EA045907B1 - PARAFFIN DEPOSITION INHIBITORS WITH IMPROVED FLUIDITY - Google Patents

Description

The present invention describes wax inhibitors that facilitate low temperature operation and can be used as a low temperature flow improver, pour point depressant, viscosity reducer, and the like. to improve the properties of paraffin-containing hydrocarbon liquids.

Crude oil, its distillates and distillation residues are complex mixtures of various types of substances, such as saturated and unsaturated hydrocarbons, aromatics, resins and asphaltenes. Some of them may cause problems during production, transportation, storage and/or further processing.

In particular, long-chain n-paraffins containing at least 18 carbon atoms tend to crystallize and form waxy solids when the oil cools. The solubility of these components, for example in crude oil, is highly dependent on temperature. They are generally soluble in crude oil under well conditions, i.e. at high temperature and high pressure. However, when oil is brought to the surface, its temperature and pressure drop. When the temperature drops below the oil's specific wax formation temperature, the wax begins to crystallize in the form of thin plates, flakes and/or fine needles. Upon further cooling, these platelets, flakes and/or needles transform into a three-dimensional network in which a relatively large number of liquid components are included and retained. Accordingly, oil loses its fluidity, even though most of the oil remains liquid. As a result, transportation through pipelines and other production equipment may be impaired, and in storage facilities significant quantities of oil may be retained in waxes, which crystallize particularly near the walls of the storage facility. This phenomenon is often called gelation. Gelation is not limited to crude oil, but is also observed in heavy crude oil products such as middle distillates, heavy fuel oils, fuel oils, marine boiler oils and bottoms, which contain large amounts of n-paraffins and suffer from this phenomenon.

Flow problems that are caused by gelation of petroleum products can be reduced in a variety of ways, including heating pipelines and/or storage facilities, diluting the petroleum with a solvent, or adding so-called wax inhibitors. Wax inhibitors prevent the gelation of petroleum products by modifying the crystal structure of waxes that precipitate when cooled. In some cases, these additives promote the formation of large numbers of small wax crystals that are too small to form a gel; they partially disrupt further crystal growth and prevent the formation of large plates and/or flakes. By both of these mechanisms, the formation of a three-dimensional network of paraffin crystals (wax) can be delayed or even prevented. Since additives of this kind usually lower the pour point of oil, they are also called oil pour point depressants (PPDs). Pour point is the lowest temperature at which an oil sample is still fluid during cooling. The pour point of oil can be determined, for example, according to DIN ISO 3016, ASTM D5853 or ASTM D97.

Most conventional wax inhibitors are oil-soluble synthetic polymer compounds, e.g., ethylene copolymers with vinyl esters and/or alkyl(meth)acrylates, poly(alkyl(meth)acrylates), ethylene copolymers with grafted alkyl(meth)acrylates, esterified, amidated and/or imidized copolymers of maleic acid and olefins, and alkylphenol-aldehyde resins.

However, wax inhibitor technology based on synthetic polymer compounds suffers from the disadvantage that these solvent-free polymers are solids or at least highly viscous liquids at ambient temperatures. Solvent-free polymers typically have melting points above 40°C and often even above 60°C. Therefore, transporting wax inhibitor from tanks (fixed or truck mounted) after storage or transportation, and pumping wax inhibitor to the point of application, requires precautions such as heating and/or dilution with a solvent. Accordingly, most common wax inhibitors are applied in highly dilute formulations with active concentrations typically below 50 wt.% and often between 3 and 30 wt.%. Because common polymer pour point depressants are typically oil-soluble, their formulations in organic, preferably aromatic, solvents such as toluene, xylene or xylene tails are the preferred choice. However, many of the pour point depressants and wax inhibitors currently available on the market cure at temperatures ranging from 5 to 35°C, making such systems not particularly useful in low temperature areas or winter conditions. Alternatively, dispersions of pour point depressants in water and/or other polar solvents having low solubility of the pour point depressants have also been proposed. Of course, highly dilute formulations in turn introduce other disadvantages, including solvent costs, storage, transportation and large volume applications.

Another approach to inhibiting paraffin deposition and, accordingly, lowering the temperature

- 1 045907 ry of oil solidification is the use of specific surfactants. These preferentially monomeric additives have a long-chain hydrocarbyl group that is capable of adsorbing or cocrystallizing with waxes, and a polar group that prevents other waxes from attaching to the already formed crystal.

US 3,169,980 describes polyamides formed from a polyalkylene polyamine and a fatty acid mixture containing primarily branched chain fatty acids containing 12-30 carbon atoms, and wherein the polyamides contain 1-3 amino groups in addition to amide groups. Polyamides can be used as pour point depressants for base oils with lubricating viscosity and in hydrocarbon fuels.

However, large quantities of such polyamides are required to effectively lower the pour point, making the process commercially unattractive, particularly for processing fossil feedstocks such as crude oil. In another approach, the reaction products of fatty acids with polyamines were used in combination with well-known polymeric wax inhibitors. In some cases, synergistic effects on the pour point of treated crude oil have been reported.

EP 0326356 demonstrated further reductions in cold filterability point (CFPP) and boiler fuel pour point when an oleic acid oleyl imidazoline salt was used in addition to a cross-linked ester compound and a polymer flow improver.

WO 98/33846 discloses dispersions of ester polymers (for example, poly(alkyl acrylates)) for reducing the formation of wax or deposits in wax-containing petroleum, where the ester polymer is present in the form of solid particles or in the form of droplets of a solution or suspension of the ester polymer in the first liquid, dispersed as an emulsion in a second liquid. Dispersions may also contain a monomer additive with a long chain hydrocarbon group containing at least 10 carbon atoms and a polar group. A polar group may contain one or more nitrogen atoms, for example, as part of a primary, secondary or tertiary amino group, or as part of an amide group. This may be a polyamine having a long chain hydrocarbon group directly attached to one nitrogen atom, an amidoamine, for example N-talloyl-1,3propylene diamine, or an N-heterocyclic compound with a long chain aliphatic hydrocarbyl, for example N2-aminoethyl-2-oleyl- imidazoline.

WO 2004/037953 discloses reaction products of fatty acids and hydroxyalkylamines or aminoalkylamines to further improve the cold flow of fuels containing an EVA copolymer.

US 2007/0051033 discloses a method of lowering the pour point and/or inhibiting or suppressing the formation of wax deposits in liquid hydrocarbons such as crude oil and fuel oils using imidazolines. It also discloses a method for increasing the effectiveness of a non-imidazoline wax inhibitor, e.g., acrylate copolymer, alkyl acrylate-vinylpyridine copolymer, ethylene-vinyl acetate copolymer, maleic anhydride ester copolymer, branched polyethylene, naphthalene, anthracene, microcrystalline wax and/or asphaltene, by adding imidazoline to it. The combination of an imidazoline and a non-imidazoline wax inhibitor demonstrates a synergistic reduction in the pour point of oil. These imidazolines can be prepared by reacting a polyamine with a fatty acid.

WO 2013/123160 discloses lubricant compositions containing esterified copolymers having a backbone containing units formed from an α-olefin monomer and an ethylenically unsaturated carboxylic acid or a derivative thereof. These preparations may further contain a corrosion inhibitor, such as a fatty acid polyamine condensate, and/or a pour point depressant.

WO 2014/071041 discloses a method for reducing the viscosity of heavy bottom hydrocarbons, comprising mixing the heavy bottom hydrocarbons with an additive containing: a first component selected from the group consisting of optionally alkoxylated alkylphenol-aldehyde (amine) resins, α-olefin copolymers with maleic anhydride, and graft polymers including half-ester/amide and full-ester/amide derivatives; and a second component which is a synergist and is selected from the group consisting of polyamines, amidoamines, imidazolines and combinations thereof. When the synergist is an amidoamine, it may be a tallow fatty acid amide and a polyamine; when the synergist is an imidazoline, it can be obtained from tallow amidoamine fatty acid and a polyamine. The only example given is a combination of an alkoxylated phenolic resin and an imidazoline.

However, there is a continuing need for more effective means of reducing the pour point of wax-containing hydrocarbon fluids and inhibiting or suppressing wax deposits therein. This also includes additives that can further reduce the temperature

- 2 045907 hardening agents, additives that are more effective in inhibiting and/or suppressing the formation of paraffin deposits, additives that provide the same effect at lower dosages, additives that can be applied (pumped) at lower temperatures, and/or additives that are suitable for processing a wider range of different hydrocarbon liquids. Particularly problematic hydrocarbon liquids to be processed are heavy and extra-heavy crude oils, and especially those containing a high percentage of waxes, e.g. more than 40% and in particular more than 50% waxes, and grades containing large amounts of waxes and asphaltenes, e.g. , with a total amount of paraffins and asphaltenes of more than 65%, and in particular - more than 70%, where the content of paraffins (saturated) and asphaltenes is determined by analysis using the SARA method. In addition, there remains a need for wax inhibitors that are more convenient to use. This may manifest itself, for example, in a decrease in the pour point of an additive having the same concentration of a polymer active, or in a decrease in the viscosity of an additive having the same concentration of a polymer active at a certain temperature, or vice versa - in a higher content of the active in an additive having the same pour point and/or viscosity. Both options are desirable because they facilitate logistics, including a reduction in warehouse space and transportation costs.

Accordingly, there is a need for concentrated wax inhibitors that are pumpable and preferably flowable at low temperatures, such as ambient temperature, without the need to heat them. Preferably, such concentrated wax inhibitors should be capable of being pumped, for example, at temperatures below 25°C, more preferably below 20°C, even more preferably below 15°C and in extreme cases even below 10°C, or even below 0 °C, while maintaining a high content of the asset. Likewise, such additives should be highly soluble in the wax-containing hydrocarbon liquid being processed at these low temperatures. Likewise, the development of wax inhibitors that can further reduce the pour point is desirable.

Surprisingly, it was discovered that a composition containing a polymeric paraffin deposition inhibitor and a minor amount of a co-additive, which is a reaction product of a carboxylic acid containing a cycloaliphatic structural unit with a polyamine, solves many of these problems. In such a formulation (composition), the pour point and viscosity of the polymer paraffin deposition inhibitor are reduced compared to a composition that does not contain the specified co-additive, and therefore its workability at low temperatures increases. In additives containing two or more polymeric wax inhibitors with limited compatibility, the addition of said co-additive improves polymer compatibility and results in clear formulations having reduced viscosity. In addition, the presence of this additive significantly improves the dissolution of the polymeric wax inhibitor in the paraffin-containing hydrocarbon liquid. In addition, the presence of said additive in such a composition synergistically increases the effectiveness of the polymeric wax inhibitor in wax-containing hydrocarbon fluids and, in particular, in mineral oils, such as crude oil, and in fluids derived from mineral oil.

In a first aspect of the present invention, there is described a wax inhibitor composition comprising

A) the reaction product obtained by the reaction

i) a carboxylic acid containing an optionally substituted cycloaliphatic hydrocarbyl (hydrocarbon) residue, with ii) an alkylene polyamine,

B) a polymeric wax inhibitor, and

C) organic solvent.

In a second aspect, the present invention describes the use of a reaction product (A) obtained by reacting a carboxylic acid containing an optionally substituted cycloaliphatic hydrocarbyl moiety (i) with an alkylene polyamine (ii) to reduce the pour point and/or viscosity of a polymeric wax inhibitor (B ), where (A) and/or (B) are dissolved or dispersed in an organic solvent (C).

In a third aspect, the present invention describes a method for reducing the viscosity of a polymeric wax inhibitor (B) comprising mixing the polymeric wax inhibitor (B) with a reaction product (A) obtained by reacting a carboxylic acid containing an optionally substituted cycloaliphatic hydrocarbyl moiety (i), with an alkylene polyamine (ii), where (A) and/or (B) are dissolved or dispersed in an organic solvent (C).

In a fourth aspect, the present invention describes the use of a reaction product (A) obtained by reacting a carboxylic acid containing an optionally substituted cycloaliphatic hydrocarbyl moiety (i) with an alkylene polyamine (ii) to improve the dissolution of a polymeric wax inhibitor (B) in a wax-containing hydrocarbon liquid , where (A) and/or (B) are dissolved or dispersed in an organic solvent (C).

In a fifth aspect, the present invention describes a method for further improving the cold flow of oil and/or oil-derived liquid containing a polymeric scale inhibitor

- 3 045907 paraffins (B), where the method involves mixing the reaction product (A), obtained by reacting a carboxylic acid containing an optionally substituted cycloaliphatic hydrocarbyl residue (i), with an alkylene polyamine (ii), with a paraffin-containing hydrocarbon liquid containing a polymeric scale inhibitor paraffins (B).

In a sixth aspect, the present invention describes a paraffin-containing hydrocarbon liquid containing

A) the reaction product obtained by the reaction

i) a carboxylic acid containing an optionally substituted cycloaliphatic hydrocarbyl residue, with ii) an alkylene polyamine, and

B) polymeric wax inhibitor.

In a seventh aspect, the present invention describes the use of the wax inhibitor composition according to the first aspect of the present invention as a pour point depressant for a wax-containing hydrocarbon liquid.

In an eighth aspect, the present invention describes a method for lowering the pour point of a paraffin-containing hydrocarbon liquid by adding the wax deposition inhibitor composition of the first aspect of the present invention to the paraffin-containing hydrocarbon liquid.

The additional improvement in cold flow means that the pour point of a wax-containing hydrocarbon liquid containing (A) and (B) is lower than the pour point of a wax-containing hydrocarbon liquid containing only the same amount of (B). Hereinafter, the reaction product obtained by reacting carboxylic acid (i), containing an optionally substituted cycloaliphatic hydrocarbyl residue, with an alkylene polyamine (ii) is also referred to as co-additive (A).

Co-additive (A)

Preferred reaction products obtained by reacting a carboxylic acid containing an optionally substituted cycloaliphatic hydrocarbyl (hydrocarbon) moiety (i) with an alkylene polyamine (ii) include amidoamines, imidazolines, and mixtures thereof.

In a first preferred embodiment, the reaction product (A) of a carboxylic acid containing an optionally substituted cycloaliphatic hydrocarbyl moiety (i) and an alkylene polyamine (ii) is an amidoamine of general formula (1)

R ¹ -C(=0)-NR ² -(CH2)o-[NR ³ -(CH2)m] _P -NR ⁴ R ⁵ (1) where R ¹ is an optionally substituted hydrocarbyl residue containing 5-70 atoms carbon, which contains at least one cycloaliphatic structural fragment,

R ² and R ³ are independently selected from hydrogen and a hydrocarbyl residue containing 1 to 20 carbon atoms,

R ⁴ represents hydrogen or a hydrocarbyl residue containing 1-20 carbon atoms,

R ⁵ , regardless of R ⁴ , is selected from hydrogen, an optionally substituted hydrocarbyl moiety containing 1-20 carbon atoms, and an acyl group having the structure -C(=O)-R ¹ , with the proviso that R ⁴ and R ⁵ together can form A 5- or 6-membered ring, o is an integer from 2 to 5, and preferably 2 or 3, m is an integer from 2 to 5, and preferably 2 or 3, and p is 0 or an integer from 1 to 10, and preferably an integer from 1 to 3.

In a second preferred embodiment, the reaction product (A) of a carboxylic acid containing an optionally substituted cycloaliphatic hydrocarbyl moiety (i) and an alkylene polyamine (ii) is an imidazoline of general formula (2):

where R ¹ , R ² , R ³ , R ⁴ , R ⁵ and m have the same meanings as given above for the general formula (1), and q is equal to 0 or an integer from 1 to 9, and is preferably equal to 1 or 2 .

The reaction products of formulas (1) and (2) can be obtained by reacting a carboxylic acid containing an optionally substituted cycloaliphatic hydrocarbyl moiety (i) with an alkylene polyamine (ii). While low reaction temperature promotes the formation of amidoamines of formula (1), high temperature and/or increased reaction time promotes the formation of cyclic imidazolines of formula (2). In a preferred embodiment, co-additive (A) contains both amidoamines of formula (1) and imidazolines of formula (2). Preferably, the ratio of amidoamines (1) to imidazolines (2) is between 50:1 and 1:20, more preferably between 20:1 and 1:10, more preferably between 10:1 and 1:5, and especially preferably between 5: 1 and 1:2 parts by weight of active ingredients, for example between 50:1 and 1:10, or between 50:1 and 1:5, or between 50:1 and 1:2, or me

- 4 045907 waiting for 20:1 and 1:20, or between 20:1 and 1.5, or between 20:1 and 1:2, or between 10:1 and 1: 20, or between 10:1 and 1: 10, or between 10:1 and 1:1, or between 5:1 and 1:20, or between 5:1 and 1:10, or between 5:1 and 1:5 parts by mass of active ingredients.

Cycloaliphatic carboxylic acids (i)

In a preferred embodiment, the carboxylic acid (i) used to prepare additive (A) contains an optionally substituted cycloaliphatic hydrocarbyl moiety containing from 6 to 70, more preferably from 10 to 50 and especially preferably from 12 to 40 carbon atoms, e.g. 6 to 50, or 6 to 40, or 10 to 70, or 10 to 40, or 12 to 70, or 12 to 50 carbon atoms. Preferably, the cycloaliphatic structural moiety is connected to the carboxyl group either directly through a C-C bond or through a spacer (connecting moiety). Preferred spacers are alkylene groups containing from 1 to 10, and preferably from 1 to 5 carbon atoms.

In a preferred embodiment, carboxylic acid (i) contains a monocyclic structural moiety. In a more preferred embodiment, carboxylic acid (i) contains a polycyclic structural moiety. Preferred polycyclic structural units contain 2-10 rings, and more preferably 3-6 rings, for example 2-6 rings, and especially preferably 2 or three rings. When two or more rings are present, they are preferably annulated through two atoms common to the rings. In a more preferred embodiment, each cyclic hydrocarbyl moiety is a five- and/or six-membered ring. In a more preferred embodiment, carboxylic acid (i) contains at least two five- and/or six-membered rings, preferably connected to each other through two vicinal carbon atoms. Preferably, the cycloaliphatic structural units contain at most one heteroatom, such as an oxygen or nitrogen atom, but more preferably all atoms in the rings are carbon atoms. The cycloaliphatic hydrocarbyl moiety in a carboxylic acid may be saturated or unsaturated. Preferably, the unsaturated cycloaliphatic hydrocarbyl residues contain one, two or three C=C double bonds. Double bonds may be found in or attached to cyclic units, but each ring contains a maximum of one double bond.

In a preferred embodiment, the cycloaliphatic hydrocarbyl moiety in the carboxylic acid (i) contains one or more additional substituents. Examples of preferred additional substituents are alkyl groups containing 1-10 carbon atoms, alkenyl groups containing 2-10 carbon atoms, hydroxyl, alkoxy group and halogen such as chlorine, fluorine or bromine. In a particularly preferred embodiment, the cycloaliphatic structural moiety contains at least one alkyl group containing 1-10 carbon atoms, or an alkenyl group containing 2-10 carbon atoms.

Preferred carboxylic acids (i) for preparing co-additive (A) are naphthenic acids and resin acids. Commercially available mixtures of these acids are particularly preferred.

In a first preferred embodiment, the carboxylic acid (i) is naphthenic acid. The term naphthenic acid refers to a group of carboxylic acids present in crude oil, which are naphthenes (cycloparaffins) containing a carboxyl group. They may contain one or more cycloaliphatic structural units. The cycloaliphatic structural moiety (fragment) includes one or more cyclopentane and cyclohexane rings. In naphthenic acids containing two or more cyclic moieties, they are preferably fused. The carboxyl group may be linked directly to the cycloaliphatic moiety or to an alkyl moiety linked to the cycloaliphatic moiety. In a preferred embodiment, the carboxyl group is attached to the alkyl side chain rather than directly to the ring. Preferred naphthenic acids consist primarily of alkyl-substituted cycloaliphatic carboxylic acids.

Naphthenic acids are described by the general formula C _n F _2n+z O ₂ , in which n is the number of carbon atoms and z is a negative integer that represents the deficiency of hydrogen atoms resulting from ring formation. The absolute value of z divided by 2 gives the number of rings in a particular compound. For example, z is -2 in monocyclic naphthenic acids, -4 in bicyclic naphthenic acids, -6 in tricyclic acids, and -8 in tetracyclic acids. In preferred naphthenic acids, n is an integer from 7 to 71, more preferably from 11 to 51, and especially preferably from 13 to 41, for example from 7 to 51, or from 7 to 41, or from 11 to 71, or from 11 to 41, or 13 to 71, or 13 to 51. Preferably, z is an integer between -2 and -12, such as -2, -4, -6, -8, -10 or -12.

Examples of the chemical structures of naphthenic acids are given below, where R ⁶ represents an alkyl residue containing from 1 to 20 carbon atoms, and s is zero or an integer between 1 and 10, and preferably between 1 and 4. The formulas of different naphthenic acids are grouped by family rings, i.e. according to general structures having different numbers of rings (z).

- 5 045907

It has been shown that the use of a mixture of two or more individual naphthenic acids is particularly preferred. Acids may vary, for example, in the number of carbon atoms, number of ring members, and/or stereochemistry. For example, for a given z homolog, there is more than one isomer, and the molecular weights differ by 2 mass units (H ₂ ) between the z series and 14 mass units (CH ₂ ) between the n series.

In a more preferred embodiment, the naphthenic acids described above are reacted with an alkylene polyamine (ii) in a mixture with a minor amount of an acyclic carboxylic acid of the formula _{CnH2n + zO2} , where z is zero. These acyclic compounds are highly branched, unlike fatty acids, and are often associated with cyclic naphthenic acids. Preferably, the content of acyclic components in the mixture of cyclic and non-cyclic naphthenic acids is below 50 mol%, more preferably below 30 mol%, and especially preferably below 25 mol%.

Naphthenic acids can be obtained by extraction from mineral oils, such as crude oil or its distillates such as diesel fuel, jet fuel and kerosene. The main fraction is carboxylic acids with a carbon skeleton containing from 7 to about 30 carbon atoms per molecule, and in particular from 10 to about 22 carbon atoms per molecule, for example from 7 to 22 carbon atoms per molecule or from 9 to about 30 carbon atoms per molecule. The composition of naphthenic acid mixtures extracted from mineral oils can vary depending on the composition of the crude oil as well as the extraction method. Naphthenic acids isolated from crude oil may contain, for example, components with a carbon number primarily in the range of C6 to _C16 (corresponding to a molecular weight range of about 116 to 250) and with a ring number distribution approximately as follows: 0 rings (24 %), 1 ring (39%), 2 rings (30%), 3 rings (5%) and 4 rings (2%). In another example, they may have a carbon number ranging from 14 to 27 (corresponding to a molecular weight range of about 220 to 368) and with a ring number distribution approximately as follows: 0 rings (20%), 1 ring (23%), 2 rings (20%), 3 rings (20%) and 4 rings (18%).

The average molecular weight of naphthenic acids and mixtures of naphthenic acids preferred for various aspects of the present invention is generally between 120 and up to more than 700 g/mol, more preferably between 180 and 420 g/mol, and especially preferably between 190 and 350 g/mol. mole, for example between 120 and 420 g/mol, or between 120 and 350 g/mol, or between 180 and more than 700 g/mol, or between 180 and 350 g/mol, or between 190 and more than 700 g/mol, or between 190 and 420 g/mol.

The acid value of preferred naphthenic acids and mixtures of naphthenic acids is preferably in the range between 80 and 400 mg KOH/g, more preferably in the range between 120 and 270 mg KOH/g, and especially between 140 and 250 mg KOH/g, for example in the range between 80 and 270 mg KOH/g, or between 80 and 250 mg KOH/g, or between 120 and 400 mg KOH/g, or between 120 and 250 mg KOH/g, or between 140 and 400 mg KOH/g, or between 140 and 270 mg KOH/g.

In a second preferred embodiment of the present invention, the carboxylic acid containing the optionally substituted cycloaliphatic hydrocarbyl moiety (i) is a natural resin acid. These natural resins can be obtained, for example, by extraction from resinous trees, especially resinous conifers, and can be isolated from the resulting extracts by distillation. Among the resin acids, preferred are abietic acid, dihydroabietic acid, tetrahydroabietic acid, dehydroabietic acid, neoabietic acid, pimaric acid, levopimaric acid and palustric acid, as well as their derivatives. In practice, it has been found that mixtures of different polycycles can be used

- 6 045907 ical carboxylic acids. Preferred mixtures of resin acids have an acid number between 150 and 200 mg KOH/g, and in particular between 160 and 185 mg KOH/g, for example between 150 and 185 mg KOH/g, or between 160 and 200 mg KOH/g.

In a preferred embodiment, carboxylic acid (i) is a hydrocarbon compound of general formula (3):

where X represents carbon, nitrogen and/or oxygen, provided that each of the structural fragments consisting of four Xs connected to each other consists of either 4 carbon atoms, or 3 carbon atoms and one oxygen atom, or one atom nitrogen,

R ⁷ , R ⁸ , R ⁹ and R ¹⁰ are the same or different and each represents a hydrogen atom or a hydrocarbyl group, each of which is bonded to at least one atom of one of the two rings, and these hydrocarbyl groups are selected from alkyl groups containing 1 -5 carbon atoms, aryl groups and hydrocarbyl rings containing 5-6 atoms, which optionally contain a heteroatom such as nitrogen or oxygen, where the hydrocarbon ring is saturated or unsaturated, unsubstituted or optionally substituted by an olefinic aliphatic radical containing 1-4 carbon atoms where in each case two of the R ⁷ , R ⁸ , R ⁹ and R ¹⁰ radicals form a hydrocarbyl ring, and

Z represents a carboxyl group or an alkyl radical containing at least one carboxyl group.

In a more preferred embodiment, carboxylic acid (i) is a hydrocarbon compound of general formula (4):

in which X is carbon, nitrogen and/or oxygen, provided that at most one X in each ring is a heteroatom such as nitrogen or oxygen, and the remaining X atoms are carbon atoms,

R ⁷ , R ⁸ , R ⁹ and R ¹⁰ each have the above meanings, and

Z is bonded to at least one atom of at least one of the two rings and represents a carboxyl group or an alkyl radical containing at least one carboxyl group.

Particularly preferred carboxylic acids (i) containing a polycyclic hydrocarbyl residue of formula (3) or (4) contain from 12 to 32 carbon atoms, more preferably from 16 to 28 carbon atoms, and especially preferably from 18 to 24 carbon atoms, including carboxylic acid group, for example 12 to 28, or 12 to 24, or 16 to 32, or 16 to 24, or 18 to 32, or 18 to 28 carbon atoms, including a carboxyl group. The R ⁷ , R ⁸ , R ⁹ and R ¹⁰ radicals are preferably each alkyl radicals such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl and vinyl. Preferably, the carboxyl group Z is bonded directly to the ring system. Alternatively, the carboxyl group of Z is linked to the ring system via an alkylene group, for example a methylene group.

In formulas (3) and (4), the cycloaliphatic hydrocarbyl residue of the carboxylic acid (i) may be saturated or unsaturated. Preferably, the unsaturated cycloaliphatic hydrocarbyl residues contain one, two or three C=C double bonds. Double bonds may be present in or attached to cyclic units, but each ring contains a maximum of one double bond. Preferably, at least one ring system contains a double bond.

Particularly preferred resin acids have the empirical formula C ₁₉ H ₂₉ COOH and contain three fused aliphatic rings. Examples of preferred resin acids are abietic acid (5) and pimaric acid (6).

- 7 045907

Mixtures of naphthenic acids and resin acids are also suitable. Preferably, they are mixed in a weight ratio of between 1:10 and 10:1, and especially preferably between 1:5 and 5:1, for example between 1:5 and 10:1, or between 1:10 and 5:1.

In a more preferred embodiment, a carboxylic acid containing an optionally substituted cycloaliphatic hydrocarbyl moiety (i) is used to prepare co-additive (A) in mixture with a minor amount of a substantially linear carboxylic acid. The term substantially linear means that the hydrocarbyl moiety of the carboxylic acid may have branches, such as alkyl branches and/or double bonds, but does not contain cyclic structures. Preferred substantially linear carboxylic acids contain 10-28, more preferably 12-26, and especially preferably 14-24 carbon atoms, for example 10-26, or 10-24, or 12-28, or 12-24, or 14-28 , or 14-26 carbon atoms. A preferred group of substantially linear carboxylic acids are fatty acids. Particularly preferred fatty acids are linear. Preferred fatty acids may be saturated or unsaturated, and more preferably they are unsaturated. Preferred unsaturated fatty acids contain one, two or three C=C double bonds. Examples of unsaturated fatty acids are palmitoleic acid, oleic acid, linoleic acid. Preferably, the content of substantially linear carboxylic acids in mixture with carboxylic acids containing an optionally substituted cycloaliphatic hydrocarbyl moiety (i) is less than 50 mol%, more preferably less than 30 mol% and especially preferably less than 25 mol%. When substantially linear carboxylic acids are present, said mole fraction refers to the total content of the carboxylic acid containing the optionally substituted cycloaliphatic hydrocarbyl moiety (i) and the substantially linear carboxylic acid.

It is also acceptable to use derivatives of carboxylic acids (i), for example their anhydrides or esters with lower alcohols, for the synthesis of co-additive (A). Preferred lower alcohols contain 1-6 carbon atoms and in particular 1-4 carbon atoms. Examples of preferred lower alcohols are methanol, ethanol, propanol, isopropanol and various butanol isomers.

Alkylene polyamines (ii)

The term alkylene polyamine as used herein refers to organic molecules containing two or more amino groups separated from each other by alkylene groups containing at least two carbon atoms. It includes diamines as well as polyamines containing three or more amino groups, for example up to 10 amino groups. Preferred alkylene polyamines (ii) contain from 2 to 30 carbon atoms, more preferably from 3 to 20 carbon atoms, and especially preferably from 3 to 12 carbon atoms, for example from 2 to 20 carbon atoms, or from 2 to 12, or from 3 to 30 carbon atoms. In a preferred embodiment, the alkylene polyamine (ii) has the general formula (7)

HNR ² -(CH2)o-[NR ³ -(CH ₂ )m] _P -NR ⁴ R ⁵ (7) where R ² and R ³ are independently selected from hydrogen and a hydrocarbyl residue containing 1-20 carbon atoms ,

R ⁴ represents hydrogen or a hydrocarbyl residue containing 1-20 carbon atoms,

R ⁵ is, independently of R ⁴ , selected from hydrogen, an optionally substituted hydrocarbyl moiety containing 1-20 carbon atoms, and an acyl group having the structure -C(=O)^\ with the proviso that R ⁴ and R ⁵ together can form 5- or a 6-membered ring, o is an integer from 2 to 5, and preferably 2 or 3, m is an integer from 2 to 5, and preferably 2 or 3, and p is 0 or an integer from 1 to 10.

In preferred alkylene polyamines of formula (7), p is 0. Particularly preferred are alkylene diamines wherein the alkylene group -(CH ₂ ) _o - contains from 1 to about 10 carbon atoms, more preferably from 2 to 6 carbon atoms, and especially preferably 2 or 3 carbon atoms, for example 2 carbon atoms. Preferably, R ² represents hydrogen or an aliphatic group containing up to 10 carbon atoms. Most preferably, R ² is hydrogen. Preferably, R ⁴ represents hydrogen or a hydrocarbyl residue containing from 1 to 10, and especially preferably from 1 to 5 carbon atoms. Preferably, ^R5, regardless of ^R4 , is

- 8 045907 is hydrogen or an optionally substituted hydrocarbyl radical containing from 1 to 10, and especially preferably from 1 to 5 carbon atoms. In a preferred embodiment, R ⁴ and R ⁵ are both hydrogen. In a more preferred embodiment, R ⁴ is hydrogen and R ⁵ is an optionally substituted hydrocarbyl residue. The preferred substituent on alkyl groups R ⁵ is hydroxy; accordingly, in a preferred embodiment, R ⁵ represents a hydroxyalkyl group.

Preferred alkylene diamines (ii) include ethylene diamine, propylene diamine, 1,2 diaminopropane, tetramethylene diamine, 1,2-diaminobutane, 2,3-diaminobutane, hexamethylene diamine, octamethylene diamine and higher homologues thereof; examples of preferred alkylene diamines containing N-alkylated amino groups include N-methylethylenediamine, N-ethylethylenediamine, N-octadecylethylenediamine, N(hydroxyethyl)ethylenediamine, N.N-dimethylaminoethylamine. N,Ndimethylaminopropylamine, N,Ndimethylaminopropylamine, N,Ndimethylaminopropylamine, N,Ndimethylaminobutylamine, KX-dimethylaminopentylamine and mixtures thereof.

In more preferred alkylene polyamines of formula (7), p is an integer between 1 and 7, and more preferably between 2 and 4, for example between 1 and 4, or between 2 and 10, or between 2 and 7. Particularly preferred are alkylene polyamines where p is 1, 2 or 3. Preferred alkylene groups -(CH ₂ ) _o - and -(CH ₂ ) _m - independently contain from 1 to about 10 carbon atoms, more preferably from 2 to 6 carbon atoms, and particularly preferably 2 or 3 carbon atoms. The corresponding indices o and m can be the same or different. In a preferred embodiment they are the same. Preferably, R ² and R ³ are independently hydrogen or an aliphatic group containing up to 10 carbon atoms. Most preferably, R ² and R ³ are both hydrogen. Preferably, R ⁴ represents hydrogen or a hydrocarbyl residue containing from 1 to 10, and especially preferably from 1 to 5 carbon atoms. Preferably, R ⁵ regardless of R ⁴ is hydrogen or an optionally substituted hydrocarbyl residue containing from 1 to 10, and especially preferably from 1 to 5 carbon atoms. In a preferred embodiment, R ⁴ and R ⁵ are both hydrogen. In a more preferred embodiment, R ⁴ is hydrogen and R ⁵ is an optionally substituted hydrocarbyl residue. The preferred substituent on alkyl groups R ⁵ is hydroxy; accordingly, in a preferred embodiment, R ⁵ represents a hydroxyalkyl group.

In a preferred embodiment, the alkylene polyamine (7) contains a cyclic structure, where R ⁴ and R ⁵ together form a ring containing, together with the nitrogen atom to which they are attached, a 5- or 6-membered ring and containing one additional nitrogen atom. Preferred structures are imidazoline and piperazine structures.

Preferred alkylene polyamines (ii) include ethylene polyamines, propylene polyamines, butylene polyamines, pentylene polyamines, etc., containing 3, 4, 5 or more amino groups, and mixtures thereof. Ethylene polyamines are particularly preferred. Ethylene polyamines can be prepared by reacting ethylene dichloride with ammonia or reacting ethyleneimine with a ring-opening reagent such as water, ammonia, etc. These reactions produce a complex mixture of polyalkylene polyamines, including cyclic condensation products such as piperazines.

In a more preferred embodiment, the amine is a bottoms polyamine or a heavy polyamine. Such mixtures of higher polyamines are obtained by distilling a mixture of polyamines obtained, for example, during the preparation processes described above, after removing low molecular weight polyamines and volatile components, which leaves a polyamine residue as a residue.

Examples of preferred higher alkylene polyamines (ii) are diethylene triamine, triethylene tetramine, tetraethylene pentamine, pentaethylene hexamine, hexaethylene heptamine, heptaethylene octamine, dipropylene triamine, tripropylene tetramine and higher homologues thereof. Examples of preferred polyalkylene amines containing N-alkylated amino groups include 1-methyl diethylenetriamine, N,N-dibutyl diethylenetriamine and N-(hydroxyethyl)diethylenetriamine. Preferred alkylene polyamines containing cyclic moieties are 1-(2-aminoethyl)piperazine, 2-methyl-1(2-aminobutyl)piperazine, 2-heptyl-3-(2-aminopropyl)imidazoline, 4-methyl-3-( aminoethyl)imidazoline, 1,3-bis(2-aminoethyl)imidazoline and 1,4-bis(2-aminoethyl)piperazine.

In a preferred embodiment, the carboxylic acid (i) and the alkylene polyamine (ii) react in a molar ratio between 5:1 and 1:5, more preferably in a molar ratio between 2:1 and 1:2, and especially preferably in a molar ratio between 1.2:1 and 1:1.2, for example in a mole ratio between 5:1 and 1:2, or in a mole ratio between 5:1 and 1:1.2, or in a mole ratio between 2:1 and 1 :5, or in a mole ratio between 2:1 and 1.2, or in a mole ratio between 1.2:1 and 1:5, or in a mole ratio between 1.2:1 and 1:2. For alkylene polyamines (ii) containing 4 or more nitrogen atoms, the carboxylic acid mole fraction can be doubled to produce diamides and/or bis-imidazolines.

Preferably, the reaction is carried out by mixing the reactants and heating the resulting mixture, preferably with stirring, to a temperature of from about 100°C up to a temperature

- 9 045907 decomposition of the reaction mixture. The presence of a solvent in the reaction mixture is often preferred to facilitate stirring and temperature control. The solvent may be a hydrocarbon or an inert polar solvent. Examples of suitable solvents are benzene, toluene, xylene, naphtha, n-hexane, cyclohexane, dodecane, octane and commercially available mixtures of hydrocarbons including mineral oils, as well as chlorobenzene, ethylene dichloride, dioxane, ether, chloroform, carbon tetrachloride or nitrobenzene.

The reaction temperature depends mainly on the nature of the reagents used and the target products that are desired to be obtained. In general, temperatures above 100°C and up to 150°C are used to prepare amidoamines of formula (1) having primarily amide linkers. At higher temperatures, typically above about 150°C, the formation of imidazolines of formula (2) becomes the main reaction. As will be appreciated by those skilled in the art, the formation of imidazolines (2) requires the presence of a primary amine group on the alkylene polyamine (7), for example when R ² is hydrogen. In addition, for the formation of imidazolines (2), alkylene polyamine (7), where o is equal to 2, is preferred.

It should be understood that because the available mono- and polycyclic carboxylic acids are mixtures, because some of the alkylene polyamines are mixtures, and because the acid to amine molar ratios may vary, the products are more properly described as reaction products rather than as individual compounds.

Polymeric paraffin inhibitors (B)

Preferred polymeric wax inhibitors (B) in various aspects of the present invention are, for example,

a) copolymers of ethylene with ethylenically unsaturated esters, ethers and/or C ₃ -C ₃₀ -alkenes,

b) homo- or copolymers of ethylenically unsaturated carboxylic acids containing C ₁₂ -C ₅₀ -alkyl radicals linked through ester, amide and/or imide groups,

c) copolymers of ethylene with grafted ethylenically unsaturated esters and/or ethers, and

d) condensation products of alkyl-substituted phenols with aldehydes and/or ketones.

Preferred copolymers of ethylene with ethylenically unsaturated esters, ethers or alkenes (a) are in particular those which, in addition to ethylene, contain 4-18 mol.%, especially 7-15 mol.%, of at least one of the following : vinyl ester, acrylic ester, methacrylic ester, alkyl vinyl ether and/or alkene.

Vinyl esters contained in copolymers of ethylene with ethylenically unsaturated esters, ethers and/or C ₃ -C ₃₀ -alkenes (a) preferably have the formula (8)

CH2=CH-OCOR ^u (8) in which R ¹¹ represents C ₁ -C ₃₀ -alkyl, preferably C ₄ -C ₁₆ -alkyl, in particular C ₆ -C ₁₂ -alkyl, for example Q-Cm-alkyl, Q -Cn-alkyl, C ₄ -C ₃₀ -alkyl, C ₄ -C ₁₂ -alkyl, C ₆ -C ₃₀ -alkyl or C ₆ -C ₁₆ -alkyl.

Alkyl radicals R ¹¹ can be linear or branched. In a preferred embodiment, the alkyl radicals are linear alkyl radicals containing 1-18 carbon atoms. Particularly preferred alkyl radicals are methyl and ethyl. In a more preferred embodiment, R ¹¹ is a branched alkyl radical containing 3 to 30 carbon atoms, and more preferably 5 to 16 carbon atoms. Particularly preferred vinyl esters are formed from secondary and especially tertiary carboxylic acids whose branching is in the alpha position to the carbonyl group. Particularly preferred are vinyl esters of tertiary carboxylic acids, which are also known as vinyl esters of versatic acid and which contain neoalkyl radicals containing 5-11 carbon atoms, in particular those containing 8, 9 or 10 carbon atoms. Suitable vinyl esters include vinyl acetate, vinyl propionate, vinyl butyrate, vinyl isobutyrate, vinyl hexanoate, vinyl heptanoate, vinyl octanoate, vinyl pivalate, vinyl 2-ethylhexanoate, vinyl laurate, vinyl stearate and versatic esters such as vinyl neononanoate, vinyl neodecanoate , vinyl neoundecanoate. A particularly preferred vinyl ester is vinyl acetate.

In another embodiment, said alkyl groups may be replaced by one or more hydroxyl groups.

In a more preferred embodiment, the ethylene copolymers contain vinyl acetate and at least one additional vinyl ester of formula 1, in which R ¹¹ represents C ₄ -C ₃₀ -alkyl, preferably C ₄ -C ₁₆ -alkyl, and especially C ₆ -C ₁₂ -alkyl. Preferred additional vinyl esters are the vinyl esters described above

- 10 045907 ry with such a chain length interval.

Acrylic and methacrylic esters contained in copolymers of ethylene with ethylenically unsaturated esters, ethers and/or C3-C30 alkenes (a) preferably have the formula (9)

CH ₂ =CR ¹² -COOR ¹³ (9) in which R ¹² represents hydrogen or methyl, and

R ¹³ represents C ₁ -C ₃₀ -alkyl, preferably C ₄ -C ₂ 4 -alkyl, in particular C ₆ -C ₁₈ -alkyl, for example C 1 -C ₁₈ -alkyl, C ₁ -C ₂₄ -alkyl, C ₄ -C ₃₀ -alkyl, C4-C ₁₈ -alkyl, C6-C ₃₀ -alkyl or C6-C ₂₄ -alkyl.

Alkyl radicals R ¹³ can be linear or branched. In a preferred embodiment, they are linear. In a more preferred embodiment, they have a branch at the 2-position to the ester moiety. Suitable acrylic esters include, for example, methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n- and isobutyl (meth)acrylate, hexyl (meth)acrylate, octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, 2-propylheptyl (meth)acrylate, 4-methyl-2-propylhexyl (meth)acrylate, decyl (meth)acrylate, dodecyl (meth)acrylate, isotridecyl (meth)acrylate, tetradecyl (meth)acrylate, hexadecyl (meth)acrylate, iso-heptadecyl (meth)acrylate, octadecyl (meth)acrylate, eicosyl (meth)acrylate, and mixtures of these comonomers, the formulation (meth)acrylate includes the corresponding esters of acrylic acid and methacrylic acid.

Alkyl vinyl ethers contained in copolymers of ethylene with ethylenically unsaturated esters, ethers and/or C3-C30 alkenes (a) are preferably compounds of formula (10)

CH ₂ =CH-OR ¹⁴ (10) in which R ¹⁴ represents C ₁ -C ₃₀ alkyl, preferably C ₄ -C ₁₆ alkyl, in particular C6-C ₁₂ alkyl, for example C1-C ₁₆ alkyl, C1-C ₁₂ -alkyl, C ₄ -C ₃₀ -alkyl, C ₄ -C ₁₂ -alkyl, C6-C ₃₀ -alkyl or C6-C ₁₆ -alkyl.

Alkyl radicals can be linear or branched. Suitable alkyl vinyl ethers include, for example, methyl vinyl ether, ethyl vinyl ether, isobutyl vinyl ether, and mixtures thereof.

Alkenes contained in copolymers of ethylene with ethylenically unsaturated esters, ethers and/or C ₃ -C ₃₀ -alkenes (a) are preferably monounsaturated hydrocarbons containing 3-30 carbon atoms, more particularly 4-16 carbon atoms , and in particular 5-12 carbon atoms, for example 3-16 carbon atoms, 3-12 carbon atoms, 4-30 carbon atoms, 4-12 carbon atoms, 5-30 carbon atoms or 5-16 carbon atoms. Suitable alkenes include propene, butene, isobutene, pentene, hexene, 4-methylpentene, heptene, octene, decene, diisobutylene and norbornene, and derivatives thereof such as methylnorbornene and vinylnorbornene.

Alkyl radicals R ¹¹ , R ¹³ and R ¹⁴ may contain minor amounts of functional groups, for example, amino, amido, nitro, cyano, hydroxy, keto groups, carbonyl, carboxyl, ester and sulfo groups and/or halogen atoms, provided that they do not significantly interfere with the hydrocarbon character of these radicals.

Particularly preferred ethylene terpolymers contain, in addition to ethylene, preferably 3.5-17 mol.%, and in particular 5-15 mol.% vinyl acetate, and 0.1-10 mol.%, in particular 0.2-5 mol.% at least one long chain vinyl ester, (meth)acrylic ester, vinyl ether and/or alkene, where the total comonomer content is between 4 and 18 mol%, and preferably between 7 and 15 mol%. Particularly preferred thermonomers are vinyl 2-ethylhexanoate, vinyl neononanoate, vinyl neodecanoate, 2-ethylhexyl acrylate, 2-propylheptyl acrylate, 4-methyl-2-propylhexyl acrylate, and mixtures thereof. Other particularly preferred copolymers contain, in addition to ethylene and 3.5-17.5 mol% vinyl esters, also 0.1-10 mol% olefin such as propene, butene, isobutene, hexene, 4-methylpentene, octene, diisobutylene, norbornene, styrene or any combination thereof.

The number average molecular weight of the ethylene(a) copolymers according to gel permeation chromatography in THF relative to polystyrene standards is preferably from 2000 to 50000, and in particular from 2500 to 30000 g/mol, for example from 2000 to 30000 g/mol, or from 3000 to 50000 g/mol. The weight average molecular weight is preferably from 5000 to 300,000 g/mol, and in particular from 7,000 to 250,000 g/mol, for example from 5,000 to 250,000 g/mol, or from 7,000 to 300,000 g/mol. The MFI ₁₉₀ values for ethylene(a) copolymers, measured according to DIN 53735 at 190°C and a load of 2.16 kg, are preferably from 0.1 to 1200 g/min, and in particular from 1 to 900 g/min. The degree of branching, determined by 1H-NMR spectroscopy, is preferably from 1 to 12 CH3/100 CH ₂ groups, in particular from 2 to 8 CH3/100 CH ₂ groups that are not part of the comonomers.

In a preferred embodiment, a mixture of two or more of the above ethylene(a) copolymers is used, wherein the polymers underlying the mixture differ in at least one characteristic. For example, they may contain different comonomers and/or have different ratios of comonomers, and/or they may have different molecular weights and/or degrees of branching.

- 11 045907

Copolymers of ethylene with ethylenically unsaturated esters, ethers and/or C ₃ -C ₃₀ -alkenes (a) are prepared by known methods (on this topic see, for example, Ullmanns Encyclopadie der Technischen Chemie, 5 ^th edition, vol A 21, pages 305 to 413). Suitable methods are polymerization in solution, suspension and gas phase, and bulk polymerization at high temperature. Preferred bulk polymerization at high temperature is carried out at pressures of 50-400 MPa, preferably 100-300 MPa, and temperatures of 50-350°C, preferably 100-300°C. The reaction between comonomers is initiated by free radical generating initiators (free radical chain initiators). This class of substances includes, for example, oxygen, hydroperoxides, peroxides and azo compounds such as cumene hydroperoxide, t-butyl hydroperoxide, dilauroyl peroxide, dibenzoyl peroxide, bis(2-ethylhexyl) peroxodicarbonate, t-butyl permaleate, t-butyl perbenzoate , dicumyl peroxide, t-butylcumyl peroxide, di(t-butyl) peroxide, 2,2'-azobis(2-methylpropanonitrile), 2,2'-azobis(2-methylbutyronitrile).

The desired molecular weight of the copolymer(s) for a particular comonomer mixture composition is adjusted by varying the pressure and temperature during the reaction, and, if necessary, adding regulators. Suitable regulators have been found to be hydrogen, saturated or unsaturated hydrocarbons such as propane and propene, aldehydes such as propionaldehyde, n-butyraldehyde and isobutyraldehyde, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone, or alcohols such as butanol. . Depending on the target molecular weight, regulators are added in amounts up to 20% by weight, preferably 0.05-10% by weight, based on the total weight of the comonomer mixture.

Preferred homo- or copolymers of ethylenically unsaturated carboxylic acids having C ₁₂ -C ₅₀ -alkyl radicals linked through ester, amide and/or imide groups (b) contain repeating structural elements of formulas (11A) and/or (11B)

where R ¹⁵ and R ¹⁶ each independently represent hydrogen, phenyl or a group of the formula COXR ¹⁸ , R ¹⁷ represents hydrogen, methyl or a group of the formula -CH2COXR ¹⁸ ,

X represents O, NH or NR ¹⁸ ,

R ¹⁸ is hydrogen or R ²⁴ , and

R ²⁴ represents a C ₁₂ -C ₅₀ alkyl or alkylene radical, preferably a C ₁₄ -C ₃₀ alkyl or alkylene radical, and particularly preferably a C ₁₈ -C ₂₄ alkyl or alkylene radical, for example a _{C 12} -C ₃₀ alkyl or alkylene radical, C ₁₂ -C ₂₄ -alkyl or alkylene radical, C ₁₄ -C ₅₀ -alkyl or alkylene radical, C ₁₄ -C ₂₄ -alkyl or alkylene radical, C ₁₈ -C ₅₀ -alkyl or alkylene radical, or C ₁₈ -C ₃₀ -alkyl or alkylene radical, provided that the repeating structural units (11A) contain at least one and at most two groups of the formula -COXR ¹⁸ in one structural unit, wherein at least one radical R ¹⁸ represents R ²⁴ .

The repeating structures of formula (11A) include, but are not limited to, structures formed from ethylenically unsaturated monocarboxylic acid esters, monocarboxylic acid amides, dicarboxylic acid monoesters, dicarboxylic acid diesters, dicarboxylic acid monoamides, dicarboxylic acid diamides, and mixtures thereof.

Particularly preferred homo- and copolymers (b) are those containing structural units 11A wherein R ¹⁵ and R ¹⁶ are each hydrogen, X is O, and R ¹⁷ is hydrogen or methyl. These structural units 11A are formed from esters of monocarboxylic acids, for example acrylic acid or methacrylic acid. Acrylic acid esters are particularly preferred.

Other particularly preferred homo- and copolymers (b) are those containing structural units of Formula 11A, wherein one of R ¹⁵ and R ¹⁶ is COXR ²⁴ and the other is hydrogen, and R ¹⁷ is hydrogen. Such structural fragments are formed from monoesters, diesters, monoamides and diamides of ethylenically unsaturated dicarboxylic acids, for example maleic acid, fumaric acid or itaconic acid. Other particularly preferred homo- and copolymers (b) are those containing structural units of formula 11B which are formed from imides of dicarboxylic acids, for example maleic acid, fumaric acid or itaconic acid.

Preferred alcohols for the esterification of ethylenically unsaturated mono- and dicarboxylic acids to produce esters as starting compounds for the preparation of homo- or copolymers (b), or for polymer-analog reactions with the corresponding polymers, with

- 12 045907 containing acid groups are those containing 12-50 carbon atoms, preferably containing 14-30 carbon atoms, and in particular those containing 18-24 carbon atoms, for example containing 12-30 carbon atoms, 12-24 carbon atoms, 14-50 carbon atoms, 14-24 carbon atoms, 18-50 carbon atoms, or 18-30 carbon atoms. They can be of natural or synthetic origin. Alkyl radicals are preferably linear or at least substantially linear. The term substantially linear means that at least 75 mol.%, and in particular at least 90 mol.% of the alcohols are linear. Suitable fatty alcohols include 1-decanol, 1-dodecanol, 1-tridecanol, isotridecanol, 1-tetradecanol, 1-hexadecanol, 1-octadecanol, eicosanol, docosanol, tetracosanol, hexacosanol, and mixtures thereof. Particularly preferred are mixtures obtained from renewable natural sources, for example, coconut oil fatty alcohol, tallow alcohol, hydrogenated tallow alcohol and behenyl alcohol.

Preferred amines for the amidation and/or imidation of ethylenically unsaturated mono- and dicarboxylic acids to produce amides/imides as starting compounds for the preparation of homo- or copolymers (b), or for polymer-like reaction with corresponding polymers containing acid groups, are containing 12-50 carbon atoms, preferably containing 14-30 carbon atoms, and in particular containing 18-24 carbon atoms, for example containing 12-30 carbon atoms, 12-24 carbon atoms, 14-50 carbon atoms, 14-24 carbon atoms, 18-50 carbon atoms or 18-30 carbon atoms. They can be of natural or synthetic origin. Alkyl radicals are preferably linear or at least substantially linear. Suitable fatty amines include 1-decylamine, 1-dodecylamine, 1-tridecylamine, isotridecylamine, 1-tetradecylamine, 1-hexadecylamine, 1-octadecylamine, eicosylamine, oleylamine, and mixtures thereof. Particularly preferred are mixtures derived from renewable natural sources, for example fatty cocoamine, tallow amine, hydrogenated tallow amine and behenylamine.

In a preferred embodiment, the polymeric wax inhibitor (b) is a copolymer containing, in addition to structural moieties formed from alkyl esters of unsaturated carboxylic acids of formulas 11A and/or 11B, additional comonomers such as vinyl esters of formula (8 ), Q-Qs-alkyl (meth)acrylic esters of formula (9), alkyl vinyl esters of formula (10) and/or alkenes. Preferred vinyl esters are as defined for Formula (8). Vinyl acetate is particularly preferred.

Preferred alkenes as comonomers in the polymeric wax inhibitor (b) are α-olefins, i.e. linear olefins with a terminal double bond, preferably containing from 6 to 50 carbon atoms, more preferably containing from 10 to 36 carbon atoms, more preferably containing from 16 to 30 carbon atoms, and especially preferably containing from 18 to 24 carbon atoms, for example containing from 10 to 50, or from 10 to 30, or from 10 to 24, or from 16 to 50, or from 16 to 36, or from 16 to 24, or from 18 to 50, or from 18 to 36, or from 18 to 30 carbon atoms. Examples of suitable α-olefins are 1-octene, 1-nonene, 1-decene, 1-dodecene, 1-tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 1-nonadecene, 1- eicosene, 1-henicosene, 1-docosene, 1-tetracosene and mixtures thereof. Also suitable are commercially available mixtures with a fixed chain length range, for example, C _13-18 a-olefins, C _13-16 a-olefins, C _14-16 a-olefins, C _14-18 a-olefins, C _16-18 -a-olefins, C _16-20 -a-olefins, C _22-28 -a-olefins, C ₃₀₊ -a-olefins.

In addition, preferred copolymers (b) may contain one or more additional comonomers. Preferred additional comonomers are ethylenically unsaturated compounds containing a functional group, where the functional group preferably contains oxygen and/or nitrogen. Examples of such comonomers are allyl polyglycols, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, dimethylaminoethyl acrylate, (meth)acrylic acid amides, vinylpyridine, vinylpyrrolidone, acrylic acid, methacrylic acid, p-acetoxystyrene, vinyl methoxyacetate and perfluoroalkyl acrylate. Their content in the polymer is preferably less than 20 mol.%, in particular between 1 and 15 mol.%, for example between 2 and 10 mol.%, for example between 1 and 20 mol.%, between 2 and 20 mol.% or between 1 and 10 mol.%.

Allyl polyglycols suitable as comonomers, in a preferred embodiment of the present invention, may contain 1-50 ethoxy and/or propoxy moieties and correspond to formula (12):

where R ¹⁹ represents hydrogen or methyl,

- 13 045907

Z represents C1-C3 alkyl,

R ²⁰ represents hydrogen, C1-C ₃₀ -alkyl, cycloalkyl, aryl or -C(O)-R ²² ,

R ²¹ represents hydrogen or C1-C ₂₀ -alkyl,

R ²² represents C1 -C ₃₀ -alkyl, C ₃ -C ₃₀ -alkenyl, cycloalkyl or aryl, and r is a number from 1 to 50, preferably from 1 to 30.

Particularly preferred are comonomers of formula 12 in which R ¹⁹ and R ²¹ are each hydrogen, R ²⁰ is hydrogen or a C.'1-C-halkyl group, and Z is a methylene group.

Preferred homo- or copolymers (b) contain at least 10 mol% and up to 100 mol%, preferably 20-95 mol%, more preferably 30-90 mol%, and especially preferably 4080 mol%, e.g. at least 30 mol.%, or at least 40 mol.%, or 10-95 mol.%, or 10-90 mol.%, or 10-80 mol.%, or 20-100 mol.%, or 20-90 mol.%, or 20-80 mol.%, or 30-95 mol.%, or 30-80 mol.%, or 40-100 mol.%, or 40-95 mol.%, or 40- 90 mol.% structural fragments of formulas 11A and/or 11B. In a particularly preferred embodiment, the wax inhibitors (b) contain at least 90 mol.% structural moieties derived from esters of ethylenically unsaturated monocarboxylic acids, these esters containing C ₁₂ -C ₅₀ -alkyl radicals, such as described above.

Because of the specific copolymerization mechanism, preferred ethylenically unsaturated dicarboxylic acid-olefin copolymers (b) contain between 25 and 75 mol%, more preferably between 40 and 60 mol%, and for example between 25 and 60 mol%, or between 40 and 75 mol.% fragments derived from dicarboxylic acid; and between 75 and 25 mol%, more preferably between 60 and 40 mol%, for example between 75 and 40 mol%, or between 60 and 25 mol% olefin.

Preferred homo- or copolymers (b) are, for example, poly(alkyl acrylates); poly(alkyl methacrylates); copolymers of alkyl (meth)acrylates with vinylpyridine; copolymers of alkyl (meth)acrylates with allyl polyglycols; esterified and/or amidated copolymers of alkyl (meth)acrylates with maleic anhydride; copolymers of esterified and/or amidated ethylenically unsaturated dicarboxylic acids, for example dialkyl maleates or dialkyl fumarates, with α-olefins; copolymers of esterified and/or amidated ethylenically unsaturated dicarboxylic acids, for example dialkyl maleates or dialkyl fumarates, with unsaturated vinyl esters, for example vinyl acetate; copolymers of esterified ethylenically unsaturated dicarboxylic acids, for example dialkyl maleates or dialkyl fumarates, with styrene; or also copolymers of amidated and/or imidized ethylenically unsaturated dicarboxylic acids, for example dialkyl maleimides or dialkyl fumaramides, with α-olefins.

The molecular weight and therefore the molecular weight distribution of the preferred homo-copolymers (b) is characterized by a K value (measured according to Fickencher in 5% toluene solution) from 10 to 100, preferably from 15 to 80, for example from 10 to 80 or from 15 to 100. The weight average molecular weight (Mw) may be in the range from 5000 to 1000000 g/mol, preferably from 10000 to 300000 g/mol, and in particular from 25000 to 100000 g/mol, for example from 5000 to 300000 g/mol, from 5000 to 100000 g/mol, 10000 to 1000000 g/mol, 10000 to 100000 g/mol, 25000 to 1000000 g/mol, or 25000 to 300000 g/mol, as determined by gel permeation chromatography (GPC) relative polystyrene standards.

Homo- and copolymers (b) can be prepared by (co)polymerizing esters, amides and/or imides of ethylenically unsaturated carboxylic acids, especially alkyl acrylates and/or alkyl methacrylates, optionally with other comonomers, by standard free radical polymerization methods. Solution polymerization is particularly preferred. Controlled radical chain polymerization techniques can also be used.

Another method for preparing homo- and copolymers (b) is polymer-analogous esterification, amidation and/or imidation of already polymerized ethylenically unsaturated carboxylic acids or acid anhydrides with fatty alcohols containing 12-50 carbon atoms. Similarly, polymer-analogous transesterification or aminolysis of esters of ethylenically unsaturated carboxylic acids with short-chain alcohols with fatty alcohols or fatty amines containing 12-50 carbon atoms is suitable. For example, transesterification of poly(meth)acrylic acid with fatty alcohols containing 12-50 carbon atoms gives homo- and copolymers (b) which are suitable for the purposes of the present invention. A particularly preferred class of polymeric wax inhibitors (b) can be prepared by copolymerizing unsaturated dicarboxylic acid anhydrides, and in particular maleic anhydride, with the comonomers described above in substantially equimolar amounts (i.e., in a molar ratio of 1:1.5 to 1.5 :1) and subsequent polymer-analogous esterification of the copolymers with fatty alcohols containing 10-50 carbon atoms, as described above. Similarly, said copolymers of maleic anhydride with α-olefins can be amidated and/or imidated with amines containing at least one C1 ₂ -C ₅₀ -alkyl radical, and in particular containing at least one

- 14 045907

C14-C ₂ 4-alkyl residue.

Preferred copolymers of ethylene with grafted ethylenically unsaturated esters (c) are, for example, those containing

I) an ethylene copolymer which, in addition to ethylene, contains 4-20 mol.%, and preferably 6-18 mol.% of at least one vinyl ester, acrylic ester, methacrylic ester, alkyl vinyl ether and/or alkene, to which

II) a homo- or copolymer of an α,β-unsaturated carboxylic acid ester with a C ₁₂ -C ₅ o-alcohol is grafted.

Preferably, the ethylene copolymer (I) is one of the copolymers described as a copolymer of ethylene and an ethylenically unsaturated ester, ether and/or C3-C ₃₀ alkene (a). Ethylene copolymers preferred as grafting copolymer (I) are in particular those which, in addition to ethylene, contain 7.5-15 mol% vinyl acetate. Moreover, preferred ethylene(I) copolymers have MFI190 values between 1 and 900 g/min, and in particular between 2 and 500 g/min, for example between 1 and 500 g/min, or between 2 and 900 g/min.

(Co)polymers (II) grafted onto ethylene copolymers (I) contain preferably 40-100 wt.%, and in particular 50-90 wt.%, for example 40-90 wt.% or 50-100 wt.% one or more structural moieties derived from alkyl acrylates and/or alkyl methacrylates. Preferably at least 10 mol.%, more preferably 20-100 mol.%, especially preferably 30-90 mol.%, and especially preferably 40-70 mol.%, for example more than 20 mol.%, or more than 30 mol.% %, or 10-100 mol.%, or 10-90 mol.%, or 10-70 mol.%, or 20-90 mol.%, or 20-70 mol.%, or 30-100 mol.%, or 30-70 mol.%, or 40-100 mol.% or 40-70 mol.% of the grafted structural fragments contain alkyl radicals containing at least 12 carbon atoms, and especially preferably at least 18 carbon atoms. Particularly preferred grafting monomers are alkyl (meth)acrylates containing Cl ₂ -C ₅₀ -alkyl radicals, more preferably containing Cl ₄ -C ₃₀ -alkyl radicals, and especially containing C 18 -C ₂₄ -alkyl radicals, for example containing Cl ₈ -C ₅₀ -alkyl radicals, C ₁₈ -C ₃₀ -alkyl radicals, C ₁₈ -C ₂₄ -alkyl radicals or C20-C24-alkyl radicals. The preferred alcohols for the preparation of alkyl acrylates and/or methacrylates are the same as those described for the preparation of the unsaturated carboxylic acid esters used to prepare homo- and copolymers (b).

The graft (co)polymers (II) optionally contain up to 60 wt%, preferably 1-50 wt%, and more preferably 2-10 wt% one or more additional structural moieties that are derived from additional ethylenically unsaturated compounds . Suitable additional ethylenically unsaturated compounds are, for example, vinyl esters of carboxylic acids containing 1-20 carbon atoms, α-olefins containing 6-40 carbon atoms, vinyl aromatic compounds, dicarboxylic acids and their anhydrides and esters containing C ₁₀ -C ₅₀ -fatty alcohols, acrylic acid, methacrylic acid and especially ethylenically unsaturated compounds containing heteroatoms, for example, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, p-acetoxytyrol, vinyl methoxyacetate, dimethylaminoethyl acrylate, perfluoroalkyl acrylate, vinylpyridine isomers and their derivatives, Nvinylpyrrolidone and (meth)acrylamide and its derivatives, such as N-alkyl (meth)acrylamides with C1- _C20 alkyl radicals. Also, allyl polyglycols of formula (12), in which R ¹⁹ , R ²⁰ , R ²¹ , R ²² , Z and r are each as indicated in (b), are suitable additional ethylenically unsaturated compounds.

Ethylene copolymers with grafted esters and/or ethers of ethylenically unsaturated carboxylic acids (c) preferably contain an ethylene copolymer (I) and a homo- or copolymer of an α,β-unsaturated carboxylic acid ester with a C ₁₂ -C ₅₀ alcohol ( ii) in a weight ratio of 1:10 to 10:1, and more preferably 1:8 to 5:1, for example 1:5 to 1:1.

Graft polymers (c) are produced by known methods. For example, graft polymers (c) can be prepared by mixing an ethylene copolymer (I) and a comonomer or mixture of comonomers to form (II), optionally in the presence of an organic solvent, and adding a free radical chain initiator.

Preferred condensation products of alkyl-substituted phenols with aldehydes and/or ketones (d) are polymers containing structural moieties that contain at least one phenolic OH group, i.e. one OH group bonded directly to the aromatic system, and at least one alkyl, alkenyl, alkyl ether or alkyl ester group bonded directly to the aromatic system.

Preferred polymeric wax inhibitors (d) contain oligo- or polymers with a repeating structural moiety of formula (13)

- 15 045907

Where

R ²³ represents C1-C ₂₀₀ -alkyl or C ₂ -C ₂₀₀ -alkenyl, O-C1-C ₂₀₀ -alkyl or O-C ₂ -C ₂₀₀ -alkenyl, C(O)-O-C ₂ -C ₂₀₀ -alkyl or C(O)-O-C ₂ -C ₂₀₀ -alkenyl, O-C(O)-C1-C ₂₀₀ -alkyl or O-C(O)-C ₂ -C ₂₀₀ -alkenyl, and t represents is an integer from 2 to 250.

Preferably, the alkyl and alkenyl radicals in the R ²³ radicals contain 2-100, more preferably 4-50, and especially preferably 6-36 carbon atoms, for example 2-50 carbon atoms, or 2-36 carbon atoms, or 4-100 atoms carbon, or 4-36 carbon atoms, or 6-50 carbon atoms, or 6-36 carbon atoms. Alkyl radicals can be linear or branched, preferably they are linear. Examples of preferred alkyl radicals are n-, iso- and tert-butyl, n- and isopentyl, n- and isohexyl, n- and isooctyl, n- and isononyl, n- and isodecyl, n- and isododecyl, tetradecyl, hexadecyl, octadecyl , tripropenyl, tetrapropenyl, poly(propenyl) and poly(isobutenyl) radicals. In the case of ester type substituents, preference is given to substantially linear alkyl radicals derived from commercially available raw materials, for example fatty acids and corresponding fatty alcohols with chain lengths in the range, for example, C ₁₃ . ₁₈ , C ₁₂ - ₁₆ , C14-16, C14-18, C16-18, C16-20, C22-28 ^and C30+.

Preferably, t is an integer from 3 to 100, more preferably from 5 to 50, and especially preferably from 10 to 35, for example from 3 to 50, or from 3 to 35, or from 5 to 100, or from 5 to 35, or from 10 to 100, or from 10 to 50. The molecular weight of suitable alkyl-substituted phenol-aldehyde resins can vary widely. However, a condition for their suitability is that the alkyl-substituted phenolic resins are fat-soluble at least in a concentration appropriate to their use, i.e. that they are soluble in the concentration range from 0.001 to 1 wt.% in xylene. The number average molecular weight, measured by gel permeation chromatography (GPC) relative to polystyrene standards in THF, is preferably between 400 and 50,000 g/mol, more preferably between 800 and 30,000 g/mol, and in particular between 1000 and 20,000 g/mol , for example, between 400 and 30,000 g/mol, or between 400 and 20,000 g/mol, or between 800 and 50,000 g/mol, or between 800 and 30,000 g/mol, or between 1,000 and 50,000 g/mol, or between 1,000 and 30000 g/mol.

Preferred aldehydes for preparing alkyl-substituted phenolic resins are those containing 1-12 carbon atoms, and more preferably those containing 1-4 carbon atoms, for example, formaldehyde, acetaldehyde, propionic aldehyde, butyraldehyde, 2-ethylhexanal, benzaldehyde, glyoxalic acid and the like. reactive equivalents such as paraformaldehyde and trioxane. Formaldehyde is particularly preferred.

In a preferred embodiment, the condensation products of alkyl-substituted phenols and aldehydes or ketones (d) are alkylphenol-aldehyde resins. Alkylphenol aldehyde resins are known in principle and are described, for example, in Rompp Chemie Lexikon, ^9th edition, Thieme Verlag 1988-92, Volume 4, p. 3351 ff Preferred alkylphenol aldehyde resins of the present invention are particularly those derived from alkylphenols containing 1 or 2 alkyl radicals in the ortho and/or para position to the OH group. Particularly preferred starting materials are alkylphenols containing at least two hydrogen atoms capable of condensation with aldehydes on the aromatic ring, and in particular monoalkylated phenols whose alkyl radicals are in the para position to the OH group. The alkyl radicals in the alkylphenol aldehyde resins of the present invention may be the same or different. They can be saturated or unsaturated, preferably they are saturated. Particularly suitable alkylphenol aldehyde resins are derived from alkylphenols with branched alkyl radicals containing 8 or 9 carbon atoms. Other particularly suitable alkylphenol aldehyde resins are derived from linear alkyl radical alkylphenols with chain lengths ranging from C20 ^to C36.

Alkyl-substituted phenol-aldehyde resins (d) are prepared by known methods, for example by condensation of the corresponding alkyl-substituted phenols with formaldehyde, namely 0.5-1.5 moles, and preferably 0.8-1.2 moles, e.g. 0.5-1.2 moles or with 0.8-1.5 moles of formaldehyde per mole of alkyl-substituted phenol. The condensation can be carried out without a solvent, but is preferably carried out in the presence of a water-miscible or only partially water-miscible inert organic solvent such as mineral oil, alcohol, ether and the like. Solvents based on biogenic raw materials, such as methyl esters of fatty acids, can also be used as reaction media.

- 16 045907

The polymeric wax inhibitor (B) may be an individual wax inhibitor or a mixture of two or more different wax inhibitors. When (B) is a mixture of different wax inhibitors, the components may belong to different groups (;-i)-(d). Alternatively, wax inhibitors may belong to the same group but differ in their chemical and/or physicochemical characteristics, for example, molecular weight, degree of branching, comonomer type, comonomer content and/or alkyl chain length. In preferred polymeric wax inhibitor mixtures (B), the proportion of individual wax inhibitors is in the range between 5 and 95 wt.%, more preferably between 10 and 90 wt.%, and especially preferably between 20 and 80 wt.%, for example between 5 and 90% by weight, or between 5 and 80% by weight, or between 10 and 95% by weight, or between 10 and 80% by weight, or between 20 and 95% by weight, or between 20 and 90% by weight , relative to the total amount of polymeric wax inhibitors (B), provided that the sum of all components does not exceed 100%.

The content of the polymeric wax inhibitor (B) in the wax inhibitor composition of the present invention is determined by one skilled in the art in accordance with the target properties of the composition, for example, physical properties, which are determined by the dosage of administration. By adding a co-additive (A) and an organic solvent (C), the fluidity of the wax inhibitor composition, including its pour point, viscosity and solubility, is adjusted in accordance with the required target performance characteristics in a wax-containing hydrocarbon liquid. Preferred wax inhibitor compositions contain between 3 and 60 wt.%, more preferably between 5 and 50 wt.%, and especially preferably between 10 and 40 wt.% polymeric wax inhibitor (B), for example between 3 and 50 wt.% , or between 3 and 40 wt.%, or between 5 and 60 wt.%, or between 5 and 40 wt.%, or between 10 and 60 wt.%, or between 10 and 50 wt.%, based on the total the weight of a paraffin deposition inhibitor composition containing a co-additive (A), a polymeric paraffin deposition inhibitor (B) and an organic solvent (C).

In the wax deposition inhibitor composition of the present invention, the addition percentage of co-additive (A) is preferably between 0.1 and 50 mass%, more preferably between 1 and 30 mass%, and especially preferably between 2 and 15 mass%, based on the total mass (A) and (B), for example, between 0.1 and 30% by weight, or between 0.1 and 15% by weight, or between 1 and 50% by weight, or between 1 and 15% by weight, or between 2 and 50 wt.%, or between 2 and 30 wt.% relative to the total mass of (A) and (B). Accordingly, the content percentage of the polymeric wax inhibitor (B) in the wax inhibitor composition of the present invention is preferably between 50 and 99.9 mass%, more preferably between 70 and 99 mass%, and especially preferably between 85 and 98 mass%. %, for example between 50 and 99% by weight, or between 50 and 98% by weight, or between 70 and 99.9% by weight, or between 70 and 98% by weight, or between 85 and 99.9% by weight , or between 85 and 99 wt.% relative to the total mass of (A) and (B). In a more preferred embodiment, the weight ratio between the co-additive (A) and the polymeric wax inhibitor (B) is between 1:100 and 1:1, more preferably between 1:50 and 1:3, and especially preferably between 1:30 and 1:6, for example between 1:100 and 1:3, or between 1:100 and 1:6, or between 1:50 and 1:1, or between 1:50 and 1:6, or between 1:30 and 1:1, or between 1:30 and 1:3.

Organic solvent (C)

In a preferred embodiment, the wax inhibitor composition of the present invention contains, in addition to (A) and (B), an organic solvent (C) selected from aliphatic, cycloaliphatic, aromatic and/or alkylaromatic hydrocarbons and mixtures thereof. Particularly preferred solvents are those that have a flash point above 60°C, since there are fewer restrictions on transport and storage of concentrates when such solvents are used.

The first group of preferred solvents are alkyl aromatic hydrocarbons. Examples of preferred alkyl aromatic hydrocarbons are toluene, ethylbenzene, xylene, diethylbenzene, naphthalene and mixtures thereof. The second group of preferred solvents are saturated aliphatic hydrocarbons. They can be paraffin or naphthenic, i.e. saturated linear or cyclic hydrocarbons. Examples of preferred hydrocarbons include decane, n-undecane, n-dodecane, tetralin, decalin, and mixtures thereof. Particularly preferred are technical solvent mixtures such as Shellsol®, Exxsol®, Isopar®, Solvesso®, solvent naphtha and/or kerosene. In preferred embodiments, the organic solvent (C) contains at least 10 wt.%, preferably 20-100 wt.%, and especially preferably 30-90 wt.%, for example 10-100 wt.%, or 20-90 wt. .%, or 30-100 wt.% aromatic components.

Another group of preferred solvents are saturated aliphatic alcohols containing at least eight carbon atoms, and esters of saturated aliphatic carboxylic acids and saturated aliphatic alcohols. Examples of suitable alcohols include 1-octanol, 2-ethylhexanol, 1-decanol, 1-dodecanol and iso-tridecanol. Examples of suitable esters include saturated fatty acid esters containing at least eight

- 17 045907 carbon atoms, with saturated aliphatic alcohols, for example methyl laurate or methyl stearate. Technical mixtures of various aliphatic esters are commercially available. In another embodiment of the present invention, it is preferable to use esters of aliphatic or cycloaliphatic dicarboxylic acids, for example, dialkyl esters of cyclohexane-1,2-dicarboxylic acid, such as diisononyl cyclohexane-1,2-dicarboxylate.

The wax deposition inhibitor composition of the present invention can be prepared by mixing components (A) and (B) with a solvent (C). It is often preferable to carry out mixing at elevated temperatures, i.e. above the melting point of the polymeric wax inhibitor (B). Preferred is a temperature between 30 and 100°C, and in particular a temperature between 40 and 65°C, for example a temperature between 30 and 65°C, or between 40 and 100°C. The present invention also includes mixing wax inhibitor components (A), (B) and (C) with additional active ingredients for the same or different purposes.

The wax inhibitor composition of the present invention provides significantly lower pour point and viscosity compared to a comparable composition containing the same amount of wax inhibitor (B) dissolved in the same solvent (C) but not containing (A). In addition, the presence of co-additive (A) improves the dissolution of the wax inhibitor composition of the present invention in a paraffin-containing hydrocarbon liquid, compared to a preparation containing the same amount of wax inhibitor (B) dissolved in the same solvent (C). This provides an advantage especially when processing paraffin-containing hydrocarbon liquids at low temperatures. Without wishing to be bound by any theory, it is believed that the improved solubility at low temperatures results from a decrease in the crystallinity of the wax inhibitor (B) in the presence of (A). Therefore, in the presence of a co-additive (A), the pour point (the lowest temperature at which fluidity is maintained), viscosity and solubility of a wax inhibitor composition containing a certain amount of a polymeric wax inhibitor (B) and an organic solvent (C) are significantly improved. Therefore, replacing the organic solvent (C) with a co-additive (A) makes it easier to work with the paraffin deposition inhibitor composition at low temperatures of storage, transportation and use. This is especially true when part of the organic solvent (C) in the preparation containing the polymeric wax inhibitor (B) and the organic solvent (C) is replaced by a co-additive (A).

The wax inhibitor composition of the present invention improves the low temperature performance of wax-containing hydrocarbon fluids. This is advantageous especially when processing waxy mineral oils, such as crude oils and waxy products derived from them, such as bottoms, marine boiler fuels or heavy fuel oils. The term crude oil as used herein refers to the mineral oils produced at the wellhead and includes, for example, gas condensate and bitumen. In a preferred embodiment, crude oil and residual oil are treated, and in a particularly preferred embodiment, crude oil is treated.

The wax inhibitor composition of the present invention modifies the structure of waxes that precipitate from wax-containing hydrocarbon liquids at low temperatures more effectively than the polymeric wax inhibitor component (B) alone. Accordingly, the presence of a minor amount of co-additive (A) synergistically improves the effectiveness of the polymeric wax inhibitor (B). This results in an additional decrease in the pour point and often also in the viscosity of the paraffin-containing hydrocarbon fluid containing the wax inhibitor (B) in the presence of a co-additive (A), compared to a decrease in the pour point and viscosity when only the polymeric wax inhibitor (B) is added. Surprisingly, it has been found that the reaction product (A) is more efficient than the comparable reaction product of a fatty acid containing a linear alkyl moiety with an alkylene polyamine (ii).

The wax inhibitor composition of the present invention can be added to a wax-containing hydrocarbon liquid at any point. For example, crude oil may be processed at the wellhead, in storage tanks, or before being transported through a pipeline. In some cases, repeated applications at different points provide additional benefit.

Preferably, the amount of the wax inhibitor composition added to the wax-containing hydrocarbon liquid is 10-20,000 ppm by weight, more preferably 50-10,000 ppm by weight, and especially preferably 100-5000 ppm by weight, for example 10-10000 ppm by weight, or 10-5000 ppm by weight, or 50-20000 ppm by weight, or 50-5000 ppm by weight, or 50-3000 ppm by weight, or 100-20000 ppm parts by weight, or 100-10,000 ppm by weight, relative to the amount of paraffin-containing hydrocarbon liquid being processed.

- 18 045907

Examples

The reagents used to obtain condensation products (A) were of technical grade. The molar amounts of carboxylic acid and amine given in table. 1, were calculated from the acid number of the carboxylic acid and the amine number of the amine, which were determined by potentiometric titration with a base relative to the acid. The reaction products were characterized by IR spectroscopy: imidazoline has an intense absorption band at 1605 cm ^-1 , and amidoamine has an absorption band at 1645 cm ^-1 . Polymeric wax inhibitors were commercially available products. The molecular weight of the EVA copolymers was determined by melt flow index (MFI ₁₉₀ ) according to ISO 1133 at a temperature of 190°C and a load of 2.16 kg. Organic solvents of technical purity were used.

Table 1

List of components used

Reaction products of carboxylic acid with alkylene polyamine (A) A1 The product of the reaction of naphthenic acid (acid number 225 mg KOH/g) with an equimolar amount of diethylenetriamine (DETA), obtained by heating the reagents for 6 hours at 160°C in naphtha solvent. According to the characteristic indicators, the product is an amidoamine. A2 Product of the reaction of rosin acid (acid value 174 mg KOH/g) with an equimolar amount of diethylenetriamine (DETA); obtained by heating the reagents for 6 hours at 155°C in naphtha solvent. According to the characteristic indicators, the product is an amidoamine. AZ The product of the reaction of naphthenic acid (acid number 225 mg KOH/g) with an equimolar amount of triethylenetetramine (TETA), obtained by heating the reagents for 6 hours at 160°C in naphtha solvent. According to the characteristic indicators, the product is an amidoamine. A4 The reaction product of equimolar amounts of naphthenic acid (acid number 225 mg KOH/g) and diethylenetriamine (DETA), obtained by heating the reagents for 6 hours at 250°C. According to the characteristic indicators, the product is an imidazoline. A5 (comparative) The reaction product of rapeseed oil with three molar equivalents of diethylenetriamine, obtained by heating the reactants for 6 hours at 255°C in vacuum. The resulting product contains mainly imidazoline. Ab (comparative) The reaction product of rapeseed oil with three equivalents of diethylenetriamine (DETA), obtained by heating the reactants for 6 hours at 155°C. According to the characteristic indicators, the product is an amidoamine. Polymeric paraffin inhibitors (B) IN 1 EVA copolymer having a vinyl acetate content of 28 wt.% and an MFI190 value of 7g/10min, grafted with behenyl acrylate in a weight ratio of 1:3. AT 2 EVA copolymer having a vinyl acetate content of 22 wt.% and an MFI190 value of 40g/10min, grafted with stearyl acrylate in a weight ratio of 1:4. VZ Copolymer of maleic anhydride with CgO/24-a-olefin, esterified with behenyl alcohol; having an acid number of 38 mg KOH/g and an average molecular weight Mw = 10000 g/mol

- 19 045907

AT 4 Copolymer of maleic anhydride with Cgo/gg-a-olefin, esterified with behenyl alcohol; having an acid number of 9 mg KOH/g and an average molecular weight Mw = 11500 g/mol AT 5 Copolymer of maleic anhydride with Cro-a-olefin, imidized with stearylamine; having an average molecular weight of 8500 g/mol Wb EVA copolymer having a vinyl acetate content of 28 wt.% and an MFI190 value of 24g/10min AT 7 Poly(stearyl acrylate), Mw 100,000 Dalton, measured by GPC against polystyrene standards Organic solvents (C) SI Solvent naphtha; a mixture of aromatic hydrocarbons having a carbon number mainly in the range Ce - Cu and a boiling point from 177°C to 216°C Xyl xylene, mixture of isomers (technical purity)

Of the components listed in table. 1, compositions of paraffin deposition inhibitor were prepared in the proportions given in table. 2. The percentages of components A and B indicate the amounts of active ingredients. The final content of active ingredients was adjusted with solvent naphtha or xylene. The pour point of the compositions was measured according to ASTMD5853, but with a 1°C pour point increment.

table 2

Compositions of paraffin deposition inhibitor and their pour point

Composition A IN WITH Pour point WI01 4.5% A1 30.0%B1 65.5% HF + 10°С WI 02 (comparative) - 30.0%B1 70.0% HF + 18°C WI 03 10.0% A2 20.0% B2 70.0% HF + 11°С WI 04 (comparative) - 20.0% B2 80.0% HF + 14°C WI 05 4.5% A1 33.5% EOI 62.0% HF + 12°С WI 06 22.0% A1 33.5% EOI 44.5% HF +7°С WI 07 (comparative) - 33.5% EOI 66.5% HF + 15°C WI 08 2.2% A1 36.7%B1 61.1% Xyl +16°С WI 09 4.5% A1 36.7%B1 58.8% Xyl + 14°C WI 10 (comparative) - 36.7%B1 63.3% Xyl +21 °C WI AND 4.5% A1 20.0% EOI 75.5% HF -3°C WI 12 (comparative) - 20.0% EOI 80.0% HF + 10°С WI 13 (comparative) 4.5% A5 20.0% EOI 75.5% HF +2°С WI 14 (comparative) 4.5% Ab 20.0% EOI 75.5% HF +6°С WI 15 4.4% A1 18.3%B5 77.3% HF -10°С WI 16 (comparative) - 18.3%B5 81.7%CH -8°C WI 17 (comparative) 4.4% A5 18.3%B5 77.3% HF -8°C WI 18 4.5% A1 23.5% EOI 8.3% B5 68.2% HF 6°C WI 19 (comparative) - 23.5% EOI 8.3% B5 72.7% HF 13°C WI 20 4.0% A2 4.5% Wb 93.4% HF -12°С WI21 (comparative) - 4.5% Wb 97.8% HF -9°С WI 22 9.0% AZ 20.0% B7 71.0% Xyl +5°С WI 23 (comparative) - 20.0% B7 80.0% Xyl +7°С WI 24 4.5% A4 40.0%B1 16.5% B7 39.0% Xyl +16°С WI 25 (comparative) - 40.0%B1 16.5% B7 43.5% Xyl +21 °C WI 26 (comparative) 4.5% Ab 40.0%B1 16.5%B7 43.5% Xyl + 18°C

The viscosity of the compositions was measured according to DIN 53019 (Brookfield) with Haake Rheo Stress 600 in a 70 ml Z40DIN titanium beaker, at a shear rate of 10 s- ¹ and a cooling rate of 0.5 °C/min. In table Figure 3 shows the temperature at which the sample exceeds a viscosity of 1000 mPa-s during the process

- 20 045907 cooling. For comparison, the table shows some additional viscosity values.

Table 3

Viscosity of wax inhibitor compositions at different temperatures

Example Wax inhibitor composition Viscosity Temperature 1 WI 03 1000 mPa s +8°С 2 (comparative) WI 04 (comparative) 1000 mPa s + 11°С 3 WI AND 1000 mPa s -4°C 4 WI AND 20 mPa s +4°С 5 (comparative) WI 12 (comparative) 1000 mPa s +4°С 6 WI 20 1000 mPa s -6°C 7 (comparative) WI 21 (comparative) 1000 mPa s -7°C 8 WI 15 40 mPa s -7°C 9 WI 15 1000 mPa s <-15°С 10 (comparative) WI 16 (comparative) 1000 mPa s -7°C And (compare) WI 17 (comparative) 1000 mPa s -9°С 12 WI 18 1000 mPa s +8°С 13 (compared) WI 19 (comparative) 1000 mPa s +4°С 14 WI 20 1000 mPa s -6°C 15 (compared) WI 21 (comparative) 1000 mPa s -7°C 16 WI 22 1000 mPa s +w°s 17 (compared) WI 23 (comparative) 1000 mPa s +5°С

Reducing the pour point for paraffin inhibitor compositions from table. 2 in hydrocarbon liquids was tested in two types of crude oil. The characteristics of crude oil according to the SARA analysis method in accordance with IP 469 are given in table. 4; pour points measured when adding paraffin inhibitor compositions from Table 1 to these types of oil. 2, are given in table. 5 and 6. For comparison, A3 was tested when diluted with xylene to a solution with 9 wt.% active.

Table 4

Characteristics of crude oil

Crude Oil A Crude Oil B Saturates) - saturated 56% 71% ^(romatics) - aromatic 22% 15 % 7?(esins) - resins 7% 4% /l(spalthenes) - asphaltenes 15 % 10% Pour point 27°C 27°C

Table 5

Reducing the pour point of crude oil 1

Example Wax inhibitor composition Dosage Pour point 18 - 0 27°C 19 WI01 1000 ppm 9°C 20 (compared) WI 02 (comparative) 1000 ppm 12°C 21 (compared) A1 100 ppm 27°C 22 WI 20 1200 ppm 6°С 23 (compared) WI 21 (comparative) 1200 ppm 12°C 24 WI 24 1000 ppm 6°С 25 (compared) WI25 1000 ppm 9°С 26 (compared) WI 26 1000 ppm 12°C

- 21 045907

Table 6

Reducing the pour point of crude oil 2

Example Wax inhibitor composition Dosage Pour point 27 - 0 27°C 28 WI01 1000 ppm 11°C 29 (compared) WI 02 (comparative) 1000 ppm 12°С thirty WI 22 1200 ppm 12°С 31 (compared) WI 23 (comparative) 1200 ppm 15°C 32 (compared) AZ (9% in Xil) 1200 ppm 27°C

To evaluate the solubility of a wax inhibitor composition (additive) in a hydrocarbon liquid, 5000 ppm. compositions from table. 2 was added with a syringe to 100 ml of diesel fuel in a cylindrical glass 20 cm high. Dissolution was assessed visually according to the scale given in table. 7. Results obtained with different wax inhibitors from table. 2, are given in table. 8.

Table 7

Dissolution assessment

Grade Visual observations 1 The additive dissolves as it sinks into the liquid, but does not reach the bottom of the glass. 2 Part of the additive reaches the bottom of the glass and dissolves with gentle shaking. 3 The additive reaches the bottom of the glass and requires shaking to dissolve.

Table 8

Dissolution of wax inhibitor compositions

Example Wax inhibitor composition Temperature Grade 33 WI01 22°C 1 34 (compared) WI 02 (comparative) 22°C 3 35 WI03 22°C 1 36 (compared) WI 04 (comparative) 22°C 3 37 WI 06 20°C 1 38 (compared) WI 07 (comparative) 20°C 3 39 WI24 25°C 1 40 (compared) WI 25 (comparative) 25°C 2

Claims (29)

1. A paraffin deposition inhibitor composition containing A) a reaction product obtained by reacting i) a carboxylic acid containing an optionally substituted cycloaliphatic hydrocarbyl moiety with ii) an alkylene polyamine, B) a polymeric wax inhibitor, and C) an organic solvent, wherein the cycloaliphatic hydrocarbyl moiety a) contains from 5 to 70 carbon atoms, b) the cycloaliphatic structural moiety is connected to the carboxyl group either through a C-C bond or through a spacer, and c) if a spacer is present, it contains 1 to 10 carbon atoms. 2. The paraffin deposition inhibitor composition according to claim 1, wherein the reaction product of a carboxylic acid containing an optionally substituted cycloaliphatic hydrocarbyl residue (i) and an alkylene polyamine (ii) is an amidoamine of general formula (1) R ¹ -C(=O)-NR ² -(CH2)o-[NR ³ -(CH2)m] _P -NR ⁴ R ⁵ (1) where R ¹ is an optionally substituted hydrocarbyl residue containing 5-70 atoms carbon, which contains at least one cycloaliphatic structural fragment, R ² , R ³ are independently selected from hydrogen and a hydrocarbyl residue containing 120 carbon atoms, R ⁴ represents hydrogen or a hydrocarbyl residue containing 1-20 carbon atoms, - 22 045907 R ⁵ , regardless of R ⁴ , is selected from hydrogen, an optionally substituted hydrocarbyl moiety containing 1-20 carbon atoms, and an acyl group having the structure -C(=O)-R ¹ , with the proviso that R ⁴ and R ⁵ together can form A 5- or 6-membered ring, o is an integer from 2 to 5, and preferably 2 or 3, m is an integer from 2 to 5, and preferably 2 or 3, and p is 0 or an integer from 1 to 10. 3. The paraffin deposition inhibitor composition according to claim 1, where the reaction product of a carboxylic acid containing a cycloaliphatic structural moiety (i) and an alkylene polyamine (ii) is an imidazoline of general formula (2): R? R ³ N t 1 ₂ з 4 (2) where R ¹ , R ² , R3, R ⁴ , R ⁵ and m have the same meanings as indicated in paragraph 2, and q is equal to 0 or an integer from 1 to 9, preferably 1 or 2. 4. The composition of a paraffin deposition inhibitor according to any one of claims 1 to 3, where the reaction product of a carboxylic acid containing an optionally substituted cycloaliphatic hydrocarbyl residue (i) and an alkylene polyamine (ii) contains an amidoamine of the general formula (1) and an imidazoline of the general formula (2 ). 5. The paraffin deposition inhibitor composition according to claim 4, wherein the ratio between the amidoamine of the general formula (1) and the imidazoline of the general formula (2) is from 50:1 to 1:20. 6. The wax deposition inhibitor composition according to any one of claims 1 to 5, wherein the carboxylic acid containing the cycloaliphatic structural moiety (i) contains from 6 to 70 carbon atoms. 7. The wax inhibitor composition according to any one of claims 1 to 6, wherein the carboxylic acid (i) used to obtain the reaction product (A) is naphthenic acid. 8. The wax deposition inhibitor composition according to any one of claims 1 to 7, wherein the carboxylic acid (i) used to obtain the reaction product (A) is rosin acid. 9. The composition of a paraffin deposition inhibitor according to any one of claims 1 to 8, where the main amount of a carboxylic acid containing a cycloaliphatic structural fragment (i) reacts in a mixture with a linear carboxylic acid taken in an amount of less than 50 mol.%, giving a co-additive (A). 10. The wax inhibitor composition according to any one of claims 1 to 9, wherein the alkylene polyamine (ii) contains from 2 to 20 carbon atoms and preferably from 4 to 10 carbon atoms. 11. A paraffin deposition inhibitor composition according to any one of claims 1 to 10, wherein the alkylene polyamine (ii) contains from 2 to 10 nitrogen atoms. 12. The wax inhibitor composition according to any one of claims 1 to 11, wherein the polymeric wax inhibitor (B) is selected from the group consisting of a) copolymers of ethylene with ethylenically unsaturated esters, ethers and/or C3-C3 ₀ -α alkenes, b) homo- or copolymers of ethylenically unsaturated carboxylic acids containing C ₁₂ -C ₅₀ -alkyl radicals linked through ester, amide and/or imide groups, c) copolymers of ethylene with grafted ethylenically unsaturated esters and/or ethers, and d) condensation products of alkyl-substituted phenols with aldehydes and/or ketones. 13. The wax inhibitor composition according to any one of claims 1 to 12, wherein the polymeric wax inhibitor (B) is a mixture of two or more different polymeric wax inhibitors. 14. The composition of a paraffin deposition inhibitor according to any one of claims 1 to 13, where the proportion of the reaction product (A) is from 1 to 50 wt.% relative to the total mass of (A) and (B). 15. The composition of a paraffin deposition inhibitor according to any one of claims 1 to 14, where the proportion of the reaction product (A) is from 1 to 30 wt.% relative to the total mass of (A) and (B). 16. The paraffin deposition inhibitor composition according to any one of claims 1 to 15, where the proportion of the polymeric paraffin deposition inhibitor (B) is from 50 to 99 wt.% relative to the total mass of (A) and (B). 17. The wax inhibitor composition according to any one of claims 1 to 16, wherein the organic solvent (C) is a hydrocarbon or a mixture of hydrocarbons. 18. The wax deposition inhibitor composition according to any one of claims 1 to 17, wherein the organic solvent (C) is an aliphatic hydrocarbon, a cycloaliphatic hydrocarbon, an aromatic hydrocarbon, an alkyl aromatic hydrocarbon, or a mixture thereof. 19. The wax inhibitor composition according to any one of claims 1 to 18, wherein the organic solvent (C) has a flash point higher than 60°C. - 23 045907 20. Use of the reaction product (A) obtained by reacting a carboxylic acid (i) containing an optionally substituted cycloaliphatic hydrocarbyl residue with an alkylene polyamine (ii) as specified in claim 1, to reduce the pour point and/or viscosity of a polymeric wax inhibitor (B), where (A) and/or (B) are dissolved or dispersed in an organic solvent (C). 21. A method for reducing the viscosity of a polymeric wax inhibitor (B), comprising mixing a polymeric wax inhibitor (B) with a reaction product (A) obtained by reacting a carboxylic acid containing an optionally substituted cycloaliphatic hydrocarbyl residue (i) with an alkylene polyamine (ii) as specified in claim 1, where (A) and/or (B) are dissolved or dispersed in an organic solvent (C). 22. A method for improving the cold flow of a paraffin-containing hydrocarbon liquid, comprising mixing the paraffin-containing hydrocarbon liquid with a wax deposition inhibitor composition according to any one of claims 1 to 19. 23. The method of claim 22, wherein the paraffin-containing hydrocarbon liquid is crude oil, bottoms, marine boiler fuel or heavy fuel oil. 24. The method according to claim 22 or 23, wherein the wax inhibitor composition according to any one of claims 1 to 19 is introduced to lower the pour point. 25. The method according to any one of claims 22 to 24, wherein the amount of the wax inhibitor composition added to the wax-containing hydrocarbon liquid is from 50 to 3000 ppm by weight based on the wax-containing hydrocarbon liquid. 26. The method according to any one of claims 22 to 25, wherein the wax inhibitor composition is injected into the crude oil pipeline. 27. The method according to any one of claims 22 to 26, wherein the wax inhibitor composition is injected into the production well. 28. A composition for improving cold flow, comprising a paraffin-containing hydrocarbon liquid and a paraffin deposition inhibitor composition according to any one of claims 1 to 19. 29. The composition of claim 28, wherein the paraffin-containing hydrocarbon liquid is crude oil, bottoms, marine boiler fuel or heavy fuel oil.