Compositions comprising 1, 3, 5-triazine, 2, 4, 6-tris [1, 1 '-biphenyl]-4-yl having lower impurity amount

Abstract

A composition comprising 1, 3, 5-triazine, 2, 4, 6-tri [1, 2, 4] triazine, 2, 4, 6-tri [1, 2, 4] triazine, 2, 4 1, 1 '-biphenyl]-4-yl (TBPT) and a first impurity consisting of one or more halogen-containing triazines and a second impurity consisting of biphenyl wherein the amount of the first impurity is in the range of 1 to equal to or less than 900 ppm by weight relative to the total weight of the composition, and wherein the amount of the second impurity is equal to or less than 4000 ppm by weight relative to the total weight of the composition.

Description

Technical Field

[0001] The present invention relates to a composition comprising 1,3,5-triazine, 2,4,6-tris[1,1'-biphenyl]-4-yl with few impurities, in particular in the new crystalline form A, a process for its preparation and a composition containing the composition, and the use of the composition as a UV filter. Background Art

[0002] To comply with cosmetic regulations, purity standards are set for the chemical ingredients in cosmetic products. These purity standards may be particularly relevant for cosmetic products containing chemical ingredients that may contain impurities, which may be detrimental to the health of the user. In particular, aromatic hydrocarbon impurities, when present in cosmetic products, may cause adverse effects on humans or animals. To reduce the undesirable side effects of impurities, the chemical ingredients in cosmetic products should be produced in a manner that focuses on reducing these impurities.

[0003] A widely used chemical ingredient in cosmetics is 1,3,5-triazine, 2,4,6-tris[1,1'-biphenyl]-4-yl (TBPT). TBPT is typically used as a highly effective photostable filter against UVB and UVA II radiation in cosmetic products designed to protect human or animal hair or skin from the damaging effects of UV radiation, such as anti-aging facial care products or sunscreens. TBPT is also known for use in electroluminescent devices (e.g., US 6,225,467 B1, WO 2020 / 226300, WO 2020 / 231197).

[0004] US 2004 / 0191191 A1 describes a synthetic procedure for obtaining TBPT from cyanuric chloride and 1,1′-biphenyl in 1,2-dichlorobenzene in an aluminum chloride-catalyzed reaction. Without adequate purification steps, there is a risk that residual starting materials may remain in the final product and, consequently, in the cosmetic product.

[0005] In order to avoid impurities that may appear during the synthesis of TBPT in, for example, cosmetic products, it is necessary to reduce impurities that are already present during the synthesis or purification steps.

[0006] Therefore, there is a continuing need for a rapid and efficient method for the production of TBPT. In this regard, the object of the present invention is to provide an optimized method for the synthesis, isolation and purification of TBPT. Summary of the Invention

[0007] One object of the present disclosure is to provide TBPT with high purity. A specific object of the present disclosure is to provide a crystalline form of TBPT with high purity and low impurity content that is particularly suitable for cosmetic applications.

[0008] Another object of the present disclosure is to provide a method for synthesizing, isolating and purifying a crystalline form of TBPT.Another specific object of the present disclosure is to provide a method for synthesizing, isolating and purifying a crystalline form of TBPT with high purity and low impurity content.

[0009] In a first aspect, the present invention provides a composition comprising 1,3,5-triazine, 2,4,6-tris[1,1'-biphenyl]-4-yl (TBPT) and a first impurity consisting of one or more halogen-containing triazines and a second impurity consisting of biphenyl, wherein the amount of the first impurity is equal to or less than 900 ppm by weight relative to the total weight of the composition, and wherein the amount of the second impurity is equal to or less than 4000 ppm by weight relative to the total weight of the composition.

[0010] In a second aspect, the present invention provides a crystalline Form A of TBPT, which exhibits in its X-ray powder diffraction pattern using Cu-Kα radiation at room temperature (20°C) at least three of the following five reflections given as 2θ values: 11.6 ± 0.2, 17.8 ± 0.2, 21.1 ± 0.2, 23.4 ± 0.2, and 24.4 ± 0.2 °θ.

[0011] In a third aspect, the present invention provides a method for purifying a composition comprising 1,3,5-triazine, 2,4,6-tris[1,1'-biphenyl]-4-yl (TBPT): a) providing an unpurified composition comprising TBPT, at least a first impurity consisting of one or more halogen-containing triazines, and a second impurity consisting of biphenyl; b) suspending the unpurified composition in a solvent (S1) to provide a first suspension; c) heating the first suspension to a temperature T1 to provide a heated first suspension or first solution of TBPT in the solvent (S1); d) maintaining the heated first suspension or first solution of TBPT at a temperature T2 between 100°C and 235°C and a pressure p1; e) cooling the heated first suspension or the first solution to a temperature T3 to allow crystallization; f) separating the crystals from the solution to obtain a purified composition.

[0012] In a fourth aspect, the present invention provides a cosmetic product comprising a composition according to the first aspect of the invention, preferably wherein TBPT is present in crystalline Form A in micronized form.

[0013] In a fifth aspect, the present invention provides the use of a composition according to the first aspect of the invention as a UV filter in a cosmetic product for protecting the hair and / or skin of a subject from the damaging effects of UV radiation.

[0014] The present invention will be described with respect to particular embodiments and with reference to certain examples but the invention is not limited thereto and only by the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 The DSC graph of RE1 is shown. TBPT is indicated by an endothermic peak at 221°C-256°C with ΔH = 39-43 J / g.

[0016] Figure 2 PXRD pattern of RE1, Cu Kα radiation is shown.

[0017] Figure 3 PXRD pattern of IE1, Cu Kα radiation is shown.

[0018] Figure 4 PXRD pattern of CE3, Cu Kα radiation is shown.

[0019] Figure 5 PXRD pattern of CE2, Cu Kα radiation is shown.

[0020] Figure 6 Comparison of PXRD patterns of Forms A (top) and B (bottom) with Cu Kα radiation is shown.

[0021] Figure 7 A comparison of the UV absorption spectra of TBPT Forms A and B is shown.

[0022] definition

[0023] Before describing exemplary embodiments of the present invention in detail, definitions important to understanding the present invention are given.

[0024] Unless otherwise indicated, the terms set forth below should generally be understood in their common sense.

[0025] The term "comprising" does not exclude other elements. For the purposes of the present invention, the term "consisting of" is considered a preferred embodiment of the term "comprising". If a group is defined below as comprising at least a certain number of embodiments, this should also be understood as disclosing a group that preferably consists only of these embodiments.

[0026] Where an indefinite or definite article is used when referring to a singular noun, for example "a / an" or "the", this includes a plural of that noun unless something else is specifically stated.

[0027] The term "at least one" numerically means "one or more." In a preferred embodiment, the term numerically means "one."

[0028] The terms "include" and "comprising" mean that other components may be present in addition to those mentioned. These terms are intended to be inclusive and thus include "consisting of." "Consisting of" is intended to be explicit and means that no additional ingredients may be present. In embodiments, the terms "comprise" and "comprising" mean "consisting of."

[0029] Terms like "obtainable" and "obtained" are used interchangeably. For example, this means that, unless the context clearly dictates otherwise, the term "obtained" is not intended to indicate that, for example, an embodiment must be obtained by, for example, the sequence of steps following the term "obtained," even though such a limited understanding is always encompassed by the term "obtained" as a preferred embodiment.

[0030] In addition, the terms "first", "second", "third" or "(a)", "(b)", "(c)", "(d)" and the like in this specification and claims are used to distinguish similar elements and are not necessarily used to describe a sequential order or a chronological order. It is to be understood that the terms so used are interchangeable where appropriate and that the embodiments of the invention described herein are capable of operation in other sequences than those described or illustrated herein. Where the terms "first", "second", "third" or "(a)", "(b)", "(c)", "(d)", "i", "ii" and the like refer to steps of a method or use or an assay, unless otherwise indicated in this application as described above or below, there is no temporal or temporal time interval coherence between such steps, i.e., the steps may be performed simultaneously or there may be a time interval of seconds, minutes, hours, days, weeks, months or even years between such steps.

[0031] It should be understood that the present invention is not limited to the specific methodology, protocols, reagents, etc. described herein, as these may vary. It should also 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, which will be limited only by the appended claims.

[0032] The terms "about" or "approximately" allow deviations from the indicated numerical value of ± 20%, preferably ± 15%, more preferably ± 10%, even more preferably ± 5%, in strongly preferred embodiments ± 1%, and in the most preferred embodiments, "about" and "approximately" mean "exactly".

[0033] A numerical range such as "80°C to 120°C" means that the endpoints and each value within the range are disclosed individually.

[0034] As used herein, the term "room temperature" relates to 20° C. As used herein, the term "standard pressure" relates to 1013 mbar.

[0035] The organic moieties mentioned above in the definitions of the variables, like the term halogen, are collective terms for individual lists of individual group members. The prefix Cn-Cm indicates in each case the possible number of carbon atoms in the group.

[0036] The term "halogen" denotes in each case fluorine, bromine, chlorine or iodine, in particular fluorine, chlorine or bromine.

[0037] The term "crystalline form" with respect to TBPT according to the present disclosure specifically includes crystalline form A and crystalline form B. However, it is not excluded that additional crystalline forms may exist.

[0038] The term "polymorph" describes an interconversion relationship, meaning that each form has a temperature range within which it is stable relative to the other form and a transition point at which the forms are equally stable and, in principle, interchangeable. Above this temperature, the thermodynamic tendency is to form only the form that is stable at the higher temperature. Below the transition temperature, the lower-temperature form is the only stable form relative to the other form, although the higher-temperature form is generally more likely to freeze and persist outside its stability range than the lower-temperature form. Forms outside their stability range are described herein as "metastable."

[0039] The term "alkyl" as used herein denotes in each case a straight-chain or branched alkyl group generally having 1 to 5 carbon atoms, preferably 1 to 4 carbon atoms. Examples of alkyl groups are methyl, ethyl, n-propyl, isopropyl, n-butyl, 2-butyl, isobutyl, tert-butyl, n-pentyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 2,2-dimethylpropyl, 1-ethylpropyl, 1,1-dimethylpropyl and 1,2-dimethylpropyl. Methyl, ethyl, n-propyl, isopropyl and isobutyl are particularly preferred.

[0040] The term "aryl" preferably includes a 6-membered aromatic carbocyclic ring based on carbon atoms as ring members. A preferred example is phenyl. In aromatic ring systems, the Hückel (4n + 2) rule is satisfied.

[0041] In this context, the term "purity" relates to the purity of a batch obtained by a "production process," wherein the product obtained from the production process typically contains impurities. The purity of a batch can be determined by quantifying the TBPT content in the batch via HPLC. Experimental details of the method used for quantification are further described in the examples given below. According to the present disclosure, TBPT can exhibit a purity of, for example, 95 wt-%, 98 wt-%, 98.5 wt-%, 99.0 wt-% or even 100 wt-%. Thus, a purity of 98.5 wt-% can represent a mixture of 98.5 wt-% pure TBPT and 1.5 wt-% impurities.

[0042] As used herein, the term "impurities" refers to compounds other than TBPT in the batch of TBPT obtained by the production process. Thus, the term "impurities" encompasses both inorganic and organic impurities. In the context of the present disclosure, particularly relevant impurities are those from residual starting materials, intermediates, or solvents, which may be used or present during the production process. Among these impurities, problematic due to toxicological issues may be aromatic hydrocarbons such as biphenyl or xylene, or halogenated triazines such as 2,4-bis([1,1′-biphenyl]-4-yl)-6-chloro-1,3,5-triazine (BBCT). The list of "impurities" is not to be understood as a comprehensive or definitive list of impurities. In the context of the present disclosure, certain known "impurities" are quantified by GC or HPLC. The experimental details of the quantification methods are further described in the examples given below.

[0043] The term "xylene" as referred to herein encompasses all xylene isomers and mixtures thereof, including 1,2-dimethylbenzene, 1,3-dimethylbenzene and 1,4-dimethylbenzene, corresponding to ortho-xylene, meta-xylene, para-xylene, as well as o-xylene, m-xylene and p-xylene.

[0044] The term "production method" refers to a method that may include the steps of synthesis, isolation and purification. A production method may consist of only one or two of these steps and may optionally include additional steps. Therefore, if not otherwise stated, a production method should not be understood as being limited to these steps or even the order of the steps.

[0045] The term 'TBPT' as used herein must be understood as an abbreviation of the compound name 1,3,5-triazine, 2,4,6-tris[1,1′-biphenyl]-4-yl (CAS No. 31274-51-8, i.e. 2,4,6-tris([1,1′-biphenyl]-4-yl)-1,3,5-triazine), which is described according to formula (I).

[0046]

[0047] (I)

[0048] TBPT can occur in amorphous or crystalline forms and mixtures thereof. The compound of formula (I) can exist in at least two crystal modifications or as a mixture of two or more crystalline states. Polymorph A can be distinguished from polymorph B by powder X-ray diffraction (XRD) and differential scanning calorimetry (DSC). Only polymorph A is known due to its specific UV absorption properties (see Figure 7 ) and is suitable for sunscreen applications. Furthermore, polymorph Form B is metastable at room temperature. Methods and data for polymorph Forms A and B are provided.

[0049] The term "raw TBPT" or "TBPT raw material" according to the present disclosure refers to TBPT as a crude product. "Raw TBPT" or "TBPT raw material" can be obtained from a production process that produces a product with a higher level of impurities. The TBPT raw material can include TBPT in crystalline Form A. DETAILED DESCRIPTION

[0050] Thus, in a first aspect, the present invention relates to a composition comprising TBPT and a first impurity consisting of one or more halogen-containing triazines and a second impurity consisting of biphenyl, wherein the amount of the first impurity is equal to or less than 900 ppm by weight relative to the total weight of the composition, and wherein the amount of the second impurity is equal to or less than 4000 ppm by weight relative to the total weight of the composition.

[0051] Both the first and second impurities, but particularly the second impurity, biphenyl, are byproducts of a commonly used TBPT production process, such as that described in US 2004 / 0191191 A1. Both impurities contain aromatic entities, which are known to increase the risk of diseases such as cancer. Therefore, a first aspect of the present invention provides a composition comprising TBPT having lower levels of such impurities than achieved in the prior art.

[0052] Therefore, preferably, the halogen-containing triazine of the first impurity of the composition of the first aspect of the present invention is selected from the group consisting of chlorine-containing triazines, bromine-containing triazines and mixtures thereof. Halogen-containing triazines such as chlorine-containing triazines and bromine-containing triazines include 1,3,5-triazines, in particular phenyl-substituted 1,3,5-triazines such as 2,4,6-triphenyl or biphenyl-substituted 1,3,5-triazines such as 2,4-di([1,1'-biphenyl]-4-yl), wherein one or more hydrogen atoms are replaced by halogen atoms such as chlorine or bromine, for example, on the 1,3,5-triazine ring or the phenyl ring. In various embodiments, the first impurity is more preferably 1,3,5-triazine, 2,4,6-tris(4-bromophenyl) and / or 1,3,5-triazine, 2,4-bis([1,1′-biphenyl]-4-yl)-6-chloro (BBCT), and most preferably 1,3,5-triazine, 2,4-bis([1,1′-biphenyl]-4-yl)-6-chloro (BBCT).

[0053] Particularly preferably, the amount of the first impurity in the composition of the first aspect of the present invention is equal to or less than 800 ppm by weight, more preferably equal to or less than 600 ppm by weight, and most preferably equal to or less than 400 ppm by weight relative to the total weight of the composition. If the composition is used in a cosmetic product, this further reduces the risk of disease.

[0054] In a preferred embodiment of the first aspect of the present invention, the amount of the first impurity in the composition of the present invention is equal to or greater than 0.01 ppm by weight relative to the total weight of the composition, preferably equal to or greater than 0.1 ppm by weight relative to the total weight of the composition, more preferably equal to or greater than 1 ppm by weight, still more preferably equal to or greater than 10 ppm by weight and most preferably equal to or greater than 100 ppm by weight.

[0055] It should be understood that the amounts of first impurities given above may refer to the total amount of all compounds that qualify as halogen-containing triazines within the meaning of the present invention, or to the more specifically defined first impurities described herein. In various embodiments, the amount may also refer to one of the more specifically defined first impurities defined above, such as 1,3,5-triazine, 2,4,6-tris(4-bromophenyl) and / or 1,3,5-triazine, 2,4-bis([1,1′-biphenyl]-4-yl)-6-chloro (BBCT). However, it may be preferred that the maximum amount of first impurities given encompasses the total amount of all compounds that qualify as halogen-containing triazines. These amounts may also be combined such that the total amount of halogen-containing triazines is equal to or less than 900 ppm by weight, relative to the total weight of the composition, and the amount of a specific impurity, such as 1,3,5-triazine, 2,4-bis([1,1′-biphenyl]-4-yl)-6-chloro (BBCT), is equal to or less than 400 ppm by weight.

[0056] For the same reasons as explained above for the first impurity, preferably, the amount of the second impurity in the composition of the first aspect of the invention is equal to or less than 3000 ppm by weight, more preferably equal to or less than 600 ppm by weight, and most preferably equal to or less than 300 ppm by weight relative to the total weight of the composition.

[0057] In a further preferred embodiment of the first aspect of the invention, the amount of the second impurity in the composition is equal to or greater than 0.01 ppm by weight, more preferably equal to or greater than 0.1 ppm by weight, still more preferably equal to or greater than 1 ppm by weight, and even more preferably equal to or greater than 10 ppm by weight, and most preferably equal to or greater than 100 ppm by weight, relative to the total weight of the composition.

[0058] In the production process for TBPT, as described in US 2004 / 0191191 A1, aromatic solvents are typically used. These aromatic solvents can be condensed aromatic systems. Examples of such solvents include benzene, toluene, xylene, ethylbenzene, naphthalene, fluorene, and mixtures thereof. However, these aromatic compounds can also be problematic in view of the health effects associated with the use of TBPT-containing compositions in cosmetic products. Therefore, the present invention further aims to reduce the amount of these solvents in TBPT-containing compositions.

[0059] Therefore, preferably, the composition according to the first aspect of the present invention further comprises a third impurity comprising, preferably consisting of, an aromatic hydrocarbon, wherein the third impurity does not comprise biphenyl. This means that the third impurity may comprise or consist of an aromatic hydrocarbon. Preferably, the one or more aromatic hydrocarbons are selected from the group consisting of monocyclic aromatic hydrocarbons, polycyclic aromatic hydrocarbons (PAHs), and mixtures thereof, preferably from the group consisting of alkyl-substituted benzene compounds (Cn-benzenes), condensed aromatic hydrocarbons, and mixtures thereof, more preferably from the group consisting of benzene, toluene, xylene, ethylbenzene, naphthalene, fluorene, and mixtures thereof, and most preferably xylene.

[0060] In a preferred embodiment of the first aspect of the present invention, the amount of the third impurity in the composition is equal to or lower than 4000 ppm by weight, preferably equal to or lower than 800 ppm by weight, and more preferably equal to or lower than 400 ppm by weight, relative to the total weight of the composition. Preferably, the amount of the third impurity in the composition of the present invention is equal to or higher than 5 ppm by weight, preferably equal to or higher than 10 ppm by weight, and more preferably equal to or higher than 20 ppm by weight, relative to the total weight of the composition.

[0061] Similar to the definition of the amount of the first impurity given above, it should be understood that the amount of the third impurity can refer to the compound that meets the third impurity, that is, the total amount of all compounds that are aromatic hydrocarbons in the sense of the present invention, or to the more specifically defined third impurity described herein. In various embodiments, the amount can therefore also refer to one of the more specifically defined third impurities defined above, such as xylene. However, it may be preferred that the given maximum amount of the third impurity covers the total amount of all compounds that meet the aromatic hydrocarbons. These amounts can also be combined so that the total amount of aromatic hydrocarbons is equal to or less than 4000 ppm by weight relative to the total weight of the composition, and the amount of a specific impurity such as xylene is equal to or less than 400 ppm by weight.

[0062] Preferably, the composition according to the first aspect of the invention comprises TBPT in an amount ranging from 98.0 to 99.9 wt-%, more preferably ranging from 98.5 to 99.9 wt-%, relative to the total weight of the composition.

[0063] Due to the method of the third aspect of the invention described in further detail below, the composition of the first aspect of the invention may comprise an additional compound, such as a solvent (S1), wherein the additional compound is soluble in water at a pressure of 5 mbar p B1 The boiling point B1 is at a temperature equal to or lower than 235°C, preferably at a temperature equal to or lower than 230°C. B1 Furthermore, preferably, the additional compound is at a pressure p of 1 bar. B2 The boiling point B2 is equal to or higher than 230°C, preferably 235°C. B2 It is preferred, but not necessarily required, that the additional compound is at a temperature T in the range of 100°C to 235°C, preferably in the range of 150°C to 230°C. S 5 wt-% to 50 wt-% TBPT relative to the total weight of the additional compound can be dissolved.

[0064] Preferably, the additional compound is selected from the group consisting of esters, triglycerides, vegetable oils, modified vegetable oils, carbonates, hydrocarbons (preferably excluding aromatic hydrocarbons as a third impurity), alcohols, ethers, and mixtures thereof, preferably the additional compound is a linear or branched, preferably linear, saturated or unsaturated, preferably saturated C6-C 50 Fatty acids, preferably C6-C 25 Esters of fatty acids.

[0065] Preferred esters are selected from the group consisting of myristate, palmitate, benzoate, laurate and mixtures thereof.

[0066] A preferred myristate ester is isopropyl myristate.

[0067] A preferred palmitic acid ester is isopropyl palmitate.

[0068] Preferred benzoates are selected from the group consisting of: Benzoic acid C 12-C15 Alkyl esters, dipropylene glycol dibenzoate, methyl gluceth-20 benzoate, and mixtures thereof.

[0069] Especially preferred esters are selected from the group consisting of: benzoic acid C 12-15 Alkyl Esters, Caprylyl Caprylate / Caprylate, Cetearyl Ethylhexanoate, Cetearyl Isononanoate, Cetyl Palmitate, Coco-Caprylate, Coco-Caprylate / Caprate, Coco-Caprylate / Caprate, Decyl Oleate, Oleyl Oleate, Dibutyl Adipate, Ethylhexyl Palmitate, Ethylhexyl Stearate, Hexyl Laurate, Hexyldecyl Stearate, Isopropyl Stearate, Octyl Stearate, Isopropyl Myristate, Isopropyl Palmitate, Myristyl Myristate, Oleyl Erucate, Propylene Glycol Dicaprylate / Dicaprate, Propylheptyl Caprylate, PEG-7 Glyceryl Cocoate, Cetearyl Isononanoate, and mixtures thereof.

[0070] Preferred ethers are dicaprylyl ether and PPG-15 stearyl ether.

[0071] Preferred alcohols are selected from the group consisting of octyldodecanol, hexyldecanol, oleyl alcohol, and mixtures thereof.

[0072] Preferably, the hydrocarbon is selected from the group consisting of hydrogenated polyisobutene, undecane, tridecane, dioctylcyclohexane, and mixtures thereof.

[0073] Preferred triglycerides are selected from the list consisting of caprylic / capric triglyceride, caprylic / capric triglyceride, cocoglycerides, and mixtures thereof.

[0074] Preferred vegetable oils are butyrospermum parkii oil, elaeis guineensis (palm) oil, passionflower (passiflora incarnata) seed oil, shoreastenoptera butter, and mixtures thereof.

[0075] Preferably, the modified vegetable oil is selected from the group consisting of shea butter and olive oil.

[0076] Most preferably, the additional compound is isopropyl palmitate (IPP).

[0077] Furthermore, it has surprisingly been found that TBPT occurs in two crystalline polymorphic forms, referred to herein as polymorphs A and B or (crystalline) forms A and B. Crystalline form A can be distinguished from crystalline form B by X-ray powder diffraction spectroscopy. It has been observed that the quantitative ratio of the two crystalline forms varies depending on the conditions used during the production of TBPT. Furthermore, it has been observed that crystalline form A, in particular, exhibits thermal stability at temperatures between approximately 15°C and 45°C. Thus, while crystalline form B also exhibits a long storage time, crystalline form A of TBPT has improved storability compared to crystalline form B. Furthermore, due to the specific UV filter properties, namely the UV absorption spectrum of form A (see Figure 7 ), Form A of TBPT is suitable for sunscreen applications.

[0078] Thus, in the second aspect of the present invention, the composition preferably comprises at least a portion, preferably all, of the TBPT in crystalline form A, which exhibits in its X-ray powder diffraction pattern at room temperature using Cu-Ka radiation at least three of the following five reflections, given as 2θ values: 11.6 ± 0.2, 17.8 ± 0.2, 21.1 ± 0.2, 23.4 ± 0.2, and 24.4 ± 0.2 °θ. More preferably, the crystalline form A exhibits in its X-ray powder diffraction pattern at room temperature using Cu-Ka radiation at least three of the following reflections: 11.6 ± 0.2, 17.8 ± 0.2, and 21.1 ± 0.2 °θ, and preferably at least five of the following reflections: 11.6 ± 0.2, 17.8 ± 0.2, 21.1 ± 0.2, 23.4 ± 0.2, and 24.4 ± 0.2 °θ.

[0079] It has been found that Form A provides an optimal UV absorption spectrum for sunscreen applications compared to Form B, also found as a metastable polymorph of TBPT (see Figure 7). Thus, it is beneficial to have a majority of the TBPT present in the composition in Form A. Thus, preferably, the amount of TBPT in the composition in crystalline Form A is greater than 50 wt-%, preferably greater than 60 wt-%, greater than 65 wt-%, greater than 70 wt-%, greater than 75 wt-%, greater than 80 wt-%, greater than 81 wt-%, greater than 82 wt-%, greater than 83 wt-%, greater than 84 wt-%, greater than 85 wt-%, greater than 86 wt-%, greater than 87 wt-%, greater than 88 wt-%, greater than 89 wt-%, greater than 90 wt-%, greater than 91 wt-%, greater than 92 wt-%, greater than 93 wt-%, greater than 94 wt-%, greater than 95 wt-%, greater than 96 wt-%, greater than 97 wt-%, greater than 98 wt-%, greater than 99 wt-%, and most preferably 100 wt-%, relative to the total weight of TBPT in the composition.

[0080] Preferably, the crystalline form A exhibits an endothermic peak from 221°C to 256°C in a DSC curve, wherein the DSC curve is measured by a differential scanning calorimeter at a scanning rate of 10°C / min (see Figure 1 ). More preferably, the crystalline form A exhibits an endothermic peak from about 221°C to about 256°C in the DSC curve, further preferably wherein the enthalpy ΔH measured at the endothermic peak is in the range of about 35 J / g to about 50 J / g, more preferably wherein the enthalpy ΔH measured at the endothermic peak is in the range of about 38 J / g to about 45 J / g.

[0081] It has further been found that polymorphic forms A and B interconvert with each other. The transition temperature between these two forms is in the range of 230°C to 250°C. Heating TBPT to this high temperature induces a phase transition from the low-temperature stable form A to the high-temperature stable form B. These two forms are presumably an interconverting system of polymorphic forms, but the transition is not readily reversed upon cooling.

[0082] Form A is suitable for sunscreen applications due to its specific UV absorption properties. However, biphenyl and xylene in the TBPT raw material are problematic aromatic hydrocarbons due to toxicological concerns. Significant impurity reduction through multiple recrystallizations from xylene or from xylene / biphenyl mixtures is not possible because the low-temperature stable Form A readily incorporates small amounts of almost any solvent. However, further purification of the TBPT raw material is necessary, at least for therapeutic or personal care applications (e.g., sunscreen applications).

[0083] Thus, in a third aspect, the present disclosure provides a method for purifying a composition comprising 1,3,5-triazine, 2,4,6-tris[1,1'-biphenyl]-4-yl (TBPT): a) providing (in a TBPT providing step) an unpurified composition, wherein the unpurified composition comprises TBPT and at least a first impurity and a second impurity consisting of biphenyl, the first impurity consisting of one or more halogen-containing triazines; b) suspending (in a suspending step) the unpurified composition in a solvent (S1) to provide a first suspension; c) heating (in a heating step) the first suspension to a temperature T1 to provide a heated first suspension or first solution of TBPT in the solvent (S1); d) maintaining (in a temperature maintaining step) the heated first suspension or first solution of TBPT at a temperature T2 between 100°C and 235°C and a pressure p1; e) cooling (in a cooling step) the heated first suspension or the first solution to a temperature T3 to allow crystallization; f) The crystals are separated (in a separation step) from the solution to obtain a purified composition.

[0084] Generally, the method of the third aspect of the present invention can be used to purify any starting TBPT. However, the method is preferably carried out using a composition comprising TBPT prepared using a method involving biphenyl and / or xylene. Therefore, in the method according to the third aspect of the present invention, the TBPT-providing step preferably further comprises reacting 2,4,6-trihalogen-1,3,5-triazine with biphenyl. More preferably, the step of reacting 2,4,6-trihalogen-1,3,5-triazine with biphenyl comprises the following steps: a') reacting cyanuric chloride with biphenyl in heptane at a temperature ranging from about 90°C to about 120°C after adding hydrochloric acid and aluminum chloride; b') removing heptane from the reaction mixture under reduced pressure; and c') adding water, sodium hydroxide, and xylene to the reaction mixture.

[0085] Preferably, the step of reacting 2,4,6-trihalo-1,3,5-triazine with biphenyl further comprises one or more of the following optional steps:

[0086] d') optionally separating the organic phase from the aqueous phase and washing the organic phase with water, separating the organic phase from the aqueous phase and completely removing water from the organic phase by azeotropic distillation, heating the suspension at a temperature of about 130° C. to about 160° C.,

[0087] e') optionally filtering the suspension at a temperature of about 130°C to about 160°C, cooling the filtrate to a temperature of about 40°C to about 60°C and allowing TBPT to crystallize, isolating the product by filtration, washing the filtered product with a solvent (S2) and drying the product to obtain raw material TBPT.

[0088] Preferably, in the step of reacting 2,4,6-trihalogen-1,3,5-triazine with biphenyl, 2,4,6-trihalogen-1,3,5-triazine is cyanuric chloride. Further preferably, in the step of reacting 2,4,6-trihalogen-1,3,5-triazine with biphenyl, a solvent is used in the reaction mixture. In another preferred embodiment, the solvent is a non-polar solvent. In particular, a C1-C3 alkyl, alkyl-aryl ether, alkyl-alkyl ether containing C1-C3 alkyl radicals can be used. 20 A linear, branched, or cyclic aliphatic or aromatic hydrocarbon of carbon atoms, optionally substituted with an alkoxy, halide, or carbonyl moiety. In a preferred embodiment, a linear aliphatic hydrocarbon is used, most preferably hexane. The step of reacting 2,4,6-trihalo-1,3,5-triazine with biphenyl can be carried out in the absence of a solvent such as 1,2-dichlorobenzene.

[0089] In one embodiment, a catalyst is used in the step of reacting 2,4,6-trihalo-1,3,5-triazine with biphenyl. The catalyst can act as a Lewis acid. The catalyst can be selected from the group consisting of acid halides, metal alkyls and alkoxides, protic acids, acidic oxides, cation exchange resins, and mixtures thereof, preferably selected from the group consisting of AlCl3, AlBr3, BF3, BCl3, BBr3, BeCl2, CdCl2, ZnCl2, GaCl3, GaBr3, FeCl3, SbCl3, BiCl3, TiCl4, ZrCl4, SnCl4, UCl4, SbCl5, and mixtures thereof. In preferred embodiments, the catalyst is used in a stoichiometric amount or in excess. Co-catalysts include alcohols, water, HCl, HF, H2SO4, H2PO4, RCOOH (organic acid), and sulfonic acids (such as p-toluenesulfonic acid). Most preferably, gaseous HCl is used as a co-catalyst. The co-catalyst can also be used in a stoichiometric amount or in excess. The step of reacting 2,4,6-trihalogen-1,3,5-triazine with biphenyl works particularly well when gaseous HCl is discharged into the reaction mixture. Preferably, in the step of reacting 2,4,6-trihalogen-1,3,5-triazine with biphenyl, the reaction temperature is from about -10°C to about 250°C, more preferably from about 5°C to about 150°C, and most preferably from about 70°C to about 130°C.

[0090] Furthermore, the step of reacting 2,4,6-trihalo-1,3,5-triazine with biphenyl can be carried out in an ionic fluid such as, for example, 1-butyl-pyridinium chloride-aluminum chloride (HI) and 1-butyl-3-methylimidazolium chloride-aluminum chloride (HI) (see, for example, 1-ethyl-3-methylimidazolium halogenoaluminate ionic liquids as solvents for Friedel-Crafts acylation reactions of ferrocene. Journal of the Chemical Society, Dalton Transactions: Inorganic Chemistry 1999 (1), 63).

[0091] Preferably, in the method according to the third aspect of the present invention, the TBPT providing step further comprises treating the unpurified composition with a second solvent (S2) (see step e'). Furthermore, preferably, the separation step of the method according to the third aspect of the present invention further comprises filtering and washing the crystals with at least one second solvent (S2).

[0092] In a preferred embodiment of the third aspect of the present invention, the second solvent (S2) is immiscible with water, preferably a hydrocarbon solvent, more preferably selected from the list consisting of toluene, mesitylene, xylene, and mixtures thereof. These additional steps further improve the purity of the product in view of the first and second impurities contained in the unpurified composition.

[0093] In the method according to the third aspect of the invention, the suspending step preferably comprises the step of adding the unpurified composition to the suspension in an amount ranging from 5 wt-% to 50 wt-% relative to the total weight of the first suspension.

[0094] In another preferred embodiment of the third aspect of the present invention, in the heating step, the temperature T1 is in the range of 100° C. to 235° C., preferably in the range of 150° C. to 230° C. Similarly, preferably, in the third aspect of the present invention, in the temperature maintaining step, the pressure p1 is maintained in the range of 5 mbar to standard pressure, preferably 900 mbar to standard pressure.

[0095] Preferably, in the method according to the third aspect of the present invention, in the cooling step, the temperature T3 is in the range of 40° C. to 60° C. This ensures optimal crystallization conditions for TBPT.

[0096] As already mentioned above, in the methods known from the prior art, it is not possible to significantly reduce impurities by multiple recrystallizations from xylene or from a xylene / biphenyl mixture, because the low-temperature stable form A readily incorporates small amounts of almost any solvent. These small amounts of solvent cannot be removed from the crystals by other means such as evaporation. However, it has now been found that in the method of the third aspect of the present invention, the problematic compounds (i.e., the first impurity, the second impurity, and optionally the third impurity) can be removed by replacement with the solvent (S1).

[0097] Preferably, the solvent (S1) is at a pressure p of 5 mbar. B1 The boiling point B1 is equal to or lower than 235°C, preferably equal to or lower than 230°C. B1 In addition, preferably, the solvent (S1) is at a pressure of 1 bar p B2 The boiling point B2 is equal to or higher than 230°C, preferably 235°C. B2 It is preferred, but not necessarily required, that the solvent (S1) is at a temperature T in the range of 100°C to 235°C, preferably in the range of 150°C to 230°C. S 5 wt-% to 50 wt-% of TBPT relative to the total weight of the solvent (S1) can be dissolved.

[0098] Alternatively, preferably, the solvent (S1) complies with cosmetic regulations. The liquid is listed as an "emollient" and / or "solvent" in the International Nomenclature Cosmetic Ingredients Dictionary and Handbook (INCI).

[0099] The solvent (S1) is preferably selected from the group consisting of esters, triglycerides, vegetable oils, modified vegetable oils, carbonates, hydrocarbons (preferably excluding aromatic hydrocarbons as third impurities), alcohols, ethers, and mixtures thereof, preferably the solvent (S1) is a linear or branched, preferably linear, saturated or unsaturated, preferably saturated C6-C 50 Fatty acids, preferably C6-C 25 Esters of fatty acids.

[0100] Preferred esters are selected from the group consisting of myristate, palmitate, benzoate, laurate and mixtures thereof.

[0101] A preferred myristate ester is isopropyl myristate.

[0102] A preferred palmitic acid ester is isopropyl palmitate.

[0103] Preferred benzoates are selected from the group consisting of: Benzoic acid C 12-C15 Alkyl esters, dipropylene glycol dibenzoate, methyl gluceth-20 benzoate, and mixtures thereof.

[0104] Especially preferred esters are selected from the group consisting of: benzoic acid C 12-15 Alkyl Esters, Caprylyl Caprylate / Caprylate, Cetearyl Ethylhexanoate, Cetearyl Isononanoate, Cetyl Palmitate, Coco-Caprylate, Coco-Caprylate / Caprate, Coco-Caprylate / Caprate, Decyl Oleate, Oleyl Oleate, Dibutyl Adipate, Ethylhexyl Palmitate, Ethylhexyl Stearate, Hexyl Laurate, Hexyldecyl Stearate, Isopropyl Stearate, Octyl Stearate, Isopropyl Myristate, Isopropyl Palmitate, Myristyl Myristate, Oleyl Erucate, Propylene Glycol Dicaprylate / Dicaprate, Propylheptyl Caprylate, PEG-7 Glyceryl Cocoate, Cetearyl Isononanoate, and mixtures thereof.

[0105] Preferred ethers are dicaprylyl ether and PPG-15 stearyl ether.

[0106] Preferred alcohols are selected from the group consisting of octyldodecanol, hexyldecanol, oleyl alcohol, and mixtures thereof.

[0107] Preferably, the hydrocarbon is selected from the group consisting of hydrogenated polyisobutene, undecane, tridecane, dioctylcyclohexane, and mixtures thereof.

[0108] Preferred triglycerides are selected from the list consisting of caprylic / capric triglyceride, caprylic / capric triglyceride, cocoglycerides, and mixtures thereof.

[0109] Preferred vegetable oils are shea butter, oil palm (palm) oil, passionflower seed oil, sallow tartar oil, and mixtures thereof.

[0110] Preferably, the modified vegetable oil is selected from the group consisting of shea butter and olive oil.

[0111] Most preferably, the solvent (S1) is isopropyl palmitate (IPP).

[0112] The isopropyl palmitate filtrate can be used several times before it is recovered. Recovery methods: (1) distillation, or (2) washing with aqueous base or acid, or (3) adsorption of impurities using specific absorbents like charcoal or silica gel or zeolite or activated carbon or cellulose or diatomaceous earth or kieselgur or other siliceous sedimentary rocks, or a combination of (1), (2) and (3). Adsorbents are usually used in the form of spherical pellets, rods, moldings, or monoliths with a hydrodynamic radius between 0.25 mm and 5 mm. They must have high abrasion resistance, high thermal stability and small pore size, which leads to a higher exposed surface area and therefore a high adsorption capacity.

[0113] The procedure can also be performed at higher concentrations using a TBPT suspension (14%-50% TBPT).

[0114] Solvent residues of halogenated hydrocarbons (US 2004 / 191191) can be removed by using the method of the third aspect of the present invention. When TBPT is synthesized without a solvent (US 2004 / 191191), biphenyl residues can be removed by using the method of the third aspect of the present invention. Furthermore, when TBPT is synthesized without AlCl₃, biphenyl residues can be removed by using the method of the third aspect of the present invention.

[0115] The particle size distribution (PSD) of TBPT crystals is controlled by the nucleation and growth rates during crystallization, which are in turn influenced by the supersaturation in the crystallizer. Therefore, to manage PSD and impurities during crystallization, the supersaturation, nucleation rate, and growth rate in the crystallizer must be considered. Further control of PSD can be achieved through the addition of seed crystals. Finally, the PSD of TBPT can be readily adjusted by grinding the product or by Ostwaldt ripening in a TBPT suspension.

[0116] In a fourth aspect, the present invention provides a cosmetic product comprising a composition according to the first aspect of the invention, preferably wherein TBPT is present in crystalline Form A in micronized form.

[0117] In a fifth aspect, the present invention provides the use of a composition according to the first aspect of the invention as a UV filter in a cosmetic product for protecting the hair and / or skin of a subject from the damaging effects of UV radiation.

[0118] Examples

[0119] The present invention is further illustrated by the following examples.

[0120] List of abbreviations

[0121] DSC Differential Scanning Calorimetry

[0122] PXRD powder X-ray diffraction spectrometry

[0123] GC gas chromatography

[0124] HPLC high performance liquid chromatography

[0125] Flame Ionization Detector (FID)

[0126] DAD diode array detector

[0127] g grams

[0128] min

[0129] h hours

[0130] T temperature

[0131] K Kelvin

[0132] °C degrees Celsius

[0133] ΔH enthalpy change

[0134] J Joule

[0135] m meters

[0136] L rise

[0137] k thousand

[0138] mmm

[0139] µ

[0140] TBPT1,3,5-Triazine, 2,4,6-tris[1,1'-biphenyl]-4-yl

[0141] BBCT2,4-Bis([1,1′-biphenyl]-4-yl)-6-chloro-1,3,5-triazine

[0142] approx.

[0143] PSD particle size distribution

[0144] method

[0145] a) Characterization of TBPT polymorphs

[0146] DSC experiments were performed in an open pan. In this case, volatile solvents and impurities evaporated irreversibly. Scan rate: 10 K / min, 20°C–300°C, N₂ 50 ml / min. Instrument: DSC3+ module, Mettler-Toledo or equivalent. PXRD patterns were recorded using a PANalytical X Pert Pro X-ray diffractometer (Bragg-Brentano) using Cu Kα radiation in reflection geometry. The sample was placed in a silicon single crystal sample holder at a depth of 0.2 mm and gently and precisely flattened. The tube voltage was 45 kV and the current was 40 mA. PXRD data were collected at room temperature over the 2θ range of 3.0°–40.0° with 0.017° increments and a measurement time of 20 s / step. PXRD data were analyzed using HighScore Plus 4.9 (Malvern Panalytical BV). Peak picking was performed using the following parameters: minimum significance: 7.00, minimum cap width: 0.01° 2θ, maximum cap width: 1.00° 2θ, peak base width: 2.00° 2θ, and peak tops were smoothed.

[0147] b) Quantification of impurities

[0148] GC analysis was used for the quantification of 2-propanol, xylene (mixture of isomers), biphenyl, and isopropyl palmitate. Instrument: Agilent 6850-2 GC. Column: Agilent HP-5, 30 m x 320 µm x 0.25 µm. Oven temperature: 70°C for 3 min, 50 K / min → 300°C; 300°C for 5 min. Sample preparation: Complete dissolution of the sample in 1,4-dioxane at 80°C (filter the turbid solution after cooling to 20°C). Detector: FID. Calibration was performed using external standards of 2-propanol, xylene (mixture of isomers), biphenyl, and isopropyl palmitate. HPLC analysis was used for the quantification of TBPT and BBCT. Instrument: Agilent 1200 HPLC. Column: Phenomenex C18 / 5 µm, 150 mm length. Oven temperature: 40°C. Injection volume: 5 µL. Eluent: 900 parts acetonitrile + 50 parts tetrahydrofuran + 50 parts water (isocratic elution). Sample preparation: Dissolve the sample completely in tetrahydrofuran. Detector: DAD. Calibration was performed using external standards of TBPT and BBCT.

[0149] c) UV absorption

[0150] The UV spectra of micronized TBPT forms A and B were recorded as described in WO 2004 / 085412 A1 (Example 7: Preparation of micronized UV absorbers).

[0151] Therefore, d(50) is the average particle size. In the case of UV absorbers for cosmetics, the spectral range between 290 nm and 400 nm is of greatest interest. The wavelength of the extinction maximum can be searched for, and the extinction value at this wavelength is taken to characterize the absorptive capacity of the substance. Using the Beer-Lambert law, the molar decimal extinction coefficient at any wavelength is obtained, where:

[0152] (I)

[0153] The corresponding specific extinction E1,1(λ) can be obtained by

[0154] The equation is obtained:

[0155] (II)

[0156] Where M = molecular weight of the UV absorber.

[0157] d) Solubility of TBPT

[0158] The measurement is performed in a three-necked flask with a stirrer and reflux condenser. The solvent is heated to the specified temperature under inert gas. TBPT is added to the solvent in small portions at the specified temperature. If the crystals dissolve within the next ten minutes, additional product is added until the product no longer dissolves within 10 minutes. The solubility is calculated from the amount of solvent and the amount of TBPT that can be dissolved at the specified temperature. The mixture is then heated to the next temperature to be tested, and the process is repeated until the end point of the analysis temperature is reached.

[0159] Reference Example RE1 – Preparation of 1,3,5-Triazine, 2,4,6-tris[1,1'-biphenyl]-4-yl (TBPT)

[0160] Suitable materials for the reactor / container include, for example, Hastelloy C, enameled steel, or glass. 207 kg of cyanuric chloride, 2080 kg of biphenyl (melted), and 340 kg of heptane are placed in a container (T = 105°C-110°C). 21 kg of gaseous hydrochloric acid is metered in below the surface of the stirred mixture (T = 105°C-110°C). At 110°C, 300 kg of aluminum chloride is added in batches depending on the temperature development. After the final aluminum chloride addition, which lasts for approximately 4 hours, the reaction mixture is stirred at 110°C-114°C for approximately one hour until the reaction is complete. The heptane is then removed by distillation under vacuum (≥ 100 mbar). The reaction mixture is hydrolyzed by carefully adding it to a mixture of 2500 kg of water, 135 kg of sodium hydroxide, and 1670 kg of xylene at 85°C. The mixture was stirred at 85°C-90°C for approximately 30 minutes until complete hydrolysis. The lower aqueous phase was separated from the organic product suspension at 90°C. The organic phase (suspension) was then washed with 1000 kg of water at 90°C. After separation of the aqueous phase, the organic phase (suspension) was dried by azeotropic distillation under vacuum. The water was completely removed from the suspension. The yellow suspension was heated to 143°C-150°C, dissolving the product and obtaining a turbid solution. Hot filtration was performed to remove traces of insoluble impurities. The orange to brown solution was cooled to 40°C over 4 hours to obtain crystalline TBPT. The product was isolated by filtration, washed with 2000 kg of xylene, and dried under vacuum at 100°C-140°C.

[0161] Comparative Examples CE1-3: Conventional Purification of TBPT

[0162] Purification of TBPT starting materials was performed in a Büchi glass oven Kugelrohr (BÜCHI Labortechnik AG, 9230 Flawil, Switzerland).

[0163] CE1: 1-5 g of TBPT starting material, synthesized according to the synthetic procedure of RE1, was heated under reduced pressure (<100 mbar, 1-22 h) until it became liquid (melting point approximately 285°C). Volatile impurities were removed, and the product solidified until cooled to room temperature. The longer the product was heated, the darker it became.

[0164] CE2: 1-5 g of TBPT starting material synthesized according to the synthetic procedure of RE1 was heated under reduced pressure (<100 mbar, 8-24 h) until it did not melt at 245-255°C. Volatile impurities were removed.

[0165] CE3: 1-5 g of TBPT starting material synthesized according to the synthetic procedure of Example 1 was heated under reduced pressure (<10 mbar, 22 h) to 240° C. without melting. Volatile impurities were removed.

[0166] Inventive Example IE1: Purification of TBPT

[0167] The TBPT starting material synthesized according to the synthetic procedure of RE1 was mixed with isopropyl palmitate (approximately 13% TBPT). The suspension was heated to 220°C (approximately 10 mbar) under vacuum. During this process, xylene and biphenyl were removed. At 220°C-223°C, the isopropyl palmitate was distilled off and the TBPT concentration was increased to approximately 15%. The stirred solution was slowly cooled to 50°C, causing the product to crystallize. The product was filtered at 50°C, washed with isopropyl alcohol, and dried at 100°C-140°C.

[0168] Inventive Example IE2: Solubility of TBPT in Solvent (S1) (w / w%)

[0169] According to the test method as described above, the solubility of TBPT at different temperatures was studied for several solvents (S1). The corresponding results are plotted in Tables 8 to 13.

[0170] Table 8: Phenethyl benzoate (CAS 94-47-3, benzoic acid, 2-phenylethyl ester)

[0171]

[0172] Table 9: Isopropyl myristate (CAS 110-27-0, tetradecanoic acid, 1-methylethyl ester)

[0173]

[0174]

[0175] Table 10: White mineral oil (petroleum, Pionier 2071 white oil)

[0176]

[0177] Table 11: Polydecene (Nexbase 2008)

[0178]

[0179] Table 12: Isopropyl Palmitate (CAS 142-91-6, Palmitic Acid, Isopropyl Ester)

[0180]

[0181] Table 13: Oleic acid (CAS 112-80-1, 9-octadecenoic acid (9Z)-)

[0182]

[0183]

[0184] result

[0185] Quantification of impurities

[0186] Table 1: Overview of the purity in % and the impurity contents in ppm of 2,4-bis([1,1′-biphenyl]-4-yl)-6-chloro-1,3,5-triazine (BBCT), biphenyl, and xylene for the corresponding examples. (**Contains 0.34% isopropyl palmitate, 0.1% 2-propanol).

[0187]

[0188] In CE1-3 and IE1, the concentrations of impurities such as xylene, toluene, 1,1′-biphenyl, and BBCT were reduced after purification, with IE1 showing the highest purity.

[0189] Characterization of TBPT polymorphs

[0190] DSC measurements

[0191] Table 2: Comparative ΔH of DSC endothermic peaks at 221°C-256°C and 282°C-293°C.

[0192]

[0193]

[0194] PXRD measurements

[0195] Table 3: Polymorph types determined based on DSC and PXRD data (*may contain residues of polymorph A. Complete conversion can be achieved by prolonged thermal treatment).

[0196]

[0197] In CE1-3, polymorph A transforms into polymorph B due to high temperature. Only polymorph A transforms into polymorph B due to its specific UV absorption characteristics (see Figure 7 ) and is suitable for sunscreen applications. In addition, polymorph B is metastable at room temperature.

[0198] XRD peak

[0199] Table 4: PXRD peaks of RE1

[0200]

[0201]

[0202] Table 5: PXRD peaks of CE3

[0203]

[0204]

[0205] Table 6: PXRD peaks of CE2

[0206]

[0207]

[0208] Table 7: PXRD peaks of TBPT pure batch IE1

[0209]

[0210]

Claims

1. A composition comprising 1,3,5-Triazine, 2,4,6-tris[1,1'-biphenyl]-4-yl (TBPT), and a first impurity consisting of one or more halogen-containing triazines, and A second impurity consisting of biphenyl, wherein the amount of the first impurity is equal to or less than 900 ppm by weight relative to the total weight of the composition, and wherein the amount of the second impurity is equal to or less than 4000 ppm by weight relative to the total weight of the composition, in, Optionally, more than 80 wt-%, preferably more than 90 wt-%, more preferably more than 95 wt-%, and most preferably 100 wt-% of the TBPT is contained in the composition in the form of crystalline form A, which exhibits in an X-ray powder diffraction pattern at room temperature (20°C) using Cu-Kα radiation at 2θ values ​​at least 3 of the following 5 reflections: 11.6 ± 0.2, 17.8 ± 0.2, 21.1 ± 0.2, 23.4 ± 0.2 and 24.4 ± 0.2 °θ, preferably at least three of the following reflections: 11.6 ± 0.2, 17.8 ± 0.2 and 21.1 ± 0.2 °θ, and more preferably at least five of the following reflections: 11.6 ± 0.2, 17.8 ± 0.2, 21.1 ± 0.2, 23.4 ± 0.2 and 24.4 ± 0.2 °θ.

2. The composition according to claim 1, wherein (1) the amount of the first impurity is equal to or less than 800 ppm by weight, preferably equal to or less than 600 ppm by weight, and more preferably equal to or less than 400 ppm by weight, relative to the total weight of the composition; and / or (2) The halogen-containing triazine is selected from chlorine-containing triazines, bromine-containing triazines, and mixtures thereof, preferably 1,3,5-triazine, 2,4,6-tris(4-bromophenyl) and / or 1,3,5-triazine, 2,4-bis([1,1′-biphenyl]-4-yl)-6-chloro(BBCT), and most preferably 1,3,5-triazine, 2,4-bis([1,1′-biphenyl]-4-yl)-6-chloro(BBCT).

3. The composition according to claim 1 or 2, wherein The amount of the second impurity in the composition is equal to or less than 3000 ppm by weight, preferably equal to or less than 600 ppm by weight, and more preferably equal to or less than 300 ppm by weight, relative to the total weight of the composition.

4. The composition according to any one of claims 1 to 3, wherein The composition further comprises a third impurity comprising, preferably consisting of, an aromatic hydrocarbon, wherein the third impurity does not comprise biphenyl, wherein the amount of the third impurity in the composition is equal to or lower than 4000 ppm by weight, preferably equal to or lower than 800 ppm by weight, and more preferably equal to or lower than 400 ppm by weight, relative to the total weight of the composition.

5. The composition according to claim 4, wherein The aromatic hydrocarbon is selected from the group consisting of monocyclic aromatic hydrocarbons, polycyclic aromatic hydrocarbons (PAH), and mixtures thereof, preferably selected from the group consisting of alkyl-substituted benzene compounds (Cn-benzene), condensed aromatic hydrocarbons, and mixtures thereof, more preferably selected from the group consisting of benzene, toluene, xylene, ethylbenzene, naphthalene, fluorene, and mixtures thereof, and most preferably xylene.

6. A composition according to any one of the preceding claims, wherein The composition further comprises an additional compound, wherein the additional compound With a pressure p at 5 mbar B1 At a temperature T equal to or lower than 230°C B1 below the boiling point B1, and / or With a pressure p at 1 bar B2 At a temperature equal to or higher than 230°C B2 below the boiling point B2, and / or 5 wt-% to 50 wt-% of TBPT, relative to the total weight of the further compound, can be dissolved at a temperature TS in the range of 150° C. to 230° C., The additional compound is preferably a solvent (S1), which is selected from esters, triglycerides, vegetable oils, modified vegetable oils, carbonates, hydrocarbons other than the aromatic hydrocarbons of the third impurity, alcohols, ethers, and mixtures thereof, more preferably linear or branched, preferably linear, saturated or unsaturated, preferably saturated C6-C 50 Esters of fatty acids.

7. A composition according to any one of the preceding claims, wherein At least a portion of the TBPT, preferably all of the TBPT, is contained in the composition in crystalline form A, which crystalline form A exhibits in an X-ray powder diffraction pattern at room temperature using Cu-Kα radiation at least three of the following five reflections given as 2θ values: 11.6 ± 0.2, 17.8 ± 0.2, 21.1 ± 0.2, 23.4 ± 0.2 and 24.4 ± 0.2 °θ.

8. A method for purifying a composition comprising 1,3,5-triazine, 2,4,6-tris[1,1'-biphenyl]-4-yl (TBPT): a) providing an unpurified composition comprising TBPT, at least a first impurity consisting of one or more halogen-containing triazines, and a second impurity consisting of biphenyl; b) suspending the unpurified composition in a solvent (S1) to provide a first suspension; c) heating the first suspension to a temperature T1, thereby providing a heated first suspension or first solution of TBPT in the solvent (S1); d) maintaining the heated first suspension or first solution of TBPT at a temperature T2 between 100° C. and 235° C. and a pressure p1; e) cooling the heated first suspension or the first solution to temperature T3 to allow crystallization; and f) separating the crystals from the solution to obtain a purified composition.

9. The method according to claim 8, wherein Step a) comprises the step of reacting 2,4,6-trihalo-1,3,5-triazine with biphenyl.

10. The method according to claim 8 or 9, wherein: Step a) further comprises the step of treating the unpurified composition with a second solvent (S2).

11. The method according to any one of claims 8 to 10, wherein In step d), the pressure p1 is maintained in the range from 5 mbar to standard pressure, preferably from 900 mbar to standard pressure.

12. The method according to any one of claims 8 to 11, wherein The solvent (S1) has a pressure p at 5 mbar B1 At a temperature T equal to or less than 230°C B1 below the boiling point and / or having a pressure p at 1 bar B2 At a temperature equal to or higher than 230°C B2 and / or at a temperature T in the range of 100°C to 235°C, preferably in the range of 150°C to 230°C. S 5 wt-% to 50 wt-% TBPT relative to the total weight of the additional compound can be dissolved.

13. A cosmetic product comprising the composition according to any one of claims 1 to 7, preferably wherein the TBPT is present in crystalline form A in micronized form.

14. Use of a composition according to any one of claims 1 to 7 as a UV filter in a cosmetic product for protecting the hair and / or skin of a subject from the damaging effects of UV radiation.

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