one insoluble organic UV absorber in the first aqueous dispersion in step a) has a mean particle size distribution as determined by laser diffraction of Dv90 >1 pm, preferably 1 to 400 pm, more preferably 20 to 200 pm, most preferably 50 to 200 pm;(2) the at least one insoluble organic UV absorber in the second aqueous dispersion after step b) has a mean particle size distribution as determined by laser diffraction of Dv90 >400 nm, preferably Dv50 >145 nm and Dv90 >400 nm; and / or(3) the at least one insoluble organic UV absorber in the aqueous dispersion after step c) has a mean particle size distribution as determined by laser diffraction of Dv50 <200 nm and Dv90 <400 nm, preferably Dv50 <150 nm and Dv90 <300 nm, more preferably a Dv50 particle size in the range of from 50 to 180 nm, even more preferably 75 to 150 nm or 75 to 140 nm, most preferably 80 to 130 nm.

6. The method of any one of claims 1 to 5, wherein the specific energy input to achieve a mean particle size distribution of the at least one insoluble organic UV absorber in the aqueous dispersion after step c) as determined by laser diffraction of Dv50 <150 nm and Dv90 <300 nm is less than 3 kWh / kg, preferably less than 2.5 kWh / kg, more preferably less than 2.0 kWh / kg.

7. The method according to any one of claims 1 to 6, wherein the at least one insoluble UV absorber is selected from(1) a compound of formula (I)whereinRi and R2 independent from each other are Ci-C2oalkyl, C2-C2oalkenyl, Cs-Ciocycloalkyl, C3- Ciocycloalkenyl, or R1 and R2 together with the linking nitrogen atom form a 5- or 6-membered heterocyclic ring;A is -N(Rs)-, -O- or a direct bond;B is a bivalent radical selected from alkylene, cycloalkylene, alkenylene or phenylene radical which is optionally substituted by a carbonyl- or carboxy group; a radical of formula -CH2-CSC-CH2-; or the divalent radical -B- corresponds to the formula (la)wherein m is a number from 1 to 3;A is -N(R3)- or -O-; andR3 is hydrogen; Ci-Csalkyl or hydroxy-Ci-Csalkyl;(2) a compound of formula (II)whereinTi is hydrogen, Ci-Ci2alkyl, preferably iso-octyl, or Ci-C4alkyl substituted by phenyl;(3) a compound of formula (III)whereinR4 and R5 independently from each other are hydrogen, Ci-Cisalkyl, or Cs-Ci2aryl;Re, RT and Ra independently from each other are hydrogen or Ci-Cisalkyl or a radical of formula (Illa)whereinRs, R10 and Rn independently from each other are hydrogen or Ci-Cisalkyl; and(4) a compound of formula (IV)whereinR12 and R13 independent from each other represent hydrogen, halogen, Ci-Ci2alkyl, Ci-Ciehydroxyalkyl, Ci-Cisalkoxy, poly(ethoxy)-alkoxy with a C1-C4 alkyl fragment and an ethoxy number ranging from 1 to 4, C1-C4 mono- or dialkylamino;R14 represents halogen, hydroxy, amino, or phenyl, with phenyl being optionally substituted 1 to 3 times by a hydroxy radical situated at least in para position, 1 to 3 times by a Ci-Ci2alkoxy, cyano or Ci-Cyalkylaminogroup in an ortho, meta or para position, and / or 1 time by a group in an meta or para position, preferably para position.

8. The method according to claim 7, wherein the at least one insoluble organic UV absorber is selected from tris-biphenyl triazine, phenylene bis-diphenyltriazine, bis-(diethylaminohydroxybenzoyl benzoyl) piperazine and methylene bis-benzotriazolyl tetramethylbutylphenol or combinations thereof.

9. The method according to any one of claims 1 to 8, wherein the at least one micronized insoluble organic UV absorber is comprised in the aqueous dispersion in an amount of 20 to 80 wt.-%, preferably 30 to 70 wt.-%, more preferably 35 to 65 wt.-%, e.g., 40 to 60 wt.-%, relative to the total weight of the aqueous dispersion.

10. The method according to any one of claims 1 to 9, wherein the method further comprises the steps of(d) removing the grinding beads; and, optionally,(e) adding at least one additive to the obtained aqueous dispersion.

11. The method according to any one of claims 1 to 10, wherein the aqueous dispersion further comprises at least one additive, preferably selected from the group consisting of surfactants, rheology modifiers, pH-adjusters, buffering agents, preservatives, and mixtures thereof.

12. The method according to claim 11 , wherein the at least one additive is i) at least one wetting agent, preferably (poly)propylene glycol and / or butylene glycol, optionally in an amount of 0.05 to 5 wt.-% based on the total weight of the aqueous dispersion; and / or ii) at least one rheology modifier, preferably xanthan gum, gellan gum and / or carboxymethylcellulose, optionally in an amount of 0.05 to 5 wt.-% based on the total weight of the aqueous dispersion; and / or iii) at least one surfactant, preferably a non-ionic surfactant, optionally in an amount of 0.5 to 25 wt.-% based on the total weight of the aqueous dispersion; and / or(iv) selected from the group of preservatives, buffering agents, pH adjusters.

13. The method according to claim 11 or 12, wherein(1) the at least one surfactant is selected from alkyl(poly)glycosides, preferably alkyl polyglucosides, more preferably Ca-Ciealkyl polyglucosides, most preferably Ca-Cioalkyl polyglucosides; and / or(2) the surfactant is contained in the aqueous dispersion of step a) of the method.

14. An aqueous dispersion comprising at least one micronized organic insoluble UV absorber obtainable by a process according to any one of claims 1 to 13.

15. A composition, preferably a sunscreen composition, a daily care composition, a hair care composition, or a make-up / foundation composition, comprising an aqueous dispersion according to claim 14.

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