EP4638538A1

EP4638538A1 - Liquid rheology control agent

Info

Publication number: EP4638538A1
Application number: EP23837223.9A
Authority: EP
Inventors: Florian FRIESE; Nico HEITZER; Alexander GERS-BARLAG; René NAGELSDIEK; Christiane KNAPPKE-BONGARTZ; Sylvia Bühne; André TIEMANN
Original assignee: BYK Chemie GmbH
Current assignee: BYK Chemie GmbH
Priority date: 2022-12-21
Filing date: 2023-12-20
Publication date: 2025-10-29
Also published as: JP2026502150A; WO2024133435A1; CN120303314A; KR20250112841A

Abstract

The invention deals with a composition comprising a liquid carrier which is liquid at a temperature of 20° C, a component having a number average molecular weight Mn in the range of 400 g/mol to 30000 g/mol and having at least one urea group, dissolved in the liquid carrier, and a urea compound having a molecular weight below 350 g/mol dissolved in the liquid carrier.

Description

LIQUID RHEOLOGY CONTROL AGENT The invention relates to a composition comprising a liquid carrier which is liquid at a temperature of 20° C, a component having a number average molecular weight Mn in the range of 400 g/mol to 30000 g/mol and having at least one urea group, dissolved in the liquid carrier, and a urea compound having a molecular weight below 350 g/mol dissolved in the liquid carrier. It further relates to the use of the composition for controlling the rheology of a liquid composition, a liquid composition, and a coated article. In the field of coating materials, adhesives, sealants, and molding compounds, as well as oil- drilling fluids and the like, it is necessary to customize the rheological properties of such liquid systems, primarily through adjusting the viscosity. This can for example be done by the selection of binding agents, solvents, and the concentration of pigments and/or fillers. Often, the addition of so-called rheology additives to these liquids is required. The effect of these additives lays in adjusting the rheological properties of the system, like the viscosity and the viscoelastic properties. By doing so, the system properties are usually improved with respect to sag resistance, improved storage stability (due to reduced settling of solid particles), or a general increase in viscosity, often referred to as “thickening”. The rheology of liquid systems is often controlled using clays, e. g., bentonites, and/or silicas, which may optionally be organically modified, hydrogenated castor oil, and polyamide waxes. A disadvantage of these rheology control auxiliaries is that they are mostly dry solids, which must be processed to a semi-finished form using solvents and shear forces, and/or introduced into the liquid system by means of targeted temperature control. Non-observance of these temperatures and/or appropriate incorporation conditions can lead not only to poor rheological performance, but also to detrimental properties of the products. In case the liquid systems are coating compositions, these rheology control auxiliaries frequently lead to instances of clouding and haze in clear, transparent coatings. Moreover, operating with dry, powderous products, which cause dusts during processing, may be technologically unfavorable. A liquid application alternative to these rheology control auxiliaries is provided by solutions of particular urea components as described for example in EP 1188779 A. Alternatively, instead of classical organic diluents, ionic liquids can be used as described in DE 102008059702 A. A further aspect, which should be noted in connection with rheology control auxiliaries provided in liquid form, is the storage stability thereof. For instance, prolonged storage times or elevated storage stress, for example in the case of storage with temperature variations, can lead to reduced storage stability, accompanied by reduced efficacy in the target systems. Therefore, it is desirable that rheology control auxiliaries have a good storage stability and will not easily precipitate or gelate on storage. To prevent early precipitation on storage from happening, small amounts of salts, especially halides such as LiCl are usually added, which act as a stabilizer. Since salts also give rise to numerous issues in application performance, especially in the case of halides such as LiCl, these ionic compounds have negative effects on properties such as influence on corrosion caused by the coating system, resistance of the coated material against environmental effects, discoloration, whitening, pollution, or conductivity. All these parameters mentioned above limit the choice of adequate preparations. The choice of suitable rheology control auxiliaries is therefore difficult since these especially have to be compatible with the later application systems and need to comply with a multiplicity of requirements. They have to show not only an improved rheological activity in the application system, but also a broad compatibility in application-relevant formulations. There is still an ongoing need to provide improved rheology additives. Using the improved rheology additive should lead to very reliable and increased thickening effects in various formulations while storage stability of these rheology control auxiliaries needs to be favorable. Moreover, the rheology additive should show a reduced influence on the discoloration of the application system, for example when added to a clear coat. Thus, it is a particular object of the present invention to provide a high-quality rheology control agent of good effectiveness, which is employable in numerous application systems. More particularly, the intention was to find rheology control agents resulting in a pronounced anti-sag behavior. Another object of the invention was to provide a rheology control agent that leads to an improved storage stability and a further object of the invention is to provide a rheology control agent which is essentially devoid of salts. Another object of the invention was to provide a rheology control agent, which leads to lesser discoloration when incorporated into the application system. Surprisingly, it has been found that these objectives can be achieved by a composition comprising a liquid carrier which is liquid at a temperature of 20 °C, a component having a number average molecular weight Mn in the range of 400 g/mol to 30000 g/mol and having at least one urea group, dissolved in the liquid carrier, and a urea compound having a molecular weight below 350 g/mol dissolved in the liquid carrier. In one embodiment, the component having a number average molecular weight Mn in the range of 400 g/mol to 30000 g/mol and having at least one urea group comprises a urea- urethane-compound. In another embodiment, the component comprises molecules containing at least one urea group and at least one urethane group. In another embodiment, the component comprises molecules containing at least one urea group and at least two urethane groups. In another embodiment, the component comprises molecules containing at least two urea groups; in a different embodiment the component comprises two urea and two urethane groups; in yet another embodiment, the component comprises molecules containing at least four urea or more than four urea groups. In a different embodiment, the component comprises molecules containing at least two urea groups and at least two urethane groups. In a different embodiment of the invention, urethane groups may even be absent. Suitably, urea-based compounds according to claim 11 of WO 2015/158407, claim 13 of WO 2015/158407, claim 16 of WO 2015/158407 and claim 1 of EP 1396510 A1 are employed. A preferred class of the component having a number average molecular weight Mn in the range of 400 g/mol to 30000 g/mol and having at least one urea group can be described according to the following general formula (U-1) R31-[R33-Z-R34-W-]_n-R32 (U-1) where R31 and R32 independently of one another and independently of each occurrence represent a branched or unbranched, saturated or unsaturated organic group which contains 1 to 100 carbon atoms and which has not more than one urea group each and not more than one urethane group each, R33 and R34 independently of one another and independently of each occurrence represent branched or unbranched polyester groups containing 1 to 300 carbon atoms and optionally containing ether groups, branched or unbranched polyether groups containing 2 to 300 carbon atoms, branched or unbranched polyamide groups containing 1 to 300 carbon atoms, polysiloxane groups containing 3 to 100 silicon atoms, branched or unbranched C2 to C22 alkylene groups, branched or unbranched C2 to C22 cycloalkylene groups branched or unbranched C2 to C18 alkenylene groups, C6 to C12 arylene groups and/or branched or unbranched C7 to C22 arylalkylene groups, Z and W independently of one another and independently in case of multiple occurrences represent NH—CO—O and/or NH—CO—NH, n represents an integer from 1 to 150, preferably 2 to 150, in case of multiple occurrences of n, n independently represents an integer from 1 to 150, preferably 2 to 150. In another preferred embodiment the component is selected from the general formulas (U- 2a), (U-2b), (U-2c), (U-2d), and (U-2e). where AM is selected from a linear or branched, saturated or unsaturated, aliphatic, cycloaliphatic, aromatic or aliphatic-aromatic organic group having 2 to 50 C atoms, in case of multiple occurrences of AM, AM is independently selected from a linear or branched, saturated or unsaturated, aliphatic, cycloaliphatic, aromatic or aliphatic-aromatic organic group having 2 to 50 C atoms, AM1 and AM2 independently of one another and independently in case of multiple occurrences represent a linear or branched, saturated or unsaturated, aliphatic, aromatic or aliphatic-aromatic organic group having 1 to 50 C atoms, IC1 and IC2 independently of one another and independently in case of multiple occurrences represent a linear or branched, saturated or unsaturated, aliphatic, aromatic or aliphatic- aromatic hydrocarbon organic group having 2 to 40 C atoms, IC3 represents a linear or branched, saturated or unsaturated, aliphatic, aromatic or aliphatic-aromatic hydrocarbon organic group having 2 to 24 carbon atoms, in case of multiple occurrences of IC3, IC3 independently represents a linear or branched, saturated or unsaturated, aliphatic, aromatic or aliphatic-aromatic hydrocarbon organic group having 2 to 24 carbon atoms, IC4 is selected from a group as described for IC1 and IC2 or a urethane group containing segment having the structure -[IC2-NH-(C=O)-O-RP3-O-(C=O)-NH-IC2]- in which RP3 represents a linear or branched, saturated or unsaturated, aliphatic, aromatic or aliphatic-aromatic organic group having 2 to 24 C atoms and/or a (poly)ether group having 1 to 120 ether oxygen atoms and/or a polyamide group having 1 to 100 amide groups and/or a polysiloxane group having 3 to 100 silicon atoms and/or a polyester group having 1 to 100 ester groups and optionally containing ether groups, in case of multiple occurrences of RP3, RP3 independently represents a linear or branched, saturated or unsaturated, aliphatic, aromatic or aliphatic-aromatic organic group having 2 to 24 C atoms and/or a (poly)ether group having 1 to 120 ether oxygen atoms and/or a polyamide group having 1 to 100 amide groups and/or a polysiloxane group having 3 to 100 silicon atoms and/or by polyester group having 1 to 100 ester groups and optionally containing ether groups. RP1 and RP2 independently of one another and independently in case of multiple occurrences represent a linear or branched, saturated or unsaturated, aliphatic, aromatic or aliphatic-aromatic organic group having 1 to 24 C atoms and/or a polyether group having 1 to 120 ether oxygen atoms and/or a polyester group having 1 to 100 ester groups and optionally containing ether groups, and/or a polyamide group having 1 to 100 amide groups, and/or a polysiloxane group having 3 to 100 silicon atoms, RP3 represents a linear or branched, saturated or unsaturated, aliphatic, aromatic or aliphatic-aromatic organic group having 2 to 24 C atoms and/or a (poly)ether group having 1 to 120 ether oxygen atoms and/or a polyamide group having 1 to 100 amide groups and/or a polysiloxane group having 3 to 100 silicon atoms and/or a polyester group having 1 to 100 ester groups and optionally containing ether groups, in case of multiple occurrences of RP3, RP3 independently represents the above mentioned groups and m is an integer from 0 to 20, preferably from 1 to 20, more preferably from 1 to 5. p represents 0 and/or 1. q is an integer from 0 to 20. Preferably, the component having a number average molecular weight Mn in the range of 400 g/mol to 30000 g/mol and having at least one urea group has a structure according to formula (U-2a) in which RP1 is selected from a hydrocarbyl group having 4 to 24 carbon atoms or a polyether segment having up to 50 alkylene oxide repeating units, preferably a segment Q-(O-AO)_r in which Q is a C1 to C18 alkyl or alkenyl group, AO is a group C2H4 or C3H6 and r is an integer of 2 to 35, IC1 and IC2 are preferably selected from one of the following bivalent groups (with “*” indicating the connection sites) . and in which AM is selected from a group C₂H₄, C₃H₆, C₄H₈, C₅H_10, C₆H₁₂, C₆H_10, –CH₂-C₆H₄-CH₂- or a group in which Rx and Ry represent H or CH3. In a very preferred embodiment of (U-2a), IC1 and/or IC2 are selected from Even more preferably, IC1 and IC2 are selected from In a very preferred embodiment of (U-2a), AM is selected from C₂H₄ and –CH₂-C₆H₄-CH₂- . In a very preferred embodiment of (U-2a), m is an integer from 0 to 10. In a special embodiment, m is an integer from 1 to 5. In another embodiment, m is 0. In another preferred embodiment, the component having a number average molecular weight Mn in the range of 400 g/mol to 30000 g/mol and having at least one urea group has a structure according to formula (U-2b) in which the preferred embodiments of IC1 and IC2 are as described for (U-2a), in particular a group C7H6 or a group -C6H4-CH2-C6H4- , AM1 and AM2 are selected from a linear or branched, saturated or unsaturated C1 to C24 alkyl or alkenyl group or a group C6H5-CH2- , and RP3 is selected from a hydrocarbyl group having 2 to 20 carbon atoms or a polyether segment having 1 to 40 ether oxygen atoms, preferably a polyether segment comprising 1 to 30 ethylene oxide and/or propylene oxide based repeating units. In a further preferred embodiment, the component has a structure according to formula (U- 2c) in which the preferred embodiments of AM1 and AM2 are as described for (U-2b), the preferred embodiments of AM are as described for (U-2a), and IC4 is selected from a group as described for IC1 and IC2 or a urethane group containing segment having the structure -[IC2-NH-(C=O)-O-RP3-O-(C=O)-NH-IC2]- in which IC2 is defined as described for (U-2a) and RP3 is defined as described for (U-2b). For (U-2c), it is particularly preferred that IC4 is selected from a group C₇H_6, a group -C₆H₄- CH₂-C₆H₄-, and a group -[IC2-NH-(C=O)-O-RP3-O-(C=O)-NH-IC2]- in which IC2 represents a group C₇H₆ or a group -C₆H₄-CH₂-C₆H₄- and RP3 represents a polyether segment comprising 1 to 30 ethylene oxide and/or propylene oxide based repeating units. In a preferred embodiment of (U-2c), q is an integer from 0 to 15, even more preferably from 0 to 7 and most preferably from 0 to 4, like from 1 to 4. In a preferred embodiment, at least 50 wt. % of the component having a number average molecular weight Mn in the range of 400 g/mol to 30000 g/mol and having at least one urea group have a structure according to formula (U-2a) or (U-2c). In a very preferred embodiment, at least 50 wt. % of all components having a number average molecular weight Mn in the range of 400 g/mol to 30000 g/mol and having at least one urea group have a structure according to formula (U-2a) and m is 0 or m is 1 to 5; very preferably, m is 0. In a preferred embodiment, the component having a number average molecular weight Mn in the range of 400 g/mol to 30000 g/mol and having at least one urea group is a urea urethane and 95 – 100% by weight of the component contain at least one molecule segment of the general formula (U-3a) —O—CO—NH—Y1—NH—CO—NH— (U-3a) where Y1 represents a saturated or unsaturated, branched or unbranched hydrocarbon group containing 6 to 20 carbon atoms, in case of multiple occurrences of Y1, Y1 independently represents a saturated or unsaturated, branched or unbranched hydrocarbon group containing 6 to 20 carbon atoms and in each case contains no molecule segment of the general formula (U-3b) —O—CO—NH—Y2—NH—CO—O— (U-3b) where Y2 represents a saturated or unsaturated, branched, or unbranched hydrocarbon group containing 6 to 20 carbon atoms. In case of multiple occurrences of Y2, Y2 independently represents a saturated or unsaturated, branched or unbranched hydrocarbon group containing 6 to 20 carbon atoms. The synthesis of the component having a number average molecular weight Mn in the range of 400 g/mol to 30000 g/mol and having at least one urea group may suitably take place directly in the presence of the liquid carrier and the urea compound having a molecular weight below 350 g/mol. In another embodiment, the component having a number average molecular weight Mn in the range of 400 g/mol to 30000 g/mol and having at least one urea group is synthesized in the presence of the liquid carrier and the urea compound having a molecular weight below 350 g/mol is added afterwards. In yet another embodiment, the component is synthesized in the presence of the urea compound having a molecular weight below 350 g/mol and the liquid carrier is added afterwards. In a further embodiment, the component having a number average molecular weight Mn in the range of 400 g/mol to 30000 g/mol and having at least one urea group is synthesized in the presence of the urea compound having a molecular weight below 350 g/mol and the liquid carrier, and a second liquid carrier different from the first one is added afterwards. The component having at least one urea group has a number average molecular weight of from 400 g/mol to 30000 g/mol. Preferably, the component has a number average molecular weight (Mn) of at least 400 g/mol, preferably at least 500 g/mol. More preferably, the number average molecular weight is above 600 g/mol, even more preferably above 650 g/mol, and most preferably above 800 g/mol. Furthermore, the number average molecular weight (Mn) of the component is preferably below 20000 g/mol, more preferably below 10000 g/mol, and most preferably below 8000 g/mol. Preferably, the number average molecular weight (Mn) is in the range of 650 g/mol to 20000 g/mol, more preferably in the range of 800 g/mol to 8000 g/mol, even more preferably in the range of 800 g/mol to 5000 g/mol. In a further preferred embodiment, the number average molecular weight is at least 800 g/mol, preferably 1000 g/mol, preferably at least 1500 g/mol, preferably in the range of 1500 g/mol to 20000 g/mol and more preferred in the range of 1500 g/mol to 8000 g/mol and even more preferred 1500 to 5000 g/mol. The number and weight average molecular weights can be determined by gel permeation chromatography (eluent: solution of lithium bromide (content 5 g/l) in dimethylacetamide, standard: polymethylmethacrylate, column temperature: 50 °C) according to DIN EN ISO 13885-2 (November 2021). Alternatively, the number average molecular weight may be determined by calculation. Additionally, the number average molecular weight for small molecules up to 1000 g/mol may be determined by other methods such as mass spectroscopy or nuclear magnetic resonance spectroscopy. Preferably, the component having a number average molecular weight Mn in the range of 400 g/mol to 30000 g/mol and having at least one urea group, dissolved in the liquid carrier is not cross-linked. A typical example of cross-linked components are elastomers. It is preferred that the component having at least one urea group does not contain any cross-linked sections, furthermore it is preferred that the component is not an elastomer or comprises elastomers. The composition according to the invention comprises a liquid carrier which is liquid at a temperature of 20 °C and 1013 mbar. It is preferred that the liquid carrier comprises at least one of 1-(2-hydroxyethyl)-2- pyrrolidone, N,N-dimethyl lactamide (2-hydroxy-N,N-dimethylpropanamide) or a polar aprotic solvent. It is more preferred that the liquid carrier is a polar aprotic solvent. Suitably the liquid carrier comprises a compound having at least one of a N-substituted amide group, and a sulfoxide group. Preferably, the liquid carrier comprises at least one of an amide group and a sulfoxide group, wherein the amide nitrogen of the amide group has two substituents, wherein the substituents are selected from aliphatic and aromatic groups. Suitably, the amide nitrogen of the amide group has two substituents, in this case the amide group cannot be an NH amide group. The liquid carrier suitably comprises at least one of a N-substituted cyclic amide, non-cyclic dialkyl amide of mono- and difunctional carboxylic acids, N-acyl morpholines, and sulfoxides. Suitable liquid carriers are for example N-substituted cyclic amides: N-alkyllactams, preferably N-alkyl butyrolactams, N-alkyl valerolactams, and N-alkyl caprolactams, wherein the alkyl groups suitably have 1 to 18 carbon atoms, more preferably 1 to 12 carbon atoms, even more preferably 1 to 8 carbon atoms), as well as hydroxyalkyllactams (e.g., hydroxyethylpyrrolidone) and N-cycloalkyllactams. Cyclic amides are amides wherein the amide nitrogen and amide carbonyl carbon are part of the cyclic structure. Suitable examples of N-alkylbutyrolactams are N-methylbutyrolactam, N-ethylbutyrolactam, N-butylbutyrolactam, N-octylbutyrolactam and N-hydroxyethyl butyrolactam. N- cyclohexylbutyrolactam is a further suitable example. Suitable examples of N-substituted caprolactams are N-ethyl caprolactam, N-methyl caprolactam, N-butyl caprolactam, N-propyl caprolactam. Further suitable liquid carriers are non-cyclic dialkyl amides of mono- and difunctional carboxylic acids: N,N-dialkylamides of C1 to C18 monocarboxylic acids, bis(N,N- dialkyl)amides of C1 to C18 dicarboxylic acids; optionally these carboxylic acids comprise hydroxyl, ether or ester groups, such as N,N-dialkylamidoalkylesters, N,N-dialkylamidoalkyl ethers, N,N-dialkyllactamides. Sulfoxides are suitable as well, preferably dimethyl sulfoxide. Non-cyclic amides are amides wherein the amide nitrogen and amide carbonyl carbon are not both part of the cyclic structure. Under this definition e. g. N-formylmorpholine is considered to be a non-cyclic amide. Further suitable liquid carriers are non-cyclic amides that are available from reaction of diamines and monocarboxylic acids. Suitable examples are reaction products of C1 to C18 monocarboxylic acids and C2 to C12 alkylene diamines. Suitable liquid carriers are also linear amides, for example N,N-dimethylformamide, N,N- dimethylacetamide, N,N-dimethylamides of C3 to C18 monocarboxylic acids (preferably N,N- dimethylamides of C6 to C10 monocarboxylic acids), N,N-dialkylamidoalkylesters, N,N- dialkylamidoalkyl ethers, and acylmorpholines. Preferred examples of these are also N,N-dimethylamidoalkyl ester, N,N-dimethylamidoalkyl ether, N-formylmorpholine and N-acetylmorpholine. Further suitable liquid carriers are N-acetyl caprolactam, epsilon-caprolactam, and 2- pyrrolidone; preferably, they are used in combination with at least one further carrier comprising at least one of an amide group and a sulfoxide group. The composition according to the invention comprises a urea compound having a molecular weight below 350 g/mol dissolved in the liquid carrier. Preferably, the composition comprises the urea compound having a molecular weight below 350 g/mol in an amount in the range of 0.05 to 15.00 weight %, calculated on the total weight of the composition. More preferably, the composition comprises the urea compound in an amount in the range of 0.1 to 10.0 weight %, even more preferably 0.2 to 8.0 weight % and most preferably 0.25 to 7.00 weight %, calculated on the total weight of the composition, such as 0.3 to 6.0 weight % or 0.4 to 5.0 weight % In another embodiment, the composition comprises the urea compound having a molecular weight below 350 g/mol in an amount of less than 40 weight %, calculated on the total weight of the composition. It is preferred that the urea compound having a molecular weight below 350 g/mol comprises a structure according to formula (I) (I) HR1N-C(=O)-NR2R3 in which R1, R2, and R3 independently represent an organic group or hydrogen, or wherein R1 and R2 are linked to each other. Preferably, R1, R2 and R3 independently represent an organic group or hydrogen with the proviso that at least one of R1, R2 and R3 is an organic group. In a different embodiment R1, R2 and R3 independently represent an organic group or hydrogen with the proviso that R1 and R2 are linked to each other. In a further embodiment R1, R2 and R3 independently represent an organic group. In a preferred embodiment, two of the groups R1, R2, and R3 independently represent an organic group, while the third group represents hydrogen. In one preferred embodiment, R1 and R2 independently represent an organic group, while R3 represents hydrogen. In another preferred embodiment, R2 and R3 independently represent an organic group, while R1 represents hydrogen. In a further preferred embodiment, R1 represents an organic group, while R2 and R3 represent hydrogen. Preferably, the urea compound having a molecular weight below 350 g/mol contains one urea group. Suitably, the organic groups may comprise 1 to 8 carbon atoms. More suitably the organic groups may comprise 1 to 4 carbon atoms and most suitably 1 to 2 carbon atoms. In other embodiments the organic groups may additionally comprise hydroxyl groups, amine groups or a combination of the aforementioned. It is also preferred that urea compound having a molecular weight below 350 g/mol comprises a structure according to formula (I) HR1N-C(=O)-NR2R3 in which R1, R2 and R3 are independently organic groups consisting of the elements carbon and hydrogen having 1 to 8 carbon atoms, or hydrogen. In a preferred embodiment, two of the groups R1, R2, and R3 independently represent an organic group, while the third group represents hydrogen. In one preferred embodiment, R1 and R2 independently represent an organic group, while R3 represents hydrogen. In another preferred embodiment, R2 and R3 independently represent an organic group, while R1 represents hydrogen. In a further preferred embodiment, R1 represents an organic group, while R2 and R3 represent hydrogen. In one embodiment, R1, R2 and R3 are independently organic groups consisting of the elements carbon and hydrogen having 1 to 8 carbon atoms, or hydrogen with the proviso that at least one of R1, R2 and R3 is an organic group. Preferably, R1, R2 and R3 are independently organic groups consisting of the elements carbon and hydrogen having 1 to 8 carbon atoms. Suitably, the organic groups consisting of the elements carbon and hydrogen consist of 1 to 4 carbon atoms and most suitably of 1 to 2 carbon atoms. Preferably, the urea compound having a molecular weight below 350 g/mol comprises at least one of 2-imidazolidinone, 1,3-dimethyl urea, 1-(2-hydroxyethyl)imidazolidin-2-one,1- methyl urea, urea, biuret, N,N'-diethylurea, 1,1-dimethylurea, N-ethylurea, 1,3-diphenylurea, N-phenylurea, N-butylurea, 1,1-diethylurea, N-tert-butylurea, 3-methyl-1,1-diphenylurea, 1,1- dimethyl-3-phenylurea, N,N′-dicyclohexylurea, benzoyleneurea, N,N′-trimethyleneurea, or glycoluril. Preferably, the urea compound having a molecular weight below 350 g/mol comprises at least one of 2-imidazolidinone, 1,3-dimethyl urea, 1-(2-hydroxyethyl)imidazolidin-2-one,1- methyl urea, urea or biuret. It is preferred that the urea compound has a molecular weight from 55 to 349 g/mol. It is more preferred that the urea compound has a molecular weight from 55 to 310 g/mol. It is most preferred that the urea compound has a molecular weight from 55 to 280 g/mol, such as 55 to 250 g/mol. In another embodiment, it is preferred that the urea compound has a molecular weight from 72 to 349 g/mol. It is more preferred that the urea compound has a molecular weight from 72 to 310 g/mol. It is most preferred that the urea compound has a molecular weight from 72 to 280 g/mol, such as 72 to 250 g/mol. In another embodiment, it is preferred that the urea compound has a molecular weight from 84 to 349 g/mol. It is more preferred that the urea compound has a molecular weight from 84 to 310 g/mol. It is most preferred that the urea compound has a molecular weight from 84 to 280 g/mol, such as 84 to 250 g/mol. In one preferred embodiment, the urea compound has a molecular weight from 84 to 200 g/mol or from 84 to 150 g/mol. The urea compound having a molecular weight below 350 g/mol and the liquid carrier are preferably present in the composition in a weight ratio from 1 : 5 to 1 : 200. More preferably in a weight ratio from 1 : 7 to 1 : 150 and even more preferred from 1 : 8 to 1: 140, such as 1 : 10 to 1 : 120 , such as 1 : 12 to 1 : 80, or 1 : 12 to 1 : 50. Preferably, the amount of urea compound having a molecular weight below 350 g/mol compared to the total weight of urea compound having a molecular weight below 350 g/mol and liquid carrier is at least 0.5 % by weight, preferably at least 0.6 % by weight, more preferably at least 0.7% by weight, even more preferably at least 0.8 % by weight, such as at least 1.2 % by weight or at least 1.5 % by weight. Also preferably, the amount of urea compound having a molecular weight below 350 g/mol compared to the total weight of urea compound having a molecular weight below 350 g/mol and liquid carrier is at most 20.0 % by weight, preferably at most 14 % by weight, more preferably at most 12 % by weight, and at most 10 % by weight, such as at most 8 % by weight. Suitably, the amount of urea compound compared to the total weight of the urea compound having a molecular weight below 350 g/mol and liquid carrier is in the range of 0.5 % by weight to 20 % by weight, more suitably in the range of 0.7 % by weight to 14 % by weight, even more suitably 0.8 % by weight to 12 % by weight and most suitably 1.2 % by weight to 10 % by weight. In another suitable embodiment the amount of urea compound having a molecular weight below 350 g/mol compared to the total weight of the urea compound and liquid carrier is in the range of 1.5 % by weight to 8 % by weight. The weight ratio of the urea compound having a molecular weight below 350 g/mol and the component having a number average molecular weight Mn is in the range of 400 g/mol to 30000 g/mol and having at least one urea group is suitably from 1 : 2 to 1 : 100, more suitably from 1 : 3 to 1 : 80 and most suitably from 1 : 4 to 1 : 60, such as 1 : 5 to 1 : 40. Generally, the composition is a liquid at 23 °C and 1013 mbar. Generally, the composition may comprise one or more salts. The salts according to the present invention suitably comprise cations of elements of the main groups I and II of the Periodic Table of the Elements (alkali and alkaline earth metals) or ammonium ions and mixtures thereof. Preferred salts are such containing lithium, calcium or magnesium, particularly preferably lithium and calcium cations, preferably in chloride, acetate, and/or nitrate form. In some embodiments, the salts contain as anions preferably monovalent anions, particularly preferably halides, pseudohalides, formate, acetate and/or nitrate, most particularly preferably chloride, acetate and/or nitrate. The salts described herein generally do not have surface active properties. Salts having surface active properties fall under the definition of surfactants as described below. Particularly preferred as salts are inorganic lithium salts, such as lithium chloride or lithium nitrate, as well as ammonium salts. The composition suitably comprises from 0.01 to 15.00 weight-% of a salt, calculated on the total weight of the liquid carrier, the component having a number average molecular weight Mn in the range of 400 g/mol to 30000 g/mol and having at least one urea group, the urea compound, and the salt. Preferably, the composition comprises salt in an amount of 0.1 to 10.0 % by weight, more preferably 0.1 to 8.0 % by weight, even more preferably 0.1 to 5.0 % by weight and most preferably, 0.1 to 3.0 % by weight. In one preferred embodiment, the composition does not comprise a salt selected from lithium salts and halide salts or comprises such salts in low amounts. Low amounts are salt amounts that do not exceed 1.0% by weight, and it is more preferred that the amount does not exceed 0.5 % by weight, and it is more preferred that the amount does not exceed 0.3 % by weight, preferably not exceed 0.1 % by weight, calculated on the weight of the composition. In a further preferred embodiment, the composition does not comprise a salt. If the composition does not comprise a salt, it is preferred that the salt content does not exceed 0.50 % by weight, and it is more preferred that is does not exceed 0.30 % by weight, preferably not exceed 0.10 % by weight, for example not exceed 0.05% by weight, calculated on the weight of the composition. In another preferred embodiment, the composition does not comprise a salt but a surfactant. In even another preferred embodiment, the composition does not comprise a salt but comprises at least one of a surfactant and an ionic liquid. In some embodiments the composition further comprises a surfactant. Preferably, the salt in the composition may be substituted by surfactants. The surfactants may preferably substitute the salt completely or may be added in addition to salt. In the latter case, the surfactant may substitute the salt partially which leads to a reduced salt content, or the surfactant may be added in addition to the salt and the salt content remains unreduced. Suitable surfactants are anionic surfactants, e. g., sulfosuccinates, alk(en)yl sulfates, alk(en)yl ether sulfates, ester sulfonates, soaps, ether carboxylic acids; nonionic surfactants, e. g., alcohol alkoxylates, alkylglycosides, fatty acid ester alkoxylates, amine oxides, gemini surfactants; cationic surfactants, e. g., alkyl ammonium salts, such as tetraalkyl ammonium salts, quaternary ammonium salts, esterquats; amphoteric or zwitterionic surfactants, e. g., betaines, alkylamido betaines, imidazolines. Especially preferred are quaternary ammonium salts and sulfosuccinates. Suitably, the surfactants are employed in amounts of 0.1 to 15.0 % by weight, preferably 0.2 to 14.0 % by weight, more preferably 0.4 to 13.0 % by weight, even more preferably 0.5 to 12.0 % by weight, most preferably 0.8 to 11.0 % by weight, such as 1.0 to 10.0 % by weight, calculated on the total weight of the composition. In other embodiments, the composition further comprises an ionic liquid. Ionic liquids have a relatively high molecular weight and also an ionogenic character and hence are generally substantially or completely involatile and therefore can be regarded as free of volatile organic compounds. The term “ionic liquids” herein is to be understood as meaning organic salts or mixtures of organic salts which are liquid at room temperature (23° C) and 1013 mbar, wherein organic salts as well as salts in general are solid at 23 °C and 1013 mbar and have a crystal structure. The cations of the ionic liquids used are preferably based on ammonium, pyridinium, pyrrolidinium, pyrrolium, oxazolium, oxazolinium, imidazolium, thiazolium or phosphonium ions and also mixtures thereof. Particular preference is given to cations based on imidazolium and oxazolium ions. The anions are preferably selected from alkylsulfates, arylsulfates, sulfate, hydrogensulfate, phosphate, alkylphosphates, arylphosphates, tosylates, alkylborates, haloborates such as tetrafluoroborate for example, haloaluminates such as tetrachloroaluminate for example, carboxylates such as acetate and trifluoroacetate for example, perchlorate and also mixtures thereof.Alkylsulfates, tosylates and acetates are particularly preferred. Suitably, the composition comprises at least one ionic liquid having a cation selected from imidazolium and oxazolium, and having an anion selected from alkylsulfates, tosylates, tetrafluoroborates, and acetates. It is preferred that the composition comprises 0.05 – 40.00 weight-% of the urea compound having a molecular weight below 350 g/mol, 5.00 – 90.00 weight-% of the liquid carrier, 5.00 – 60.00 weight-% of the component having a number average molecular weight Mn in the range of 400 g/mol to 30000 g/mol and having at least one urea group, dissolved in the liquid carrier calculated on the total weight of the urea compound having a molecular weight below 350 g/mol, the liquid carrier and the component having a number average molecular weight Mn in the range of 400 g/mol to 30000 g/mol and having at least one urea group. In a particularly preferred embodiment, the composition comprises 0.1 – 15.0 weight-% of the urea compound having a molecular weight below 350 g/mol, 10.0 – 90.0 weight-% of the liquid carrier, 5.0 – 60.0 weight-% of the component having a number average molecular weight Mn in the range of 400 g/mol to 30000 g/mol and having at least one urea group, dissolved in the liquid carrier calculated on the total weight of the urea compound having a molecular weight below 350 g/mol, the liquid carrier and the component having a number average molecular weight Mn in the range of 400 g/mol to 30000 g/mol and having at least one urea group. In a more preferred embodiment, the composition comprises 0.2 – 12.0 weight-% of the urea compound having a molecular weight below 350 g/mol, 20.0– 90.0 weight-% of the liquid carrier, 7.0 – 55.0 weight-% of the component having a number average molecular weight Mn in the range of 400 g/mol to 30000 g/mol and having at least one urea group, dissolved in the liquid carrier calculated on the total weight of the urea compound having a molecular weight below 350 g/mol, the liquid carrier and the component having a number average molecular weight Mn in the range of 400 g/mol to 30000 g/mol and having at least one urea group. In another preferred embodiment, the composition comprises 0.3 – 10.0 weight-% of the urea compound having a molecular weight below 350 g/mol, 25.0– 90.0 weight-% of the liquid carrier, 9.7 – 50.0 weight-% of the component having a number average molecular weight Mn in the range of 400 g/mol to 30000 g/mol and having at least one urea group, dissolved in the liquid carrier calculated on the total weight of the urea compound having a molecular weight below 350 g/mol, the liquid carrier and the component having a number average molecular weight Mn in the range of 400 g/mol to 30000 g/mol and having at least one urea group. In another preferred embodiment, the composition comprises 0.4 – 9.0 weight-% of the urea compound having a molecular weight below 350 g/mol, 30.0– 85.0 weight-% of the liquid carrier, 14.6 – 45.0 weight-% of the component having a number average molecular weight Mn in the range of 400 g/mol to 30000 g/mol and having at least one urea group, dissolved in the liquid carrier calculated on the total weight of the urea compound having a molecular weight below 350 g/mol, the liquid carrier and the component having a number average molecular weight Mn in the range of 400 g/mol to 30000 g/mol and having at least one urea group. In another preferred embodiment, the composition comprises 0.5 – 8.0 weight-% of the urea compound having a molecular weight below 350 g/mol, 35.0– 84.5 weight-% of the liquid carrier, 15.0 – 40.0 weight-% of the component having a number average molecular weight Mn in the range of 400 g/mol to 30000 g/mol and having at least one urea group, dissolved in the liquid carrier calculated on the total weight of the urea compound having a molecular weight below 350 g/mol, the liquid carrier and the component having a number average molecular weight Mn in the range of 400 g/mol to 30000 g/mol and having at least one urea group. In another preferred embodiment, the composition comprises 0.7 – 7.5 weight-% of the urea compound having a molecular weight below 350 g/mol, 50.0– 80.0 weight-% of the liquid carrier, 15.0 – 40.0 weight-% of the component having a number average molecular weight Mn in the range of 400 g/mol to 30000 g/mol and having at least one urea group, dissolved in the liquid carrier calculated on the total weight of the urea compound having a molecular weight below 350 g/mol, the liquid carrier and the component having a number average molecular weight Mn in the range of 400 g/mol to 30000 g/mol and having at least one urea group. In a special embodiment, the composition comprises at least two liquid carriers different from each other, with the proviso that one of the liquid carriers is dimethyl sulfoxide (DMSO) and the second liquid carrier is a liquid carrier comprising at least one of a di-aliphatic-substituted amide group. It is preferred that the weight amount of DMSO compared to the total weight of DMSO, the second liquid carrier comprising at least one of a di-aliphatic-substituted amide group, is at least 1%, preferably at least 2%, more preferably at least 5%, even more preferably at least 7%, most preferably at least 10%. It is also preferred that the weight amount of DMSO compared to the total weight of DMSO, the second liquid carrier comprising at least one of a di-aliphatic-substituted amide group is at most 60%, preferably at most 50%, more preferably at most 45%, even more preferably at most 40%, most preferably at most 35%, such as at most 30%. Additionally, the invention deals with the use of the composition for controlling the rheology of a liquid composition. The term “liquid composition” according to the present invention denotes a composition, being liquid at 23 °C and 1013 mbar. The composition of the present invention may be employed to control the rheology of various kinds of liquid compositions. Therefore, in one embodiment, the liquid composition may be an aqueous composition. The primary or even the only liquid diluting agent of a liquid aqueous composition is water. Additionally, the liquid aqueous composition may comprise certain amounts of organic diluents. The organic diluents are the same or different from the at least one liquid carrier. It is preferred that a liquid aqueous composition comprises less than 35% by weight, preferably less than 25% by weight, more preferably less than 20% by weight and most preferably less than 10% or even less than 5% by weight of organic diluents, calculated on the total weight of the liquid composition. In a special embodiment, the liquid aqueous composition does not contain organic diluents at all. In general, a liquid aqueous composition comprises at least 10%, preferably at least 15%, more preferably at least 20% by weight of water. In certain cases, a liquid aqueous composition can comprise at least 25%, more preferably at least 30% by weight of water. In general, a liquid aqueous composition comprises at most 90% by weight of water, such as up to 80% or up to 70% by weight. In special embodiments, the liquid aqueous composition comprises up to 95%, or even up to 97, 98, or 99% by weight of water. In another embodiment, the liquid composition may be a non-aqueous composition. A non- aqueous liquid composition is essentially free from water. That denotes a liquid composition suitably comprising water in an amount in the range of 0.0 to 10.0 % by weight, preferably in the range of 0.0 to 7.0 % by weight of water, calculated on the total weight of the liquid composition. More preferably, the non-aqueous liquid composition comprises less than 5.0 % by weight of water. For example, the liquid composition comprises less than 3.0 % by weight or less than 1.0% by weight of water, calculated on the total weight of the liquid composition. Suitably, the liquid composition is selected from a coating composition, a clear coat composition, a lacquer, a varnish, a plastic formulation, a pigment paste, an effect pigment paste, a polymer formulation, a sealant formulation, a cosmetic formulation, a homecare or industrial care formulation (including perfume and fragrance formulations), a ceramic formulation, an adhesive formulation, a liquid formulation for use in gas and oil production, a composition for the manufacture of electrical components and circuits, a liquid formulation for use in energy storage media, a cleaning agent, a potting compound, a building material formulation, a lubricant, a filling compound, a wax emulsion, a metalworking fluid, a metal- processing product, a liquid composition in the form of a spraying agent, a so-called deposition aid (e.g., for use in plant protection agents or for the general purpose of drift reduction), a ink, a printing ink and a ink jet ink or a composition that may be used as corrosion protection in the field of marine and protective coatings and mixtures thereof. Further liquid compositions wherein the composition according to the present invention can be used are solvent-based or solvent-free paints, printing inks and inks and lacquers as e. g., lacquers for varnishing of plastics, wire enamels, floor coatings, coating compositions for coating foodstuffs and seeds, and as so-called color resists, which are used for color filters, for example in flat panel displays such as liquid-crystal displays. The field of application lacquers also includes pasty materials which generally have a very high proportion of solids and a small proportion of liquid components, for example so-called pigment pastes or also pastes based on effect pigments, for example metal effect pigments such as, for example, aluminum pigments, silver pigments, brass pigments, zinc pigments, copper pigments, bronze pigments such as gold bronzes, fire-dyed bronzes or iron oxide aluminum pigments. The effect pigments also include, for example, interference pigments or pearlescent pigments such as, for example, metal oxide mica pigments, fish silver, bismuth oxide chloride or basic lead carbonate. The plastic formulations can be liquid or non-liquid starting materials to produce plastic materials, which are preferably converted into a duromer by a chemical cross-linking process ("curing"). Preferred plastic preparations are unsaturated polyester resins, vinyl ester resins, acrylate resins, epoxy resins, polyurethane resins, formaldehyde resins (such as melamine- formaldehyde or urea-formaldehyde). These can be cured under very different conditions, e.g. at room temperature (cold-curing systems) or at elevated temperature (hot-curing systems), optionally with application of pressure ("closed mold" application, sheet molding compound or bulk molding compound). The plastic formulations also include PVC plastisols. The cosmetic preparations can be various liquid compositions, which are used in the so- called personal care or healthcare sector, e.g., lotions, creams, pastes such as, for example, toothpaste, foams such as, for example, shaving foam, gels such as, for example, shaving gels, shower gels or active ingredients in gel formulations, hair shampoos, liquid soaps, nail varnishes, lipsticks and hair dyes. The so-called wax emulsions are preferably dispersions of solid waxes in particulate form at room temperature in water or an organic medium. The building material formulations may be liquid or paste-like materials, which are used in the construction sector and solidify after curing. Examples are hydraulic binders such as concrete, cement, mortar, tile glue and plaster. The metal working fluids may be cutting liquids, drilling fluids (such as are used in metal processing), or forging fluids or lubricants in general. Potential other areas are release agents (often in the form of aqueous emulsions, for example, aluminum die casting and foundry applications), foundry washes (foundry coatings) and liquids for the surface treatment of metals (for example "surface finishing", surface treatment and plating). The lubricants are means, which are used for lubrication, that is to say, which serve to reduce friction and wear, as well as to provide power, cooling, vibration dampening, sealing action and corrosion protection; liquid lubricants being preferred here. Cleaning agents can be used to clean a wide range of objects, for example in the area of homecare or industrial care. They effect or assist the removal of impurities, residues and attachments. The cleaners also include detergents (primarily for cleaning textiles, their precursors, leather, and dish), and personal care products. Formulations containing perfumes and other fragrances (either as liquid raw materials or in encapsulated form), e.g., as perfume gels, also belong to this area of application. Liquid formulations used for gas and oil production are formulations used to develop and exploit a deposit. Drilling fluids or “drilling muds” are preferred examples. Another application example are liquids used to prepare or perform a hydraulic fracturing process and liquids that support the production process of gas and oil. The adhesives can be all adhesive materials which are liquid under processing conditions, and which can join parts by surface adhesion and internal strength. The liquid compositions of the invention may further comprise customary additives. Examples of additives are antiblocking agents, stabilizers, antioxidants, pigments, wetting agents, dispersants, emulsifiers, additional rheology additives, UV absorbers, free-radical scavengers, slip additives, defoamers, adhesion promoters, leveling agents, waxes, nanoparticles, film-forming auxiliaries, and flame retardants. Preferred additives are wetting agents, dispersants and/or emulsifiers and rheology additive which are different from the composition of the present invention, such as clay-based thickeners (including organoclays), (poly)amides, polysaccharides (like cellulose derivatives, guar, xanthan), polyacrylates, or associative thickeners. In an example, the inventive composition can be used in combination with other thickeners affecting the low, medium, and/or high shear performance of the liquid composition that needs to be modified concerning its rheological behavior. In a further embodiment, the invention also relates to a process for controlling the rheology of a liquid composition comprising the steps of providing the composition according to the present invention, providing a liquid composition and mixing the composition according to the present invention and the liquid composition. Suitable liquid compositions are the liquid compositions as aforementioned amongst others. The step of mixing the components may be executed according to current processes known by the person skilled in the art. This may involve mixing by manual or electrical means inter alia. Mixing is combining the compositions and exerting shear force on the combined compositions. The invention further deals with a liquid composition comprising the composition according to the invention and a binder. Suitably binders comprise at least one of alkyd resins (such as short, medium, or long oil alkyd), unsaturated polyester resins, vinylester resins, acrylate resins, epoxy resins, polyurethane resins, polyaspartic resins, phenolic binders, silicones, chlorinated rubbers, vinyl based binders, poly(vinyl alcohol), poly(vinyl acetates), saturated polyester binders, polyacrylates and acrylate copolymers, urea and melamine resins, silicate binders, cellulose based binders, and silyl modified polymers. Preferred binders comprise at least one of alkyd resins (such as short, medium, or long oil alkyd), unsaturated polyester resins, vinylester resins, acrylate resins, epoxy resins, polyurethane resins, polyacrylates and acrylate copolymers, polyaspartic resins, and silyl modified polymers. These binders can preferably be solvent-borne, solvent-free, or aqueous binders. Solvent- borne and aqueous binders can be delivered both as solutions, emulsions, or dispersions. Therefore, the above-mentioned binders also comprise aqueous binder systems like styrene- acrylic dispersions, urethane-acrylic dispersions, and alkyd emulsions. The binders also comprise non-aqueous dispersion (NAD) systems. Another object of the invention is an article, wherein at least a part of the surface of the article is coated with the liquid composition. In a different embodiment, the coated article is obtainable by the steps of providing an article, providing the liquid composition according to the present invention and coating at least a part of the surface of the article with the liquid composition. Furthermore, in an even different embodiment the invention relates to a coated article, wherein at least a part of the surface of the article is coated with the liquid composition according to the present invention and wherein the liquid composition is hardened. In another embodiment, the coated article is obtainable by the steps of providing an article, providing the liquid composition according to the present invention, coating at least a part of the surface of the article with the liquid composition and hardening the liquid composition. Suitable articles are all three-dimensional objects, irrespective of their size and volume and whether they are mobile or immobile. Illustrative, but not limiting examples are building interiors and exteriors, flooring, furniture, vehicles used for transportation (like automobiles, bikes, boats, aircrafts, agricultural machines, and all kinds of freight vehicles), bridges and tunnels, machinery and production equipment, electrical devices, cans, metal coils, wires, containers, household articles and hardware, pulp and paper, as well as all kind of articles made of wood, metal, plastics or glass (e.g., for functional or ornamental use). The meaning of the wording “coating” is well-known to the person skilled in the art. In this context, it relates to the application of the liquid composition on the surface or other areas of said article to cover it at least partly or even encasing the article in its entirety. In this case, the liquid composition toughens or hardens after it has been applied to said article. Hardening means converting the liquid composition into a solid state. This can be achieved by evaporation of liquid diluents (physical drying) or by chemical crosslinking reaction (curing), and by combinations thereof. The invention is illustrated further below giving reference to examples. The choice of the respective reaction conditions, as e. g., the reaction temperature, reaction time and dosing rates are known to the skilled person and are illustrated in more detail in the working examples. Experimental part Preparation of intermediates Table 1: Explanation of Abbreviations Product name Chemical Composition TDI T80 80/20 mixture of 2,4-toluylene diisocyanate and 2,6-toluylene diisocyanate TDI T65 65/35 mixture of 2,4-toluylene diisocyanate and 2,6-toluylene diisocyanate TDI T100 2,4-toluylene diisocyanate Manufacture of Intermediates I1 to I3: Table 2: Intermediates Intermediate Mono alcohol Diisocyanate I1 butyl triglycol TDI T65 I2 polyethylene glycol monomethyl ether (hydroxyl TDI T80 number: 125 mg KOH/g) I3 1-dodecanol TDI T100 I4 Ethylene oxide/propylene oxide random copolymer TDI T100 mono butyl ether (hydroxyl number: 42 mg KOH/g, molar ratio of ethylene oxide to propylene oxide: 1 to 1) Intermediates I1 to I3: 2 mol of TDI T65, TDI T80, or TDI T100 respectively and 200 ppm benzoyl chloride were weighed into a glass flask equipped with stirrer, reflux condenser and nitrogen inlet and heated to 40 °C. Subsequently 1 mol of the mono alcohol (according to the above table 2) was added dropwise to the reaction mixture over a period of 30 min. The reaction mixture was stirred for additional 5 hours at 60 °C. A clear, light yellow, liquid crude intermediate containing excessive diisocyanate is obtained. The excessive diisocyanate contained in the crude reaction products obtained was removed by distillation, whereby intermediates I1 to I3 were obtained. Intermediate I4: 3.5 mol of TDI T100 and 200 ppm benzoyl chloride were weighed into a glass flask equipped with stirrer, reflux condenser and nitrogen inlet and heated to 40 °C. Subsequently 1 mol of the mono alcohol (according to the above table 2) was added dropwise to the reaction mixture over a period of 30 min. The reaction mixture was stirred for additional 5 hours at 60 °C. A clear, light yellow, liquid intermediate I4 is obtained. Examples General synthesis protocol (C1-C6, C9-C11, E1-E28, E30-E38): In a four-neck flask with stirrer, the liquid carrier and the stabilizing agent (urea compound having a molecular weight below 350 g/mol or lithium chloride) were heated up to 80 °C under nitrogen atmosphere under stirring. m-xylylenediamine was added and the mixture was homogenized. The intermediate I1, I3 or a mixture of intermediates I1 and I2 was added dropwise under stirring within 30 min in such a way that the temperature did not exceed 85°C. Afterwards the mixture was stirred for 3 hours at 80°C. The result is a transparent, yellowish product. The exact amounts are displayed in table 3. Liquid carrier and stabilizing agents are specified in table 4. Table 3: Inventive and non-inventive examples

Liquid Stabilizing Intermediate Intermediate Intermediate carrier agent MXDA I1 I2 I3 Example [g] [g] [g] [mmol] [g] [mmol] [g] [mmo [mmo l] [g] l] ^C1 LC1 75.0 3.61 26.5 21.40 53.0 ^C2 LC1 73.9 LiCl 1.06 3.61 26.5 21.40 53.0 ^C3 LC1 70.0 3.36 24.7 6.64 16.4 20.0 32.9 C4 LC1 69.1 LiCl 0.86 3.36 24.7 6.64 16.4 20.0 32.9 ^C5 LC1 80.0 3.14 23.1 16.9 46.2 ^C6 LC1 78.9 LiCl 1.15 3.14 23.1 16.9 46.2 C9 LC2 55.0 6.50 47.7 38.50 95.4 C10 LC3 70.0 4.33 31.8 25.70 63.6 C11 LC4 70.0 4.33 31.8 25.70 63.6 ^E1 LC1 72.5 S6 2.50 3.61 26.5 21.40 53.0 E2 LC1 70.0 S6 5.00 3.61 26.5 21.40 53.0 E3 LC1 72.5 S7 2.50 3.61 26.5 21.40 53.0 ^E4 LC1 70.0 S7 5.00 3.61 26.5 21.40 53.0 ^E5 LC1 67.5 S7 7.50 3.61 26.5 21.40 53.0 ^E6 LC1 70.0 S8 5.00 3.61 26.5 21.40 53.0 ^E7 LC1 67.5 S8 7.50 3.61 26.5 21.40 53.0 ^E8 LC1 72.5 S9 2.50 3.61 26.5 21.40 53.0 ^E9 LC1 70.0 S9 5.00 3.61 26.5 21.40 53.0 ^E10 LC1 67.5 S9 7.50 3.61 26.5 21.40 53.0 ^E11 LC1 74.0 S10 1.00 3.61 26.5 21.40 53.0 ^E12 LC1 73.5 S10 1.50 3.61 26.5 21.40 53.0 ^E13 LC1 67.5 S6 2.50 3.36 24.7 6.64 16.4 20.0 32.9 ^E14 LC1 65.0 S6 5.00 3.36 24.7 6.64 16.4 20.0 32.9 E15 LC1 67.5 S7 2.50 3.36 24.7 6.64 16.4 20.0 32.9 ^E16 LC1 65.0 S7 5.00 3.36 24.7 6.64 16.4 20.0 32.9 ^E17 LC1 62.5 S7 7.50 3.36 24.7 6.64 16.4 20.0 32.9 ^E18 LC1 67.5 S8 2.50 3.36 24.7 6.64 16.4 20.0 32.9 E19 LC1 65.0 S8 5.00 3.36 24.7 6.64 16.4 20.0 32.9 ^E20 LC1 62.5 S8 7.50 3.36 24.7 6.64 16.4 20.0 32.9 ^E21 LC1 67.5 S9 2.50 3.36 24.7 6.64 16.4 20.0 32.9 ^E22 LC1 65.0 S9 5.00 3.36 24.7 6.64 16.4 20.0 32.9 E23 LC1 62.5 S9 7.50 3.36 24.7 6.64 16.4 20.0 32.9 ^E24 LC1 69.5 S10 0.50 3.36 24.7 6.64 16.4 20.0 32.9 ^E25 LC1 69.0 S10 1.00 3.36 24.7 6.64 16.4 20.0 32.9 E26 LC1 68.5 S10 1.50 3.36 24.7 6.64 16.4 20.0 32.9 E27 LC1 75.0 S6 5.00 3.14 23.1 16.9 46.2 ^E28 LC1 75.0 S7 5.00 3.14 23.1 16.9 46.2 E30 LC2 50.0 S7 5.00 6.50 47.7 38.50 95.4 E31 LC2 50.0 S8 5.00 6.50 47.7 38.50 95.4 E32 LC3 65.0 S7 5.00 4.33 31.8 25.70 63.6 E33 LC3 65.0 S8 5.00 4.33 31.8 25.70 63.6 E34 LC4 65.0 S6 5.00 4.33 31.8 25.70 63.6 E35 LC4 65.0 S7 5.00 4.33 31.8 25.70 63.6 E36 LC4 65.0 S8 5.00 4.33 31.8 25.70 63.6 E37 LC4 65.0 S9 5.00 4.33 31.8 25.70 63.6 E38 LC4 69.0 S10 1.00 4.33 31.8 25.70 63.6 Table 4: List of liquid carrier and stabilizing agents 1-butylpyrrolidin-2-one LC1 DMSO (dimethyl sulfoxide) LC2 1-cyclohexylpyrrolidin-2-one LC3 1-ethylazepan-2-one LC4 Lithium chloride LiCl 2-imidazolidinone S6 1,3-dimethylurea S7 1-(2-hydroxyethyl)imidazolidin-2-one S8 1-methylurea S9 urea S10 Comparative Rheology Additive C7: In a four-neck flask with stirrer, 80.0 g of DMSO were heated to 80 °C under nitrogen atmosphere.1.68 g (28.0 mmol) ethane-1,2-diamine were added, and the mixture was homogenized.18.3 g of the intermediate I4 were added dropwise under stirring within 30 min in such a way that the temperature did not exceed 85 °C. Afterwards the mixture was stirred for 3 hours at 80°C. The result is a transparent, yellowish product. Comparative Rheology Additive C8: In a four-neck flask with stirrer, 1.22 g of lithium chloride were added to 78.8 g of DMSO under stirring. The mixture was heated up to 80 °C under nitrogen atmosphere. The lithium chloride was dissolved within 30 min under stirring.1.68 g (28.0 mmol) ethane-1,2-diamine were added, and the mixture was homogenized.18.3 g of the intermediate I4 were added dropwise under stirring within 30 min in such a way that the temperature did not exceed 85 °C. Afterwards the mixture was stirred for 3 hours at 80°C. The result is a transparent, yellowish product. Rheology Additive According to the Invention E29: In a four-neck flask with stirrer, 6.00 g of 1,3-dimethylurea were added to 74 g of DMSO under stirring. The mixture was heated up to 80°C under nitrogen atmosphere. The 1,3- dimethylurea was dissolved within 30 min under stirring.1.68 g (28.0 mmol) ethane-1,2- diamine were added, and the mixture was homogenized.18.3 g of the intermediate I4 were added dropwise under stirring within 30 min in such a way that the temperature did not exceed 85 °C. Afterwards the mixture was stirred for 3 hours at 80°C. The result is a transparent, yellowish product. Storage Stability 100 g of the inventive and non-inventive examples were stored at room temperature (23 °C) in a closed glass bottle until any optical changes became noticeable. Optical changes include gelling of the material and/or formation of precipitate. Table 5a: Results Group of Non-inventive and Storage Stability**: corresponding inventive examples*: examples I C1 2 days E1 7 weeks E2 7 weeks E3 4 weeks E4 9 weeks E5 9 weeks E6 3 weeks E7 3 weeks E8 4 weeks E9 19 weeks E10 33 weeks E11 4 weeks E12 4 weeks II C2 4 weeks E13 12 weeks E14 11 weeks E15 7 weeks E16 11 weeks E17 10 weeks E18 11 weeks E19 5 weeks E20 5 weeks E21 6 weeks E22 5 weeks E23 11 weeks E24 39 weeks E25 11 weeks E26 39 weeks III C7 3 months E29 12 months IV C10 3 days E32 3 weeks E33 7 weeks V C11 10 days E34 10 weeks E35 10 weeks E36 7 weeks E37 10 weeks E38 10 weeks *) The inventive and non-inventive examples sharing the same roman numeral are corresponding examples. The inventive examples comprise a liquid carrier and a stabilizing agent (urea compound having a molecular weight below 350 g/mol) whereas the corresponding non-inventive examples only contain the liquid carrier. The inventive example and corresponding non-inventive example contain the same amount of the component having a number average molecular weight Mn in the range of 400 g/mol to 30000 g/mol and having at least one urea group. **) Time between synthesis and formation of precipitate or gelation. From table 5a it is visible that the inventive examples E 1- 26, E 29 and E 32- 38 show a significantly increased storage stability compared to their corresponding non-inventive examples. The Hazen color numbers and Gardner color numbers of examples C9, E30 and E31 were determined using a spectral photometer LCS IV (BYK-Gardner GmbH). The Hazen scale is a color standard used to assess the intensities of transparent, light yellow-tinted samples compared to a color reference standard solution according to DIN EN ISO 6271 reaching from 0 (no color) to 500 (light yellow). The Gardner scale is a color standard used to assess the intensities of transparent, more strongly colored samples compared to color reference standard solutions according to DIN EN ISO 6271 reaching from 1 (light yellow) to 18 (dark brown). Table 5b Hazen color Gardner color Example number (20 °C) number (20 °C) Not applicable/value too high and therefore off the C9 scale 5.2 E30 419 2.6 E31 288 1.7 From table 5b it is visible that the inventive examples E30 and E31 show significantly lower Gardner color numbers than the non-inventive, comparative example C9, which means that the inventive examples E30 and E31 show significantly lower yellow tints than comparative example C9. The Hazen color number of non-inventive comparative example 9 was not determinable, because the value was too high and thus off the scale. The inventive examples E30 and E31 on the other hand lay well within the Hazen color scale and therefore show significantly lesser yellowing than comparative example C9. Application tests Table 6: Raw materials Name Description Supplier Acetone Propan-2-on Brenntag GmbH Methylamylketone 2-Heptanon Sigma-Aldrich Chemie GmbH Dowanol DPnB Dipropylenglycol-n-butylether DOW DEUTSCHLAND GmbH Xylene Dimethylbenzene OQEMA Contract GmbH Oxsol 100 Parachlorobenzotrifluoride Univar Solutions Inc. Tert. Butyl Acetic acid tert-butyl ester Sigma-Aldrich Chemie acetate GmbH n-Butyl acetate Acetic acid n-butyl ester INEOS N.V. Dowanol PMA 2-Methoxy-1-methylethyl acetate DOW DEUTSCHLAND GmbH Paraloid B66 100% solid grade thermoplastic acrylic DOW DEUTSCHLAND resin GmbH Setalux DA 870 Polyisocyanate cross-linking acrylic Allnex GmbH BA resin BYK-066 N Solution of foam destroying BYK-Chemie GmbH polysiloxane Desmodur N Aliphatic polyisocyanate (HDI trimer) Covestro AG 3390 BA Bayhydrol A145 Hydroxyfunctional polyacrylic Covestro AG dispersion BYK-1711 Polymer-based silicone-free defoamer BYK-Chemie GmbH BYK-346 Solution of a polyether-modified BYK-Chemie GmbH polysiloxane Bayhydur 3100 Hydrophilic aliphatic polyisocyanate Covestro AG based on HDI Worléekyd S365 Long oil alkyd resin, 60% in white spirit Worlée Chemie GmbH White spirit White spirit 145/200 Hydrocarbons, C9- Julius Hoesch GmbH & Co. C12 KG Nuodex Combi ready-to-use Cobalt/Calcium/Zirconium Huntsman International APB drier combination LLC Borchinox M 2 Anti-skinning agent, Methylethyl ketone Borchers Inc oxime BYK-066 N Defoamer, solution of foam destroying BYK-Chemie GmbH polysiloxanes Setal 1603 BA-78 Polyester polyol resin Allnex GmbH Setalux 1903 BA- Acrylic polyol Allnex GmbH 75 Tinuvin 1130 Liquid hydrophilic benzotriazole-based BASF SE UV absorber Tinuvin 292 Liquid hindered amine light stabilizer BASF SE Tolonate HDT-LV Aliphatic polyisocyanate Vencorex Chemicals BYK-378 Polyether modified BYK-Chemie GmbH dimethylpolysiloxane DMEA 2-(Dimethylamino)ethan-1-ol Huntsman International LLC Test 1: Whitening of a waterbased 2-pack PU clearcoat Production of the waterbased 2-pack PU clearcoat was carried out using the formulation in table 7. All ingredients of component A were added under stirring conditions into a PE beaker and homogenized with a Dispermat LC3 (VMA Getzmann), 1000 rpm, 4 cm diameter toothed plate, 10 minutes at room temperature (23 °C). Afterwards the pH of component A was adjusted with DMEA solution (10% in water) to pH 8.2-8.5. Component B was produced with the same stirring conditions. Component A was divided into smaller amounts (50 g in 175 ml PE beaker) and the inventive and non-inventive compositions were incorporated with a dosage of 0.5 weight-% of the component having a number average molecular weight Mn in the range of 400 g/mol to 30000 g/mol and having at least one urea group (calculated on the total clearcoat) under stirring with Dispermat LC3 (VMA Getzmann), 1500 rpm, 2.5 cm diameter toothed plate, 5 minutes at room temperature (23 °C). After storage at room temperature over night the hardener solution was added with the specified mixing ratio and homogenized by stirring with spatula. The samples were applied with a frame film applicator (BYK Gardner GmbH) with 120 µm wet film thickness on glass and dried at room temperature for 1 week. For the whitening test a household sponge (2 cm x 2 cm) soaked with water was placed for 24 hours on the lacquer film. Direct after removing of the sponge and drying, the whitening of the lacquer film was evaluated visually with a scale from 1 – 5 for no whitening (rating “1”) to strong whitening (rating “5”). Table 7: Waterbased 2-pack PU Clearcoat Component A: Bayhydrol A145 82.5 g BYK-1711 0.5 g BYK-346 0.9 g DI water 16.1 g 100.0 g Dispermat: 10 min. at 1000 rpm with 4 cm diameter toothed plate adjustment of the pH with DMEA solution, 10% in DI water to pH 8.2-8.5 Component B: Bayhydur 3100 82.3 g Dowanol PMA 17.7 g 100.0 g Dispermat: 5 min. at 1000 rpm with 4 cm diameter toothed plate Ratio Comp. A : Comp. B = 50 : 15 mixing with spatula Table 8: Results Example Whitening Control without rheology 1 additive C4 3 E14 1 E16 1 E19 1 E22 1 E25 1 While the control without rheology additive exhibits a low viscosity, the samples with the rheology additives C4, E14, E16, E19, E22, and E25 show a significantly higher viscosity. From table 8 it was surprisingly found that the inventive rheology additives E14, E16, E19, E22, and E25 show no impact on the whitening of the waterbased clear coat whereas the comparative rheology additive C4 shows a significant worsening on the whitening. Test 2: Whitening of a solventbased 2-pack PU Clearcoat Production of the solventbased 2-pack PU clearcoat was carried out using the formulation in table 9. All ingredients of component A were added under stirring conditions into a PE beaker and homogenized with a Dispermat LC3 (VMA Getzmann), 1000 rpm, 4 cm diameter toothed plate, 5 minutes at room temperature (23 °C). Component A was divided in smaller amounts (50 g in 100 ml glass bottle) and the inventive and non-inventive compositions were incorporated with a dosage of 0.5 weight-% of the component having a number average molecular weight Mn in the range of 400 g/mol to 30000 g/mol and having at least one urea group (calculated on the total clearcoat) under stirring with Dispermat LC3 (VMA Getzmann), 1500 rpm, 2.5 cm diameter toothed plate, 5 minutes at room temperature (23 °C). After storage at room temperature over night the hardener was added with the specified mixing ratio and homogenized by stirring with spatula. The samples were applied with a frame film applicator (BYK Gardner GmbH) with 120 µm wet film thickness on glass and dried at room temperature for 1 week. For the whitening a water immersion test was carried out where the draw downs were placed for 1 week at 60 °C in a water bath (Gesellschaft für Labortechnik mbH). Direct after the samples were removed from the bath and dried the whitening of the lacquer film was evaluated visually with a scale from 1 – 5 for no whitening (rating “1”) to strong whitening (rating “5”). Table 9: Solvent based 2-pack PU Clearcoat Component A: Setalux DA 870 80.0 g BA n-Butyl acetate 9.9 g Dowanol PMA 9.9 g BYK-066 N 0.2 g 100.0 g Dispermat: 5 min. at 1000 rpm with 4 cm diameter toothed plate Component B: Desmodur N3390BA 50.0 g Ratio Comp. A : Comp. B = 2 : 1 mixing with spatula Table 10: Results Example Whitening Control without rheology 1 additive C2 5 E2 1 E4 1 E6 1 E9 1 E11 1 While the control without rheology additive exhibits a low viscosity, the samples with the rheology additives C2, E2, E4, E6, E9 and E11 and E25 show a significantly higher viscosity. From table 10 it was surprisingly found that the inventive rheology additives E2, E4, E6, E9, and E11 show no impact on the whitening of the solvent based clear coat whereas the comparative rheology additive C2 shows a significant worsening of the whitening. Test 3: Sag resistance in a thermoplastic acrylic clearcoat Production of the thermoplastic acrylic clearcoat was carried out using the formulation in table 11. All ingredients were added under stirring conditions into a PE beaker and homogenized with a Dispermat LC3 (VMA Getzmann), 1000 rpm, 4 cm diameter toothed plate, 15 minutes at room temperature (23 °C). The clearcoat was divided in smaller amounts (50 g in 100 ml glass bottle) and the inventive and non-inventive compositions were incorporated with a dosage of 0.75 weight-% (column I in table 12) and 1.0 weight-% (column II in table 12) of the component having a number average molecular weight Mn in the range of 400 g/mol to 30000 g/mol and having at least one urea group (calculated on the total clearcoat) under stirring with Dispermat LC3 (VMA Getzmann), 1500 rpm, 2.5 cm diameter toothed plate, 5 minutes at room temperature (23°C). After storage at room temperature over night the samples were applied for the sag resistance test with a stepped doctor blade Model 421/S (Erichsen GmbH & Co KG) with 50-500 respectively 550-1000 µm wet film thickness. The application was done on contrast cards 2801 (BYK-Gardner GmbH) using the automatic applicator byko-drive XL (BYK-Gardner GmbH) with an application speed of 50 mm/s. Directly after application, the draw down was hanged up vertically at room temperature until it was dry. After drying the visual evaluation of the sag resistance was done. Therefor the wet film thickness was considered that shows after drying a clear separation of the draw down, no runner and no bulge building between the applied film thickness. Table 11: Solvent based thermoplastic acrylic clearcoat Paraloid B66 25.0 g Oxsol 100 48.7 g Tert.-Butyl acetate 11.3 g Acetone 15.0 g 100.0 g Dispermat: 15 min. at 1000 rpm with 4 cm diameter toothed plate Table 12: Results Example Sag resistance [µm] I II (0.75 wt.%) (1.0 wt.%) Control (without < 50 < 50 rheology additive) C2 150 150 E2 500 750 E4 500 800 E6 550 750 E9 400 800 E11 450 750 From table 12 it was surprisingly found that the inventive rheology additives E2, E4, E6, E9, and E11 show a better sag resistance in the thermoplastic acrylic clearcoat than the comparative rheology additive C2. Test 4: Rheology effect and compatibility in various solvents Various solvents were filled with an amount of 50 g in 100 ml glass bottles. The inventive and non-inventive compositions were incorporated with a dosage of 1.0 weight% of the component having a number average molecular weight Mn in the range of 400 g/mol to 30000 g/mol and having at least one urea group (calculated on the amount of the solvent) under stirring with Dispermat LC3 (VMA Getzmann), 1500 rpm, 2.5 cm diameter toothed plate, 5 minutes at room temperature (23 °C). After storage over night at room temperature, the samples were evaluated regarding gel strength (rheology effect) and turbidity (compatibility). The visual evaluation of the gel strength can vary from a strong gel (gel strength rating “1”) to no gel (gel strength rating “5”) and the turbidity from clear (turbidity rating “1”) to strong turbidity (turbidity rating “5”). Table 13: Tested solvents Acetone Methylamylketone (MAK) Xylene Table 14a: Results Example Gel strength Acetone MAK Xylene Control (without 5 5 5 rheology additive) C2 5 5 5 E2 1 1 1 E4 1 1 1 E6 1 1 1 E9 1 1 1 E11 1 1 1 From table 14a it was surprisingly found that the inventive rheology additives E2, E4, E6, E9, and E11 show a better gel strength, in the respective solvents than the comparative rheology additive C2. Table 14b: Results Example Turbidity MAK Xylene Control (without rheology 1 1 additive) C2 5 5 E2 1 2 E4 1 1 E6 1 1 E9 2 4 E11 1 1 From table 14b it was surprisingly found that the inventive rheology additives E2, E4, E6, E9, and E11 show less influence on turbidity in the respective solvents than the comparative rheology additive C2. Test 5: Sag resistance in a long oil alkyd clearcoat Production of the solventbased long oil alkyd clearcoat was carried out using the formulation in table 15. All ingredients of the formulation were added under stirring conditions into a PE beaker and homogenised with a Dispermat LC3 (VMA Getzmann), 1000 rpm, 4 cm diameter toothed plate, 10 minutes at room temperature (23 °C). The clear coat was divided in smaller amounts (50 g in 100 ml glass bottle) and the inventive and non-inventive compositions were incorporated with a dosage of 1.0 weight-% of the component having a number average molecular weight Mn in the range of 400 g/mol to 30000 g/mol and having at least one urea group (calculated on the total clearcoat) under stirring with Dispermat LC3 (VMA Getzmann), 1500 rpm, 2.5 cm diameter toothed plate, 5 minutes at room temperature (23 °C). After storage at room temperature over night the samples were applied for the sag resistance test with a stepped doctor blade Model 421/S (Erichsen GmbH & Co KG) with 30-300 µm wet film thickness. The application was done on contrast cards 2801 (BYK-Gardner GmbH) using the automatic applicator byko-drive XL (BYK-Gardner GmbH) with an application speed of 50 mm/s. Directly after application, the draw down was hanged up vertically at room temperature until it was dry. After drying the visual evaluation of the sag resistance was done. Therefore, the wet film thickness was considered that shows after drying a clear separation of the draw down, no runner and no bulge building between the applied film thickness. Additionally, the gloss of the draw down was measured with a Micro-Tri-gloss (BYK-Gardner GmbH) at 60 µm wet film thickness after 2 days drying at room temperature. Table 15: Solvent based long oil alkyd clearcoat Worléekyd S365, 60% in white spirit 80.9 g White spirit 13.7 g Nuodex Combi APB 4.9 g Borchinox M 2 0.3 g BYK-066 N 0.2 g 100.0 g Dispermat: 10 min. at 1000 rpm with 4 cm diameter toothed plate Table 16: Results Example Sag resistance [µm] Gloss 20° Control without <30 87 rheology additive C6 150 51 E27 270 70 E28 300 76 From table 16 it was surprisingly found that the inventive rheology additives E27 and E28 show a better sag resistance and higher gloss in the long oil alkyd clearcoat than the comparative rheology additive C6. Test 6: Whitening of a solventbased long oil alkyd clearcoat Production of the solventbased long oil alkyd clearcoat was carried out using the formulation in table 17. All ingredients of the formulation were added under stirring conditions into a PE beaker and homogenized with a Dispermat LC3 (VMA Getzmann), 1000 rpm, 4 cm diameter toothed plate, 10 minutes at room temperature (23 °C). The clear coat was divided into smaller amounts (50 g in 100 ml glass bottle) and the inventive and non-inventive compositions were incorporated with a dosage of 1.0 weight-% of the component having a number average molecular weight Mn in the range of 400 g/mol to 30000 g/mol and having at least one urea group (calculated on the total clearcoat) under stirring with Dispermat LC3 (VMA Getzmann), 1500 rpm, 2.5 cm diameter toothed plate, 5 minutes at room temperature (23 °C). After storage at room temperature over night, the samples were applied with a frame film applicator (BYK Gardner GmbH) with 120 µm wet film thickness on glass and dried at room temperature for 1 week. For the whitening test a household sponge (2 cm x 2 cm) soaked with water was placed for 24 hours on the lacquer film. Direct after removing of the sponge and drying the whitening of the lacquer film was evaluated visually with a scale from 1 – 5 for no whitening (rating “1”) to strong whitening (rating “5”). Table 17: Solvent based long oil alkyd clearcoat Worléekyd S365, 60% in white spirit 80.9 g White spirit 13.7 g Nuodex Combi APB 4.9 g Borchinox M 2 0.3 g BYK-066 N 0.2 g 100.0 g Dispermat: 10 min. at 1000 rpm with 4 cm diameter toothed plate Table 18: Results Example Visual evaluation of Whitening viscosity Control without low 2 rheology additive C6 high 5 E27 high 3 E28 high 3-4 While the control without rheology additive exhibits a low viscosity, the samples with the rheology additives C6, E27 and E28 show a significantly higher viscosity. From table 18 it is also visible that the inventive rheology additives E27 and E28 show less impact on the whitening of the long oil alkyd clearcoat than the comparative rheology additive C6. Test 7: Yellowing in a solvent based clear coat Production of the solventbased 2-pack PU clearcoat was carried out using the formulation in table 19. All ingredients of component A were added under stirring conditions into a PE beaker and homogenized with a Dispermat LC3 (VMA Getzmann), 1000 rpm, 4 cm diameter toothed plate, 5 minutes at room temperature (23 °C). Component A was divided in smaller amounts (50 g in 100 ml glass bottle) and the inventive compositions were incorporated with a dosage of 1.0 weight-% of the component having a number average molecular weight Mn in the range of 400 g/mol to 30000 g/mol and having at least one urea group (calculated on the total lacquer) under stirring with Dispermat LC3 (VMA Getzmann), 1500 rpm, 2.5 cm diameter toothed plate, 5 minutes at room temperature (23 °C). After storage at room temperature over night the hardener was added with the specified mixing ratio and homogenized by stirring with spatula. The samples were applied with a wire bar (BYK Gardner GmbH) with 200 µm wet film thickness on DIN A4 white primered aluminium panels (Novelis Deutschland GmbH) and dried at room temperature for 1 day. The degree of yellowing was determined using the color spectrophotometer Color Guide 45/0 (BYK-Gardner GmbH) one day after application. The YE 98 values were measured and compared. DYE 98 was calculated as the difference of the degree of yellowing of the sample without rheology additive (control) to the respective samples with rheology additive. Table 19: Solvent based 2-pack PU Clearcoat Component A: Setalux DA 870 80.0 g BA n-Butyl acetate 9.9 g Dowanol PMA 9.9 g BYK-066 N 0.2 g 100.0 g Dispermat: 5 min. at 1000 rpm with 4 cm diameter toothed plate Component B: Desmodur N3390 BA 50.0 g Ratio Comp. A : Comp. B = 2 : 1 mixing with spatula Table 20: Results Example YE98 DYE98 Control (without rheology -3.04 additive) C9 -2.74 0.30 E30 -2.84 0.20 E31 -2.93 0.11 From table 20 it was surprisingly found that the inventive rheology additives E30 and E31 show less impact on yellowing of the 2-pack PU clearcoat than the comparative rheology additive C9. Test 8: Rheology effect and compatibility in a 2-pack PU clear coat Production of the solventbased 2-pack PU clearcoat was carried out using the formulation in table 21. All ingredients of component A were added under stirring conditions into a PE beaker and homogenized with a Dispermat LC3 (VMA Getzmann), 1000 rpm, 4 cm diameter toothed plate, 5 minutes at room temperature (23 °C). The inventive compositions were incorporated with a dosage of 0.55 weight-% of the component having a number average molecular weight Mn in the range of 400 g/mol to 30000 g/mol and having at least one urea group (calculated on the total lacquer) under stirring with Dispermat LC3 (VMA Getzmann), 1500 rpm, 2.5 cm diameter toothed plate, 5 minutes at room temperature (23 °C). After storage 2 days at room temperature the gel strength and turbidity were evaluated visually with a scale of 1 – 5 for gel strength (no gel formation – strong gel formation) and turbidity (clear – strong turbidity). The hardener was added with the specified mixing ratio and homogenized by stirring with spatula until the clear coat composition was optically homogeneous. The efflux time of the clear coat composition was then determined using a DIN 4 mm flow cup (BYK-Gardner GmbH). The clear coat composition was diluted with a solvent mixture (n-butylacetate / Dowanol PMA; 40:60 w/w) to adjust a DIN 4 efflux time of 21 s (+/- 1 s) for the application. The application of the clear coat composition was carried out by means of pneumatic spray application Eisenmann LaTec GmbH (spray gun AGMD Pro (De Vilbiss), 1.2 mm nozzle De Vilbiss GTI PRO High Efficiency TE 40 C; air flow speed: 0.6 m/s) on vertically suspended, primed and perforated steel plates (N / 16300500L cold rolled fine sheet incl 16 holes a 10 mm with protective coating (gray/white, application side gray 300 mm x 500 mm x 0.60 - 0.70 mm). The clear coat was applied in three spray passes to determine the sag limit of the clear coat composition. After spray application, the coated sheets were vented vertically at room temperature for 10 minutes and then dried vertically at 60 °C for 60 minutes in a VTL 60/90 reflow oven (from Votsch Industrietechnik GmbH). After 24 h the determination of the sag limit was made by optically determining that spot on the perforated plate, that had no clear coat accumulation under the hole (no distinct bulg or runner formation). The determination of the dry layer thickness above and below the determined hole with the dry-film measuring device Byko-Test 1500 (BYK-Gardner GmbH) was carried out by a 3-time measurement and the subsequent averaging. Table 21: Solvent based 2-pack PU Clearcoat Component A: Setal 1603 BA-78 45.8 g Setalux 1903 BA-75 109.4 g n-Butylacetate 32.2 g Dowanol PMA 8.8 g Tinuvin 1130 2.9 g Tinuvin 292 0.8 g BYK-378 0.1 g 200.0 g Dispermat: 5 min. at 1000 rpm with 4 cm diameter toothed plate Component B: Tolonate HDT-LV 59.7 g n-Butylacetate 20.5 g Dowanol PMA 19.8 g 100.0 g Mixing ratio Comp.A : Comp.B = 2: 1 Table 22: Results Example Gel strength in Turbidity Sag limit dry comp. A [µm] Control (without 5 1 24 rheology additive) C8 4 5 27 E29 3 1 41 From table 22 it was surprisingly found that the inventive rheology additive E29 shows a better rheology effect in the liquid clear coat (gel strength) and after application (sag limit) and also no impact on turbidity of the 2-pack PU clearcoat, in contrast to the comparative rheology additive C8.

Claims

Claims 1. A composition comprising a liquid carrier which is liquid at a temperature of 20° C, a component having a number average molecular weight Mn in the range of 400 g/mol to 30000 g/mol and having at least one urea group, dissolved in the liquid carrier, a urea compound having a molecular weight below 350 g/mol dissolved in the liquid carrier. 2. The composition according to claim 1 wherein the composition comprises the urea compound having a molecular weight below 350 g/mol in an amount in the range of 0.05 to 15.00 weight %, calculated on the total weight of the composition. 3. The composition according to any one of the preceding claims, wherein the urea compound having a molecular weight below 350 g/mol comprises a structure according to formula (I) HR1N-C(=O)-NR2R3 (I) in which R1, R2, and R3 independently represent an organic group or hydrogen, or wherein R1 and R2 are linked to each other. 4. The composition according to any one of the preceding claims, wherein the urea compound having a molecular weight below 350 g/mol comprises a structure according to formula (I) HR1N-C(=O)-NR2R3 (I) in which R1, R2 and R3 are independently organic groups consisting of the elements carbon and hydrogen having 1 to 8 carbon atoms, or hydrogen. 5. The composition according to any one of the preceding claims, wherein the urea compound comprises at least one of 2-imidazolidinone, 1,3-dimethyl urea, 1-(2- hydroxyethyl)imidazolidin-2-one,1-methyl urea, urea, biuret, N,N'-diethylurea, 1,1- dimethylurea, N-ethylurea, 1,3-diphenylurea, N-phenylurea, N-butylurea, 1,1- diethylurea, N-tert-butylurea, 3-methyl-1,1-diphenylurea, 1,1-dimethyl-3-phenylurea, N,N′-dicyclohexylurea, benzoyleneurea, N,N′-trimethyleneurea, or glycoluril. 6. The composition according to any one of the preceding claims, wherein the liquid carrier comprises at least one of 1-(2-hydroxyethyl)-2-pyrrolidone, 2-hydroxy-N,N- dimethylpropanamide or a polar aprotic solvent. 7. The composition according to any one of the preceding claims, wherein the liquid carrier comprises a compound having at least one of a N-substituted amide group, and a sulfoxide group. 8. The composition according to any one of the preceding claims, wherein the component having a number average molecular weight Mn in the range of 400 g/mol to 30000 g/mol and having at least one urea group, dissolved in the liquid carrier comprises at least 2 urea groups and at least 2 urethane groups. 9. The composition according to any one of the preceding claims, wherein the component having a number average molecular weight Mn in the range of 400 g/mol to 30000 g/mol and having at least one urea group comprises at least one of formulas U-2a, U-2b, U-2c, U-2d and U-2e wherein AM is selected from a linear or branched, saturated or unsaturated, aliphatic, cycloaliphatic, aromatic or aliphatic-aromatic organic group having 2 to 50 C atoms, in case of multiple occurrences of AM, AM is independently selected from a linear or branched, saturated or unsaturated, aliphatic, cycloaliphatic, aromatic or aliphatic- aromatic organic group having 2 to 50 C atoms, AM1 and AM2 independently of one another and independently in case of multiple occurrences represent a linear or branched, saturated or unsaturated, aliphatic, aromatic or aliphatic-aromatic organic group having 1 to 50 C atoms, IC1 and IC2 independently of one another and independently in case of multiple occurrences represent a linear or branched, saturated or unsaturated, aliphatic, aromatic or aliphatic-aromatic hydrocarbon group having 2 to 40 C atoms, IC3 represents a linear or branched, saturated or unsaturated, aliphatic, aromatic or aliphatic-aromatic hydrocarbon group having 2 to 24 carbon atoms, in case of multiple occurrences of IC3, IC3 independently represents a linear or branched, saturated or unsaturated, aliphatic, aromatic or aliphatic-aromatic hydrocarbon group having 2 to 24 carbon atoms, IC4 is selected from a group as described for IC1 and IC2 or a urethane group containing segment having the structure -[IC2-NH-(C=O)-O-RP3-O-(C=O)-NH-IC2]- in which RP3 represents a linear or branched, saturated or unsaturated, aliphatic, aromatic or aliphatic-aromatic organic group having 2 to 24 C atoms and/or a (poly)ether group having 1 to 120 ether oxygen atoms and/or a polyamide group having 1 to 100 amide groups and/or a polysiloxane group having 3 to 100 silicon atoms and/or a polyester group having 1 to 100 ester groups and optionally containing ether groups, in case of multiple occurrences of RP3, RP3 independently represents RP3 represents a linear or branched, saturated or unsaturated, aliphatic, aromatic or aliphatic-aromatic organic group having 2 to 24 C atoms and/or by a (poly)ether group having 1 to 120 ether oxygen atoms and/or a polyamide group having 1 to 100 amide groups and/or a polysiloxane group having 3 to 100 silicon atoms and/or a polyester group having 1 to 100 ester groups and optionally containing ether groups RP1 and RP2 independently of one another and independently in case of multiple occurrences represent a linear or branched, saturated or unsaturated, aliphatic, aromatic or aliphatic-aromatic organic group having 1 to 24 C atoms and/or a polyether group having 1 to 120 ether oxygen atoms and/or a polyester group having 1 to 100 ester groups and optionally containing ether groups, and/or a polyamide group having 1 to 100 amide groups, and/or a polysiloxane group having 3 to 100 silicon atoms, m is an integer from 0 to 20, p represents 0 and/or 1, q is an integer from 0 to 20. 10. The composition according to any one of the preceding claims, wherein the weight ratio of the urea compound having a molecular weight below 350 g/mol and the component having a number average molecular weight Mn in the range of 400 g/mol to 30000 g/mol and having at least one urea group is from 1 : 2 to 1 : 100. 11. The composition according to any one of the preceding claims, wherein the composition comprises from 0.01 to 15.00 weight-% of a salt, calculated on the total weight of the urea compound having a molecular weight below 350 g/mol, the liquid carrier, the component having a number average molecular weight Mn in the range of 400 g/mol to 30000 g/mol and having at least one urea group and the salt. 12. The composition according to any one of the preceding claims, wherein the composition comprises 0.05 – 40.00 weight-% of the urea compound having a molecular weight below 350 g/mol, 5.00 – 90.00 weight-% of the liquid carrier, 5.00 – 60.00 weight-% of the component having a number average molecular weight Mn in the range of 400 g/mol to 30000 g/mol and having at least one urea group, dissolved in the liquid carrier, calculated on the total weight of the urea compound having a molecular weight below 350 g/mol, the liquid carrier and the component having a number average molecular weight Mn in the range of 400 g/mol to 30000 g/mol and having at least one urea group. 13. Use of the composition according to any one of the preceding claims for controlling the rheology of a liquid composition. 14. A liquid composition comprising the composition according to any one of the preceding claims 1 to 12 and a binder. 15. A coated article, wherein at least a part of the surface of the article is coated with the liquid composition according to claim 14.