WO2025219264A1

WO2025219264A1 - Pour point depressant

Info

Publication number: WO2025219264A1
Application number: PCT/EP2025/060077
Authority: WO
Inventors: Irina GIEBELHAUS; Andreas OKKEL; Jan Von Haaren; Jörg BÖMER; Crystal JACOBS; Lilian PADULA
Original assignee: BYK Chemie GmbH; BYK USA Inc
Current assignee: BYK Chemie GmbH; BYK USA Inc
Priority date: 2024-04-18
Filing date: 2025-04-11
Publication date: 2025-10-23
Anticipated expiration: 2026-10-18

Abstract

The invention relates to a polymer comprising a core comprising at least one of urethane or isocyanurate groups and an average of 2.6 to 9.0 pending hydrocarbyl groups having 12 to 100 carbon atoms covalently linked to the core via a linking group, wherein the linking group comprises one group selected from urethane group, urea group, and amide group.

Description

Pour Point Depressant

The invention relates to a polymer having pending hydrocarbyl groups, to the use of the polymer for improving the cold flow properties of hydrocarbon-based fluids, to a method of decreasing the amount of solid precipitate in a hydrocarbon-based fluid upon temperature decrease, and to a composition comprising the polymer and a hydrocarbon-based fluid.

US 2013/0232858 relates to the use of particular substituted ureas or urethanes for further improvement of the cold flow properties of mineral oils and crude oils. In typical embodiments, the substituted ureas are prepared by reaction of diisocyanates with fatty amines, whereas the substituted urethanes are prepared by reaction of diisocyanates with fatty alcohols.

There is an ongoing need to further materials which are suitable for improving the cold flow properties of hydrocarbon based fluids. Preferably, the materials should be effective at low usage levels.

The invention provides a polymer comprising a core comprising at least one of urethane or isocyanurate groups and an average of 2.6 to 9.0 pending hydrocarbyl groups having 12 to 100 carbon atoms covalently linked to the core via a linking group, wherein the linking group comprises one group selected from urethane group, urea group, and amide group.

In typical embodiments, the hydrocarbyl groups are directly linked to the core via a linking group selected from urethane group, urea group, and amide group. Directly linked means that there are no non-hydrocarbyl groups located between the urethane group, urea group or amide group.

Preferably, the hydrocarbyl groups are linear or branched aliphatic groups. In some embodiments, hydrocarbyl groups having 12 to 50 carbon atoms are preferred. The hydrocarbyl groups may be the same or different. In some embodiments, it is preferred that the individual hydrocarbyl groups differ in number of carbon atoms or in the degree or position of branching. The hydrocarbyl groups may be saturated or unsaturated. If unsaturated, the hydrocarbyl groups preferably comprise one or two ethylenically unsaturated groups. Preferably, the ethylenically unsaturated groups are not present as terminal groups in the hydrocarbyl groups.

Generally, the polymer or oligomer of the invention comprises an average of 2.6 to 8.0, preferably 2.6 to 7.0, more preferably 2.6 to 5.0 hydrocarbyl groups, and most preferably 2.6 to 4.5 hydrocarbyl groups.

The core comprises at least one of urethane or isocyanurate groups. In some embodiments, the core comprises a plurality of urethane groups. Such cores may be obtained by reacting a diisocyanate with a compound having 3 or 4 hydroxyl groups. Examples of suitable diisocyanates include 1 ,2-propylene diisocyanate, trimethylene diisocyanate, tetramethylene diisocyanate, 2,3-butylene diisocyanate, hexamethylene diisocyanate, octamethylene diisocyanate, 2,2,4-trimethyl hexamethylene diisocyanate, dodecamethylene diisocyanate, co,co’-dipropylether diisocyanate, 1 ,3-cyclopentane diisocyanate, 1 ,2-cyclohexane diisocyanate, 1 ,4-cyclohexane diisocyanate, isophorone diisocyanate, 4-methyl-1 ,3- diisocyanatocyclohexane, trans-vinylidene diisocyanate, dicyclohexyl methane-4,4’-diisocyanate (Desmodur® W), toluene diisocyanate, 1 ,3-bis(isocyanatomethyl) benzene, xylylene diisocyanate, a,a,a’,a’-tetramethyl xylylene diisocyanate (TMXDI®), 1 ,5-dimethyl-2,4-bis(2-isocyanatoethyl) benzene, 1 ,3,5-triethyl-2,4-bis(isocyanatomethyl) benzene, 4,4’-diisocyanato-diphenyl, 3,3’- dichloro-4,4’-diisocyanato-diphenyl, 3,3’-diphenyl-4,4’-diisocyanato-diphenyl, 3,3’-dimethoxy-4,4’- diisocyanato-diphenyl, 4,4’-diisocyanato-diphenyl methane, 3,3’-dimethyl-4,4’-diisocyanato- diphenylmethane, and diisocyanatonaphthalene. Examples of suitable compounds having 3 or 4 hydroxyl groups are trimethylol propane and pentaerythritol. For preparation of the core, the diisocyanate and the compound having 3 or 4 hydroxyl groups are reacted with a molar excess of isocyanate groups. Specific examples include the adduct of 1 molecule of trimethylol propane to 3 molecules of toluene diisocyanate, the adduct of 1 molecule of trimethylol propane to 3 molecules of isophorone diisocyanate, the adduct of 1 molecule of pentaerythritol to 4 molecules of toluene diisocyanate, and the adduct of 3 moles of m-a,a,a’,a’-tetramethyl xylene diisocyanate to 1 mole of trimethylol propane.

In other embodiments, the core is based on adducts and oligomers of polyisocyanate, in particular isocyanurate oligomers of diisocyanates. Examples thereof include the isocyanurate trimer of 1 ,6- diisocyanato hexane, and the isocyanurate trimer of isophorone diisocyanate.

In preferred embodiments, the core comprises an isocyanurate group derived from toluene diisocyanate, isophorone diisocyanate, or diphenylmethane diisocyanate. Particularly preferred are isocyanurate trimers of toluene diisocyanate and isophorone diisocyanate, as well as technical mixtures of the isocyanurate trimers comprising higher oligomers of 4, 5, 6 and/or 7 diisocyanate molecules. Isocyanurates of toluene diisocyanate are suitably based on 2,4-toluene diisocyanate or 2,6-toluene diisocyanate, as well as technical mixtures thereof.

Particularly favorable properties as pour point depressant were found, when the polymer additionally comprises pendant amine groups, which optionally are neutralized by an organic acid. Pendant tertiary amine groups can be introduced by reaction of an isocyanate functional core with a compound having a tertiary amine group and an isocyanate-reactive functional group, for example a hydroxyl group or a primary or secondary amino group. Specific examples of such compounds are monohydroxy amines having a tertiary amino group, or aliphatic diamines having a tertiary amino group and a primary or secondary amino group, such as, for example, (N,N- diethylamino)ethanol, (N,N-dimethylamino)ethanol, (N,N-dimethylamino)propanol, 2-(diethyl- amino)ethylamine, 3-(dimethylamino)propylamine, 3-(diethylamino)propylamine, N,N-diethyl-1 ,4- butanediamine, 1-diethylamino-4-aminopentane, of which 3-(dimethylamino)propylamine and (N,N-diethylamino)ethanol are preferred. Further suitable compounds are N-(3-aminopropyl)- imidazole, N-(3-aminopropyl) morpholine, N-(2-aminoethyl)piperidine, 1 -methylpiperazine, and aminoethylpiperazine.

Other suitable pendant amine groups are secondary or primary amine groups. Such amine groups can be introduced by reaction of an isocyanate functional core with a compound having an amine group and an isocyanate-reactive functional group. Examples of such compounds are 2,4- diamino-1 ,3,5-triazines, preference being given particularly to 2,4-diamino-6-phenyl-1 ,3,5-triazine (benzoguanamine (BGA)) and 2,4-diamino-6-methyl-1 ,3,5-triazine (acetoguanamine (AGA)).

If present, the number of pendant amino groups is suitably lower than the number of pendant hydrocarbyl groups. Very good results have been obtained when the polymer comprises an average number of pendant amine groups in the range of 5 to 30 %, preferably 10 to 25 %, of the average number of pendant hydrocarbyl groups.

If present, the amount of amine groups in the polymer of the invention is generally selected such that the polymer has an amine value in the range of 2 to 100 mg KOH/g. Preferably, the amine value is at least 3 mg KOH/g, and more preferably at least 4 mg KOH/g. Preferably, the amine value of the comb polymer is at most 30 mg KOH/g, and more preferably at most 25 mg KOH/g. The amine values relate to the non-volatile content of the polymer. In a very preferred embodiment, the amine value of the polymer is in the range of 3 to 20 mg KOH/g.

If present, the pendant amino groups are preferably neutralized by an organic acid. Examples of suitable organic acids are carboxylic acids, sulfonic acids, and acidic esters of phosphoric acid.

Suitable carboxylic acids include monocarboxylic acids. The carboxylic acids may be aromatic or aliphatic carboxylic acids. Suitable aliphatic carboxylic acids include linear and branched aliphatic carboxylic acids. The aliphatic carboxylic acids may be saturated or olefinically unsaturated. It is preferred to use carboxylic acids having 6 to 32 carbon atoms. So far very good results have been obtained fatty acids, which are aliphatic monocarboxylic acids having 8 to 28 carbon atoms, and which are saturated or unsaturated. It also possible to use mixtures of such fatty acids.

Examples of suitable organic sulfonic acids include aromatic and aliphatic sulfonic acids. Preferred organic sulfonic aids have 6 to 28 carbon atoms, such as para-toluene sulfonic acid or dodecyl sulfonic acid.

Acidic phosphoric acid esters are suitably prepared by reacting one phosphoric acid equivalent of an ester-forming phosphorus compound with one to two equivalents of a hydroxyl-functional compound.

If one equivalent of a mono hydroxyl functional compound is used for each phosphoric acid equivalent of an ester-forming phosphorus compound, monoesters form. If two equivalents are used, diesters are formed. If between one and two equivalents are used, a mixture of monoesters and diesters is formed.

As used herein, the term "ester-forming phosphorus compound" is understood to refer to a phosphorus compound which can form a phosphoric acid ester by reaction with a hydroxy compound. For example, phosphorus oxychloride, phosphorus pentoxide, polyphosphoric acid and acetyl phosphate can be used as ester-forming phosphorus compounds. Phosphorus pentoxide and polyphosphoric acid are preferred.

In some embodiments the organic acid is a non-polymeric compound having a molecular weight in the range of 46 to 250 g/mol.

In other embodiments, the organic acid is a polymer comprising at least one acidic group, and having a number average molecular weight of 250 g/mol or higher.

A polymer comprises at least three repeating units of polymerized monomers. Generally, the molecular weight of the polymer is in the range of 300 to 20000 g/mol, preferably 300 to 15000 g/mol, and more preferably 300 to 2000 g/mol.

Individual polymer molecules of polymer may contain 1 , 2 or more acidic groups per molecule. It is preferred that the molecules contain 1 or 2 acidic groups per molecule. The number of acidic groups per molecule can also be expressed as average functionality, i.e. the number of acid groups in a sample divided by the number of molecules in a sample. Preferably, the average functionality is in the range of 0.9 to 1.2 acidic groups per molecule.

The polymer may be a linear or branched polymer. Preferably, the polymeric acid is an essentially linear polymer. The polymer may be based on one or more types of monomers. In some embodiments, the polymer comprises ester groups. The polymer may be a polyester, for example a polyester based on dicarboxylic acids, diols, and optionally monoalcohols, monocarboxylic acids, and combinations thereof. If branched polyesters are desired, it is possible to include ester forming building blocks having three or more ester-forming functional groups. Alternatively, polymers containing ester groups can be prepared by ring-opening polymerization of lactones. Examples of suitable lactones include epsilon-caprolactone and delta-valerolactone.

In further embodiments, the acidic polymer comprises ether groups. The polymer may be a polyether, for example a polyether prepared by ring opening polymerization of cyclic ether groups, such as epoxides and oxetanes. Examples of suitable epoxides include ethylene oxide, propylene oxide, glydicylethers, glycidylesters, and mixtures thereof. Suitable oxetanes include unsubstituted oxetane or a substituted oxetane, such as trimethylolpropaneoxetane. Polymerization of hydroxyl-functional cyclic ethers may lead to branched polyether structures.

In a further embodiment, the acidic polymer comprises ester groups and ether groups. In one embodiment, the acidic polymer may be a block copolymer comprising at least one polyether block and at least one polyester block. Alternatively, ester groups and ether groups may be distributed randomly.

In a still further embodiment, the organic acid is a carboxylic acid functional polyolefin. Specific examples include carboxylic acid terminated polyethylene. The number average molecular weight may be in the range of 300 to 1000 g/mol.

Number average and weight average molecular weights are suitable determined by gel permeation chromatography using polystyrene calibration standards and tetrahydrofuran a eluent.

Generally, at least 5 mol-% of the optional amine groups of the polymer are neutralized by an organic acid. In preferred embodiments, at least 10 mol-% of the amine groups of the polymer are neutralized. It is particularly preferred, that 15 to 100 mol-%, most preferred 20 to 100 mol-%, of the amine groups are neutralized. In some embodiments, the amount of acid employed for neutralization of the amine groups can be higher than the theoretical amount to neutralize 100 mol-% of the amine groups. However, generally the amount of acid is in the range of 5 to 130 % of the theoretical amount required to neutralize the amine groups.

The neutralization of the amine groups may suitably be carried out by combining the polymer and the acid, and mixing the two components. The polymer or the acid, or both, may suitably be provided as solutions in one or more organic solvents to reduce the viscosity and to facilitate handling and mixing. Neutralization and salt formation is believed to be facilitated by keeping the composition at ambient temperature or at elevated temperature for certain period of time. In exemplary embodiments, the composition is kept, after mixing, at a temperature in the range of 20 to 80 °C for a period of 20 minutes to 24 hours to equilibrate salt formation.

In some embodiments, the polymer of the invention comprises two cores as defined above. In this case, two core are suitably linked by a linking group having 2 to 32 carbon atoms. The linking group is generally connected to the two cores by urethane groups or urea groups. In some embodiments, the linking group is connected to the two cores by two urethane groups. In an alternative embodiment, the linking group is connected to the two cores by two urea groups. In a still further embodiment, the linking group is connected to the first core by a urethane group and to the second core by a urea group.

The polymer of the invention is suitably prepared by a process comprising the steps a) Providing a polyfunctional core comprising at least one of urethane or isocyanurate groups and an average of 2.6 to 9.0 isocyanate groups, b) Combining the polyfunctional core with a compound selected from the group of monoalcohol having 12 to 100 carbon atoms, monoamine having 12 to 100 carbon atoms, and monocarboxylic acid having 12 to 100 carbon atoms, and mixtures thereof. c) Reacting the isocyanate groups of the polyfunctional core with the compound provided in step b).

The polyfunctional core is typically a polyisocyanate. Suitable polyisocyanates are those described above, in particular isocyanurate trimers and oligomers based on diisocyanates.

In step b) of the process the polyfunctional core is combined with a compound selected from the group of monoalcohol having 12 to 100 carbon atoms, monoamine having 12 to 100 carbon atoms, and monocarboxylic acid having 12 to 100 carbon atoms, and mixtures thereof.

Suitable monoalcohols include those having the formula R-OH, wherein R represents a hydrocarbyl group having 12 to 100 carbon atoms. Suitable and preferred hydrocarbyl groups are as defined above. Urethane links are formed when the isocyanate groups of the polyfunctional core react with hydroxyl groups of a monoalcohol. In view of pour point depressant properties, solubility, availability of raw materials, and cost of raw materials, embodiments wherein a monoalcohol is employed are preferred. Suitable monoamines include those of the formula R-NH₂ and R₂-NH, wherein R represents a hydrocarbyl group having 12 to 100 carbon atoms. Suitable and preferred hydrocarbyl groups are as defined above. Urea links are formed when the isocyanate groups of the polyfunctional core react with amine groups of a monoamine.

Suitable monocarboxylic acids include those having the formula R-COOH, wherein R represents a hydrocarbyl group having 12 to 100 carbon atoms. Suitable and preferred hydrocarbyl groups are as defined above. Amide links are formed when the isocyanate groups of the polyfunctional core react with carboxylic acid groups of a monocarboxylic acid.

As mentioned above, in some embodiments the polymer of the invention comprises pendant tertiary amine groups which are neutralized by an organic acid. Tertiary amine groups can be introduced by reacting a part of the isocyanate groups of the polyfunctional core with an amine or alcohol having a tertiary amine group. Examples of suitable compounds having a tertiary amine groups are those described above. The compounds having a tertiary amine group can be reacted with the polyfunctional core before, after, or simultaneously with the monoalcohol, monoamine or monocarboxylic acid mentioned above.

In the process of preparing the polymer of the invention the molar ratio of isocyanate groups to isocyanate-reactive groups is selected in such a way that the resulting product is free or essentially free of isocyanate groups. This is generally achieved when the molar ratio of isocyanate groups to isocyanate-reactive groups in the in the range 0.9 to 1.10.

In the process of the invention, the optional amine or alcohol having a tertiary amine group is generally used in an amount of 5 to 30 mol-%, preferably 5 to 15 mol-%, calculated on the number of moles of monoalcohol having 12 to 100 carbon atoms, monoamine having 12 to 100 carbon atoms, and monocarboxylic acid having 12 to 100 carbon atoms.

In embodiments wherein the polymer of the invention comprises two cores, as outlined above, the process of preparing the polymer comprises the additional step d) of reacting the polyfunctional core with a compound having at least two isocyanate-reactive groups. The isocyanate-reactive groups suitably comprise at least one of hydroxyl group, primary amine groups, secondary amine group, and combinations thereof. Generally, the molar ratio of isocyanate reactive-g roups of the compound having at least two isocyanate-reactive groups to isocyanate groups of the polyfunctional core is in the range of 0.00:1 .0 to 0.25:1.00, preferably 0.00:1.00 to 0.20:1.00:

Examples of suitable compounds having at least two isocyanate-reactive groups are diols, such as alpha-omega alkylene-diols, wherein the alkylene group has 2 to 32 carbon atoms. Also suitable are diols having one primary and one secondary hydroxyl group. Other compounds having at least two isocyanate-reactive groups are diamines, for examples diamines having two primary or two secondary amine groups, or having a combination of primary and secondary amine groups. Examples of suitable amine compounds are aliphatic, cycloaliphatic, mixed aliphatic-cycloaliphatic, aromatic and/or araliphatic di- and/or polyamines, or mixtures which contain two or more of these amines. Examples include hexamethylenediamine, diethylenetriamine (DETA), triethylenetetramine (TETA), tetraethylenepentamine (TEPA).

In a further embodiment, the compound having at least two isocyanate-reactive groups is an amino-alcohol comprising a hydroxyl group and at least one primary or secondary amine group.

The polymer of the invention is very suitable for improving the cold flow properties of hydrocarbon based fluids. The polymer or oligomer is effective in improving the cold flow properties, lowering the pour point, and reducing the amount of solid precipitate when employed in relatively low amounts relative to the hydrocarbon based fluid.

Therefore, the invention also relates to the use of the polymer of the invention for improving the cold flow properties of hydrocarbon-based fluids.

In a further embodiment, the invention relates to a method of decreasing the amount of solid precipitate in a hydrocarbon-based fluid upon temperature decrease, comprising adding to the hydrocarbon-based fluid a polymer or oligomer of the invention. The polymer may be added to the hydrocarbon based fluid in neat form. If so desired, the polymer may be added to the hydrocarbon based fluid as a solution in a suitable solvent. The polymer of the invention is suitable dissolved or dispersed in eh hydrocarbon based fluid by mixing. It is preferable to add the polymer of the invention to the hydrocarbon based fluid before any precipitate is formed as a consequence of temperature decrease.

Suitably, the amount of oligomer or polymer of the invention is in the range of 0.001 to 1.000, preferably 0.010 to 0.800, more preferably 0.010 to 0.400 % by weight, calculated on the amount of hydrocarbon based fluid.

In still further embodiment, the invention relates to a composition comprising a) the polymer or oligomer of the invention, and b) a hydrocarbon-based fluid.

In preferred embodiments, the amount of oligomer or polymer a) is in the range of 0.001 to 1.000 % by weight, calculated on the total weight of the composition. The polymer or oligomer is effective in improving the cold flow properties, lowering the pour point, and reducing the amount of solid precipitate when employed in relatively low amounts relative to the hydrocarbon based fluid. Suitably, the amount of oligomer or polymer of the invention in the composition is in the range of 0.001 to 1.000, preferably 0.010 to 0.800, more preferably 0.010 to 0.400 % by weight, calculated on the total weight of the composition.

Examples of hydrocarbon based fluids in the composition include crude oil, fractions of crude oil, diesel fuel, metal working fluid, heating fuel, lubricant base oil, and lubricant.

Lubricant base oils are categorized into five groups by the American Petroleum Institute (API). Group I base oils are composed of fractionally distilled petroleum which is further refined with solvent extraction processes to improve certain properties such as oxidation resistance and to remove wax. Group II base oils are composed of fractionally distilled petroleum that has been hydrocracked to further refine and purify it. Group III base oils have similar characteristics to Group II base oils, except that Group III base oils have higher viscosity indexes. Group IV base oils are polyalphaolefins (PAOs). Group V is a catch-all group for any base oil not described by Groups I to IV.

The composition according to the present invention may comprise at least one further additive, such as an antioxidant, oxidation inhibitor, corrosion inhibitor, friction modifier, metal passivator, rust inhibitor, anti-foaming agent, viscosity index enhancer, dispersant, detergent, extremepressure agent, or additional pour point depressant.

Examples

General methods

Measurement of non-volatile components

The sample (2.0 ± 0.1 g of the tested substance) was weighed in a previously dried aluminum crucible and dried in furnace for 20 minutes at 150 °C, cooled in a desiccator and then reweighed. The residue corresponds to the solids content in the sample (ISO 3251).

Measurement of acid numbers

The acid number is the KOH quantity in mg that is required for neutralizing 1 g of substance under the defined conditions. The acid numbers were determined by a neutralization reaction with a 0.1 N KOH in Ethanol according to DIN EN ISO 2114.

R - 0 = O + KOH - R - C = O + HzO

I I

OH OK

Measurement of hydroxyl numbers

The alcoholic hydroxyl groups were reacted by acetylation with an excess of acetic anhydride. The excess acetic anhydride was cracked into acetic acid by adding water and titrated back using ethanolic KOH. The hydroxyl number was understood to be the KOH quantity in mg, which is equivalent to the acetic acid quantity bound when acetylating 1g of substance (according to DIN ISO 4629).

Measurement of amine numbers

Perchloric acid (HCIO₄) in acetic acid has proved to be a suitable titration agent for organic bases containing nitrogen as well as primary, secondary and tertiary amine groups. Acid solvents such as acetic acid have stood the test in determining weak organic bases (good dissolving properties, proton-donating acid solvent). Additions of inert solvents such as cyclohexane, dioxane, chlorobenzene, acetone and methyl ethyl ketone can improve the titration of very weak bases (according to DIN 16945). Measurement of NCO values

The free NCO content of the polyisocyanates employed and also the course of the NCO addition reactions, are determined in accordance with EN ISO 9369 by reaction with dibutylamine and subsequent titration of the amine excess.

Preparation of products

All prepared products were dissolved in solvent naphtha (non-volatile content = 52 % by weight).

Preparation of comparative products

A clean dry four-necked flask (500 ml) equipped with a condenser, KPG-stirrer, temperature sensor and a nitrogen line was charged with isocyanate component and a catalyst (DBTL 0.01 wt.%) and heated up to 80 °C. Additionally oleyl amine was added so that the temperature did not exceed 85 °C. After complete addition the reaction mixture was stirred at this temperature. NCO (DIN EN ISO 9369) and amine value DIN EN ISO 16945 were measured as a reaction control.

Table 1 : Preparation of comparative products AB

Preparation of polymers according to the invention DE

A clean dry four-necked flask (500 ml) equipped with a condenser, KPG-stirrer, temperature sensor and a nitrogen line was charged with isocyanate component and a catalyst (DBTL 0,01 wt.%) and heated up to 80 °C. Additionally a long chain alcohol or mixture of different alcohols was added. After complete addition NCO value was measured as reaction control (DIN EN ISO 9369).

Some of the products were modified with amine and salinized with different acids. In this case the amine was added to the reaction mixture at 80°C and stirred for 2h so that the temperature did not exceed 85 °C. Amine value was measured as control (DIN EN ISO 16945). After the completion of the reaction, a salinization component was added at 50°C and stirred for 1 h. Table 2: Preparation of products according to the invention

Application examples

Raw materials

Exxsol D 110: Hydrocarbons, C13-C16, isoalkanes, cyclics, <2% aromatics purchased from Exxon

Sasolwax 5203: paraffinic hydrocarbons purchased from Sasol

Sasolwax 5803: paraffinic hydrocarbons purchased from Sasol

Sasolwax C80: synthetic wax, paraffinic hydrocarbons purchased from Sasol

Table 3: Preparation of synthetic crude oil formulation (5% wt. Wax)

For the preparation of synthetic crude oil, all raw materials were mixed and placed in the oven for 4 hours at 80°C (176°F).

The warm synthetic crude oil was filled up in beakers for further application tests. Our synthetic crudes mimic the original crude of different regions.

WORKING METHOD: Cold Finger Test

Apparatus: PSL Systemtechnik Cold Finger equipment

The cold finger test was used to determine the wax deposition properties of the prepared additives. The wax inhibition was determined by exposing the crude oil to a cold metal finger surface in the presence/absence of wax inhibitor. At the beginning of the test the initial weight of metal finger was determined. The deposits on a cold metal finger surface in absence of wax additive was set to 100 %. The inhibition was calculated using formula (1)

Wa: weight of wax deposits on a cold metal finger surface in absence of wax additive (in g) Wp: weight of wax deposits on a cold metal finger surface in presence of wax additive (in g)

63.2g of crude oil was filled in a beaker and heated up to 80°C for 1h. Then using an Eppendorf pipette, 40 pL (500 ppm) of a 20% active solution of additive was added to the 63.2g of crude oil (about 80mL). The mixture of crude oil with an additive was heated up to 80°C for 30 min. A magnetic stir bar was added to each beaker. The beakers with the prepared samples were placed into the rack and the metal finger was inserted into the prepared samples. Then the magnetic stirrer was switched on (750 rpm). After two hours the cold finger was removed from the synthetic crude and the deposits were weighed.

Parameters for synthetic crude oil: Cold Finger setup synthetic Crude Oil

- Rack temperature 44°C (= 3°C above WAT)

- Finger temperature 25°C (= 13°C above Pour Point)

- Test procedure time: 2 hours

- Stirring speed: 750 rpm All products were diluted with xylene to an 20% active substance.

Application Results: Cold Finger Test

Table 4: Cold Finger Test in Synthetic Crude Oil

From the results in the table 4 it can be concluded that the oligomers and polymers of the invention bring about significant reductions of wax precipitation compared to the state-of-the-art products

Pour Point Test

Apparatus: Water bath

Pour Point reduction temperature [°C] was determined as a difference between start temperature and the last temperature at which the crude oil is still fluent. Test procedure Synthetic Crude Oil

Synthetic crude oil was heated up for 1 hour at 80°C (176°F). Then pour 50mL of the Crude Oil into the test jar (modified ASTM Norm D 5853) at room temperature. 25 pL 500 ppm) of a 20% active solution of the additive was added to the crude oil sample using an Eppendorf pipette. The sample was heated for 30 minutes at 80°C (176°F). After that the test jar was placed in a cold bath at 18°C (64.4°F) for synthetic crude oil 4. After 30 minutes in a cold bath the sample was slowly removed from the bath and held horizontal for 5 s. When movement was observed, the sample was returned to the 80°C (176°F) bath for 30 min and placed in the cold bath at 3°C (5°F) below the previous tested temperature. This cycle was repeated reducing the temperature every 3°C (5°F) until the tested crude oil would not flow within 5 s. The Pour Point is the last temperature that the crude still flows.

Application Results: Pour Point Test

Table 5: Pour Point Test in Synthetic Crude Oil

From the results in Table 5 it can be concluded that the oligomers and polymers of the invention bring about significant reductions of the pour point compared to the state-of-the-art products.

Claims

1 . A polymer comprising a core comprising at least one of urethane or isocyanurate groups and an average of 2.6 to 9.0 pending hydrocarbyl groups having 12 to 100 carbon atoms covalently linked to the core via a linking group, wherein the linking group comprises one group selected from urethane group, urea group, and amide group.

2. The polymer according to claim 1 , wherein the hydrocarbyl groups are linear or branched aliphatic groups.

3. The polymer according to claim 2, wherein the polymer comprises 2.6 to 4.5 pending hydrocarbyl groups.

4. The polymer according to any one of the preceding claims, wherein the core comprises an isocyanurate group derived from a diisocyanate.

5. The polymer according to claim 4, wherein the diisocyanate comprises at least one of toluene diisocyanate, isophorone diisocyanate, and diphenylmethane diisocyanate.

6. The polymer according to any one of the preceding claims, wherein the polymer comprises pendant amine groups.

7. The polymer according to claim 6, wherein the polymer comprises an average number of pendant amine groups in the range of 5 to 30 % of the average number of pendant hydrocarbyl groups.

8. The polymer according to claim 6 or 7, wherein the amine groups are tertiary amine groups.

9. The polymer according to anyone of the preceding claims 6 to 8, wherein the amine groups are at least partially neutralized by an organic acid.

10. Use of the polymer according to any one of the preceding claims for improving the cold flow properties of hydrocarbon-based fluids.

11. A method of decreasing the amount of solid precipitate in a hydrocarbon-based fluid upon temperature decrease, comprising adding to the hydrocarbon-based fluid a polymer or oligomer according to any one of the preceding claims 1 to 9.

12. A composition comprising a) the polymer or oligomer according to any one of the preceding claims 1 to 9 and b) a hydrocarbon-based fluid.

13. The composition according to claim 12, wherein the hydrocarbon based fluid is or comprises at least one of crude oil, metal working fluid, diesel fuel, heating fuel, a lubricant, and a lubricant base oil.

14. The composition according to claim 12 or 13, wherein the amount of oligomer or polymer a) is in the range of 0.001 to 1.000 % by weight, calculated on the total weight of the composition.