EP3380589B1 - Copolymers made from alpha-olefins and olefinic dicarboxylic acid ester and their use as pour point depressants for crude oils and mineral oils - Google Patents

Description

The present invention relates to copolymers comprising C ₁₄ - to C ₅₀ -olefins and at least two different Olefindicarbonsäureestern and optionally maleic acid or maleic acid derivatives. The olefinic acid esters are on the one hand esters with linear C ₁₈ - to C ₅₀ -alkyl groups and on the other hand esters with short-chain linear, branched or cyclic alkyl groups or esters with aromatic groups. The invention further relates to a process for the preparation of such copolymers and their use as a pour point depressant for crude oil, mineral oil and / or mineral oil products, preferably as a pour point depressant for crude oil.

The reservoir temperature of oil reservoirs is usually above room temperature, for example at 40 ° C to 100 ° C. From such deposits crude oil is still warm, and it cools during or after the pumping naturally more or less quickly to room temperature or at appropriate climatic conditions to temperatures below.

Crude oils have different proportions of long-chain n-paraffins depending on their origin. The proportion of such paraffins, depending on the nature of the crude oil, may typically be from 1 to 30% by weight of the crude oil. They are often referred to as waxes. The paraffins can usually crystallize on cooling when falling below a certain temperature in the form of platelets. The precipitated paraffins significantly affect the fluidity of the oil. The platy n-paraffin crystals can form a kind of house structure that encloses the crude oil so that the crude stagnates, although the majority is still liquid. Failed paraffins can continue to clog filters, pumps, pipelines and other equipment or deposit in tanks, causing such a high level of cleaning.

The lowest temperature at which a sample of oil just flows on cooling is called the pour point. Standardized measuring methods are used to measure the pour point. Crude oils can have pour points above room temperature. Such crude oils may solidify during or after conveying.

It is known to lower the pour point of crude oils by suitable additives. In this way, it can be prevented that paraffins precipitated in a platelet-like form on cooling of the crude oil conveyed. On the one hand, suitable additives prevent the formation of said card house-like structures and thus lower the temperature at which the crude oil solidifies. Furthermore, additives can promote the formation of fine, well-crystallized, non-agglomerating paraffin crystals, so that a trouble-free oil transport is ensured. Such additives are referred to as pour-point depressants or flow improvers.

Paraffin inhibitors or wax inhibitors are those substances which are said to prevent the deposition of paraffins or paraffin waxes on surfaces in contact with crude oils or other wax-containing oils and / or mineral oil products.

It is known to use as flow improvers ethylene copolymers, in particular copolymers of ethylene and unsaturated esters. Examples of this are in DE-A-21 02 469 or EP 84 148 A2 described.

It is also known to use for this purpose copolymers of olefins and esters of ethylenically unsaturated dicarboxylic acids.

GB 1 468 588 discloses a middle oil distillate containing an MSA-olefin copolymer esterified with C ₁₈ to C ₄₄ alcohols to improve low temperature properties. An example discloses a copolymer of MSA, C _22/28 α-monoolefins, and behenyl alcohol.

US 2,542,542 discloses copolymers of dedecene, tetradecene, hexadecene or octadecene and maleic anhydride as an additive to lubricating oils.

EP 214 786 A1 discloses the use of copolymers of straight chain olefins, for example, 1-octene, 1-decene, 1-dodecene, 1-tetradecene or 1-octadecene and maleic acid esters to improve the low temperature properties of fuels. The alcohols used for the esterification have at least 10 carbon atoms and they can be linear or branched. The document discloses that a mixture of linear and simple methyl branched alcohols can be used.

EP 1 746 147 A1 discloses the use of copolymers of olefins and esters of ethylenically unsaturated dicarboxylic acids to lower the cloud point of fuel oils and lubricants. The copolymers comprise as monomers C ₃ to C ₅₀ olefins, preferably C ₈ to C ₈₈ olefins and C ₁ to C ₄₀ mono- or diesters of ethylenically unsaturated dicarboxylic acids, in particular of maleic acid. The C ₁ - to C ₄₀ -hydrocarbon radicals of the ester groups are preferably linear or branched C ₁ - to C ₄₀ -alkyl radicals. Copolymers which comprise both linear and branched alkyl radicals are not disclosed and the document contains no information on the molecular weight of the products obtained. The copolymers described are prepared by first reacting the olefins with maleic anhydride to give an olefin-MSA copolymer and, in a second step, in o-xylene (flash point about 30 ° C.) as solvent with alcohols. In this case, the ring of polymerized MSA units is opened. The o-xylene can be removed after completion of the reaction. The document further describes additive packages in which the said copolymers, optionally with further components, are formulated in suitable diluents. Diluents may be, for example, aliphatic or aromatic solvents or alkoxyalkanols.

The preparation of such copolymers for use as pour-point depressants is usually carried out in chemical production facilities and the products are transported from there to the place of use, for example to an oil field or to an offshore platform. Such places of use can be in cold regions of the earth. In order to save on transport costs, concentrates of the copolymers are usually prepared in hydrocarbons. Such concentrates can be formulated by the users on site in the desired manner to ready-to-use formulations. For example, it is possible to dilute with solvent and / or add further additives.

Particularly advantageous pour point depressants can be obtained by using C ₂₀ - to C ₂₄ -olefins and C ₁₆ - to C ₂₈ -alcohols for the preparation of said copolymers.

Ready-to-use formulations may comprise, for example, about 20% by weight of said copolymers in high boiling organic solvents. High-boiling organic solvents are used because they also have a high flash point. In particular, solvents having a flash point of at least 60 ° C. are frequently used. Such formulations have the disadvantage that they can solidify when handled in a cold environment, for example in an Arctic environment, which is highly undesirable. The problem could be solved for example by the use of formulations with a lower concentration of polymers. As a result, however, larger amounts of solvents are needed, so that this solution must of course be more expensive. Higher costs also result in changes to the infrastructure, such as heated pipes.

It is an object of the present invention to provide improved formulations of modified olefin-MSA copolymers for use as pour point depressants for crude oils available in high boiling organic solvents. At a concentration of about 20% by weight of copolymers, the formulations should have a lower solidification temperature, while having a substantially constant action as a pour point depressant, than known formulations.

Surprisingly, it has been found that this can be achieved by small changes in the polymer architecture.

1. (A) 40 bis 60 mol-%, bezogen auf die Menge aller Monomere, mindestens eines α-Olefins (A) der allgemeinen Formel H₂C=CH-R¹,
   wobei R¹ für mindestens einen linearen, cyclischen oder verzweigten, aliphatischen und/oder aromatischen Kohlenwasserstoffrest mit 14 bis 50 Kohlenstoffatomen steht, sowie
2. (B) 60 bis 40 mol-%, bezogen auf die Menge aller Monomere, monoethylenisch ungesättigte Dicarbonsäuren oder Derivate davon,

und wobei es sich bei den Monomeren (B) um

• (B1) mindestens ein Monomer (R²OOC)R⁵C=CR⁶(COOR⁴), um
• (B2) mindestens ein Monomer (R³OOC)R⁵C=CR⁶(COOR⁴) sowie
• (B3) optional mindestens ein Monomer ausgewählt aus der Gruppe von (HOOC)R⁵C=CR⁶(COOH) (B3a) und
  
  wobei
  • R² für einen linearen Alkylrest mit 16 bis 36 Kohlenstoffatomen steht,
  • R³ für einen Rest ausgewählt aus der Gruppe von
    • ▪ R^3a: linearen 1-Alkylresten mit 1 bis 10 Kohlenstoffatomen,
    • ▪ R^3b: verzweigten und/oder sekundären Alkylresten mit 4 bis 36 Kohlenstoffatomen,
    • ▪ R^3c: unsubstituierten oder alkylsubstituierten, cyclischen Alkylresten mit 5 bis 18 Kohlenstoffatomen, oder
    • ▪ R^3d: unsubstituierten oder alkylsubstituierten aromatischen Kohlenwasserstoffesten mit 6 bis 36 Kohlenstoffatomen steht,
  • R⁴ jeweils für einen Rest ausgewählt aus der Gruppe von H, R² und R³ steht, mit der Maßgabe, dass es sich jeweils bei mindestens 50 mol-% der Reste R⁴ um H handelt,
  • R⁵ und R⁶ jeweils für H oder Methyl stehen,
  • der Anteil der Reste R³ bezüglich der Summe der Reste R² und R³ 1 mol-% bis 49 mol-% beträgt,
  • der Anteil der Monomere (B1) + (B2) bezüglich der Summe aller Monomere (B) mindestens 50 mol-% beträgt, und
  • das gewichtsmittlere Molekulargewicht M_w der Copolymere (X) 2000 g/mol bis 25000 g/mol beträgt.

Accordingly, in a first aspect of the invention, copolymers (X) have been found comprising as monomers at least

1. (A) 40 to 60 mol%, based on the amount of all monomers, of at least one α-olefin (A) of the general formula H ₂ C =CH-R ¹ ,
   wherein R ^{1 is} at least one linear, cyclic or branched, aliphatic and / or aromatic hydrocarbon radical having 14 to 50 carbon atoms, as well as
2. (B) 60 to 40 mol%, based on the amount of all monomers, monoethylenically unsaturated dicarboxylic acids or derivatives thereof,

and wherein the monomers (B) are

• (B1) at least one monomer (R ² OOC) R ⁵ C = CR ⁶ (COOR ⁴ )
• (B2) at least one monomer (R ³ OOC) R ⁵ C = CR ⁶ (COOR ⁴ ) and
• (B3) optionally at least one monomer selected from the group of (HOOC) R ⁵ C = CR ⁶ (COOH) (B3a) and
  
  in which
  • R ^{2 is} a linear alkyl radical having 16 to 36 carbon atoms,
  • R ^{3 is} a radical selected from the group of
    • R ^3a : linear 1-alkyl radicals having 1 to 10 carbon atoms,
    • R ^3b : branched and / or secondary alkyl radicals having 4 to 36 carbon atoms,
    • R ^3c : unsubstituted or alkyl-substituted, cyclic alkyl radicals having 5 to 18 carbon atoms, or
    • R ^3d : unsubstituted or alkyl-substituted aromatic hydrocarbon radicals having 6 to 36 carbon atoms,
  • R ^{4 is in} each case a radical selected from the group of H, R ² and R ³ , with the proviso that in each case at least 50 mol% of the radicals R ⁴ is H,
  • R ⁵ and R ^{6 are} each H or methyl,
  • the proportion of the radicals R ³ with respect to the sum of the radicals R ² and R ^{3 is} 1 mol% to 49 mol%,
  • the proportion of monomers (B1) + (B2) with respect to the sum of all monomers (B) is at least 50 mol%, and
  • the weight average molecular weight M _{w of} the copolymers (X) is 2000 g / mol to 25000 g / mol.

In a second aspect of the invention, a composition of the copolymer described (X) and organic solvents (Y), in particular hydrocarbons having a flash point ≥ 60 ° C was found.

1. I) Bereitstellen eines polymeren Eduktes durch Polymerisation mindestens der folgenden Monomere
   • 40 bis 60 mol-%, bezüglich der Menge aller eingesetzten Monomere- α-Olefine H₂C=CH-R¹ (A), wobei R¹ für mindestens einen linearen, cyclischen oder verzweigten, aliphatischen und/oder aromatischen Kohlenwasserstoffrest mit 14 bis 50 Kohlenstoffatomen steht, sowie
   • 60 bis 40 mol-% (B3b)
     
     wobei R⁵ und R⁶ wie oben definiert sind,
     wobei das zahlenmittlere Molekulargewicht M_n des polymeren Edukts 1000 g/mol bis 15000 g/mol beträgt,
2. II) polymeranaloge Veresterung des in Stufe I bereitgestellten polymeren Eduktes bei 130°C bis 180°C mit
   • mindestens einem Alkohol R²OH, wobei R² für einen linearen Alkylrest mit 18 bis 36 Kohlenstoffatomen steht, und
   • mindestens einem Alkohol R³OH, ausgewählt aus der Gruppe von
     • ▪ R^3aOH, wobei R^3a für lineare 1-Alkylreste mit 1 bis 10 Kohlenstoffatomen,
     • ▪ R^3bOH, wobei R^3b für verzweigte und/oder sekundäre Alkylreste mit 4 bis 36 Kohlenstoffatomen steht,
     • ▪ R^3cOH, wobei R^3c für unsubstituierte oder alkylsubstituierte, cyclische Alkylreste mit 5 bis 18 Kohlenstoffatomen steht, und
     • ▪ R^3dOH, wobei R^3d für einen unsubstituierten oder alkylsubstituierten aromatischen Kohlenwasserstoffesten mit 6 bis 36 Kohlenstoffatomen steht,
   • wobei der Anteil der Alkohole R³OH bezüglich der Summe der Alkohole R²OH und R³OH 1 mol-% bis 49 mol-% beträgt, und
   • die Menge der eingesetzten Alkohole R²OH und R³OH zusammen 0,5 bis 1,5 mol / mol (B3b) beträgt.

In a third aspect of the invention, a process for the preparation of such copolymers (X) has been found which comprises at least the following process steps:

1. I) providing a polymeric educt by polymerization of at least the following monomers
   • 40 to 60 mol%, relative to the amount of all monomers used α-olefins H ₂ C = CH-R ¹ (A), wherein R ^{1 is} at least one linear, cyclic or branched, aliphatic and / or aromatic hydrocarbon radical having 14 to 50 carbon atoms, and
   • 60 to 40 mol% (B3b)
     
     wherein R ⁵ and R ^{6 are} as defined above,
     wherein the number average molecular weight M _{n of} the polymeric starting material is 1000 g / mol to 15000 g / mol,
2. II) polymer-analogous esterification of the provided in step I polymeric educt at 130 ° C to 180 ° C with
   • at least one alcohol R ² OH, wherein R ^{2 is} a linear alkyl radical having 18 to 36 carbon atoms, and
   • at least one alcohol R ³ OH selected from the group of
     • R ^3a OH, where R ^{3a is} linear 1-alkyl radicals having 1 to 10 carbon atoms,
     • R ^3b OH, where R ^{3b is} branched and / or secondary alkyl radicals having 4 to 36 carbon atoms,
     • R ^3c OH, where R ^{3c is} unsubstituted or alkyl-substituted, cyclic alkyl radicals having 5 to 18 carbon atoms, and
     • R ^3d OH, where R ^{3d is} an unsubstituted or alkyl-substituted aromatic hydrocarbon radical having 6 to 36 carbon atoms,
   • wherein the proportion of the alcohols R ³ OH with respect to the sum of the alcohols R ² OH and R ³ OH is 1 mol% to 49 mol%, and
   • the amount of alcohols R ² OH and R ³ OH used together is 0.5 to 1.5 mol / mol (B3b).

Furthermore, copolymers (X) were found, obtainable by means of the method described.

In a further aspect of the invention, the use of such copolymers (X) has been found as a pour point depressant for crude oil, mineral oil and / or mineral oil products, in particular as a pour point depressant for crude oils and for preventing wax deposits on surfaces.

More specifically, the following is to be accomplished for the invention:
The novel copolymers (X) are synthesized from ethylenically unsaturated monomers. They comprise as monomers at least one α-olefin (A) and at least two different Olefindicarbonsäureester (B1) and (B2). In addition, optionally maleic acid, maleic anhydride, or the corresponding methyl-substituted derivatives and / or further ethylenically unsaturated monomers, in particular monoethylenically unsaturated monomers, may be copolymerized into the copolymer (X).

Monomers (A)

The monomers (A) are α-olefins which have the general formula H ₂ C =CH-R ¹ . Here, R ^{1 is} a linear, cyclic or branched, aliphatic and / or aromatic hydrocarbon radical having 14 to 50, in particular 16 to 30 carbon atoms, preferably 18 to 30 carbon atoms and particularly preferably 18 to 28 carbon atoms.

They are preferably linear or branched alkyl radicals, particularly preferably linear alkyl radicals having 14 to 50 carbon atoms, in particular linear alkyl radicals having 16 to 30 carbon atoms, preferably 18 to 30 carbon atoms, particularly preferably 18 to 28 carbon atoms and for example 18 to 24 carbon atoms.

According to the invention, a single α-olefin can be used, or it can also be used mixtures of several different α-olefins of the general formula H ₂ C = CH-R ¹ .

Advantageously, mixtures may be used which comprise at least two, preferably at least three, α-olefins having alkyl radicals R ¹ , preferably linear alkyl radicals R ¹ having 16 to 30 carbon atoms, preferably 18 to 24 carbon atoms.

The mixtures may in particular be technical mixtures of linear aliphatic α-olefins. Such technical mixtures contain as main constituents aliphatic α-olefins having an even number of carbon atoms. Advantageously, a technical mixture comprising at least three α-olefins of the general formula H ₂ C = CH-R ¹ can be used, in which the radicals R ^{1 are} n-octadecyl, n-eicosyl and n-docosyl radicals (ie a mixture from linear aliphatic C ₂₀ , C ₂₂ and C ₂₄ -α-olefins), in particular mixtures which comprise at least 80% by weight, preferably at least 90% by weight, of the stated α-olefins with respect to the amount of all olefins.

Monomers (B)

The monomers (B) are monoethylenically unsaturated dicarboxylic acids or derivatives. According to the invention, the monomers (B) are at least two different monomers (B1) and (B2). In addition, optionally monomers (B3) may be present. In addition to (B1), (B2) and, if appropriate, (B3), no further monomers (B) are present.

The monomers (B1) and (B2) are according to the invention
at least one monomer of the general formula (R ² OOC) R ⁵ C =CR ⁶ (COOR ⁴ ) (B1), and at least one monomer of the general formula (R ³ OOC) R ⁵ C =CR ⁶ (COOR ⁴ ) ( B2).

In formulas (B1) and (B2), R ⁵ and R ⁶ are each H or methyl, preferably, in R ⁵ and R ⁶ each are H.

Depending on the position of the substituents on the double bond may be E or Z isomers.

In (B1) R ^{2 is} a linear n-alkyl radical having 16 to 36 carbon atoms, preferably 16 to 32 carbon atoms, in particular 16 to 26 carbon atoms.

Examples of such radicals include n-hexadecyl, n-heptadecyl, n-octadecyl, n-nonadecyl, n-eicosyl, n-heneicosyl, n-docosyl, n-tetracosyl, n-hexacosyl, n- Octacosyl or n-tricontyl radicals.

In one embodiment of the invention, R ^{2 is} at least one linear n-alkyl radical having 16 to 22 carbon atoms.

In a further embodiment of the invention, R ^{2 is} at least one linear n-alkyl radical having 22 to 26 carbon atoms.

In (B2) R ^{3 is} at least one radical selected from the group of R ^3a , R ^3b , R ^3c and R ^3d , preferably selected from R ^3b and R ^3c .

R ^3a are linear 1-alkyl radicals having 1 to 10 carbon atoms, preferably 2 to 10 and particularly preferably 2 to 6 carbon atoms.

Examples of linear 1-alkyl radicals R ^3a include ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl and n-decyl radicals; preference is given to n- Propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl and n-decyl, particularly preferred are ethyl, n-propyl, n-butyl, n-pentyl and n-hexyl radicals and very particularly preferred are n-butyl radicals.

R ^3b are branched and / or secondary alkyl radicals having 4 to 36 carbon atoms, preferably 4 to 30, particularly preferably 4 to 17 carbon atoms.

Branched alkyl radicals can be mono- or polysubstituted. Examples of branched alkyl radicals R ^3b include i-butyl, t-butyl, 2,2'-dimethylpropyl, 2-ethylhexyl, 2-propylheptyl, i-nonanol, i-decyl, i-tridecyl, i Heptadecylreste, preferred are t-butyl, 2-ethylhexyl and 2-Propylheptylreste.

Examples of secondary alkyl radicals include 2-butyl, 2-propyl, 2-hexyl, 2-heptyl or 2-dodecyl radicals.

R ^3c are unsubstituted or alkyl-substituted, cyclic alkyl radicals having 5 to 18 carbon atoms, preferably 6 to 10 carbon atoms. In particular, they are unsubstituted or alkyl-substituted cyclic alkyl radicals containing 5, 6 or 7 rings. It may also be bicyclic radicals. Examples of R ^3c radicals include cyclopentyl, cyclohexyl, cycloheptyl, bornyl or myrthanyl radicals. Preferably, R ^{3c may} be a cyclohexyl radical.

R ^3d is unsubstituted or alkyl-substituted aromatic hydrocarbon radicals having 6 to 36 carbon atoms. Examples of such radicals include phenyl, benzyl or toluyl radicals.

R ⁴ in the formulas (B1) and (B2) are each a radical selected from the group of H, R ² and R ³ , where R ² and R ^{3 have} the meaning defined above, with the proviso that that in each case 50 mol%, preferably at least 75 mol% and particularly preferably at least 95 mol% of the radicals R ⁴ is H. In one embodiment of the invention, all radicals R ⁴ are H.

If R ⁴ in (B1) or (B2) is H, then (B1) and (B2) are monoesters. If R ⁴ in (B1) or (B2) is R ² or R ³ , it is diester.

For R ⁴ = H, the monomers (B1) and (B2) comprise COOH groups. Of course, depending on the medium, the COOH groups may be dissociated, and they may also be present in salt form as - COO- ¹ / _m X ^{m +} , where X ^{m + is} an m-valent cation. For example, X ^{m + may} be alkali metal ions such as Na ⁺ , K ⁺ or ammonium ions.

The optionally present monomers (B3) are at least one monomer selected from (HOOC) R ⁵ C = CR ⁶ (COOH) (B3a) and

It is therefore maleic acid and / or maleic anhydride or the corresponding methyl-substituted derivatives.

The proportion of the monomers (B1) + (B2) with respect to the sum of all monomers (B) (ie the sum of (B1), (B2) and (B3)) is at least 50 mol%, preferably at least 80 mol%, Particularly preferably at least 95 mol% and very particularly preferably exclusively monomers (B1) and (B2) are present.

The proportion of the radicals R ³ with respect to the sum of the radicals R ² and R ³ is 1 mol% to 49 mol%, in particular 5 mol% to 45 mol%, preferably 20 mol% to 45 mol% and for example 30 mol% to 40 mol%.

It may be only one monomer (B1), or it may be several different monomers (B1) with different radicals R ² .

In one embodiment, there are at least two, preferably at least three different monomers (B1) with different radicals R ² , wherein R ² in this embodiment, 16 to 30 carbon atoms, for example 16 to 22 carbon atoms or, for example, 20 to 28 carbon atoms, in particular 22 to 26 carbon atoms.

In one embodiment of the invention, these are at least three different monomers (B1), specifically at least one monomer (B1) in which R ^{2 is} an n-docosyl radical, a monomer (B1) in which R ^{2 is} an n Tetracosyl radical and a monomer (B1) in which R ^{2 is} an n-hexacosyl radical.

It can be only one monomer (B2), or it can be several different monomers (B2) with different radicals R ³ .

In one embodiment of the invention, the radicals R ³ are radicals R ^3a .

In one embodiment of the invention, the radicals R ³ are radicals R ^3b and / or radicals R ^3c .

In one embodiment of the invention, the radicals R ³ are radicals R ^3b .

In one embodiment of the invention, the radicals R ³ are radicals R ^3c .

In one embodiment of the invention, the radicals R ³ are radicals R ^3d .

Other monomers (C)

In addition to the monomers (A) and (B), further ethylenically unsaturated, in particular monoethylenically unsaturated, monomers (C) may optionally be present. Mention should be made here of the monomers (B) different derivatives of Olefindicarbonsäuren. Also to be mentioned are the α-olefins (A) different α-olefins, such as methyl undecenoate. It is also possible to use vinyl ethers, vinyl esters, N-vinyl comonomers such as vinylpyrrolidones, vinylcaprolactams, isobutene, diisobutene or polyisobutene.

Copolymers (X)

In the copolymers (X) according to the invention, the proportion of the monomers (A) with respect to the amount of all monomers is 40 mol% to 60 mol%, preferably 45 mol% to 55 mol% and for example 48 to 52 mol%.

The proportion of the monomers (B) with respect to the amount of all monomers is 40 mol% to 60 mol%, preferably 45 mol% to 55 mol%, and for example 48 to 52 mol%.

If present at all, the amount of additional monomers (C) is not more than 20 mol%, preferably not more than 10 mol%, more preferably not more than 5 mol%, and most preferably no further monomers (C) are present ,

The weight-average molecular weight M _{w of} the copolymers (X) is, according to the invention, 2000 g / mol to 25000 g / mol, preferably 4000 g / mol to 20 000 g / mol and, for example, 10 000 to 20 000 g / mol.

• der Anteil der Monomere (B1) + (B2) bezüglich der Summe aller Monomere (B) mindestens 95 mol-% beträgt, und
• bei denen es sich bei mindestens 95 mol-% der Reste R⁴ um H handelt.

In one embodiment of the invention is a copolymer (X) of the type described, in which

• the proportion of monomers (B1) + (B2) with respect to the sum of all monomers (B) is at least 95 mol%, and
• which is at least 95 mol% of R ⁴ is H.

In other words, this embodiment involves copolymers (X) which contain at most small amounts of maleic anhydride and / or maleic acid or the corresponding methyl derivatives, and in which the olefinic acid ester units are mainly monoesters.

• der Anteil der Monomere (B1) + (B2) bezüglich der Summe aller Monomere (B) mindestens 95 mol-% beträgt,
• es sich bei mindestens 95 mol-% der Reste R⁴ um H handelt,
• das Copolymer mindestens zwei verschiedene α-Olefine H₂C=CH-R¹ umfasst, wobei R¹ für lineare Alkylreste mit 16 bis 30 Kohlenstoffatomen, bevorzugt 18 bis 28 Kohlenstoffatomen und besonders bevorzugt 18 bis 24 Kohlenstoffatomen steht, und
• das Copolymer mindestens zwei verschiedene Monomere (B1) umfasst, wobei R² jeweils 16 bis 32 Kohlenstoffatome, bevorzugt 16 bis 26 Kohlenstoffatome umfasst,
• R³ für einen Rest ausgewählt aus der Gruppe von
  • ∘ R^3b: verzweigten und/oder sekundären Alkylresten, bevorzugt verzweigten Alkylresten mit 4 bis 36, bevorzugt 4 bis 30, besonders bevorzugt 4 bis 17 Kohlenstoffatomen, und
  • ∘ R^3c: unsubstituierten oder alkylsubstituierten, cyclischen Alkylresten mit 5 bis 18, bevorzugt 6 bis 10 Kohlenstoffatomen, insbesondere einen Cyclohexylrest.

In a further embodiment of the invention is a copolymer (X) of the type described, in which

• the proportion of monomers (B1) + (B2) with respect to the sum of all monomers (B) is at least 95 mol%,
• at least 95 mol% of the radicals R ⁴ are H,
• the copolymer comprises at least two different α-olefins H ₂ C = CH-R ¹ , wherein R ^{1 represents} linear alkyl radicals having 16 to 30 carbon atoms, preferably 18 to 28 carbon atoms and more preferably 18 to 24 carbon atoms, and
• the copolymer comprises at least two different monomers (B1), where R ² comprises in each case 16 to 32 carbon atoms, preferably 16 to 26 carbon atoms,
• R ^{3 is} a radical selected from the group of
  • R ^3b : branched and / or secondary alkyl radicals, preferably branched alkyl radicals having 4 to 36, preferably 4 to 30, particularly preferably 4 to 17 carbon atoms, and
  • 3 R ^3c : unsubstituted or alkyl-substituted, cyclic alkyl radicals having 5 to 18, preferably 6 to 10 carbon atoms, in particular a cyclohexyl radical.

Composition comprising olefin-olefinic acid ester copolymers (X) and hydrocarbons

• mindestens ein Copolymer (X), sowie
• mindestens ein organisches Lösemittel (Y).

In a further aspect, the invention relates to a composition for use as a pour point depressant at least comprising

• at least one copolymer (X), as well as
• at least one organic solvent (Y).

The copolymers (X) according to the invention and preferred embodiments of the copolymers (X) have already been described above, so that reference is made at this point only to the above description.

The organic solvents (Y) may in principle be any organic solvents, provided that the copolymers (X) are soluble therein. Preference is given to using solvents which have a flash point ≥ 60 ° C.

Organic solvents (Y) may be hydrocarbons. Examples of hydrocarbons include aliphatic, cycloaliphatic and / or aromatic solvents. Furthermore, it is also possible to use organic solvents comprising functional groups, for example alcohols or esters.

In one embodiment of the invention, the organic solvents are nonpolar solvents (Y1) comprising saturated aliphatic hydrocarbon groups, preferably those which have a flash point ≥ 60 ° C. Examples of such solvents (Y1) include saturated aliphatic alcohols or esters of saturated aliphatic ones Carboxylic acids and saturated aliphatic alcohols, with the proviso that the solvents preferably each have a flash point ≥ 60 ° C. Examples of esters include esters of saturated fatty acids having at least 8 carbon atoms with saturated aliphatic alcohols, such as methyl laurate or stearic acid methyl ester. Technical mixtures of various aliphatic esters are commercially available. In one embodiment of the invention, the solvents used may be esters of aliphatic or cycloaliphatic dicarboxylic acids, for example dialkyl esters of cyclohexane-1,2-dicarboxylic acid, such as cyclohexane-1,2-dicarboxylic acid diisononyl ester.

In one embodiment of the invention, the organic solvents (Y) are saturated aliphatic hydrocarbons (Y1) or mixtures thereof. They may be both paraffinic and naphthenic, ie saturated cyclic hydrocarbons. Hydrocarbons (Y1) are preferably high-boiling aliphatic hydrocarbons having a boiling point of at least 175 ° C. and preferably a flash point ≥ 60 ° C. Suitable hydrocarbons with a flash point ≥ 60 ° C include, for example, n-undecane (flash point 60 ° C, boiling point 196 ° C) or n-dodecane (flash point 71 ° C, boiling point 216 ° C). For example, technical mixtures of hydrocarbons can be used, for example mixtures of paraffinic hydrocarbons, mixtures of paraffinic and naphthenic hydrocarbons or mixtures of isoparaffins. It is clear to the person skilled in the art that technical mixtures may still contain small residues of aromatic or unsaturated hydrocarbons. Technical mixtures of saturated aliphatic solvents are commercially available, for example technical mixtures of the Shellsol® D series or the Exxsol® D series.

In a further embodiment of the invention, the organic hydrocarbons (Y) are aromatic hydrocarbons (Y3) or mixtures thereof. Hydrocarbons (Y3) are preferably high-boiling aromatic hydrocarbons having a boiling point of at least 175 ° C. and preferably a flash point ≥ 60 ° C. Suitable aromatic hydrocarbons having a flash point ≥ 60 ° C include, for example, naphthalene. Preferably, technical mixtures of aromatic hydrocarbons can be used. Technical blends of aromatic solvents are commercially available, for example, technical blends of the Shellsol® A series or the Solvesso® series.

The organic solvents (Y) are preferably aromatic hydrocarbons (Y3).

The concentration of the copolymers (X) in the composition according to the invention is chosen by the person skilled in the art according to the desired properties of the composition. The concentration of the copolymers (X) may be 15 to 75 wt .-%, preferably 15 to 45 wt .-%, particularly preferably 15 wt .-% to 30 wt .-%, for example 17 to 25 wt .-% or 18 to 22 wt .-%, each based on the sum of all components of the composition.

In a preferred embodiment of the invention, the composition comprises at least one copolymer (X) and at least one aromatic hydrocarbon (Y3) having a boiling point of at least 175 ° C and a flash point ≥ 60 ° C, wherein the Concentration, the concentration of the copolymers (X) is 15 to 30 wt .-%, preferably 17 wt .-% to 25 wt .-% and for example 18 to 22 wt .-% with respect to the sum of all components of the composition.

• der Anteil der Monomere (B1) + (B2) bezüglich der Summe aller Monomere (B) mindestens 95 mol-% beträgt,
• es sich bei mindestens 95 mol-% der Reste R⁴ um H handelt,
• das Copolymer mindestens zwei verschiedene α-Olefine H₂C=CH-R¹ umfasst, wobei R¹ für lineare Alkylreste mit 16 bis 30 Kohlenstoffatomen, bevorzugt 18 bis 28 Kohlenstoffatomen und besonders bevorzugt 18 bis 24 Kohlenstoffatomen steht, und
• das Copolymer mindestens zwei verschiedene Monomere (B1) umfasst, wobei R² jeweils 16 bis 32 Kohlenstoffatome, bevorzugt 16 bis 26 Kohlenstoffatome umfasst,
• R³ für einen Rest ausgewählt aus der Gruppe von
  • ∘ R^3b: verzweigten und/oder sekundären Alkylresten, bevorzugt verzweigten Alkylresten mit 4 bis 36, bevorzugt 4 bis 30, besonders bevorzugt 4 bis 17 Kohlenstoffatomen, und
  • ∘ R^3c: unsubstituierten oder alkylsubstituierten, cyclischen Alkylresten mit 5 bis 18, bevorzugt 6 bis 10 Kohlenstoffatomen, insbesondere einen Cyclohexylrest steht.

In a further preferred embodiment of the invention, the composition comprises at least one copolymer (X) and at least one aromatic hydrocarbon (Y3) having a boiling point of at least 175 ° C and a flash point ≥ 60 ° C, wherein the concentration of the concentration of the copolymers (X) 15 to 30 wt .-%, preferably 17 wt .-% to 25 wt .-% and for example 18 to 22 wt .-% with respect to the sum of all components of the composition, and wherein it is a copolymer (X) of the described Art acts in which

• the proportion of monomers (B1) + (B2) with respect to the sum of all monomers (B) is at least 95 mol%,
• at least 95 mol% of the radicals R ⁴ are H,
• the copolymer comprises at least two different α-olefins H ₂ C = CH-R ¹ , wherein R ^{1 represents} linear alkyl radicals having 16 to 30 carbon atoms, preferably 18 to 28 carbon atoms and more preferably 18 to 24 carbon atoms, and
• the copolymer comprises at least two different monomers (B1), where R ² comprises in each case 16 to 32 carbon atoms, preferably 16 to 26 carbon atoms,
• R ^{3 is} a radical selected from the group of
  • R ^3b : branched and / or secondary alkyl radicals, preferably branched alkyl radicals having 4 to 36, preferably 4 to 30, particularly preferably 4 to 17 carbon atoms, and
  • 3 R ^3c : unsubstituted or alkyl-substituted, cyclic alkyl radicals having 5 to 18, preferably 6 to 10 carbon atoms, in particular a cyclohexyl radical.

Process for the preparation of the copolymers (X)

The novel copolymers (X) can be prepared by free-radically polymerizing the said monomers (A), (B) and optionally (C) in the desired ratio. Radical polymerization techniques are known to those skilled in the art. In this technique, therefore, previously prepared monomers (B1) and (B2) are used for the polymerization.

In a preferred embodiment of the process, the preparation is carried out by means of an at least two-stage process, wherein in a first process step I provides a polymeric starting material from olefins and maleic anhydride or the corresponding methyl-substituted derivatives thereof and in a second process step II the maleic anhydride of the provided educt in a polymer-analogous reaction with alcohols esterified. This procedure results in the formation of monomers (B1) and (B2) derived repeating units of the copolymer (X) thus only in the course of the polymer-analogous reaction.

Process step I - Provision of a polymeric educt of olefins and maleic acid or methyl-substituted maleic acid

In the course of process step I, a polymeric starting material is provided. This is a copolymer of the olefins (A), a monomer (B3b) and optionally further monomers (C). Preference is given to using maleic anhydride as monomer (B3b).

Suitable α-olefins H ₂ C =CH-R ¹ (A) and preferred α-olefins (A) including preferred mixtures of α-olefins (A) have already been described.

In the polymer starting material to be provided, the proportion of the monomers (A) with respect to the amount of all the monomers is 40 mol% to 60 mol%, preferably 45 mol% to 55 mol%, and for example 48 to 52 mol%.

Further, the proportion of the monomers (B3b) with respect to the amount of all the monomers is 40 mol% to 60 mol%, preferably 45 mol% to 55 mol%, and for example 48 to 52 mol%.

The proportion of optional monomers (C), if present at all, is not more than 20 mol%, preferably not more than 10 mol%, more preferably not more than 5 mol%, and very particularly preferably no further monomers (C ) available.

The number-average molecular weight M _{n of} the polymeric educt of olefin (A) and monomer (B3b) is usually from 1000 g / mol to 15000 g / mol.

Olefin-maleic anhydride copolymers having such number average molecular weights M _n are known in the art in principle and are commercially available.

The preparation can be carried out in a manner known in principle by radical polymerization of the α-olefins (A) and the maleic anhydride or the methyl-substituted derivatives (B3b) in the desired amounts. For example, the in EP 214 786 A1 , in particular pages 6, lines 1 to 14 described procedure can be used. It can be polymerized both in bulk and using solvents.

Suitable solvents are aprotic solvents such as xylene, aliphatics, alkanes, benzene or ketones. In a preferred embodiment of the invention, the solvents are at least one organic solvent (Y), in particular a hydrocarbon, preferably hydrocarbons or hydrocarbon mixtures which have a flash point ≥ 60 ° C.

The hydrocarbons may be, for example, saturated aliphatic hydrocarbons (Y 2) or mixtures thereof. They may be both paraffinic and naphthenic, ie saturated cyclic hydrocarbons. Hydrocarbons (Y 2) are preferably high-boiling aliphatic hydrocarbons having a boiling point of at least 175 ° C. and preferably a flash point ≥ 60 ° C. With regard to examples and preferred hydrocarbons (Y2), reference is made to the above description of the hydrocarbons (Y2).

The hydrocarbons may also be aromatic hydrocarbons (Y3) or mixtures thereof. Hydrocarbons (Y3) are preferably high-boiling aromatic hydrocarbons having a boiling point of at least 175 ° C. and preferably a flash point ≥ 60 ° C. With regard to examples and preferred hydrocarbons (Y3), reference is made to the above description of the hydrocarbons (Y3).

The radical polymerization can be carried out using conventional, thermally decomposing initiators at 80 ° C to 200 ° C, preferably at 100 ° C to 180 ° C and especially at 130 ° C to 170 ° C. The amount of initiator is usually from 0.1 to 10% by weight, based on the amount of the monomers, preferably from 0.2 to 5% by weight and more preferably from 0.5 to 2% by weight. The polymerization time is usually 1 to 12 hours.

The person skilled in the art knows how to set the desired range of the number average molecular weight M _n . The molecular weight can in principle known manner by the choice of polymerization temperature (the lower, the higher M _n ) or by the choice of the reaction medium (aromatic solvents regulate more, ie lower M _n , aliphatic regulate less, ie higher M _n , without Solvent even higher M _n ) are controlled.

Depending on the type of polymerization, the resulting polymeric starting materials are obtained without solvent or as a solution. After polymerization in solution, the copolymer (X) can of course be isolated from the solvent by methods known to those skilled in the art and used as such for process step II.

In one embodiment of the invention, the preparation of the polymeric starting materials in hydrocarbons or hydrocarbon mixtures having a flash point ≥ 60 ° C, in particular high-boiling aromatic hydrocarbons having a boiling point of at least 175 ° C and a flash point ≥ 60 ° C, wherein the resulting solution without isolation of the Polymers is used directly for esterification in process step II. The person skilled in the art selects a suitable concentration of the monomers in the solvent for the polymerization. For example, a concentration of the monomers in the solvent of from 20 wt.% To 80 wt.%, For example, 30 wt.% To 60 wt.% Can be selected.

Process II - Esterification

The provided polymeric educts of olefins and maleic anhydride or methylmaleic anhydride and / or dimethylmaleic anhydride are esterified in a second step with at least one alcohol R ² OH and at least one alcohol R ³ OH polymer analogous.

During the esterification, the rings of the copolymerized anhydride groups are opened and the corresponding dicarboxylic acid monoesters or dicarboxylic acid diesters are formed in a polymer-analogous reaction, depending on the amount of the alcohols and the reaction conditions.

The alcohols R ² OH are linear aliphatic alcohols and R ² is a linear 1-alkyl radical having 16 to 36 carbon atoms, preferably 16 to 32 carbon atoms, particularly preferably 16 to 26 carbon atoms.

Examples of alcohols R ² OH include n-hexadecyl alcohol, n-octadecyl alcohol, n-nonadecyl alcohol, n-eicosyl alcohol, n-heneicosyl alcohol, n-docosyl alcohol, n-tetracosyl alcohol, n-hexacosyl alcohol, n-octacosyl alcohol or n-tricontyl alcohol. Particularly preferred are alcohols selected from the group of n-docosyl alcohol, n-tetracosyl alcohol and n-hexacosyl alcohol.

Preference is also given to using mixtures of at least two, more preferably at least three, alcohols R ² OH. These may be in particular mixtures of naturally occurring fatty alcohols or wax alcohols. Fatty or wax alcohols from natural sources usually have an even number of carbon atoms.

In a preferred embodiment of the invention, a mixture of at least three alcohols R ² OH is used which comprises at least 1-docosyl alcohol, 1-tetracosyl alcohol and 1-hexacosyl alcohol. The amount of said three alcohols is preferably at least 70% by weight, preferably at least 80% by weight, with respect to the amount of all the alcohols R ² OH used.

• ▪ Alkoholen R^3aOH, wobei R^3a für lineare Alkylreste mit 1 bis 10 Kohlenstoffatomen steht,
• ▪ Alkoholen R^3bOH, wobei R^3b für verzweigte und/oder sekundäre Alkylreste mit 4 bis 36 Kohlenstoffatomen steht,
• ▪ Alkoholen R^3cOH, wobei R^3c für unsubstituierte oder alkylsubstituierte, cyclische Alkylreste mit 5 bis 18 Kohlenstoffatomen steht, und
• ▪ Alkoholen R^3dOH, wobei unsubstituierten oder alkylsubstituierten aromatischen Kohlenwasserstoffesten mit 6 bis 36 Kohlenstoffatomen steht.

The alcohols R ³ OH are at least one alcohol selected from the group of

• Alcohols R ^3a OH, where R ^{3a is} linear alkyl radicals having 1 to 10 carbon atoms,
• ▪ alcohols R ^3b OH, where R ^{3b is} branched and / or secondary alkyl radicals having 4 to 36 carbon atoms,
• ▪ Alcohols R ^3c OH, where R ^{3c is} unsubstituted or alkyl-substituted, cyclic alkyl radicals having 5 to 18 carbon atoms, and
• ▪ Alcohols R ^3d OH, where unsubstituted or alkyl-substituted aromatic hydrocarbon radicals having 6 to 36 carbon atoms.

Preferred radicals R ^3a , R ^3b , R ^3c and R ^3d have already been mentioned above.

Examples of alcohols R ^3a OH include ethanol, n-propanol, n-butanol, n-pentanol, n-hexanol, n-heptanol, n-octanol, n-nonanol and n-decanol, preferred are n-propanol, n-butanol , n-pentanol, n-hexanol, n-heptanol, n-octanol, n-nonanol and n-decanol, particularly preferably ethanol, n-propanol, n-butanol, n-pentanol, n-hexanol and very particularly preferably n butanol.

Examples of branched and / or secondary alcohols R ^3b OH include i-butanol, t-butanol, 2,2'-dimethylpropanol-1, 2-ethylhexanol-1,2-propylheptanol-1, i-nonanol, i-decanol, i Tridecanol or i-heptadecanol, 2-butanol, 2-heptanol, 2-hexanol, 2-octanol or 2-decanol, preferred are t-butanol, 2-ethylhexanol-1 and 2-propylheptanol-1 and i-heptadecanol.

Examples of alcohols R ^3c OH include cyclopentanol, cyclohexanol, cycloheptanol, borneol, isoborneol, menthol, neomemthol, isomenthol, neoisomenthol, or myrthanol.

Examples of alcohols R ^3d include phenol, toluene or benzyl alcohol.

In one embodiment of the invention, the alcohols R ³ OH are alcohols R ^3a OH.

In one embodiment of the invention, the alcohols R ³ OH are alcohols R ^3b OH and / or alcohols R ^3c OH.

In one embodiment of the invention, the alcohols R ³ OH are alcohols R ^3b OH.

In one embodiment of the invention, the alcohols R ³ OH are alcohols R ^3c OH.

In one embodiment of the invention, the alcohols R ³ OH are alcohols R ^3d OH.

According to the invention, the proportion of the alcohols R ³ OH with respect to the sum of the alcohols used for the esterification R ² OH and R ³ OH 1 mol% to 49 mol%, preferably 5 mol% to 45 mol%, 20 mol% to 45 mol% and, for example, 30 mol% to 40 mol%.

Furthermore, the amount of the alcohols R ² OH and R ³ OH used together is 0.5 to 1.5 mol / mol of anhydride units in the copolymer (X), preferably 0.8 to 1.2 mol / mol, particularly preferably 0, 9 to 1.1 mol / mol, very particularly preferably 0.95 to 1.05 mol / mol.

The polymeranloge esterification is usually carried out at a temperature of 130 ° C to 180 ° C, preferably 140 ° C to 160 ° C.

The esterification can be carried out in bulk or in the presence of inert solvents. The reaction mixture should remain liquid and homogeneous at the reaction temperature to ensure homogeneous reaction. The reaction can be carried out without pressure or under pressure.

The alcohols can be completely charged or added sequentially. The esterification can be carried out for example in the presence of esterification catalysts such as para-toluenesulfonic acid, methanesulfonic acid or sulfuric acid. A suitable procedure is for example in the WO 2014/095408 A1 disclosed. The amount may be 0.05 to 0.5 mol% based on the alcohols.

If process step I is carried out in solvents, it is advantageously possible to use a solution of the polymeric starting materials obtained in process step II for process step II. Otherwise, the polymeric starting materials for process step II are dissolved in suitable inert solvents.

The esterification is preferably carried out in hydrocarbons, preferably in hydrocarbons or hydrocarbon mixtures with a flash point ≥ 60 ° C. In this procedure, the esterification directly gives the composition according to the invention of at least one copolymer (X) and at least one hydrocarbon.

The hydrocarbons may be, for example, saturated aliphatic hydrocarbons (Y 2) or mixtures thereof. They may be both paraffinic and naphthenic, ie saturated cyclic hydrocarbons. Prefers hydrocarbons (Y2) are high-boiling aliphatic hydrocarbons having a boiling point of at least 175 ° C and preferably a flash point ≥ 60 ° C. With regard to examples and preferred hydrocarbons (Y2), reference is made to the above description of the hydrocarbons (Y2).

The hydrocarbons may also be aromatic hydrocarbons (Y3) or mixtures thereof. Hydrocarbons (Y3) are preferably high-boiling aromatic hydrocarbons having a boiling point of at least 175 ° C. and preferably a flash point ≥ 60 ° C. With regard to examples and preferred hydrocarbons (Y3), reference is made to the above description of the hydrocarbons (Y3).

In a preferred embodiment of the invention, process step II is carried out in solution and the amount of hydrocarbons used is such that a composition of at least one copolymer (X) and at least one hydrocarbon in a concentration of 15 to 85 wt .-% is formed. It can be prepared equal to a ready-to-use composition in the concentrations as described above or it can be a concentrate, for example, produced at a concentration of 50 to 70 wt .-%, which then has to be further diluted on site to the ready-to-use concentration.

The invention further relates to copolymers (X) which are obtainable by the process just described. With regard to the process parameters, reference is made to the method just described.

1. (A) 40 bis 60 mol-%, bezogen auf die Menge aller Monomere, mindestens eines α-Olefins (A) der allgemeinen Formel H₂C=CH-R¹,
   wobei R¹ für mindestens einen linearen, cyclischen oder verzweigten, aliphatischen und/oder aromatischen Kohlenwasserstoffrest mit 14 bis 50 Kohlenstoffatomen steht, sowie
2. (B) 60 bis 40 mol-%, bezogen auf die Menge aller Monomere, monoethylenisch ungesättigte Dicarbonsäuren oder Derivate davon,

und wobei es sich bei den Monomeren (B) um

• (B1) mindestens ein Monomer (R²OOC)R⁵C=CR⁶(COOR⁴), um
• (B2) mindestens ein Monomer (R³OOC)R⁵C=CR⁶(COOR⁴) sowie
• (B3) optional mindestens ein Monomer ausgewählt aus der Gruppe von (HOOC)R⁵C=CR⁶(COOH) (B3a) und
  
  wobei
  • R² für einen linearen Alkylrest mit 16 bis 36 Kohlenstoffatomen steht,
  • R³ für einen Rest ausgewählt aus der Gruppe von
    • ▪ R^3a: linearen 1-Alkylresten mit 1 bis 10 Kohlenstoffatomen,
    • ▪ R^3b: verzweigten und/oder sekundären Alkylresten mit 4 bis 36 Kohlenstoffatomen,
    • ▪ R^3c: unsubstituierten oder alkylsubstituierten, cyclischen Alkylresten mit 5 bis 18 Kohlenstoffatomen, oder
    • ▪ R^3d: unsubstituierten oder alkylsubstituierten aromatischen Kohlenwasserstoffesten mit 6 bis 36 Kohlenstoffatomen steht,
  • R⁴ jeweils für einen Rest ausgewählt aus der Gruppe von H, R² und R³ steht, mit der Maßgabe, dass es sich jeweils bei mindestens 50 mol-% der Reste R⁴ um H handelt,
  • R⁵ und R⁶ jeweils für H oder Methyl stehen,
  • der Anteil der Reste R³ bezüglich der Summe der Reste R² und R³ 1 mol-% bis 49 mol-% beträgt,
  • der Anteil der Monomere (B1) + (B2) bezüglich der Summe aller Monomere (B) mindestens 50 mol-% beträgt, und
  • das gewichtsmittlere Molekulargewicht M_w der Copolymere (X) 2000 g/mol bis 25000 g/mol beträgt,

wobei die Copolymere (X) durch das soeben beschriebene Verfahren erhältlich sind.In particular, the invention relates to copolymers (X) comprising as monomers at least

1. (A) 40 to 60 mol%, based on the amount of all monomers, of at least one α-olefin (A) of the general formula H ₂ C =CH-R ¹ ,
   wherein R ^{1 is} at least one linear, cyclic or branched, aliphatic and / or aromatic hydrocarbon radical having 14 to 50 carbon atoms, as well as
2. (B) 60 to 40 mol%, based on the amount of all monomers, monoethylenically unsaturated dicarboxylic acids or derivatives thereof,

and wherein the monomers (B) are

• (B1) at least one monomer (R ² OOC) R ⁵ C = CR ⁶ (COOR ⁴ )
• (B2) at least one monomer (R ³ OOC) R ⁵ C = CR ⁶ (COOR ⁴ ) and
• (B3) optionally at least one monomer selected from the group of (HOOC) R ⁵ C = CR ⁶ (COOH) (B3a) and
  
  in which
  • R ^{2 is} a linear alkyl radical having 16 to 36 carbon atoms,
  • R ^{3 is} a radical selected from the group of
    • R ^3a : linear 1-alkyl radicals having 1 to 10 carbon atoms,
    • R ^3b : branched and / or secondary alkyl radicals having 4 to 36 carbon atoms,
    • R ^3c : unsubstituted or alkyl-substituted, cyclic alkyl radicals having 5 to 18 carbon atoms, or
    • R ^3d : unsubstituted or alkyl-substituted aromatic hydrocarbon radicals having 6 to 36 carbon atoms,
  • R ^{4 is in} each case a radical selected from the group of H, R ² and R ³ , with the proviso that in each case at least 50 mol% of the radicals R ⁴ is H,
  • R ⁵ and R ^{6 are} each H or methyl,
  • the proportion of the radicals R ³ with respect to the sum of the radicals R ² and R ^{3 is} 1 mol% to 49 mol%,
  • the proportion of monomers (B1) + (B2) with respect to the sum of all monomers (B) is at least 50 mol%, and
  • the weight average molecular weight M _{w of} the copolymers (X) is 2000 g / mol to 25000 g / mol,

wherein the copolymers (X) are obtainable by the process just described.

Use of the copolymers (X) as pour point depressant

The copolymers (X) according to the invention can be used as pour-point depressants for crude oil, mineral oil and / or mineral oil products by adding at least one of the described copolymers (X) to the crude oil, the mineral oil and / or the mineral oil products.

In a preferred embodiment of the invention, the copolymers (X) according to the invention are used as pour point depressants for crude oil by adding to the crude oil at least one of the copolymers (X) described above.

Pour point depressants reduce the pour point of crude oils, mineral oils and / or mineral oil products. The term "pour point" refers to the lowest temperature at which a sample of oil just flows when it cools down. Standardized measuring methods are used to measure the pour point.

For use according to the invention, the copolymers (X) can be used as such. However, the copolymers (X) according to the invention are preferably used in the form of a solution. In particular, formulations of the copolymers (X) can be used, which may contain other components in addition to solvents. The copolymers (X) according to the invention should be homogeneously dispersed in the solvents used, preferably dissolved therein. In principle, all solvents which meet these requirements are suitable. Of course, mixtures of different solvents can be used.

In one embodiment of the invention, it is at least one organic solvent (Y), preferably an organic solvent having a flash point ≥ 60 ° C.

In one embodiment of the invention, the organic solvents are nonpolar solvents (Y1) comprising saturated aliphatic hydrocarbon groups, preferably those which have a flash point ≥ 60 ° C. Examples of such solvents (Y1) include saturated aliphatic alcohols or esters of saturated aliphatic carboxylic acids and saturated aliphatic alcohols, with the proviso that the solvents preferably each have a flash point ≥ 60 ° C. Examples of esters include esters of saturated fatty acids having at least 8 carbon atoms with saturated aliphatic alcohols, such as methyl laurate or stearic acid methyl ester. Technical mixtures of various aliphatic esters are commercially available. In one embodiment of the invention, the solvents used may be esters of aliphatic or cycloaliphatic dicarboxylic acids, for example dialkyl esters of cyclohexane-1,2-dicarboxylic acid, such as cyclohexane-1,2-dicarboxylic acid diisononyl ester.

In one embodiment of the invention, the organic solvents are saturated aliphatic hydrocarbons (Y 2) or mixtures thereof. They may be both paraffinic and naphthenic, ie saturated cyclic hydrocarbons. Hydrocarbons (Y 2) are preferably high-boiling aliphatic hydrocarbons having a boiling point of at least 175 ° C. and preferably a flash point ≥ 60 ° C. With regard to examples and preferred hydrocarbons (Y2), reference is made to the above description of the hydrocarbons (Y2).

In a further embodiment of the invention, the organic solvents are aromatic hydrocarbons (Y3) or mixtures thereof. Hydrocarbons (Y3) are preferably high-boiling aromatic hydrocarbons having a boiling point of at least 175 ° C. and preferably a flash point ≥ 60 ° C. With regard to examples and preferred hydrocarbons (Y3), reference is made to the above description of the hydrocarbons (Y3).

For example, the above-described compositions of copolymers (X) and organic solvents (Y), preferably hydrocarbons, may be used. Advantageous For example, such compositions can be obtained by using hydrocarbons, in particular hydrocarbons or hydrocarbon mixtures having a flash point ≥ 60 ° C., for the preparation of the copolymers (X), likewise as described above.

Ready-to-use formulations of the copolymers (X) may of course comprise further components. For example, it is possible to add additional wax dispersants to the formulation. Wax dispersants stabilize formed paraffin crystals and prevent them from sedimenting. As wax dispersants, for example, alkylphenols, alkylphenol-formaldehyde resins or organic sulfonic acids such as dodecylbenzenesulfonic acid can be used.

The concentration of the copolymers (X) in ready-to-use formulations can be from 0.5 to 45% by weight, preferably from 15 to 45% by weight, particularly preferably from 15% by weight to 30% by weight, for example from 17 to 25% by weight. -% or 18 to 22 wt .-%, each based on the sum of all components of the composition.

To prepare ready-to-use formulations, it is possible in particular to use the above-described compositions of copolymers (X) and organic solvents (Y), preferably hydrocarbons. These can preferably be mixed on site with other components and optionally further solvents.

While the preparation of copolymers (X) and optionally of a concentrate of the copolymers (X) in solvents naturally takes place in a chemical plant, there are several possibilities with regard to the ready-to-use formulation. Advantageously, the preparation of the ready-to-use formulation can be made as close as possible to the point at which the formulation is to be injected.

The crude oil, mineral oil and / or mineral oil products, preferably the crude added amount of copolymers of the invention (X) is measured by the expert so that the desired reduction of the pour point is achieved, where it is natural for the skilled person that the necessary amount depends on the type of crude oil. On the other hand, it is desirable for economic reasons to use as little as possible pour-point depressant.

It has proven useful to use the copolymers (X) in an amount of from 50 to 1500 ppm with respect to the crude oil, mineral oil and / or mineral oil products. Preferably, the amount is 100 to 1000 ppm, more preferably 250 to 600 ppm and for example 300 to 600 ppm. The amounts indicated relate to the copolymer (X) itself.

In a preferred embodiment of the invention, the oil is crude oil.

It is advisable to add the copolymers (X) or their solutions or formulations to the crude oil before the precipitation of waxes has begun, ie. at a temperature above the pour point. For example, the addition may be made at a temperature not lower than 10 ° C above the pour point.

The location of the addition of the copolymers (X) to the crude oil is suitably selected by the person skilled in the art. The addition can be made, for example, in the formation, downhole, wellhead, or pipeline.

In one embodiment, copolymers (X) or their solutions or formulations are injected into a crude oil pipeline. Preferably, the injection may be on the oil field, i. at the beginning of the crude oil pipeline, but the injection can of course also take place at another location. For example, it may be a pipeline that leads from an offshore platform to the mainland. The copolymers (X) can prevent pipelines from clogging if the crude cools during transportation in the pipeline. This danger is inherently particularly pronounced when it is a pipeline in a cold environment, e.g. in arctic environment.

In a further embodiment of the invention, the copolymers (X) or their solutions or formulations are injected into a production well. In one embodiment, it may be an offshore production well. The injection can be made approximately at the point where oil from the formation flows into the production well. In this way, the solidification of the crude oil in the production well and in downstream transport pipelines can prevent excessive increase of its viscosity as well as the cross-sectional constriction of pipes by paraffin deposits.

In one embodiment of the invention, the injection may be umbilical. In this case, a flexible rod, comprising at least one pipe and optionally electrical lines or control lines in a protective sheath is introduced axially into a borehole or a pipeline. By piping in the flexible strand, the formulation of the copolymers (X) can be injected exactly at the desired location.

Further uses of the copolymers (X)

Of course, the copolymers (X) according to the invention can also be used for other purposes.

In a further embodiment of the invention, the above-described copolymers (X) or their solutions or formulations are used to prevent wax deposits on surfaces which are in contact with crude oil, mineral oil and / or mineral oil products. They are preferably surfaces which are in contact with crude oil. The use takes place by adding at least one of the copolymers (X) or their solutions or formulations to the crude oil, mineral oil and / or the mineral oil products. Preferred solutions and formulations have already been mentioned and also the nature of the use is analogous to the use as a pour point depressant. In addition to the formulations according to the invention, it is of course also possible to use further formulations which act as wax inhibitors.

Effects of the invention

By the partial replacement of long-chain, linear alkyl groups by short linear alkyl groups, branched alkyl groups, cyclic alkyl groups or hydrocarbon groups, copolymers (X) are obtained which can be processed into formulations, in particular about 20% formulations which have lower solidification points than those corresponding formulations of unmodified copolymers, ie exclusively copolymers comprising linear alkyl groups. As a result, the handling of such formulations is facilitated, especially in colder environment, such as Arctic environment.

The following examples are intended to explain the invention in more detail.

Used starting materials:

C _20/24 olefins Commercially available mixture of α-olefins, main components C ₂₀ , C ₂₂ and C ₂₄ olefins C ₁₈ <3% by weight C ₂₀ 35 to 55% by weight C ₂₂ 25 to 45% by weight C ₂₄ 10 to 26% by weight C ₂₆ <2% by weight > C ₂₆ <0.1% by weight Alcohol _mixture IC _16/22 -alcohols Commercially available mixture of linear alcohols, main components C _{16 to} C ₂₂ -alcohols C _16/18 16 to 21% by weight C ₂₀ 24 to 27% by weight C ₂₂ 24 to 28% by weight C ₂₄ 2 to 8% by weight C ₂₆ <5% by weight C _28/30 <3% by weight Alcohol mixture II C _22/26 -alcohols Commercially available mixture of linear alcohols, main components C _{22 to} C ₂₆ alcohols C ₁₈ <1% by weight C ₂₀ <10% by weight C ₂₂ 55 +/- 10% by weight C ₂₄ 25 +/- 6% by weight C ₂₆ 13 +/- 4% by weight C ₂₈ <9% by weight Solvesso® 150 High-boiling aromatic hydrocarbon mixture from ExxonMobil Chemical Company, aromatic content> 99% by volume, initial boiling point 181 ° C., flash point according to ASTM D 93 66 ° C. 1-isotridecanol C ₁₃ alcohol with an average of 3 branches 1-Isoheptadecanol C ₁₇ alcohol with an average of 3 branches

Preparation of unmodified olefin-MSA copolymers Copolymer I C _20/24 olefins + MSA, 1: 1 molar, without solvent

For the polymerization, a four-necked flask with stirrer, internal thermometer, nitrogen inlet and reflux condenser and feeds for maleic anhydride and initiator was used.

Melt 1 mol of maleic anhydride at 80 ° C in a heated dropping funnel. Heat with N ₂ -Gegasung template with 1 mol of C _20/24 olefin to an internal temperature of 150 ° C, then add maleic anhydride and 1 mol% (with respect to monomers) of di-tert-butyl peroxide over 5 h from separate feeds. Then polymerize for 1 h at an internal temperature of 150 ° C.

There is obtained an olefin-MSA copolymer (X) having a number average molecular weight M _n of 10,000 g / mol.

Copolymer II C _20/24 olefins + MSA, 1: 1.14 molar, in aliphatic solvents

The same apparatus as for the synthesis of the copolymer (X) I is used.

Melt 1.1 mol of maleic anhydride at 80 ° C in a heated dropping funnel. Fill the template with Solvesso® 150 under N ₂ gassing. Heat 1 mol of C _20/24 olefin to an internal temperature of 150 ° C., then add maleic anhydride and 1 mol% (with respect to monomers) of di-tert-butyl peroxide over 5 h from separate feeds. The amount of solvent is such that a solution of 50% by weight of the polymer is formed. After completion of the addition, postpolymerize at an internal temperature of 150 ° C. for 1 h.

An olefin-MSA copolymer (X) having a number average molecular weight M _n of 4000 g / mol is obtained.

measurement methods: Solids content (FG)

The solids content was determined by drying the products at 120 ° C, 2 h in a vacuum oven.

Number average molecular weight M _n and weight average molecular weight M _w

The mass-average molecular weights and polydispersities are measured with a GPC system at 35 ° C. The system includes two columns as well as refractive index detector and UV detector. The eluant used is THF with 0.1% trifluoroacetic acid. The Calibration is carried out with a narrowly distributed polystyrene standard (M _n = 580-6,870,000 g / mol).

Pour point 300 ppm in oil

The pour point determination was performed according to ASTM D 5853 Test Method for Pour Point of Crude Oils. The pour point is the minimum temperature at which a sample of a tested oil is just flowable. According to ASTM D 5853, a sample of the oil is cooled in 3 ° C increments and the flowability is tested after each step. For the tests, a crude oil from the "Landau" oil field in southwestern Germany (Wintershall Holding GmbH) with an API grade of 37 and a pour point of 27 ° C was used. To determine the lowering of the pour point, the polymers to be tested were used for the oil in a concentration of 300 ppm of polymer based on the crude oil.

PP 20% pure

In a further measurement, the pour point of a 20% strength solution of the polymer according to the invention itself was measured. The resulting solutions were diluted to a concentration of 20% by weight using Solvesso® 150. The pour point is the minimum temperature at which the 20% solution is just still flowable.

The 20% pour point was determined according to ASTM D5985-02 (approved Jan. 1, 2014).

No Flow 20% pure

In a further measurement, the no-flow point of a 20% strength solution of the polymer according to the invention itself was measured. The resulting solutions were diluted to a concentration of 20% by weight using Solvesso® 150. The no-flow point is the temperature at which the 20% solution is just no longer flowable.

The 20% pour point was determined according to ASTM D 7346-15 (approved July 1, 2015).

First series of experiments: Copolymer I, C _16/22 alcohols Comparative experiment 1 (without alcohol 2)

For the polymerization, a four-necked flask with stirrer, internal thermometer, nitrogen inlet and reflux condenser and a feed for Solvesso® 150 was used.

15 g of copolymer I (15 g) and 13.77 g of alcohol mixture I (C _16/22 -alcohols) are melted at an external temperature of 85 ° C and after melting 7.19 g of Solvesso® 150 is added. Heat to 150 ° C outside temperature and stir for 4 hours.

Trial 1

The same apparatus is used as in Comparative Experiment 1.

45 g of copolymer I and 11.71 g of isoheptadecanol are melted at an external temperature of 85 ° C and after melting 20.54 g of Solvesso® 150 and 10 mg of para-toluenesulfonic acid are added. Heat to 150 ° C outside temperature and stir for 2 hours. Then 25.45 g of alcohol mixture I (C _16/22 -alcohols) are added and the mixture is stirred for a further 4 h.

Trial 2

The same apparatus is used as in Comparative Experiment 1.

130.18 g of copolymer I and 17.20 g of 2-ethylhexanol are melted at an external temperature of 85 ° C and after melting 54.26 g of Solvesso® 150 and 30 mg of para-toluenesulfonic acid are added. Heat to 150 ° C outside temperature and stir for 2 hours. Then 73.62 g of alcohol mixture I (C _16/22 alcohols) are added and stirred for a further 4 h.

The experimental parameters and the results are summarized in Table 1.

Trial 3

The same apparatus is used as in Comparative Experiment 1.

240 g of copolymer I, 158.30 g of alcohol mixture I (C _16/22 -alcohols) and 18.34 g of cyclohexanol are melted at an external temperature of 85 ° C and after melting 104.16 g of Solvesso® 150 are added. Heat to 150 ° C outside temperature and stir for 4 hours.

Trial 4

The same apparatus is used as in Comparative Experiment 1.

130.18 g of copolymer I and 13.23 g of cyclohexanol are melted at an external temperature of 85 ° C and after melting 54.26 g of Solvesso® 150 and 30 mg of para-toluenesulfonic acid are added. Heat to 150 ° C outside temperature and stir for 2 hours. Then 73.62 g of alcohol mixture I (C _16/22 alcohols) are added and stirred for a further 4 h.

Comparative experiment 2 (more than 49 mol% alcohol 2)

The same apparatus is used as in Comparative Experiment 1.

25 g of copolymer I and 3.18 g of cyclohexanol are melted at an external temperature of 85 ° C and after melting 9.99 g of Solvesso® 150 and 10 mg of para-toluenesulfonic acid are added. Heat to 150 ° C outside temperature and stir for 2 hours. Then 11.78 g of alcohol mixture I (C _16/22 alcohols) are added and stirred for a further 4 h.

Second series of experiments: Copolymer II, C _22/26 alcohols Comparative experiment 3 (without alcohol 2)

The same apparatus is used as in Comparative Experiment 1.

15.0 g of a 50% solution of the copolymer II in Solvesso® 150 and 9.45 g of alcohol mixture II (C _22/26 alcohols) are melted at an external temperature of 85 ° C. Heat to 150 ° C outside temperature and stir for 6 hours.

Trial 5

The same apparatus is used as in Comparative Experiment 1.

15.0 g of a 50% solution of the copolymer II in Solvesso® 150 and 0.77 g of cyclohexanol are melted at an external temperature of 85 ° C and after melting 10 mg of para-toluenesulfonic acid are added. Heat to 150 ° C outside temperature and stir for 2 hours. Then 5.67 g of alcohol mixture II (C _22/26 alcohols) are added and stirred for a further 4 h.

The experimental parameters and the results are summarized in Table 2. Table 1: Experimental parameters and results with copolymers (X) based on the olefin-MSA copolymers I Two results in one column are duplicate determinations. No. MSA Olefin Type Alcohol 1 Alcohol 2 molar ratios Mw [g / mol] FG [%] PP ¹ 300 ppm in oil [° C] PP 20% [° C] No Flow Point 20% [° C] Olefin / MSA / Alk1 / Alk2 Alk 2 / Σ Alk Σ Alk / MSA V1 I C _16/22 - 1/1/1/0 1 1 17 200 80.4 9; 12 9; 9 6.2; 6.5 1 I C _16/22 1-Isoheptadecanol 1/1 / 0.6 / 0.4 0.4 1 15,800 77.0 9; 12 -3; -3 -4.2; -4.1 2 I C _16/22 2-ethylhexanol 1/1 / 0.6 / 0.4 0.4 1 15 100 77.1 12; 12 3; 3 1.5; 1.3 3 I C _16/22 cyclohexanol 1/1 / 0.7 / 0.3 0.3 1 16,300 79.3 12; 15 3; 3 1.9; 1.8 4 I C _16/22 cyclohexanol 1/1 / 0.6 / 0.4 0.4 1 15,700 78.5 9; 9 0; 0 -1.4; -1.4 V2 I C _16/22 cyclohexanol 1/1 / 0.5 / 0.5 0.5 1 15 900 80.8 18; 18 -3; -3 -5.8; -5.0 ¹ The pour point of the oil without adding a pour point depressant is 27 ° C. No. MSA olefin type Alcohol 1 Alcohol 2 molar ratios Mw [g / mol] FG% PPD 300 ppm in oil PP 20% pure in ° C No Flow 20% pure in ° C Olefin / MSA / Alk1 / Alk2 Alk 2 / ΣAlk Σ Alk / MSA V3 II C _22/26 - 1 / 1.1 / 1.1 / 0 1 1 5440 69.2 9; 12 0.5; -0.1 0; 0 5 II C _22/26 cyclohexanol 1 / 1.1 / 0.66 / 0.44 0.4 1 6500 66 9; 9 0; 0 -1.2; -0.9

In the experiments, on the one hand, the effect of the copolymers according to the invention as a pour point depressant for crude oil was determined (addition of 300 ppm of polymer to the oil). The pour point of pure crude oil is 27 ° C.

Furthermore, the properties of a 20% solution of Coplymere in high boiling hydrocarbons were determined, namely the pour point of the solution itself was determined, and continue the temperature at which the solution stops flowing ("No Flow Point").

In Comparative Experiment 1 (Table 1) a product according to the prior art was used, namely a product based on the MSA-olefin copolymer I, in which the MSA units are opened only with a linear C _16/22 alcohol. The copolymer lowers the pour point of the crude oil tested from 27 ° C to 9-12 ° C; the 20% solution solidifies at about 6.5 ° C and the pour point of the 20% solution is 9 ° C.

If (experiment 1, table 1) the linear C _16/22 -alcohol is replaced by a mixture of a linear C _16/22 -alcohol (60 mol%) and a branched aliphatic C ₁₇ -alcohol (40 mol%), then the effect as a pour point depressant for crude oil remains unchanged. The pour point of the 20% solution, however, goes back to -3 ° C and the 20% solution only solidifies at about -4 ° C. The 20% solution of the modified copolymer is therefore still manageable at lower temperatures than the solution of the unmodified copolymer in Comparative Example 1.

If 2-ethylhexanol is used as the branched alcohol (Experiment 2), improved products are likewise obtained, although not as pronounced as in Experiment 1.

Examples 3, 4 and V2 show the effect of partially replacing the linear alcohol with cyclohexanol (30, 40 and 50 mol%). As the amount of cyclohexanol increases, the temperature at which the 20% solution solidifies becomes lower and lower. Although the solidification temperature of the 20% solution is -5 ° C / -5.8 ° C for the product with 50 mol% cyclohexanol (Comparative Experiment 2), the effect as a pour point depressant for crude oil decreases markedly (only one more) Reduction from 27 ° C to 18 ° C, instead of 27 ° C to 9 to 12 ° C as in the unmodified product). The amount of cyclohexanol should accordingly be less than 50 mol%.

In Table 2, linear C _22/26 alcohols were used to open the MSA units instead of linear C _16/22 alcohols. Comparative experiment 3 and experiment 5 show that here too, the partial replacement of the linear C _22/26 alcohols reduces the solidification point of an approximately 20% solution, although not as strong as when using C _16/22 alcohols.

Claims (22)

1. A copolymer (X) comprising, as monomers, at least

   (A) 40 to 60 mol%, based on the amount of all monomers, of at least one α-olefin (A) of the general formula H₂C=CH-R¹
   where R¹ is at least one linear, cyclic or branched, aliphatic and/or aromatic hydrocarbyl radical having 14 to 50 carbon atoms, and

   (B) 60 to 40 mol%, based on the amount of all monomers, of monoethylenically unsaturated dicarboxylic acids or derivatives thereof,

   wherein the monomers (B) are

   (B1) at least one monomer (R²OOC)R⁵C=CR⁶(COOR⁴),

   (B2) at least one monomer (R³OOC)R⁵C=CR⁶(COOR⁴) and

   (B3) optionally at least one monomer selected from the group of
   (HOOC)R⁵C=CR⁶(COOH) (B3a) and

   

   where

   • R² is a linear alkyl radical having 16 to 36 carbon atoms,

   • R³ is a radical selected from the group consisting of

   ▪ R^3a: linear 1-alkyl radicals having 1 to 10 carbon atoms,

   ▪ R^3b: branched and/or secondary alkyl radicals having 4 to 36 carbon atoms,

   ▪ R^3c: unsubstituted or alkyl-substituted, cyclic alkyl radicals having 5 to 18 carbon atoms, or

   ▪ R^3d: unsubstituted or alkyl-substituted, aromatic hydrocarbyl radicals having 6 to 36 carbon atoms,

   • R⁴ in each case is a radical selected from the group of H, R² and R³, with the proviso that at least 50 mol% of the R⁴ radicals are H,

   • R⁵ and R⁶ are each H or methyl,

   • the proportion of the R³ radicals based on the sum total of the R² and R³ radicals is 1 mol% to 49 mol%,

   • the proportion of the monomers (B1) + (B2) based on the sum total of all monomers (B) is at least 50 mol%, and

   • the weight-average molecular weight M_w of the copolymers (X) is 2000 g/mol to 25 000 g/mol.
2. The copolymer (X) according to claim 1, wherein the proportion of the R³ radicals based on the sum total of the R² and R³ radicals is 5 mol% to 45 mol%.
3. The copolymer (X) according to claim 1 or 2, wherein the proportion of the monomers (B1) + (B2) based on the sum total of all monomers (B) is at least 95 mol%, and at least 95 mol% of the R⁴ radicals are H.
4. The copolymer (X) according to any of claims 1 to 3, wherein R¹ comprises linear alkyl radicals.
5. The copolymer (X) according to any of claims 1 to 3, wherein the copolymer comprises at least two different α-olefins (A) H₂C=CH-R¹ where R¹ represents linear alkyl radicals having 18 to 30 carbon atoms.
6. The copolymer (X) according to any of claims 1 to 3, wherein the copolymer comprises at least three different α-olefins (A) H₂C=CH-R¹ where R¹ comprises n-octadecyl, n-eicosyl and n-docosyl radicals.
7. The copolymer (X) according to any of claims 1 to 6, wherein R² is a linear alkyl radical having 18 to 32 carbon atoms.
8. The copolymer (X) according to any of claims 1 to 6, wherein the copolymer comprises at least two different monomers (B1) where R² in each case is a linear alkyl radical having 18 to 32 carbon atoms.
9. The copolymer (X) according to any of claims 1 to 8, wherein the copolymer comprises at least three different monomers (B1) where the R² radicals in each case are n-docosyl, n-tetracosyl and n-hexacosyl radicals.
10. The copolymer (X) according to any of claims 1 to 9, wherein the R⁵ and R⁶ radicals are H.
11. The process for preparing copolymers (X) according to claim 1, at least comprising the following process steps:

    I) providing a polymeric reactant by polymerizing at least the following monomers:

    • 40 to 60 mol%, based on the amount of all α-olefin monomers H₂C=CH-R¹ (A) used, where R¹ is at least one linear, cyclic or branched, aliphatic and/or aromatic hydrocarbyl radical having 14 to 50 carbon atoms, and

    • 60 to 40 mol% of (B3b)

    

    where R⁵ and R⁶ are as defined above,

    where the number-average molecular weight M_n of the polymeric reactant is 1000 g/mol to 15 000 g/mol,

    II) polymer-analogous esterification of the polymeric reactant provided in stage I at 130°C to 180°C with

    • at least one alcohol R²OH where R² is a linear alkyl radical having 18 to 36 carbon atoms, and

    • at least one alcohol R³OH, selected from the group of

    ▪ R^3aOH where R^3a represents linear 1-alkyl radicals having 1 to 10 carbon atoms,

    ▪ R^3bOH where R^3b represents branched and/or secondary alkyl radicals having 4 to 36 carbon atoms,

    ▪ R^3cOH where R^3c represents unsubstituted or alkyl-substituted, cyclic alkyl radicals having 5 to 18 carbon atoms, and

    ▪ R^3dOH where R^3d is an unsubstituted or alkyl-substituted aromatic hydrocarbyl radical having 6 to 36 carbon atoms,

    • where the proportion of the alcohols R³OH based on the sum total of the alcohols R²OH and R³OH is 1 mol% to 49 mol%, and

    • the amount of the alcohols R²OH and R³OH used together is 0.5 to 1.5 mol/mol of (B3b).
12. The process according to claim 11, wherein no further monomers are used aside from the monomers (A) and (B3b).
13. The process according to claim 11 or 12, wherein the amount of the alcohols R²OH and R³OH used together is 0.8 to 1.2 mol/mol of the monomers (B3b) .
14. The process according to any of claims 11 to 13, wherein process step I is conducted in at least one high-boiling aliphatic and/or aromatic hydrocarbon having a boiling point of at least 175°C and a flashpoint ≥ 60°C.
15. The process according to any of claims 11 to 14, wherein process step II is conducted in at least one high-boiling aliphatic and/or aromatic hydrocarbon having a boiling point of at least 175°C and a flashpoint ≥ 60°C.
16. A copolymer (X) obtainable by a process according to any of claims 11 to 15.
17. A composition comprising at least

    • a copolymer (X) according to any of claims 1 to 10 and 16, and

    • at least one organic solvent (Y).
18. The composition according to claim 17, wherein the solvent is a hydrocarbon.
19. The composition according to claim 18, wherein the hydrocarbons are high-boiling aliphatic and/or aromatic hydrocarbons having a boiling point of at least 175°C and a flashpoint ≥ 60°C.
20. The composition according to claims 17 to 19, wherein the concentration of the copolymers (X) is 20% to 75% by weight, based on the sum total of all components of the composition.
21. The use of copolymers (X) according to any of claims 1 to 10 and 16 as pour point depressants for crude oil, mineral oil and/or mineral oil products, by adding at least one copolymer (X) according to any of claims 1 to 10 and 16 to the crude oil, mineral oil and/or mineral oil products.
22. The use of copolymers (X) according to any of claims 1 to 10 and 16 for prevention of wax deposits on surfaces in contact with crude oil, mineral oil and/or mineral oil products, by adding at least one copolymer (X) according to any of claims 1 to 10 and 16 to the crude oil, mineral oil and/or mineral oil products.