Improved pour point depressants on the basis of hyperbranched polycondensates

Abstract

Hydrophobically modified, hyperbranched polyester obtainable by (a) reacting a hydroxyl group containing carboxylic acid (B) having at least one carboxylic acid group and at least two hydroxyl groups, with a diol (A) having a number average molecular weight Mn of from 85 to 2500 g / mol, and (b) reacting the mixture resulting from step (a) with a at least one hydrophobic, linear monocarboxylic acid (C), wherein 50 to 100 mol % of the of the monocarboxylic acids (C) are linear aliphatic, saturated monocarboxylic acid with between 20 to 36 carbon atoms, based on the total of monocarboxylic acids (C). wherein the molar ratio of carboxylic acid (B) and diol (A) is from > 5:1 to < 25:1, and wherein in step (a) no polyols having more than 2 hydroxyl groups are present.

Description

[0001] 240801

[0002] 1

[0003] IMPROVED POUR POINT DEPRESSANTS ON THE BASIS OF HYPERBRANCHED POLYCONDENSATES

[0004] The invention relates to hydrophobically modified, hyperbranched polyesters, to a process for preparing the hydrophobically modified, hyperbranched polyesters, to a formulation containing hydrocarbons and the hydrophobically modified, hyperbranched polyesters, as well as to the use of the hydrophobically modified, hyperbranched polyesters.

[0005] Subterranean mineral oil formations typically have relatively high temperatures. After the production of the crude oil to the surface, the crude oil produced therefore cools down to a greater or lesser degree depending on the production temperature and the storage or transport conditions.

[0006] According to their origin, crude oils have different proportions of waxes, which consist essentially of long-chain n-paraffi ns. According to the type of crude oil, the proportion of such paraffins may typically be 1 to 30% by weight of the crude oil. When the temperature goes below a particular level in the course of cooling, the paraffins can crystallize, typically in the form of platelets. The precipitated paraffins considerably impair the flowability of the oil. The platelet-shaped n-paraffin crystals can form a kind of house-of-cards structure which encloses the crude oil, such that the crude oil ceases to flow, even though the predominant portion is still liquid. The lowest temperature at which a sample of an oil still just flows in the course of cooling is referred to as the pour point ("yield point"). For the measurement of the pour point, standardized test methods are used. Precipitated paraffins can block filters, pumps, pipelines and other installations or be deposited in tanks, thus entailing a high level of cleaning.

[0007] The deposit temperature of oil deposits is generally above room temperature, for example 40°C to 100°C. Crude oil is produced from such deposits while still warm, and it naturally cools more or less quickly to room temperature in the course of or after production, or else to lower temperatures under corresponding climatic conditions. Crude oils may have pour points above room temperature, such that crude oils of this kind may solidify in the course of or after production.

[0008] It is known that the pour point of crude oils can be lowered by suitable additives. This can prevent paraffins from precipitating in the course of cooling of produced crude oil. Suitable additives firstly prevent the formation of said house-of-cards-like structures and thus lower the temperature at which the crude oil solidifies. In addition, additives can promote the formation of fine, well-crystallized, non-agglomerating paraffin crystals, such that undisrupted oil transport is ensured. Such additives are also referred to as pour point depressants or flow improvers.

[0009] Paraffin inhibitors or wax inhibitors refer to those substances intended to prevent the deposition of paraffins or paraffin waxes on surfaces in contact with crude oils or other wax-containing oils and / or mineral oil products.

[0010] One class of chemical compounds which have been suggested as pour point depressants, wax inhibitors, or cold flow improvers comprises dendritic or hyperbranched polymers or derivatives thereof.240801

[0011] 2

[0012] WO 96 / 12755 A1 describes an oil-soluble dendrimer-based cold-flow improver comprising an amine based central core linked through a plurality of polar groups to a dendritic body which is linked through a plurality of polar groups to a hydrocarbyl periphery consisting of n-alkyl groups from 8 to 1000 carbon atoms.

[0013] Alan R. Katritzky et al., Journal of the Chinese Chemical Society, 1997, 44, 575 - 580 describe the synthesis of dendramines and dendramides and their application in the oil industry in particular as wax-inhibitors.

[0014] EP 1 557411 A2 describes a nucleating agent on basis of hyperbranched polymers comprising a hyperbranched core to which C8 to C40 alkyl chains are linked via ester-, carbonate-, thioether-, amide-, urethane-, urea-, or -CO-CH2CH2-NR' -groups. The nucleating agent may be used for improving the cold-flow properties of paraffin containing crude oils, fuels, oils, lubricants or in fat-based fuels.

[0015] WO 2006 / 056578 A1 describes a method for improving the flowability of a mixture that contains wax and other hydrocarbons which comprises adding a hyperbranched polyester amide.

[0016] WO 2013 / 019704 A1 discloses a hydrocarbon flow improver comprising a branched dendritic core having at least 16 terminal hydroxyl groups and wherein at least one of the terminal hydroxyl groups is esterified with at least one carboxylic acid moiety comprising from 6 to 30 carbon atoms. The dendritic core comprises a quaternary carbon center. The document furthermore relates to a method of extracting hydrocarbon fluid from a well comprising the step of adding said fluid improver to the hydrocarbon fluid. WO 2015 / 070121 A1 discloses the use of the same product as asphaltene inhibitor.

[0017] Khadid I. Kabel et al., Research on Chemical Intermediates, 2015, 41 (1), 457-474, describe the synthesis and evaluation of PAMAM dendrimer and PDPF-b-POP block copolymer as asphaltene inhibitor / dispersant.

[0018] WO 2019 / 185401 A1 discloses modified hyperbranched polyesters and their use as wax inhibitor or as pour point depressant. The hyperbranched polyesters are synthesized in a 2- step reaction. In a first step, a hyperbranched polyester core is synthesized which comprises terminal OH-groups. In a second step, the terminal OH-groups are reacted with hydrophobic carboxylic acids, thereby obtaining a modified hyperbranched polyester comprising terminal hydrophobic groups. Suitable carboxylic acids preferably have the formula R-COOH, wherein R is a hydrocarbon moiety having at least 6, preferably at least 10 carbon atoms. The hydrocarbon groups may be linear saturated or linear unsaturated hydrocarbon groups or branched saturated or branched unsaturated hydrocarbon groups. It has also been suggested to use a mixture of linear, saturated aliphatic hydrocarbon groups with linear, aliphatic unsaturated hydrocarbon groups or a mixture of linear, saturated aliphatic hydrocarbon groups with branched, saturated aliphatic hydrocarbon groups.

[0019] WO 2020 / 231994 A1 discloses a method of adding a flow improver to petroleum fluids comprising a solvent and a dendrimer-based flow improver, wherein the dendrimer core is modified with a mixture of saturated and unsaturated240801

[0020] 3

[0021] fatty acids. A mixture of saturated and unsaturated fatty acids yields products having a lower viscosity at low temperatures as compared to products for which only saturated fatty acids are used.

[0022] During synthesis of the modified hyperbranched polyesters, side reactions may occur, leading to by-products which do not dissolve in mineral oil or toluene / xylol upon dilution of the polyesters and remain in solid form. Hence, such products are not suitable for subsea applications. With undissolved particulate matter, there is a risk of plugging the injection pipelines in oil recovery operations. If severe plugging of a subsea pipeline occurs, it might be necessary to unstill the pipeline, clean it and re-install it.

[0023] It is an object of the present invention to provide hydrophobically modified, hyperbranched polyesters having a reduced content of solid, particulate matter that remains undissolved in hydrocarbon solvents.

[0024] The object is achieved by a hydrophobically modified, hyperbranched polyester obtainable by the following process:

[0025] (a) reacting a hydroxyl group containing carboxylic acid (B) having at least one carboxylic acid group and at least two hydroxyl groups, with a diol (A), and

[0026] (b) reacting the mixture resulting from step (a) with a at least one hydrophobic, linear monocarboxylic acid (C), wherein the molar ratio of carboxylic acid (B) and diol (A) is from > 10 : 1 to < 25 : 1.

[0027] The object is further achieved by a process for preparing a hydrophobically modified, hyperbranched polyester comprising the step:

[0028] (a) reacting a hydroxyl group containing carboxylic acid (B) having at least one carboxylic acid group and at least two hydroxyl groups, with a diol (A), and

[0029] (b) reacting the mixture resulting from step (a) with a at least one hydrophobic, linear monocarboxylic acid (C), wherein the molar ratio of carboxylic acid (B) and diol (A) is from > 10 : 1 to < 25 : 1,

[0030] and optionally

[0031] (c) dissolving the hydrophobically modified, hyperbranched polyesters obtained in step (b) in a hydrocarbon or a mixture of different hydrocarbons having a boiling point of at least 100°C.

[0032] No polyol having more than two hydroxyl groups are used as core molecules. When the hydrophobically modified polyesters of the invention having a diol as core molecule are dissolved in xylene / solvesso solvents, particulate matter, i.e. the insoluble side-products, in the formulation are greatly reduced or completely avoided, and a clear, transparent formulation is obtained, as compared to hyperbranched polyesters containing a polyol, e.g. trimethylol propane, as the core molecule.240801

[0033] 4

[0034] This reduces the risk of plugging the injection pipelines in oil recovery activities, which is even more important for subsea / offshore wellbore. This is particularly important in subsea oil recovery activities, because the injection pipelines used therein are generally much narrower than those used in land-based oil recovery operations.

[0035] Additionally, the wall thickness of subsea pipelines is usually greater to withstand high external pressures and harsh conditions. While thicker walls can provide structural integrity, they can also create challenges if any internal deposits begin to accumulate, as it may be harder to dislodge them without the benefit of larger diameters that allow for easier flow dynamics.

[0036] Furthermore, the melting point of the hyperbranched polymers can be reduced by appropriate combination of hydrophobic carboxylic acids for the reaction with the terminal hydroxyl groups of the dendritic precursor, without significantly sacrificing the pour point reducing property. This behavior is advantageous for application of the product in regions of low temperature as less energy needs to be consumed for heating.

[0037] Preferably, in step (a) no polyols having more than two hydroxyl groups, such as trimethylolpropane, are present at all. In case that polyols are present in step (a), they are preferably present in insignificant amounts, the molar ratio of carboxylic acid (B) to such polyols being > 1000 : 1.

[0038] The hydrophobically modified, hyperbranched polyesters according to the present invention are obtainable by a 2-step process comprising at least the process steps (a) and (b). In step (a), a hyperbranched polyester comprising terminal hydroxy groups is synthesized. In the second step (b), the terminal hydroxy groups are at least partly esterified with linear carboxylic monoacids or a mixture of linear carboxylic acids, thereby obtaining a hydrophobically modified, hyperbranched polyester. The hydrophobically modified, hyperbranched polyesters are soluble in hydrocarbons. In an optional step (c), the hydrophobically modified, hyperbranched polyesters can be dissolved in hydrocarbons or mixtures of hydrocarbons.

[0039] The term "hyperbranched” is well known to the skilled artisan. Regarding the definition of dendrimeric and hyperbranched polymers in general see for example P. J. Flory, J. Am. Chem. Soc., 1952, 74, 2718 and H. Frey et al., Chem. Eur. J., 2000, 6 (14), 2499.

[0040] Step (a)

[0041] Examples of monomers (B) comprise 2,2,2-tris(hydroxymethyl)acetic acid, 2,3- dihydroxypropionic acid, sugar acids such as gluconic acid, glucaric acid, glucuronic acid, galacturonic acid or mucic acid (galactaric acid), 2,4-, 2,6-, or 3,5-dihydroxybenzoic acid, 4,4- bis(4-hydroxyphenyl)valeric acid, 2,2-bis(hydroxymethyl)alkane-carboxylic acids such as for example 2,2-bis(hydroxymethyl)propionic acid (dimethylolpropionic acid), 2,2-bis(hydroxy- methyl)butyric acid (dimethylolbutyric acid) and 2,2-bis(hydroxymethyl)valeric acid, preferably 2,2-bis(hydroxymethyl)propionic acid (dimethylolpropionic acid) or 2,2-bis(hydroxymethyl) butyric acid (dimethylolbutyric acid). In preferred embodiments of the invention, the monomers (B) are selected from 2,2-bis(hydroxymethyl)butyric acid (dimethylolbutyric acid) and240801

[0042] 5

[0043] 2.2- dihydroxymethylpropionic acid (dimethylolpropionic acid). In a particularly preferred embodiment, dimethylolpropionic acid is used as monomer (B).

[0044] In general, the diol (A) has a number average molecular weight of at least 85 g / mol, preferably from 85 to 2500, more preferably from 85 to 1500 g / mol. Examples of diols (A) comprise 1 ,6-hexanediol, 1 ,8-octanediol and cyclohexanediols, polyether diols, such as diethylene glycol, triethylene glycol, dipropylene glycol, tripropylene glycol, 2.2-dimethylolpropane (neopentylglycol), 2-methyl-1 ,3-propanediol, as well as polyethylene glycols HO(CH2CH2O)n-H, polypropylene glycols HO(CH[CH3]CH2O)n-H, and polyTHF HO-[(CH2)4O]n-H, n being an integer with a value adjusted to meet the molecular weight of the polymer may be used. Of course, mixtures of two or more than two different diols (A) may be used.

[0045] Preferably, the diol (A) is selected from the group consisting of 1 ,6-hexanediol, 1 ,8-octanediol, cyclohexanediols, diethylene glycol, triethylene glycol, dipropylene glycol, tripropylene glycol, polyethylene glycol polypropylene glycol and polyTHF.

[0046] In one embodiment of the invention, the diol (A) is selected from the group consisting of polyethylene glycol, polypropylene glycol and polyTHF, in particular those having a number average molecular weight Mn of 250 to 2500 g / mol, preferably from 250 to 1500 g / mol, more preferably from 250 to 1000 g / mol.

[0047] According to the invention, the molar ratio of the components (B) : (A) is from > 10 : 1 to < 25 : 1, preferably from 11 : 1 to 23: 1 , more preferably or from 11 : 1 to 20: 1 , in particular from 11 : 1 to 18: 1.

[0048] Step (a) is carried out by mixing the components (A) and (B) and further components and heating them to a temperature of at least 80°C. The reaction temperature should not exceed 250°C. In one embodiment, the reaction temperature is from 100°C to 200°C, preferably from 120°C to 180°C, for example from 140 to 170 °C. In certain embodiments, the reaction temperature may be slowly raised to said temperatures.

[0049] The reaction may preferably be carried out using the mixture as such, i.e. without adding a solvent. In other embodiments, step (a) may be carried out in a suitable solvent. Examples are hydrocarbons such as paraffins or aromatics, for example toluene, ortho-xylene, meta-xylene, para-xylene, xylene isomer mixture, ethylbenzene, chlorobenzene, and ortho- and meta-dichlorobenzene.

[0050] In the course of reacting components (A) and (B), water is formed which should be removed from the reaction mixture. In one embodiment of the invention, water is distilled off from the reaction mixture. For the purpose of removing water, the pressure may be reduced, for example to 50 to 500 hPa. In other embodiments, water-removing additives may be added before and / or during the reaction. Examples of water-removing additives include molecular sieves, particularly molecular sieve 4A, MgSO4 and Na2SO4.240801

[0051] 6

[0052] In one embodiment of the invention, the reaction is carried out in the presence of a catalyst for esterification.

[0053] Examples of suitable catalysts are inorganic acids, such as sulfuric acid, phosphoric acid, phosphonic acid, hypophosphorous acid, aluminum sulfate hydrate, alumina, acidic silica gel and acidic alumina, and organic acids, such as para-toluenesulfonic acid and methane sulfonic acid. Further examples comprise aluminum compounds of the general formula AI(0R)3 and titanates of the general formula Ti(OR)4, wherein R are alkyl or cycloalkyl moieties, such as for example isopropyl. Also, organometallic catalysts may be used, for example dialkyltin oxides R2SnO, where R are alkyl or cycloalkyl moieties, in particular di-n-butyltin oxide. Of course, also combinations of catalysts may be used. In one embodiment, methane sulfonic acid is used as catalyst. The amount of catalysts used - if present - may be from 0.01 to 5 % by weight, preferably from 0.1 to 2 % by weight, more preferably 0.2 to 1% by weight, each based on the total amount of the reactants.

[0054] The reaction time in step (a) of the method of the invention is usually from 10 minutes to 48 hours, preferably from 30 minutes to 24 hours and more preferably from 1 to 16 hours. The reaction may be monitored by measuring the acid value of the products formed. In one embodiment, the acid number of the hyperbranched polyesters comprising terminal hydroxy groups obtained in course of step (a) is from 10 bis 26 mg KOH / g. Determination of the acid number is described in the experimental part.

[0055] After the end of the reaction of step (a), the hyperbranched polyesters comprising terminal hydroxy groups can be isolated easily, for example, by removing the catalyst by filtration and concentrating the filtrate, usually under reduced pressure. Further highly suitable workup methods include precipitation following the addition of water and subsequent washing and drying. However, it is preferred that step (b) is carried out directly after step (a), without said isolating steps.

[0056] Step (b)

[0057] In the course of step (b), the mixture obtained in step (a) is reacted with a hydrophobic, linear monocarboxylic acid (C), or a mixture of such linear monocarboxylic acids (C), thereby esterifyi ng at least a part of the terminal OH-groups of the hyperbranched polyester obtained in step (a), wherein a hydrophobically modified, hyperbranched polyester is obtained.

[0058] Preferably, at least 30 % of the terminal OH groups are esterified by means of the hydrophobic monocarboxylic acids, more preferably at least 50 % and in particular at least 75 %.

[0059] In general, for modifying the product of step (a), a hydrophobic, linear monocarboxylic acid (C) containing from 50 to 100 mol-% of at least one linear aliphatic, saturated C20-C36 monocarboxylic acid (C1) is used.240801

[0060] 7

[0061] In certain embodiments, the at least one hydrophobic, linear monocarboxylic acid (C) contains up to 50 mol-%, in particular 10 to 50 mol-%, of one or more linear aliphatic, saturated or unsaturated C12-C18 monocarboxylic acids (C2).

[0062] Commercially available linear, saturated monocarboxylic acids are often fatty acids derived from naturally occurring fats and oil and are typically mixtures comprising two or more different linear monocarboxylic acids.

[0063] Preferably, the linear aliphatic, saturated monocarboxylic acid(s) (C1) contain from 20 to 36 carbon atoms, preferably from 20 to 30 carbon atoms, more preferably from 20 to 26 carbon atoms. Examples of suitable linear, saturated monocarboxylic acids are arachidic acid (C20), behenic acid (C22), tetracosanoic acid (C24), cerotic acid (C26), and triacontanoic acid (C30).

[0064] More preferably, the linear aliphatic, saturated carboxylic acid(s) (C1) comprise one or more linear, saturated carboxylic acid having from 22 to 36 carbon atoms, or from 22 to 30 carbon atoms, especially from 22 to 26 carbon atoms.

[0065] In general, the amount of linear aliphatic, saturated monocarboxylic acids (C1) having from 20 to 36 carbon atoms is at least 50 mol-%, relating to the total of all hydrophobic, linear monocarboxylic acids (C). In certain embodiments at least 90 mol-% or at least 95 mol-% of the hydrophobic monocarboxylic acids (C) are linear, saturated monocarboxylic acids (C1) having from 20 to 36 carbon atoms.

[0066] In a preferred embodiment of the invention, the amount of linear aliphatic, saturated monoarboxylic acids (C1) comprising 22 to 30 carbon atoms, especially from 22 to 26 carbon atoms, is at least 50 mol-%, relating to the total of all hydrophobic, linear monocarboxylic acids (C), and in one embodiment, it is at least 90 mol-%, preferably at least 95 mol-% of the hydrophobic monocarboxylic acids (C).

[0067] In another embodiment of the invention, the hydrophobic, linear monocarboxylic acids (C) comprise a mixture of linear aliphatic, saturated monocarboxylic acids having 20, 22, and 24 carbon atoms, all together in amount of at least 50 mol-%, or at least 90 or 95 mol-%, relating to the total of all hydrophobic, linear monocarboxylic acids (C).

[0068] Linear aliphatic, saturated or unsaturated monocarboxylic acids (C2) having less than 20 carbon atoms which may be present besides the carboxylic acid(s) (C1) comprise at least 12 carbon atoms, preferably at least 14 carbon atoms and more preferably at least 16 carbon atoms. Examples are stearic acid (C18), oleic acid (C18) palmitic acid (C16), and myristic acid (C14). Particularly preferred are palmitic acid and oleic acid.

[0069] In one embodiment of the invention, the hydrophobic, linear monocarboxylic acids (C) comprise a mixture of carboxylic acids having 16, 18, 20, and 22 carbon atoms, wherein the amounts of linear, saturated carboxylic acids240801

[0070] 8

[0071] (C1) comprising at least 20 carbon atoms is at least 50 mol-%, relating to the total of all hydrophobic monocarboxylic acids (C).

[0072] In a preferred embodiment, the hydrophobic, linear monocarboxylic acids (C) comprise up to 50 mol.-%, preferably from 10 to 50 mol.-% of palmitic acid and / or oleic acid as the linear aliphatic, saturated or unsaturated C12-C18 monocarboxylic acids (C2).

[0073] Step (b) is carried out by mixing the hydrophobic, linear monocarboxylic acids (C) with the mixture obtained in course of step (a) and heating them to a temperature of at least 100°C. The reaction temperature should not exceed 250°C. In one embodiment, the reaction temperature is from 100°C to 200°C, preferably from 120°C to 180°C, for example from 140°C to 170°C. In certain embodiments, the reaction temperature may be slowly raised to said temperatures. Preferably, the reaction in step (b) is carried out under reduced pressure. Step (b) may be carried out in the presence of a suitable esterification catalyst. Suitable catalysts have already been mentioned above. Methane sulfonic acid is a preferred catalyst.

[0074] The reaction time in step (b) of the method of the invention is usually from 10 minutes to 48 hours, preferably from 30 minutes to 24 hours and more preferably from 1 to 16 hours.

[0075] In general, the obtained hyperbranched polyester mixture has an acid number of below 100 mg KOH / g, preferably in the range from 0 to 50 mg KOH / g. Determination of the acid number is described in the experimental part.

[0076] Step (c)

[0077] The hydrophobically modified, hyperbranched polyesters of the invention may be used as such. In another embodiment, they are used as a formulation in hydrocarbon solvents.

[0078] Therefore, in one embodiment of the invention, the process comprises an additional step (c) comprising the dissolution of the hydrophobically modified, hyperbranched polyester obtained in course of step (b) in a hydrocarbon or a mixture of different hydrocarbons having a boiling point of at least 100°C.

[0079] Hydrocarbons or hydrocarbon mixtures may be aliphatic, naphthenic or aromatic hydrocarbons. The boiling point is at least 100°C, preferably at least 120°C, more preferably at least 130°C. Preferably, the hydrocarbons used have a flashpoint of at least 60°C. In particular, technical mixtures of hydrocarbons may be used. Technical mixtures of saturated aliphatic solvents are commercially available, for example technical mixtures of the Shellsol® D series and Exxsol® D series. Technical mixtures of aromatic solvents are also commercially available, for example the Shellsol® A series or the Solvesso® series or Caromax® series.240801

[0080] 9

[0081] The dissolving can simply be carried out for example by mixing the components while stirring. The concentration of the hydrophobically modified, hyperbranched polyesters in the formulation usually is at least 10 %, for example at least 20 % by weight, in particular at least 30 % by weight of polymers relation to the total of the formulation. The concentration may be for example from 10 to 80 % by weight. In other embodiments, the concentration is from 30 bis 80 % by weight or from 30 to 55 % by weight.

[0082] The present invention also relates to a formulation of the hydrophobically modified, hyperbranched polyester comprising at least

[0083] • a hydrocarbon or a mixture of different hydrocarbons having a boiling point of at least 100°C, and

[0084] • a hydrophobically modified, hyperbranched polyester as described above.

[0085] Use as pour point depressant

[0086] In one embodiment of the invention, the hydrophobically modified, hyperbranched polyesters of the present invention are used as pour point depressants for crude oil, by adding at least one of the hydrophobically modified, hyperbranched polyesters of the invention to the crude oil.

[0087] Pour point depressants reduce the pour point of crude oils. The pour point ("yield point") refers to the lowest temperature at which a sample of an oil, in the course of cooling, still just flows. For the measurement of the pour point, standardized test methods are used. For use as pour point depressant, the polymer may be added as such, however preferably a formulation of polyesters comprising at least

[0088] • a hydrocarbon or a mixture of different hydrocarbons having a boiling point of at least 100°C, and

[0089] • a hydrophobically modified, hyperbranched polyester as described above,

[0090] is employed.

[0091] The formulation may comprise further components. For example, additional wax dispersants can be added to the formulation. Wax dispersants stabilize paraffin crystals which have formed and prevent them from sedimenting. The wax dispersants used may, for example, be alkylphenols, al ky I phenol-formaldehyde resins or dodecylbenzenesulfonic acid.

[0092] The formulations may furthermore comprise other paraffin inhibitors such as for example ethy lene-viny lacetate copolymers, polyacrylate-based paraffin inhibitors or paraffin inhibitors based on maleic acid anhydride - olefine copolymers.

[0093] The hydrophobically modified, hyperbranched polyesters or formulations thereof are typically used in such an amount that the amount of the hydrophobically modified, hyperbranched polyesters added is 50 to 3000 ppm based on the crude oil. The amount is preferably 100 to 1500 ppm, for example, 300 to 1000 ppm. The amounts are based on the240801

[0094] 10

[0095] hydrophobically modified, hyperbranched polyesters themselves, not including any solvents present and optional further components of the formulation.

[0096] Use as wax inhibitor

[0097] In another embodiment of the invention, the above-detailed hydrophobically modified, hyperbranched polyesters are used to prevent wax deposits on surfaces in contact with crude oil. The use is effectuated by adding at least one of the above-detailed hydrophobically modified, hyperbranched polyesters to the crude oil.

[0098] Preferred formulations and concentrations of use have already been mentioned above.

[0099] In a preferred embodiment of the invention, the oil is crude oil and the formulation is injected into a crude oil pipeline. The injection can preferably be effectuated at the oilfield, i.e. at the start of the crude oil pipeline, but the injection can of course also be effectuated at another site. More particularly, the pipeline may be one leading onshore from an offshore platform, especially when the pipelines are in cold water, for example having a water temperature of less than 10°C, i.e. the pipelines have cold surfaces.

[0100] In a further embodiment of the invention, the formulation is injected into a production well. Here too, the production well may especially be a production well leading to an offshore platform. The injection is preferably effectuated approximately at the site where oil from the formation flows into the production well. In this way, the deposition of paraffins on surfaces can be prevented.

[0101] For use as wax inhibitor, the hydrophobically modified, hyperbranched polyesters or formulations thereof are typically used in such an amount that the amount of the hydrophobically modified, hyperbranched polyesters added is 20 to 1000 ppm based on the crude oil. The amount is for example from 50 to 200 ppm. The amounts are based on the hydrophobically modified, hyperbranched polyesters themselves, not including any solvents present and optional further components of the formulation.

[0102] The invention is illustrated in detail by the examples that follow.

[0103] Examples

[0104] The following chemicals were used for the synthesis of the hydrophobically modified hyperbranched polyesters.

[0105]

[0106] 240801

[0107] 11

[0108] >

[0109] > <

[0110]

[0111] Comparative examples CE 1 to CE 6 and invention examples IE 1 to IE 12

[0112] Synthesis of the hydrophobically modified, hyperbranched polyesters

[0113] Comparative Example CE 1 (according to BASF, WO 2019 / 185401)

[0114] Step 1 : Synthesis of the precursor

[0115] 0.84 g (6.3 mmol) trimethylolpropane, 166.3 g (1.24 mol) dimethylolpropionic acid, 33.1 g (8.3 mmol) polypropyleneglycol (~ 4000 g / mol; Pluriol P4000) and 0.64 g (6.7 mmol) methanesulfonic acid were charged into a 1 L reaction vessel with heating jacket, equipped with thermo-couple, mechanical stirrer and distillation column. The reaction mixture was heated with circulating thermo-oil while purging with nitrogen. At 130 °C the nitrogen purge was stopped and reduced pressure of 500 mbar applied. After 0.5 h the pressure was reduced to 150 mbar, the mixture heated to 160 °C and kept at these conditions until an acid number of 20 mg KOH / g was reached. During this step 18.3 g of water was collected in a flask attached to the distillation column. SEC: Mw = 3811; PD = 2.1

[0116] Step 2: Modification with a linear C22 carboxylic acid

[0117] 357.7 g (1.05 mol) of a C22 carboxylic acid (Radiacid 0560) was added to the precursor prepared in step 1 while the reaction temperature was kept at 110 °C until the carboxylic acid was completely molten. Subsequent, the pressure was reduced to 250 mbar and the reaction mixture heated to 160 °C and kept at these conditions until an acid number of 14 mg KOH / g was reached. During this step 14.9 g of water was collected in a flask attached to the distillation column. The overall reaction time is 9 hours. SEC: Mw = 17273; PD = 2.3240801

[0118] 12

[0119] Comparative Example CE 2

[0120] Step 1 : Synthesis of the precursor

[0121] 17.7 g (0.13 mol) trimethylolpropane, 182.9 g (1.36 mol) dimethylolpropionic acid and 0.65 g (6.8 mmol) methanesulfonic acid were charged into a 1 L reaction vessel equipped with heating jacket, equipped with thermocouple, mechanical stirrer and distillation column. The reaction mixture was heated with circulating thermo-oil while purging with nitrogen. At 130 °C the nitrogen purge is stopped and reduced pressure of 500 mbar applied. After 0.5 h the pressure is reduced to 150 mbar, the mixture heated to 160 °C and kept at these conditions until an acid number of 14 mg KOH / g was reached. During this step 15.9 g of water was collected in a flask attached to the distillation column. SEC: Mw = 1773; PD = 1.4

[0122] Step 2: Modification with a linear C22 carboxylic acid

[0123] 389.4 g (1.15 mol) of a C22 carboxylic acid (Radiacid 0560) was added to the precursor prepared in step 1 while the reaction temperature was kept at 110 °C until the carboxylic acid was completely molten. Subsequent, the pressure was reduced to 250 mbar and the reaction mixture heated to 160 °C and kept at these conditions until an acid number of 15 mg KOH / g was reached. During this step 11.4 g of water was collected in a flask attached to the distillation column. The overall reaction time is 7 hours. SEC: Mw = 7208; PD = 1.5

[0124] Comparative Example CE 3

[0125] Step 1 : Synthesis of the precursor

[0126] 9.0 g (0.07 mol) trimethylolpropane, 7.0 g Hexanediol (0.06 mol), 182.1 g (1.36 mol) dimethylolpropionic acid and 0.65 g (6.8 mmol) methanesulfonic acid were charged into a 1 L reaction vessel equipped with heating jacket, equipped with thermo-couple, mechanical stirrer and distillation column. The reaction mixture was heated with circulating thermo-oil while purging with nitrogen. At 130 °C the nitrogen purge is stopped and reduced pressure of 500 mbar applied. After 0.5 h the pressure is reduced to 150 mbar, the mixture heated to 160 °C and kept at these conditions until an acid number of 14 mg KOH / g was reached. During this step 14.5 g of water was collected in a flask attached to the distillation column. SEC: Mw = 1926; PD = 1.5

[0127] Step 2: Modification with a linear C22 carboxylic acid

[0128] 390.0 g (1.15 mol) of a C22 carboxylic acid (Radiacid 0560) was added to the precursor prepared in step 1 while the reaction temperature was kept at 110 °C until the carboxylic acid was completely molten. Subsequent, the pressure was reduced to 250 mbar and the reaction mixture heated to 160 °C and kept at these conditions until an acid number of 13 mg KOH / g was reached. During this step 16.2 g of water was collected in a flask attached to the distillation column. The overall reaction time is 7 hours. SEC: Mw = 7632; PD = 1.5

[0129] Example IE 1240801

[0130] 13

[0131] Step 1 : Synthesis of the precursor

[0132] 182.0 g (1.36 mol) dimethylolpropionic acid, 14.1 g (0.12 mol) hexanediol and 0.65 g (6.8 mmol) methanesulfonic acid were charged into a 1 L reaction vessel with heating jacket, equipped with thermo-couple, mechanical stirrer and distillation column. The reaction mixture was heated with circulating thermo-oil while purging with nitrogen. At 130 °C the nitrogen purge is stopped and reduced pressure of 500 mbar applied. After 0.5 h the pressure is reduced to 150 mbar, the mixture heated to 160 °C and kept at these conditions until an acid number of 16 mg KOH / g was reached. During this step 19.9 g of water was collected in a flask attached to the distillation column. SEC: Mw = 2018; PD = 1.5

[0133] Step 2: Modification with a linear C22 carboxylic acid

[0134] 390.0 g (1.15 mol) of a C22 carboxylic acid (Radiacid 0560) was added to the precursor prepared in step 1 while the reaction temperature was kept at 110 °C until the carboxylic acid was completely molten. Subsequent, the pressure was reduced to 250 mbar and the reaction mixture heated to 160 °C and kept at these conditions until an acid number of 11 mg KOH / g was reached. During this step 12.3 g of water was collected in a flask attached to the distillation column. The overall reaction time is 6 hours. SEC: Mw = 8883; PD = 1.6

[0135] Example IE 2

[0136] Step 1 : Synthesis of the precursor

[0137] 182.0 g (1.36 mol) dimethylolpropionic acid, 10.0 g (0.08 mol) hexanediol and 0.65 g (6.8 mmol) methanesulfonic acid were charged into a 1 L reaction vessel with heating jacket, equipped with thermo-couple, mechanical stirrer and distillation column. The reaction mixture was heated with circulating thermo-oil while purging with nitrogen. At 130 °C the nitrogen purge is stopped and reduced pressure of 500 mbar applied. After 0.5 h the pressure is reduced to 150 mbar, the mixture heated to 160 °C and kept at these conditions until an acid number of 20 mg KOH / g was reached. During this step 18.8 g of water was collected in a flask attached to the distillation column. SEC: Mw = 2288; PD = 1.5

[0138] Step 2: Modification with a linear C22 carboxylic acid

[0139] 390.0 g (1.15 mol) of a C22 carboxylic acid (Radiacid 0560) was added to the precursor prepared in step 1 while the reaction temperature was kept at 110 °C until the carboxylic acid was completely molten. Subsequent, the pressure was reduced to 250 mbar and the reaction mixture heated to 160 °C and kept at these conditions until an acid number of 10 mg KOH / g was reached. During this step 13.2 g of water was collected in a flask attached to the distillation column. The overall reaction time is 5.5 hours. SEC: Mw = 10040; PD = 1.8240801

[0140] 14

[0141] Example IE 3

[0142] Step 1 : Synthesis of the precursor

[0143] 183.3 g (1.37 mol) dimethylolpropionic acid, 10.0 g (0.08 mol) hexanediol and 0.65 g (6.8 mmol) methanesulfonic acid were charged into a 1 L reaction vessel with heating jacket, equipped with thermo-couple, mechanical stirrer and distillation column. The reaction mixture was heated with circulating thermo-oil while purging with nitrogen. At 130 °C the nitrogen purge is stopped and reduced pressure of 500 mbar applied. After 0.5 h the pressure is reduced to 150 mbar, the mixture heated to 160 °C and kept at these conditions until an acid number of 20 mg KOH / g was reached. During this step 18.0 g of water was collected in a flask attached to the distillation column. SEC: Mw = 2245; PD = 1.5

[0144] Step 2: Modification with mix of linear C22- and C16 carboxylic acid

[0145] 261.8 g (0.77 mol) of a C22 carboxylic acid (Radiacid 0560) and 130.9 g (0.51 mol) palmitic acid were added to the precursor prepared in step 1 while the reaction temperature was kept at 110 °C until the carboxylic acid was completely molten. Subsequent, the pressure was reduced to 250 mbar and the reaction mixture heated to 160 °C and kept at these conditions until an acid number of 15 mg KOH / g was reached. During this step 18.6 g of water was collected in a flask attached to the distillation column. The overall reaction time is 5 hours. SEC: Mw = 7748; PD = 2.0

[0146] Example IE 4

[0147] Step 1 : Synthesis of the precursor

[0148] 182.0 g (1.36 mol) dimethylolpropionic acid, 14.1 g (0.12 mol) 1 ,6-hexanediol and 0.65 g (6.8 mmol) methanesulfonic acid were charged into a 1 L reaction vessel with heating jacket, equipped with thermo-couple, mechanical stirrer and distillation column. The reaction mixture was heated with circulating thermo-oil while purging with nitrogen. At 130 °C the nitrogen purge is stopped and reduced pressure of 500 mbar applied. After 0.5 h the pressure is reduced to 150 mbar, the mixture heated to 160 °C and kept at these conditions until an acid number of 20 mg KOH / g was reached. During this step 16.5 g of water was collected in a flask attached to the distillation column. SEC: Mw = 1836; PD = 1.5

[0149] Step 2: Modification with a combination of saturated (C22) and monounsaturated (C18) acid

[0150] 351.0 g (1.03 mol) of a C22 carboxylic acid (Radiacid 0560) and 39.0 g (0.14 mol) of oleic acid was added to the precursor prepared in step 1 while the reaction temperature was kept at 110 °C until the carboxylic acid was completely molten. Subsequent, the pressure was reduced to 250 mbar and the reaction mixture heated to 160 °C and kept at these conditions until an acid number of 17 mg KOH / g was reached. During this step 15.9 g of water was collected in a flask attached to the distillation column. The overall reaction time is 5 hours. SEC: Mw = 6659; PD = 1.6240801

[0151] 15

[0152] Example CE 4

[0153] Step 1 : Synthesis of the precursor

[0154] 182.0 g (1.36 mol) dimethylolpropionic acid, 14.1 g (0.12 mol) 1 ,6-hexanediol and 0.65 g (6.8 mmol) methanesulfonic acid were charged into a 1 L reaction vessel with heating jacket, equipped with thermo-couple, mechanical stirrer and distillation column. The reaction mixture was heated with circulating thermo-oil while purging with nitrogen. At 130 °C the nitrogen purge is stopped and reduced pressure of 500 mbar applied. After 0.5 h the pressure is reduced to 150 mbar, the mixture heated to 160 °C and kept at these conditions until an acid number of 19 mg KOH / g was reached. During this step 15.0 g of water was collected in a flask attached to the distillation column. SEC: Mw = 1826; PD = 1.5

[0155] Step 2: Modification with a combination of linear carboxylic acid (C18)

[0156] 322.0 g (1.13 mol) of a C18 carboxylic acid (stearic acid, Radiacid 0414) was added to the precursor prepared in step 1 while the reaction temperature was kept at 110 °C until the carboxylic acid was completely molten.

[0157] Subsequent, the pressure was reduced to 250 mbar and the reaction mixture heated to 160 °C and kept at these conditions until an acid number of 15 mg KOH / g was reached. During this step 16.1 g of water was collected in a flask attached to the distillation column. The overall reaction time is 5 hours. SEC: Mw = 5485; PD = 1.5

[0158] Example CE 5

[0159] Step 1 : Synthesis of the precursor

[0160] 182.0 g (1.36 mol) dimethylolpropionic acid, 14.1 g (0.12 mol) 1 ,6-hexanediol and 0.65 g (6.8 mmol) methanesulfonic acid were charged into a 1 L reaction vessel with heating jacket, equipped with thermo-couple, mechanical stirrer and distillation column. The reaction mixture was heated with circulating thermo-oil while purging with nitrogen. At 130 °C the nitrogen purge is stopped and reduced pressure of 500 mbar applied. After 0.5 h the pressure is reduced to 150 mbar, the mixture heated to 160 °C and kept at these conditions until an acid number of 16 mg KOH / g was reached. During this step 16.4 g of water was collected in a flask attached to the distillation column. SEC: Mw = 2022; PD = 1.6

[0161] Step 2: Modification with a combination of linear carboxylic acid (C18) and monounsaturated oleic acid (C18 acid) 214.7 g (0.75 mol) of a C18 carboxylic acid (Stearic acid) and 107.4 g (0.38 mol) oleic acid was added to the precursor prepared in step 1 while the reaction temperature was kept at 110 °C until the carboxylic acid was completely molten. Subsequent, the pressure was reduced to 250 mbar and the reaction mixture heated to 160 °C and kept at these conditions until an acid number of 16 mg KOH / g was reached. During this step 17.5 g of water was collected in a flask attached to the distillation column. The overall reaction time is 5 hours. SEC: Mw = 5892; PD = 1.4

[0162] Example IE 5240801

[0163] 16

[0164] Step 1 : Synthesis of the precursor

[0165] 182.1 g (1.36 mol) dimethylolpropionic acid, 12.7 g (0,08 mol) triethylenglycol and 0.65 g (6.8 mmol) methanesulfonic acid were charged into a 1 L reaction vessel with heating jacket, equipped with thermo-couple, mechanical stirrer and distillation column. The reaction mixture was heated with circulating thermo-oil while purging with nitrogen. At 130 °C the nitrogen purge is stopped and reduced pressure of 500 mbar applied. After 0.5 h the pressure is reduced to 150 mbar, the mixture heated to 160 °C and kept at these conditions until an acid number of 19 mg KOH / g was reached. During this step 16.1 g of water was collected in a flask attached to the distillation column. SEC: Mw = 2290; PD = 1.6

[0166] Step 2: Modification with a combination of linear C22 and C16 carboxylic acid

[0167] 260.1 g (0.76 mol) of a C22 carboxylic acid (Radiacid 0560) and 130.1 g (0.51 mol) palmitic acid were added to the precursor prepared in step 1 while the reaction temperature was kept at 110 °C until the carboxylic acid was completely molten. Subsequent, the pressure was reduced to 250 mbar and the reaction mixture heated to 160 °C and kept at these conditions until an acid number of 14 mg KOH / g was reached. During this step 12.9 g of water was collected in a flask attached to the distillation column. The overall reaction time is 5 hours. SEC: Mw = 9006; PD = 1.7

[0168] Example IE 6

[0169] Step 1 : Synthesis of the precursor

[0170] 182.1 g (1.36 mol) dimethylolpropionic acid, 47.8 g (0.12 mol) Polyethyleneglycol 400 (Pluriol E 400) and 0.65 g (6.8 mmol) methanesulfonic acid were charged into a 1 L reaction vessel with heating jacket, equipped with thermocouple, mechanical stirrer and distillation column. The reaction mixture was heated with circulating thermo-oil while purging with nitrogen. At 130 °C the nitrogen purge is stopped and reduced pressure of 500 mbar applied. After 0.5 h the pressure is reduced to 150 mbar, the mixture heated to 160 °C and kept at these conditions until an acid number of 19 mg KOH / g was reached. During this step 19.4 g of water was collected in a flask attached to the distillation column. SEC: Mw = 1883; PD = 1.5

[0171] Step 2: Modification with a linear C22 carboxylic acid

[0172] 390.0 g (1.15 mol) of a C22 carboxylic acid (Radiacid 0560) was added to the precursor prepared in step 1 while the reaction temperature was kept at 110 °C until the carboxylic acid was completely molten. Subsequent, the pressure was reduced to 250 mbar and the reaction mixture heated to 160 °C and kept at these conditions until an acid number of 13 mg KOH / g was reached. During this step 17.0 g of water was collected in a flask attached to the distillation column. The overall reaction time is 7 hours. SEC: Mw = 6779; PD = 1.5240801

[0173] 17

[0174] Example IE 9

[0175] Step 1 : Synthesis of the precursor

[0176] 182.0 g (1.36 mol) dimethylolpropionic acid, 29.8 g (0.12 mol) Poly-THF 250 and 0.65 g (6.8 mmol) methanesulfonic acid were charged into a 1 L reaction vessel with heating jacket, equipped with thermo-couple, mechanical stirrer and distillation column. The reaction mixture was heated with circulating thermo-oil while purging with nitrogen. At 130 °C the nitrogen purge is stopped and reduced pressure of 500 mbar applied. After 0.5 h the pressure is reduced to 150 mbar, the mixture heated to 160 °C and kept at these conditions until an acid number of 24 mg KOH / g was reached. During this step 18.1 g of water was collected in a flask attached to the distillation column. SEC: Mw = 3592; PD = 2.1

[0177] Step 2: Modification with a linear C22 carboxylic acid

[0178] 390.0 g (1.15 mol) of a C22 carboxylic acid (Radiacid 0560) was added to the precursor prepared in step 1 while the reaction temperature was kept at 110 °C until the carboxylic acid was completely molten. Subsequent, the pressure was reduced to 250 mbar and the reaction mixture heated to 160 °C and kept at these conditions until an acid number of 17 mg KOH / g was reached. During this step 11.7 g of water was collected in a flask attached to the distillation column. The overall reaction time is 5 hours. SEC: Mw = 13903; PD = 2.2

[0179] Example IE 8

[0180] Step 1 : Synthesis of the precursor

[0181] 182.0 g (1.36 mol) dimethylolpropionic acid, 119.3 g (0.12 mol) Poly-THF 1000 and 0.65 g (6.8 mmol) methanesulfonic acid were charged into a 1 L reaction vessel with heating jacket, equipped with thermo-couple, mechanical stirrer and distillation column. The reaction mixture was heated with circulating thermo-oil while purging with nitrogen. At 130 °C the nitrogen purge is stopped and reduced pressure of 500 mbar applied. After 0.5 h the pressure is reduced to 150 mbar, the mixture heated to 160 °C and kept at these conditions until an acid number of 22 mg KOH / g was reached. During this step 16.6 g of water was collected in a flask attached to the distillation column. SEC: Mw = 35405; PD = 13.

[0182] Step 2: Modification with a linear C22 carboxylic acid

[0183] 390.0 g (1.15 mol) of a C22 carboxylic acid (Radiacid 0560) was added to the precursor prepared in step 1 while the reaction temperature was kept at 110 °C until the carboxylic acid was completely molten. Subsequent, the pressure was reduced to 250 mbar and the reaction mixture heated to 160 °C and kept at these conditions until an acid number of 15 mg KOH / g was reached. During this step 15.5 g of water was collected in a flask attached to the distillation column. The overall reaction time is 8.5 hours. SEC: Mw = 67440; PD = 7.5240801

[0184] 18

[0185] Example IE 9

[0186] Step 1 : Synthesis of the precursor

[0187] 182.2 g (1.36 mol) dimethylolpropionic acid, 13.5 g (0.13 mol) 2,2-Dimethylolpropane (Neopentylglycol) and 0.67 g (6.8 mmol) methanesulfonic acid were charged into a 1 L reaction vessel with heating jacket, equipped with thermocouple, mechanical stirrer and distillation column. The reaction mixture was heated with circulating thermo-oil while purging with nitrogen. At 130 °C the nitrogen purge is stopped and reduced pressure of 500 mbar applied. After 0.5 h the pressure is reduced to 150 mbar, the mixture heated to 160 °C and kept at these conditions until an acid number of 17 mg KOH / g was reached. During this step 19.1 g of water was collected in a flask attached to the distillation column. SEC: Mw = 2000; PD = 1.5.

[0188] Step 2: Modification with a linear C22 carboxylic acid

[0189] 390.3 g (1.15 mol) of a C22 carboxylic acid (Radiacid 0560) was added to the precursor prepared in step 1 while the reaction temperature was kept at 110 °C until the carboxylic acid was completely molten. Subsequent, the pressure was reduced to 250 mbar and the reaction mixture heated to 160 °C and kept at these conditions until an acid number of 15 mg KOH / g was reached. During this step 12.9 g of water was collected in a flask attached to the distillation column. The overall reaction time is 6.5 hours. SEC: Mw = 6712; PD = 1.6.

[0190] Example IE 10

[0191] Step 1 : Synthesis of the precursor

[0192] 181.9 g (1.36 mol) dimethylolpropionic acid, 17.4 g (0.20 mol) 2-Methylpropane-1 ,3-diol and 0.67 g (6.8 mmol) methanesulfonic acid were charged into a 1 L reaction vessel with heating jacket, equipped with thermo-couple, mechanical stirrer and distillation column. The reaction mixture was heated with circulating thermo-oil while purging with nitrogen. At 130 °C the nitrogen purge is stopped and reduced pressure of 500 mbar applied. After 0.5 h the pressure is reduced to 150 mbar, the mixture heated to 160 °C and kept at these conditions until an acid number of 18 mg KOH / g was reached. During this step 13.9 g of water was collected in a flask attached to the distillation column. SEC: Mw = 1744; PD = 1.5.

[0193] Step 2: Modification with a linear C22 carboxylic acid

[0194] 390.3 g (1.15 mol) of a C22 carboxylic acid (Radiacid 0560) was added to the precursor prepared in step 1 while the reaction temperature was kept at 110 °C until the carboxylic acid was completely molten. Subsequent, the pressure was reduced to 250 mbar and the reaction mixture heated to 160 °C and kept at these conditions until an acid number of 15 mg KOH / g was reached. During this step 15.4 g of water was collected in a flask attached to the distillation column. The overall reaction time is 6.5 hours. SEC: Mw = 6658; PD = 1.6.240801

[0195] 19

[0196] Example IE 11

[0197] Step 1 : Synthesis of the precursor

[0198] 182.0 g (1.36 mol) dimethylolpropionic acid, 47.7 g (0.12 mol) polypropyleneglycol (Pluriol P400) and 0.65 g (6.8 mmol) methanesulfonic acid were charged into a 1 L reaction vessel with heating jacket, equipped with thermocouple, mechanical stirrer and distillation column. The reaction mixture was heated with circulating thermo-oil while purging with nitrogen. At 130 °C the nitrogen purge is stopped and reduced pressure of 500 mbar applied. After 0.5 h the pressure is reduced to 150 mbar, the mixture heated to 160 °C and kept at these conditions until an acid number of 24 mg KOH / g was reached. During this step 15.6 g of water was collected in a flask attached to the distillation column. SEC: Mw = 2101; PD = 1.6

[0199] Step 2: Modification with a linear C22 carboxylic acid

[0200] 390.0 g (1.15 mol) of a C22 carboxylic acid (Radiacid 0560) was added to the precursor prepared in step 1 while the reaction temperature was kept at 110 °C until the carboxylic acid was completely molten. Subsequent, the pressure was reduced to 250 mbar and the reaction mixture heated to 160 °C and kept at these conditions until an acid number of 14 mg KOH / g was reached. During this step 14,6 g of water was collected in a flask attached to the distillation column. The overall reaction time is 5.5 hours. SEC: Mw = 8028; PD = 1.8

[0201] Example IE 12

[0202] Step 1 : Synthesis of the precursor

[0203] 182.4 g (1.36 mol) dimethylolpropionic acid, 16.9 g (0.13 mol) dipropylenglycol and 0.65 g (6.8 mmol) methanesulfonic acid were charged into a 1 L reaction vessel with heating jacket, equipped with thermo-couple, mechanical stirrer and distillation column. The reaction mixture was heated with circulating thermo-oil while purging with nitrogen. At 130 °C the nitrogen purge is stopped and reduced pressure of 500 mbar applied. After 0.5 h the pressure is reduced to 150 mbar, the mixture heated to 160 °C and kept at these conditions until an acid number of 21 mg KOH / g was reached. During this step 12.3 g of water was collected in a flask attached to the distillation column. SEC: Mw = 2173; PD = 1.57

[0204] Step 2: Modification with a combination of a C22 carboxylic acid (Radiacid 0560) and palmitic acid (C16 acid) 312.7 g (0.92 mol) of a C22 carboxylic acid (behenic acid) and 58.9 g (0.23 mol) palmitic acid was added to the precursor prepared in step 1 while the reaction temperature was kept at 110 °C until the carboxylic acid was completely molten. Subsequently, the pressure was reduced to 250 mbar and the reaction mixture heated to 160 °C and kept at these conditions until an acid number of 11 mg KOH / g was reached. During this step 18.2 g of water was collected in a flask attached to the distillation column. The overall reaction time is 5.5 hours. SEC: Mw = 7973; PD = 1.5

[0205] Comparative Example CE 6240801

[0206] 20

[0207] Step 1 : Synthesis of the precursor

[0208] 182.0 g (1.36 mol) dimethylolpropionic acid, 36.2 g (9.1 mmol) Pluriol P4000 and 0.65 g (6.8 mmol) methanesulfonic acid were charged into a 1 L reaction vessel with heating jacket, equipped with thermo-couple, mechanical stirrer and distillation column. The reaction mixture was heated with circulating thermo-oil while purging with nitrogen. At 130 °C the nitrogen purge is stopped and reduced pressure of 500 mbar applied. After 0.5 h the pressure is reduced to 150 mbar, the mixture heated to 160 °C and kept at these conditions until an acid number of 19 mg KOH / g was reached. During this step 17.8 g of water was collected in a flask attached to the distillation column. SEC: Mw = 4647; PD = 2.2

[0209] Step 2: Modification with a linear C22 carboxylic acid

[0210] 390. g (1,15 mol) of a C22 carboxylic acid (Radiacid 0560) was added to the precursor prepared in step 1 while the reaction temperature was kept at 110 °C until the carboxylic acid was completely molten. Subsequent, the pressure was reduced to 250 mbar and the reaction mixture heated to 160 °C and kept at these conditions until an acid number of 16 mg KOH / g was reached. During this step 10.4 g of water was collected in a flask attached to the distillation column. The overall reaction time is 9.5 hours. SEC: Mw = 17267; PD = 2.3

[0211] Sample Characterization

[0212] Acid number: a sample of the precursor or the hydrophobically modified polymer, respectively, weighted to an accuracy of 1 mg was dissolved in a mix of 50 ml THF and 5 ml methanol I water (100:5) and titrated with an automatic titrator from Methrohm (Titrando 888 with Tiamo-software v. 2.5) against 0.1 n KOH in methanol, using as electrode "Solvotrode # 6.0229.010" which is designed for non-aqueous pH-titrations. The acid number (AN) is expressed as consumed amount of KOH in mg per gram substance, according

[0213] AN = (consumption KOH [ml] x c(KOH) x 56.1) / Substance [g]

[0214] with e = 0.1 mol / L and 56.1 as constant for conversion (molar weight KOH = 56.1 g / mol)

[0215] Size Exclusion Chromatography (SEC) was performed with the products after dilution with THF using a Separation Module Alliance 2695 from Waters with Waters Detectors UV 2489 (wavelength 210 nm and 254 nm) and Rl 2414. Software: Empower 3 FR4. Chromatographic conditions: Precolumn PSS SDV 5pim 8x50mm, GPC columns PSS SDV 106A8x300mm, PSS SDV 103A 8x300mm, PSS SDV 102A8x300mm. Eluent: Tetrahydrofuran +0,1 Vol-% Trifluoroacetic acid with a flow rate of 0.8 mL / min at 35 °C. Injection volume: 100 piL Detection: Rl; UV = 254 nm within the retention time of 25 - 45 min and an overall detection time of 50 min. Calibration was done with 12 individual PMMA standard polymers in the range of Mp = 102 to 898000 Da.

[0216] General procedure for the dissolution of the polymers

[0217] When the polycondensation reaction was finished, the reaction mixture was cooled to ~ 120 °C prior dissolution in a commercially available aromatic hydrocarbon solvent (Solvesso™ 150 ND, flashpoint 64 °C, distillation range: 180240801

[0218] 21

[0219] °C (initial boiling point) to 193 °C (dry point), aromatics > 99 wt.%, < 1% naphthalene), yielding to products of 50 % strength.

[0220] Sample preparation for centrifugation test

[0221] The hydrophobically modified polyester in Solvesso™ 150 ND (50 % strength) was further diluted with Xylene to yield to a 25 % hydrophobically modified polyester in a Solvesso 150ND I Xylene mix. 8 g of the so prepared sample was filled into a centrifugation vial of glass and centrifuged for 1 h at ambient temperature (25 °C) and 1711 ref. The centrifuge was purchased from Hettich-Zentrifugen, model Rotana 460R.

[0222] <

[0223] <

[0224] <

[0225] <

[0226]

[0227] 240801

[0228] 22

[0229]

[0230] Table 1: Composition of polymers, determined non-flow point (NFP; see also Fig. 1) and result of centrifugation test

[0231] Performance test of the hyperbranched polycondensates as pour point depressant (PPD)

[0232] Tests were carried out using the hydrophobically modified hyperbranched polyester dissolved in Solvesso™ 150 ND (50 % strength) as described above.

[0233] Crude oil: For the tests, a crude oil from the "Landau” oilfield in the south-west Germany (Wintershall Holding GmbH) was used. The crude was homogenized at 75 °C for two hours within the sample container. The density and API gravity were determined with a device, model Anton Paar DMA 4500.

[0234] Landau Crude Oil properties:

[0235]

[0236] Table 2: Crude oil characteristics

[0237] The pour point (PP) was measured in Landau oil at a polymer concentration of 500 ppm (1000 ppm of product dissolved in Solevesso™ 150 ND). The pour point was determined by using the automatic equipment from PSL Systemtechnik GmbH Pour Point Tester model 45150. The operation principle is based on the rotational method ASTM D5985. After inserting a sample to the pour point tester, the sample is heated to 70 °C and subsequently cooled until the non-flow point is reached. Simultaneously, the sample cup is slowly rotated at 0.1 rpm. A temperature sensor inserted in the sample records the sample temperature and at the same time serves as a pendulum. As the viscosity of the sample increases the temperature sensor is deflected by the rotational motion. At a certain deflection, the upper part of the sensor passes a light barrier which indicates the occurrence of the so-called non-flow point, and the corresponding temperature is recorded. Thereof, the ASTM pour point value is calculated by increasing the non-flow point to the next higher value which is divisible by 3 without remainder: modulus 3 (pour point) = 0. Finally, the sample is heated up again to 70 °C to detach the measuring cup.

[0238] The results are summarized in Figure 1.

Claims

CLAIMS1. Hydrophobi cally modified, hyperbranched polyester obtainable by(a) reacting a hydroxyl group containing carboxylic acid (B) having one or more carboxylic acid group and two or more hydroxyl groups, with a diol (A) having a number average molecular weight Mn of from 85 to 2500 g / mol, and(b) reacting the mixture resulting from step (a) with one or more hydrophobic, linear monocarboxylic acid (C), wherein 50 to 100 mol % of the of the monocarboxylic acids (C) are linear aliphatic, saturated monocarboxylic acid with between 20 to 36 carbon atoms, based on the total of monocarboxylic acids (C).wherein the molar ratio of carboxylic acid (B) and diol (A) is from > 5:1 to < 25:1, andwherein in step (a) no polyols having more than 2 hydroxyl groups are present.

2. The hydrophobically modified, hyperbranched polyester according to claim 1, wherein the molar ratio of carboxylic acid (B) and diol (A) is from > 10:1 to < 25:1, preferably 11:1 to 20:1.

3. The hydrophobically modified, hyperbranched polyester according to claim 1 or 2, wherein up to 50 mol-% the of the monocarboxylic acids (C) are linear aliphatic, saturated or unsaturated monocarboxylic acids with between 12 to 18 carbon atoms, based on the total of monocarboxylic acids (C).

4. The hydrophobically modified, hyperbranched polyester according to any one of claims 1 to 3, wherein step (a) is carried out at a reaction temperature of 80 to 250°C, preferably 100 to 200°C, more preferably 120 to 180°C.

5. The hydrophobically modified, hyperbranched polyester according to any one of claims 1 to 4, wherein step (a) is carried out in the presence of an acid.

6. The hydrophobically modified, hyperbranched polyester according to any one of claims 1 to 5, wherein the hyperbranched polyester mixture obtained in step (b) has an acid number of below 100 mg KOH / g, preferably in the range of from 50 to 0 mg KOH / g.

7. The hydrophobically modified, hyperbranched polyester according to any one of claims 1 to 6, wherein the hydroxyl group containing carboxylic acid (B) having one or more carboxylic acid group and two or more hydroxyl groups is a hydroxyl group containing carboxylic acid (B) having one carboxylic acid group and exactly two hydroxyl groups, preferably dimethylolpropionic acid.

248. The hydrophobically modified, hyperbranched polyester according to claim any one of claims 1 to 7, wherein the diol (A) is selected from the group consisting of 1 ,6-hexanediol, 1 ,8-octanediol, cyclohexanediols, diethylene glycol, triethylene glycol, dipropylene glycol, tripropylene glycol, 2,2-dimethylolpropane, 2-methyl- 1 ,3-propanediol, polyethylene glycol polypropylene glycol and polyTHF.

9. The hydrophobically modified, hyperbranched polyester according to claim 8, wherein the diol (A) is selected from the group of polyethylene glycol, polypropylene glycol and polyTHF having a number average molecular weight Mn of 250 to 2500 g / mol, preferably from 250 to 1500 g / mol.

10. A method of preparing the hydrophobically modified, hyperbranched polyester according to any one of claims 1 to 9, comprising steps (a) and (b) as defined in any one of claims 1 to 9.

11. A formulation comprising• a hydrocarbon or a mixture of different hydrocarbons having a boiling point of > 100°C, and• a hydrophobically modified, hyperbranched polyester according to any one of claims 1 to 9.

12. The use of the hydrophobically modified, hyperbranched polyesters according to any one of claims 1 to 9 as pour point depressant for crude oil.

13. The use of the hydrophobically modified, hyperbranched polyesters according to any one of claims 1 to 9 as wax inhibitor for crude oil.

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