KR20120123344A - Multifunctional cooling additives for middle distillates, having an improved flow capability - Google Patents

Abstract

According to the present invention,
A) 2 of Class 1 OH group and at least one polyol containing a Class 2 OH group and, C ₁₆ -C ₄₀ - alkyl radical or a C ₁₆ -C ₄₀ - dicarboxylic acid or its anhydride or ester containing alkenyl radicals At least one comb polymer containing a hydroxyl group, which may be prepared by polycondensation of (characterized in that the OH value of the comb polymer is at least 40 mg KOH / g),
B) at least one copolymer of ethylene and at least one ethylenically unsaturated ester and
C) at least one organic solvent
It relates to a low temperature additive for intermediate distillates containing.

Description

MULTIFUNCTIONAL COOLING ADDITIVES FOR MIDDLE DISTILLATES, HAVING AN IMPROVED FLOW CAPABILITY}

The present invention relates to cold additives for intermediate distillates with improved ease of handling at low temperatures, and to their use for improving the low temperature properties and lubricity of intermediate distillates, and corresponding intermediate distillates.

In terms of decreasing oil reserves worldwide, heavier and therefore paraffin-richer crude oils are extracted and processed, which in turn leads to paraffin-rich fuel oils. Paraffins present in crude oils and intermediate distillates, in particular gas oils, diesel oils and heating oils, may crystallize as the temperature of the oil decreases and aggregate by intercalation of the oil. Such crystallization and flocculation can lead to filter clogging of engines and boilers, especially in winter, which can impede reliable capacity of the fuel and under certain circumstances can lead to complete shutoff of the motor fuel or boiler fuel supply. Typically, even 0.1 to 0.3% of crystallized paraffin in oil is sufficient to shut off the fuel filter. The paraffin problem is further exacerbated by the hydrodesulfurization of fuel oils, which should be carried out for the purpose of lowering sulfur content for environmental protection reasons, and the increased ratio of cold-critical paraffins and monocyclic and poly It leads to a reduced ratio of cyclic aromatics, which improves the solubility of paraffins in fuel oils.

The cold flow properties of the middle distillate are often improved by adding chemical additives known as cold flow improvers or flow improvers, which oils so added are often still pumped at temperatures above 20 ° C. than in the case of non-added oils. To modify the crystal structure and flocculation tendency of the paraffin to be precipitated. The cold flow improvers used are typically oil-soluble copolymers of ethylene and unsaturated esters.

For example, according to DE-A-11 47 799, an oil-soluble copolymer of ethylene and vinyl acetate having a molecular weight of about 1000 to 3000 is added to the mineral oil distillate fuel having a boiling range of about 120 to 400 ° C. Copolymers containing about 60 to 99 weight percent ethylene and about 1 to 40 weight percent vinyl acetate are preferably presented.

Copolymers of these ethylene and unsaturated esters are often used in combination with comb polymers, especially for the addition of intermediate distillates with high content of long chain paraffins. Comb polymers are understood to mean certain forms of branched macromolecules, which have relatively long alkyl side chains of somewhat equal length at somewhat regular intervals in the linear backbone. Often, when comb polymers and copolymers of ethylene and unsaturated esters are used together, synergistically improved efficacy as low temperature additives have been reported, and they are probably based on the nucleation action of these comb polymers in paraffin crystallization. These occur especially when using comb polymers with very long side chains.

US-3 447 916 describes condensation polymers formed from alkenylsuccinic anhydrides, polyols and fatty acids for lowering the pouring point of hydrocarbon oils. In these polymers, the hydroxyl groups of the polyols were very substantially esterified. The patent does not provide any suggestion for use with additional additives.

DE-A-19 20 849 describes condensation polymers of alkenylsuccinic anhydrides, polyols having at least four OH groups and fatty acids for lowering the pour point of hydrocarbon oils. The stoichiometry of the reactants used for the condensation is preferably selected such that the molar number of the OH group and the carboxyl group are the same, ie there is essentially complete esterification. As a result of the use of polyhydric alcohols, according to the information of the disclosure, these polymers have superior efficacy compared to the additives of US-3 447 916. The patent document does not provide any suggestion for use with further additives.

DE-A-24 51 047 describes a light, low viscosity distillate fuel oil which does not contain any residues and is added with a comb polymer having an ethylene copolymer and a C ₁₈ -C ₄₄ side chain. The comb polymer used is an alkyl (alkenyl) succinic anhydride with C ₁₆ -C ₄₄ -alkyl (alkenyl) radicals, a polyol having 2 to 6 OH groups and a polyester of C ₂₀ -C ₄₄ -monocarboxylic acid. Include. The three components of the polyester are preferably condensed in equimolar amounts to essentially achieve complete esterification of OH and also of COOH groups. Illustrated as an example (polymer G) are polycondensates of equimolar amounts of C ₂₂ -C ₂₈ -alkenylsuccinic anhydride, trimethylolpropane and C _20-22 fatty acids.

US-A-2008 / 0295397 describes additives for lowering the pour point of diesel fuel, which includes polyglyceryl esters and optionally further pour point depressants, such as ethylene / vinyl ester copolymers. The hydroxyl group of polyglycerol can be fully or partially esterified. The polyol partial esters have pronounced emulsifying properties and are therefore undesirable in fuels.

Additive blends of copolymers and comb polymers of ethylene and unsaturated esters, which are used to improve the low temperature properties of the middle distillates, are usually used as concentrates in organic solvents to improve their ease of handling. In this context, when using the additive concentrates in secluded places where there is often no means of heating the additive concentrates, it is particularly important that they remain free-flowing and blend into fuel oils which are likewise cold at minimum temperatures. However, in order to minimize the volume of the additive concentrate that is transported and stored at the same time, the active ingredient concentration in the concentrate should be at a maximum.

Prior art comb polymers produced by polycondensation are relatively high intrinsic pour points, often in some cases greater than 20 ° C., as concentrates in organic solvents and also in blends with copolymers of ethylene and unsaturated esters in organic solvents. Indicates. However, in gas stations, and also in isolated areas, for example in acids or Arctic regions, the heated storage of additive concentrates is often impossible. Dilution of the additive is undesirable for transport reasons, since the volume to be transported and stored thereafter increases significantly.

As a result, there is a need for highly effective low temperature additives for intermediate distillates, which are highly active and can be handled without problems at low ambient temperatures, and the low temperature flow characteristics of the intermediate distillates should be improved with minimal capacity. These additives will also have to be free-flowing at low temperatures and readily dissolved in the intermediate distillates to be added. In addition, they should not impair the filterability of the added intermediate distillate or at least minimize the damage. Moreover, they will improve lubricity, especially in reduced-sulfur or sulfur-free intermediate distillates.

Surprisingly, dicarboxylic acid or dicarboxylic anhydride and two primary and at least one containing copolymers of ethylene and unsaturated esters in organic solvents and linear C ₁₆ -C ₄₀ -alkyl radicals or C ₁₆ -C ₄₀ -alkenyl radicals Additive formulations comprising solutions of certain polycondensates of polyols having a secondary OH group of are free-flowing in concentrated form, even below 10 ° C., often below 0 ° C., in some cases below −10 ° C., for example It has been found that it has good solubility in low temperature intermediate distillates below -20 ° C. They also have excellent properties as low temperature flow improvers, without compromising the filterability of the oils to which they are added. In the synthesis of these polycondensates, despite the distribution by fatty acids commonly used in addition to esterification in the prior art, surprisingly they do not form crosslinked high molecular weight structures that lead to filterability damage in the added oil or only when used. Form to the slightest extent. Moreover, these additive combinations can improve the lubricating properties of low-sulfur oils.

The present invention,

A) dicarboxylic acids containing two primary OH groups and at least one secondary OH group and a C ₁₆ -C ₄₀ -alkyl radical or a C ₁₆ -C ₄₀ -alkenyl radical or anhydrides thereof or their At least one comb polymer containing hydroxyl groups, which may be prepared by polycondensation of esters (OH value of the comb polymer is at least 40 mg KOH / g),

B) at least one copolymer of ethylene and at least one ethylenically unsaturated ester and

C) at least one organic solvent

It provides a, low temperature additive for intermediate distillate.

The present invention also provides

A) dicarboxylic acids containing two primary OH groups and at least one secondary OH group and a C ₁₆ -C ₄₀ -alkyl radical or a C ₁₆ -C ₄₀ -alkenyl radical or anhydrides thereof or their At least one comb polymer containing hydroxyl groups, which may be prepared by polycondensation of esters (OH value of the comb polymer is at least 40 mg KOH / g),

B) at least one copolymer of ethylene and at least one ethylenically unsaturated ester and

C) A method of improving the low temperature flow properties of fuel oil by adding an additive comprising at least one organic solvent to an intermediate distillate.

The present invention also provides

A) dicarboxylic acids containing two primary OH groups and at least one secondary OH group and a C ₁₆ -C ₄₀ -alkyl radical or a C ₁₆ -C ₄₀ -alkenyl radical or anhydrides thereof or their At least one comb polymer containing hydroxyl groups, which may be prepared by polycondensation of esters (OH value of the comb polymer is at least 40 mg KOH / g),

B) at least one copolymer of ethylene and at least one ethylenically unsaturated ester and

C) A method of improving the lubricity of fuel oil is provided by adding an additive comprising at least one organic solvent to an intermediate distillate having a sulfur content of less than 0.05% by weight.

The present invention also provides

A) dicarboxylic acids containing two primary OH groups and at least one secondary OH group and a C ₁₆ -C ₄₀ -alkyl radical or a C ₁₆ -C ₄₀ -alkenyl radical or anhydrides thereof or their At least one polyester comb polymer containing hydroxyl groups, which may be prepared by polycondensation of esters (OH value of the comb polymer is at least 40 mg KOH / g),

B) at least one copolymer of ethylene and at least one ethylenically unsaturated ester and

C) A fuel oil comprising a low temperature additive comprising at least one organic solvent and an intermediate distillate.

Comb polymer A containing hydroxyl groups are generally di-containing C ₁₆ -C ₄₀ -alkyl radicals or -alkenyl radicals, also referred to collectively as C ₁₆ -C ₄₀ -alkyl (alkenyl) radicals. Obtained by the polycondensation of primary hydroxyl groups of carboxylic acids with polyols. It is preferred that the secondary OH groups remain essentially unesterified. Thus, the preferred structure of comb polymer A containing hydroxyl groups can be illustrated, for example, according to formula A1:

[Formula A1]

In Chemical Formula A1,

One of the R ¹ to R ⁴ radicals is a linear C ₁₆ -C ₄₀ -alkyl or -alkenyl radical, the remaining R ¹ to R ⁴ radicals are each independently hydrogen or an alkyl radical having 1 to 3 carbon atoms,

R ⁵ is a CC bond or an alkylene radical having 1 to 6 carbon atoms,

R ¹⁶ is a hydrocarbyl group containing at least one hydroxyl group and having from 3 to 10 carbon atoms,

n is a number from 1 to 100,

m is a number from 3 to 250,

p is 0 or 1,

q is 0 or 1;

Preferred dicarboxylic acids suitable for the preparation of comb polymer A) containing C ₁₆ -C ₄₀ -alkyl- and / or alkenyl radicals and containing hydroxyl groups correspond to the following formula (1).

In Formula 1,

One of the R ¹ to R ⁴ radicals is a linear C ₁₆ -C ₄₀ -alkyl or -alkenyl radical, the remaining R ¹ to R ⁴ radicals are each independently hydrogen or an alkyl radical having 1 to 3 carbon atoms,

R ⁵ is a CC bond or an alkylene radical having 1 to 6 carbon atoms.

More preferably, one of the R ¹ to R ⁴ radicals is a linear C ₁₆ -C ₄₀ -alkyl or -alkenyl radical, one is a methyl group and the other is hydrogen. In certain embodiments, one of the R ¹ to R ⁴ radicals is a linear C ₁₆ -C ₄₀ -alkyl or -alkenyl radical, and the other is hydrogen. In a particularly preferred embodiment, R ⁵ is a CC single bond. More particularly, one of the R ¹ to R ⁴ radicals is a linear C ₁₆ -C ₄₀ -alkyl or -alkenyl radical and the remaining R ¹ to R ⁴ The radical is hydrogen and R ⁵ is a CC single bond.

Dicarboxylic acids or anhydrides thereof containing alkyl and / or alkenyl radicals can be prepared by known methods. For example, they can be prepared by heating ethylenically unsaturated dicarboxylic acids with olefins (“ene reactions”) or with chloroalkanes. Thermal addition of olefins to ethylenically unsaturated dicarboxylic acids, which are usually carried out at temperatures of 100 to 250 ° C., is preferably presented. Dicarboxylic acids and dicarboxylic acid anhydrides containing the alkenyl radicals formed may be hydrogenated to dicarboxylic acids and dicarboxylic acid anhydrides containing alkyl radicals. Preferred dicarboxylic acids and anhydrides thereof for the reaction with olefins are maleic acid, more preferably maleic anhydride. Also suitable are itaconic acid, citraconic acid and anhydrides thereof and esters of the aforementioned acids, in particular lower C ₁ -C ₈ -alcohols such as methanol, ethanol, propanol and butanol.

In the preparation of dicarboxylic acids or their anhydrides containing alkyl radicals, preference is given to using linear olefins having 16 to 40 carbon atoms and especially 18 to 36 carbon atoms, for example 19 to 32 carbon atoms. In a particularly preferred embodiment, mixtures of olefins with different chain lengths are used. Mixtures of olefins and in particular α-olefins having 18 to 36 carbon atoms, for example C ₂₀ -C ₂₂ , C ₂₀ -C ₂₄ , C ₂₄ -C ₂₈ , C ₂₆ -C ₂₈ , C ₃₀ -C ₃₆ It is preferred to use a mixture in the range. These olefins also contain smaller amounts of shorter and / or longer chain olefins, but may preferably contain up to 10% by weight and in particular from 0.1 to 5% by weight. Preferred olefins have linear or at least substantially linear alkyl chains. "Linear or substantially linear" means that at least 50%, preferably 70 to 99%, in particular 75 to 95%, for example 80 to 90% by weight of the olefin has a linear component of 16 to 40 carbon atoms. I understand that means. Suitable olefins are preferably technical alkenes mixtures. They preferably contain at least 50% by weight, more preferably 60 to 99% by weight and especially 70 to 95% by weight of terminal double bonds (α-olefins). They are also internal double bonds, for example, the structural formula R ¹⁷ -CH = C (CH ₃ ) ₂ , wherein R ¹⁷ is 12 to 36 carbon atoms and in particular alkyl having 14 to 32 carbon atoms, for example 15 to 28 carbon atoms. Olefins having a vinylidene double bond of up to 50% by weight, preferably 1 to 40% by weight and especially 5 to 30% by weight, for example 10 to 25% by weight. In addition, small amounts of secondary components (eg paraffins) of technical origin may be present, but preferably up to 5% by weight. Particular preference is given to olefin mixtures containing at least 75% by weight of linear α-olefins having a carbon chain length in the range of C ₂₀ to C ₂₄ .

Preferred comb polymers A) containing hydroxyl groups are alkyl- or alkenylsuccinic acids containing linear C ₁₆ -C ₄₀ -alkyl or -alkenyl radicals and / or anhydrides thereof and two primary and at least one secondary It can be prepared by the reaction of a polyol containing hydroxyl groups.

Preferred polyols are glycerol, poly (glycerol) and mixtures thereof. Poly (glycerol) is understood to mean a structure which can be derived from glycerol, in particular by polycondensation. Preferred poly (glycerol) condensation degrees according to the invention are 2 to 50, more preferably 3 to 25 and especially 4 to 20, for example 5 to 15. The preparation of poly (glycerol) is known in the art. For example, it can be carried out via the addition of 2,3-epoxy-1-propanol (glycid) to glycerol. In addition, the production of poly (glycerol) can be carried out by polycondensation of glycerol which is known per se. The reaction temperature at the time of polycondensation is generally 150 to 300 ° C, preferably 200 to 250 ° C. Polycondensation is usually carried out at atmospheric pressure. Examples of catalyzed acids include HCl, H ₂ SO ₄ , organic sulfonic acid or H ₃ PO ₄ , and examples of catalyzed bases include NaOH or KOH. The catalyst is added to the reaction mixture in an amount of preferably 0.01 to 10% by weight, more preferably 0.1 to 5% by weight, based on the weight of the reaction mixture. The polycondensation can be carried out in a solvent-free manner or else in the presence of a solvent. If polycondensation is carried out in the presence of a solvent, the ratio thereof in the reaction mixture is preferably 0.1 to 70% by weight, for example 10 to 60% by weight. Preferred solvents are those which are also used as component C) for the additive mixture. Polycondensation generally takes 3 to 10 hours.

The reaction of the dicarboxylic acid containing an alkyl radical, anhydride thereof or ester thereof with the polyol is preferably in a molar ratio of 1: 2 to 2: 1, more preferably in a molar ratio of 1: 1.5 to 1.5: 1, and in particular 1 In a molar ratio of: 1.2 to 1.2: 1, for example, in an equimolar ratio. Particular preference is given to carrying out the reaction with excess polyols. Particularly useful molar excesses have been found to be 1 to 10 mol% and in particular 1.5 to 5 mol%, based on the amount of dicarboxylic acid used. Condensation is preferably carried out with C ₁₆ -C ₄₀ -alkyl or -alkenyl-substituted dicarboxylic acids or their anhydrides or esters and polyols at temperatures higher than 100 ° C. and preferably at temperatures between 120 and 320 ° C., for example , By heating to a temperature of 150 to 290 ℃. In order to establish the molecular weight of the comb polymer A), which is important in efficacy, it is usually necessary to remove the water or alcohol of the reaction, which can be done, for example, by distillation. Azeotropic removal with suitable organic solvents is also suitable for this purpose. In order to accelerate the polycondensation, it has often been found useful to add catalysts to the reaction mixture. Suitable catalysts are known acidic, basic and organometallic compounds.

In a preferred embodiment, in order to establish the molecular weight, a small amount of dicarboxylic acid, anhydride or ester thereof containing an alkyl (alkenyl) radical is selected from the C ₁ -C ₁₈ -monocarboxylic acid, preferably C ₂ -C, in the reaction mixture. ₁₆ -monocarboxylic acids and in particular C ₃ -C ₁₄ -monocarboxylic acids, for example C ₄ -C ₁₂ -monocarboxylic acids. However, up to 20 mol% and preferably 0.1 to 10 mol%, for example 0.5 to 5 mol%, of dicarboxylic acids, anhydrides or esters thereof containing alkyl (alkenyl) radicals are replaced by one or more monocarboxylic acids. In addition, small amounts, for example up to 10 mol% and in particular from 0.01 to 5 mol% of alkyl (alkenyl) -succinic acid or anhydrides thereof, can be added to further dicarboxylic acids such as succinic acid, glutaric acid, maleic acid and / or the like. Or fumaric acid. More preferably, the comb polymer A) containing hydroxyl groups is prepared in the absence of monocarboxylic acids.

In a further preferred embodiment, in order to establish the molecular weight, a small amount of polyol in the reaction mixture is C ₁ -C ₃₀ -monoalcohol, preferably C ₂ -C ₂₄ -monoalcohol and especially C ₃ -C ₁₈ -monoalcohol, For example, replaced by C ₄ -C ₁₂ -monoalcohol. Preferably at most 20 mol% and more preferably 0.1 to 10 mol%, for example 0.5 to 5 mol% of the polyol is replaced by one or more monoalcohols. More preferably, comb polymer A) containing hydroxyl groups is prepared in the absence of monoalcohols. In addition, polyols containing two primary hydroxyl groups and at least one secondary hydroxyl group can be replaced by one or more diols in small amounts of up to 10 mol%, for example from 0.01 to 5 mol%. For example, diols such as ethylene glycol, propylene glycol and / or neopentyl glycol are preferably presented. More preferably, comb polymer A) containing hydroxyl groups is prepared in the absence of diols.

The average degree of condensation of the comb polymer A) containing the hydroxyl groups of the invention is preferably 4 to 200, more preferably 5 to 150 and especially 7 to 100, for example 10 to 50, of the dicarboxylic acid and polyol. It is a repeating unit. The weight-average molecular weight Mw of the comb polymer A) containing hydroxyl groups, measured in THF by GPC to poly (ethylene glycol) standards, is preferably 1500 to 100000 g / mol and especially 2500 to 50000 g / mol, eg For example, it is 4000-20000 g / mol.

The acid value of the comb polymer A) containing hydroxyl groups is preferably less than 40 mg KOH / g and more preferably less than 30 mg KOH / g, for example less than 20 mg KOH / g. The acid value can be measured, for example, by titration of the polymer with an alcoholic tetra-n-butylammonium hydroxide solution in xylene / isopropanol. Also preferably, the hydroxyl value of the comb polymer A) is 45 to 500 mg KOH / g, more preferably 50 to 300 mg KOH / g and especially 60 to 250 mg KOH / g. The hydroxyl value can be measured by ¹ H NMR spectroscopy by quantitative measurement of the formed urethane after the reaction with an isocyanate of free OH group.

Preferred copolymers B) of ethylene and olefinically unsaturated esters are in particular those containing 8 to 21 mol% and especially 10 to 19 mol% of olefinically unsaturated esters as comonomers.

 The olefinically unsaturated esters are preferably vinyl esters, acrylic esters and / or methacrylic esters. One or more esters may be present as comonomer in the polymer.

The vinyl ester is preferably a compound of formula (2).

In Formula 2,

R ¹² is C ₁ -C ₃₀ -alkyl, preferably C ₁ -C ₁₆ -alkyl, in particular C ₁ -C ₁₂ -alkyl. In a further embodiment, the alkyl group mentioned may be substituted by one or more hydroxyl groups.

Particularly preferred vinyl esters are derived from secondary and especially tertiary carboxylic acids whose branches are in the alpha-position relative to the carbonyl group. Preferably, R ¹² in these vinyl esters is C ₄ -C ₁₆ -alkyl and especially C ₆ -C ₁₂ -alkyl. In a further preferred embodiment, R ¹² is a branched alkyl radical or neoalkyl radical having 7 to 11 carbon atoms, in particular 8, 9 or 10 carbon atoms. Suitable vinyl esters include vinyl acetate, vinyl propionate, vinyl butyrate, vinyl isobutyrate, vinyl hexanoate, vinyl heptanoate, vinyl octanoate, vinyl pivalate, vinyl 2-ethylhexanoate, vinyl laurate, Vinyl stearate and versaic acid esters such as vinyl neononanoate, vinyl neodecanoate, vinyl neodecanoate.

In a further preferred embodiment, these ethylene copolymers are vinyl acetate and at least one further vinyl ester of the formula (2) wherein R ¹² is C ₄ -C ₃₀ -alkyl, preferably C ₄ -C ₁₆ -alkyl, in particular C ₆ -C ₁₂ -alkyl). More preferably, the further vinyl ester is alpha-branched.

Acrylic acid and methacrylic acid esters (hereinafter abbreviated as (meth) acrylic acid esters) are preferably compounds of formula (3).

In Formula 3,

R ¹³ is hydrogen or methyl,

R ¹⁴ is C ₁ -C ₃₀ -alkyl, preferably C ₄ -C ₁₆ -alkyl, in particular C ₆ -C ₁₂ -alkyl.

Suitable acrylic acid esters are, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n- and isobutyl (meth) acrylate, hexyl, octyl, 2-ethylhexyl, Decyl, dodecyl, tetradecyl, hexadecyl, octadecyl (meth) acrylate and mixtures of these comonomers. In a further aspect, the alkyl groups mentioned may be substituted by one or more hydroxyl groups. One example of such acrylic esters is hydroxyethyl methacrylate.

Copolymer B) contains not only olefinically unsaturated esters but also further olefinically unsaturated compounds as comonomers. Preferred comonomers of this kind are alkyl vinyl ethers and alkenes.

The alkyl vinyl ether is preferably a compound of formula (4).

In Chemical Formula 4,

R ¹⁵ is C ₁ -C ₃₀ -alkyl, preferably C ₄ -C ₁₆ -alkyl, in particular C ₆ -C ₁₂ -alkyl.

Examples include methyl vinyl ether, ethyl vinyl ether, isobutyl vinyl ether. In a further aspect, the alkyl groups mentioned may be substituted by one or more hydroxyl groups.

Alkenes are preferably monounsaturated hydrocarbons having 3 to 30 carbon atoms, in particular 4 to 16 carbon atoms and especially 5 to 12 carbon atoms. Suitable alkenes are propene, butene, isobutylene. Pentene, hexene, 4-methylpentene, octene, diisobutylene and norbornene and derivatives thereof such as methylnorbornene and vinylnorbornene. In a further aspect, the alkyl groups mentioned may be substituted by one or more hydroxyl groups.

Except for ethylene, particularly preferred terpolymers are 3.5 to 20 mol%, in particular 8 to 15 mol% of vinyl acetate and 0.1 to 12 mol%, in particular 0.2 to 5 mol% of at least one relatively long chain and preferably branched vinyl ester For example, it contains vinyl 2-ethylhexanoate, vinyl neononanoate or vinyl neodecanoate, and the total comonomer content of the terpolymer is preferably 8.1 to 21 mol%, in particular 8.2 to 19 mol%. For example, it is 12-18 mol%. Particularly preferred copolymers are in addition to ethylene and vinyl esters of 8 to 18 mol% C ₂ -C ₁₂ -carboxylic acids, in addition to 0.5 to 10 mol% of olefins such as propene, butene, isobutylene, hexene, 4-methylpentene , Octene, diisobutylene and / or norbornene), and the total comonomer content is preferably 8.5 to 21 mol% and especially 9.0 to 19 mol%.

These ethylene copolymers and terpolymers preferably have a melt viscosity at 140 ° C. of up to 5000 mPas, more preferably 20 to 2500 mPas, in particular 30 to 1000 mPas, in particular 50 to 500 mPas. ¹ degree of branching, as measured by H NMR spectroscopy, is preferably 1 to 9 CH _3/100 CH ₂ groups, in particular from 2 to 6 CH _3/100 CH ₂ groups, which do not result from the comonomer.

Preference is given to using mixtures of two or more of the aforementioned ethylene copolymers. More preferably, the polymers on which the mixture is based differ in at least one property. For example, they may contain different comonomers or have different comonomer content, molecular weight and / or degree of branching. For example, mixtures of ethylene copolymers with different comonomer contents have been found to be particularly useful, and their comonomer contents differ by at least 2 mol% and in particular by more than 3 mol%.

The low temperature additive of the present invention preferably contains at least one organic solvent C) at 25 to 95% by weight and preferably at 28 to 80% by weight, for example 35 to 70% by weight. Preferred solvents are relatively high boiling point, low viscosity organic solvents. These solvents preferably contain only minor amounts of heteroatoms, which in particular consist solely of hydrocarbons. Also preferably, its kinematic viscosity measured at 20 ° C. is less than 10 mm 2 / s and in particular less than 6 mm 2 / s.

Particularly preferred solvents are aliphatic and aromatic hydrocarbons and mixtures thereof. Preferred aliphatic hydrocarbons as solvents have 9 to 20 carbon atoms and in particular 10 to 16 carbon atoms. They may be linear, branched and / or cyclic. They may also be saturated or unsaturated; They are preferably saturated or at least very saturated. Preferred aromatic hydrocarbons as solvents are 7 to 20 carbon atoms and in particular 8 to 16 carbon atoms, for example 9 to 13 carbon atoms. Preferred aromatic hydrocarbons are mono-, di-, tri- and polycyclic aromatics. In a preferred embodiment, they contain one or more, for example 2, 3, 4, 5 or more substituents. In the case of a plurality of substituents, they may be the same or different. Preferred substituents are alkyl radicals having 1 to 20 carbon atoms and especially 1 to 5 carbon atoms, for example methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl , Tert-pentyl and neopentyl radicals. Examples of suitable aromatic compounds are alkylbenzenes and alkylnaphthalenes. Particularly suitable examples are aliphatic and / or aromatic hydrocarbons or hydrocarbon mixtures such as gasoline fractions, kerosene, decane, pentadecane, toluene, xylene, ethylbenzene or commercially available solvent mixtures (eg Solvent Naphtha, Shellsoll ^® AB, Solvesso ^® 150, Solvesso ^® 200, Exxsol ^® , ISOPAR ^® and Shellsol ^® D). The solvent mixtures specified contain different amounts of aliphatic and / or aromatic hydrocarbons. Solvent C) may optionally also contain polar solubilizers, for example alcohols, organic acids, ethers of organic acids and / or esters of organic acids. Preferred solubilizers have 4 to 24 carbon atoms, more preferably 6 to 18 carbon atoms and especially 8 to 16 carbon atoms. Examples of suitable solubilizers include butanol, 2-ethylhexanol, decanol, isodecanol, isotridecanol, nonylphenol, benzoic acid, oleic acid, dihexyl ether, dioctyl ether, 2-ethylhexyl acid butyrate, ethyl octa Noate, ethyl hexanoate, butyl 2-ethylhexanoate and 2-ethylhexyl butyrate, and higher ethers and / or higher esters such as di (2-ethylhexyl) ether, 2-ethylhexyl 2- Ethylhexanoate and 2-ethylhexyl stearate. The proportion of polar solubilizer in solvent C) is preferably 5 to 80% by weight and in particular 10 to 65% by weight. In addition to solvents based on mineral oils, other suitable solvents C) are those based on renewable raw materials, such as vegetable oils and methyl esters derived therefrom, in particular rapeseed oil methyl esters, and for example Fischer. Biodiesel based on synthetic hydrocarbons obtainable from the Fischer-Tropsch process. Mixtures of the solvents mentioned are also suitable.

The low temperature additive of the invention preferably contains 1.5 to 73.5% by weight, in particular 15 to 70% by weight and especially 25 to 60% by weight of component B).

The low temperature additive of the invention preferably contains 0.1 to 50% by weight, in particular 0.5 to 30% by weight and in particular 1 to 20% by weight of component A).

The low temperature additive of the invention is preferably added to the middle distillate in an amount of 0.001 to 1.0% by weight, more preferably 0.002 to 0.5% by weight, for example 0.005 to 0.2% by weight.

The low temperature additive of the present invention may be used with one or more additional low temperature flow improvers. They are preferably used with one or more cold flow improvers III) to VII).

Further suitable cold flow improvers are oil-soluble polar nitrogen compounds (component III). These are preferably reaction products of compounds containing acyl groups with fatty amines. Preferred amines are compounds of formula NR ⁶ R ⁷ R ⁸ , wherein R ⁶ , R ⁷ And R ⁸ may be the same or different and at least one of these groups is C ₈ -C ₃₆ -alkyl, C ₆ -C ₃₆ -cycloalkyl or C ₈ -C ₃₆ -alkenyl, in particular C ₁₂ -C _24- Alkyl, C ₁₂ -C ₂₄ -alkenyl or cyclohexyl, with the remaining groups hydrogen, C ₁ -C ₃₆ -alkyl, C ₂ -C ₃₆ -alkenyl, cyclohexyl or the formula-(AO) _x -E or- A group of (CH ₂ ) _k -NYZ, wherein A is an ethyl or propyl group, x is from 1 to 50, E is H, C ₁ -C ₃₀ -alkyl, C ₅ -C ₁₂ -cycloalkyl or C ₆ -C ₃₀ -aryl, k is 2, 3 or 4 and Y and Z are each independently H, C ₁ -C ₃₀ -alkyl or-(AO) _x ). Alkyl and alkenyl radicals may each be linear or branched, and may contain up to two double bonds. They are preferably linear and highly saturated, ie they have an iodine number of less than 75 g I ₂ / g, preferably less than 60 g I ₂ / g and in particular less than 1-10 g I ₂ / g. R ⁶ , R ⁷ And R ⁸ Two of the groups are each C ₈ -C ₃₆ -alkyl, C ₆ -C ₃₆ -cycloalkyl or C ₈ -C ₃₆ -alkenyl, in particular C ₁₂ -C ₂₄ -alkyl, C ₁₂ -C ₂₄ -alkenyl or cyclo Particularly preferred are secondary fatty amines which are hexyl and third are hydrogen. Suitable fatty amines are, for example, octylamine, decylamine, dodecylamine, tetradecylamine, hexadecylamine, octadecylamine, eicosylamine, behenylamine, didecylamine, dididodecylamine, ditetedecyl Amines, dihexadecylamine, dioctadecylamine, diecosylamine, dibehenylamine and mixtures thereof. The amines are in particular chain cuts based on natural raw materials such as coconut fatty amines, tallow fatty amines, hardened tallow fatty amines, dicoconut fatty amines, ditallow fatty amines and di (cured tallow fatty amines) chain cuts). Particularly preferred amine derivatives are amine salts, imides and / or amides, for example secondary fatty amines, in particular amide-ammonium salts of dicoconut fatty amines, dietaro fatty amines and distearylamines.

Acyl groups are understood to mean functional groups of the formula:

> C = O

Carbonyl compounds suitable for reaction with amines are monomeric or polymeric compounds having at least one carboxyl group. Monomeric carbonyl compounds having 2, 3 or 4 carbonyl groups are preferably shown. They may also contain heteroatoms such as oxygen, sulfur and nitrogen. Suitable carboxylic acids include, for example, maleic acid, fumaric acid, crotonic acid, itaconic acid, succinic acid, C ₁ -C ₄₀ -alkyl (alkenyl) succinic acid, adipic acid, glutaric acid, sebacic acid and malonic acid, Also benzoic acid, phthalic acid, trimellitic acid and pyromellitic acid, nitrilotriacetic acid, ethylenediaminetetraacetic acid and reactive derivatives thereof such as esters, anhydrides and acid halides. Useful polymeric carbonyl compounds have been found to be in particular copolymers of ethylenically unsaturated acids such as acrylic acid, methacrylic acid, maleic acid, fumaric acid and itaconic acid; Particular preference is given to copolymers of maleic anhydride. Suitable comonomers are those which impart oil solubility to the copolymer. Oil-solubility here means that the copolymer is dissolved without residue in the middle distillate, which is actually added at the relevant volume after reaction with the fatty amine. Suitable comonomers are, for example, alkyl esters of olefins, acrylic acid and methacrylic acid, alkyl vinyl esters and alkyl vinyl ethers (each having from 2 to 75 carbon atoms, preferably from 4 to 40 and especially from 8 to 20 carbon atoms in the alkyl radicals). Is). In the case of olefins, the carbon number is based on the alkyl radicals bonded to the double bond. The molecular weight of the polymeric carbonyl compound is preferably 400 to 20000, more preferably 500 to 10000, for example 1000 to 5000.

Particularly useful oil-soluble polar nitrogen compounds have been found to be those obtained by reaction of aliphatic or aromatic amines, preferably long chain aliphatic amines with aliphatic or aromatic mono-, di-, tri- or tetracarboxylic acids or their anhydrides. (US 4 211 534). Equally suitable as oil-soluble polar nitrogen compounds are the amide and ammonium salts of aminoalkylenepolycarboxylic acids (eg nitrilotriacetic acid or ethylenediaminetetraacetic acid) with secondary amines (see EP-A-0 398 101). Other oil-soluble polar nitrogen compounds are copolymers of maleic anhydride and α, β-unsaturated compounds which may optionally react with primary monoalkylamines and / or aliphatic alcohols (see EP-A-0 154 177, EP- A-0 777 712), the reaction products of alkenyl-spiro-bislactones with amines (see EP-A-0 413 279 B1) and α, β-unsaturated dicarboxylic acids according to EP-A-0 606 055 A2 Reaction products of terpolymers based on polyoxyalkylene ethers of anhydrides, α, β-unsaturated compounds and lower unsaturated alcohols.

The mixing ratio between the oil-soluble polar nitrogen compound as the low temperature additive A) and the component III) of the present invention may vary depending on the application. The additive mixture is preferably 0.1 to 10 parts by weight, preferably 0.2 to 5 parts by weight of at least one oil-soluble polar nitrogen compound per part by weight of the additive mixture of A) and B) of the present invention, based on the active ingredient. (Component III) is contained.

Another preferred further cold flow improver is resin of phenols with phenol derivatives containing alkyl radicals as component IV. In a preferred embodiment of the present invention, these are phenol-formaldehyde resins containing oligo- or polymers having repeating structural units of the formula:

Wherein R ¹¹ is C ₁ -C ₂₀₀ -alkyl or -alkenyl, OR ¹⁰ or OC (O) —R ¹⁰ , R ¹⁰ is C ₁ -C ₂₀₀ -alkyl or -alkenyl, h is 2 To 100. R ¹⁰ is preferably C ₁ -C ₂₀ -alkyl or -alkenyl and especially C ₄ -C ₁₆ -alkyl or -alkenyl, for example C ₆ -C ₁₂ -alkyl or -alkenyl. R ¹¹ is more preferably C ₁ -C ₂₀ -alkyl or -alkenyl and especially C ₄ -C ₁₆ -alkyl or -alkenyl, for example C ₆ -C ₁₂ -alkyl or -alkenyl. h is preferably a number from 2 to 50 and in particular from 3 to 25, for example from 5 to 15.

In a particularly preferred embodiment, component IV comprises resins derived from alkylphenols having one or two alkyl radicals in the ortho and / or para position for the OH group. Particularly preferred starting materials are alkylphenols which contain, in aromatics, at least two hydrogen atoms which can be condensed with aldehydes, and in particular monoalkylated phenols. The alkyl radical is more preferably in the para position relative to the phenolic OH group. The alkyl radicals (in the case of component IV, which generally means hydrocarbon radicals as defined below) may be the same or different in the alkylphenol-aldehyde resins which may be used in the process according to the invention, which may be saturated or unsaturated. May have from 1 to 200 carbon atoms, preferably 1 to 20 carbon atoms, in particular 4 to 16 carbon atoms, for example 6 to 12 carbon atoms; They are preferably n-, iso- and tertiary butyl, n- and isopentyl, n- and isohexyl, n- and isooctyl, n- and isononyl, n- and isodecyl, n- and isododecyl , Tetradecyl, hexadecyl, octadecyl, tripropenyl, tetrapropenyl, poly (propenyl) and poly (isobutenyl) radicals. In a preferred embodiment, the alkylphenol resin is prepared using a mixture of alkylphenols having different alkyl radicals. For example, resins based on butylphenol and secondly octyl-, nonyl- and / or dodecylphenol first in molar ratios of 1:10 to 10: 1 have been found to be particularly useful.

Resins suitable as component IV may also contain or consist of structural units of further phenolic homologues such as salicylic acid, hydroxybenzoic acid, aminophenols and derivatives thereof such as esters, amides and salts.

Suitable aldehydes for the preparation of resins are compounds having from 1 to 12 carbon atoms and preferably from 1 to 4 carbon atoms, for example formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, 2-ethylhexanal, benzaldehyde, glyoxalic acid and Reactive equivalents thereof such as paraformaldehyde and trioxane. Particularly preferred are formaldehyde in the form of paraformaldehyde and in particular formalin.

The molecular weight of suitable resins, as determined by gel permeation chromatography on poly (styrene) standards in THF, is preferably 500 to 25000 g / mol, more preferably 800 to 10000 g / mol and especially 1000 to 5000 g / mol, eg For example, 1500-3000 g / mol. A precondition here is that the resin is oil-soluble at concentrations associated with the use of at least 0.001 to 1% by weight.

These resins can be obtained by known methods, for example by condensation of formaldehyde with corresponding phenol derivatives containing alkyl radicals.

Suitable further cold flow improvers are also comb polymers. Such a comb polymer (component V) can be represented by the following formula, for example.

In the above formulas,

A is R ', COOR', OCOR ', R "-COOR', OR ';

D is H, CH ₃ , A or R ";

E is H, A;

G is H, R ", R" -COOR ', an aryl radical or heterocyclic radical;

M is H, COOR ", OCOR", OR ", COOH;

N is H, R ", COOR", OCOR, aryl radical;

R 'is a hydrocarbyl chain having 8 to 50 carbon atoms;

R ″ is a hydrocarbyl chain having 1 to 10 carbon atoms;

a is a number from 0.4 to 1.0;

b is a number from 0 to 0.6.

These are in particular addition polymers obtainable by free-radical polymerization with the formation of CC bonds between monomers. Suitable comb polymers are, for example, copolymers of ethylenically unsaturated dicarboxylic acids (eg maleic acid or fumaric acid) with other ethylenically unsaturated monomers (eg olefins or vinyl esters such as vinyl acetate). Particularly suitable olefins are α-olefins having 10 to 36 carbon atoms and in particular 12 to 24 carbon atoms, for example 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene and mixtures thereof to be. Also suitable as comonomers are long chain olefins based on oligomerized C ₂ -C ₆ -olefins, for example poly (isobutylene) with high proportions of terminal double bonds. These copolymers are usually esterified with at least 50% with alcohols having 10 to 22 carbon atoms. Suitable alcohols are n-decane-1-ol, n-dodecane-1-ol, n-tedecane-1-ol, n-hexadecane-1-ol, n-octadecane-1-ol, n-eico Acid-1-ols and mixtures thereof. Particularly preferred are presented as a mixture of n-tetradecane-1-ol and n-hexadecane-1-ol. Likewise suitable as comb polymers are poly (alkyl acrylate), poly (alkyl methacrylate) and poly (alkyl vinyl ether) derived from alcohols having 12 to 20 carbon atoms and poly (vinyl) derived from fatty acids having 12 to 20 carbon atoms. Ester).

Likewise suitable as further cold flow improvers are homopolymers and copolymers of olefins having 2 to 30 carbon atoms (component VI). They can be prepared directly from monoethylenically unsaturated monomers or indirectly by hydrogenation of polymers derived from polyunsaturated monomers such as isoprene or butadiene. Preferred copolymers are derived from not only ethylene but also α-olefins having 3 to 24 carbon atoms and contain structural units having a molecular weight of 120000 g / mol or less. Preferred α-olefins are propylene, butene, isobutene, n-hexene, isohexene, n-octene, isooctene, n-decene and isodecene. The comonomer content of the olefins is preferably 15 to 50 mol%, more preferably 20 to 35 mol% and especially 30 to 45 mol%. These copolymers may also contain small amounts, for example up to 10 mol% of additional comonomers, for example non-terminal olefins or unconjugated olefins. Particularly preferred are ethylene-propylene copolymers. Preference is also given to copolymers of different olefins having 5 to 30 carbon atoms, for example poly (hexene-co-decene). Olefin homopolymers and copolymers can be prepared by known methods, for example by Ziegler or metallocene catalysts.

Further suitable olefin copolymers are block copolymers containing blocks of olefinically unsaturated aromatic monomers A and blocks of hydrogenated polyolefins B. Particularly suitable block copolymers are those of the structure (AB) _c A and (AB) _d , where c is a number from 1 to 10 and d is a number from 2 to 10.

Likewise suitable as further cold flow improvers are esters, ethers and ethers / esters of oil-soluble polyoxyalkylene compounds (component VII), for example polyols containing at least one alkyl radical having 12 to 30 carbon atoms. In a preferred embodiment, the oil-soluble polyoxyalkylene compound comprises at least two, for example three, four or five aliphatic hydrocarbon radicals. These radicals preferably comprise independently 16 to 26 carbon atoms, for example 17 to 24 carbon atoms. These radicals of oil-soluble polyoxyalkylene compounds are preferably linear. Also preferably, they are very fairly saturated, especially alkyl radicals. Esters are particularly preferred.

Particularly suitable polyols according to the invention are polyethylene glycols, polypropylene glycols, polybutylene glycols and copolymers thereof having a molecular weight of approximately 100 to approximately 5000 g / mol, preferably 200 to 2000 g / mol. In a particularly preferred embodiment, the oil-soluble polyoxyalkylene compounds are prepared from polyols having at least 3 OH groups, preferably from polyols having from 3 to about 50 OH groups, for example from 4 to 10 OH groups, In particular derived from neopentyl glycol, glycerol, trimethylolethane, trimethylolpropane, sorbitan, pentaerythritol, and oligomers having 2 to 10 monomeric units, which can be obtained by condensation therefrom, for example polyglycerol do. Also suitable as polyols are higher polyols such as sorbitol, sucrose, glucose, fructose and oligomers thereof such as cyclodextrins, provided that the esterified or etherified alkoxylates are at least application-related. In amount, they are oil-soluble. Accordingly, preferred polyoxyalkylene compounds have branched polyoxyalkylene cores bound to a plurality of alkyl radicals that impart oil solubility.

The polyols generally react with 3 to 70 mol of alkylene oxides, preferably 4 to 50 mol and especially 5 to 20 mol of alkylene oxide per hydroxyl group of the polyol. Preferred alkylene oxides are ethylene oxide, propylene oxide and / or butylene oxide. Alkoxylation is carried out by known methods.

Fatty acids suitable for esterification of alkoxylated polyols preferably have from 12 to 30 and in particular from 16 to 26 carbon atoms. Suitable fatty acids are, for example, lauric acid, tridecanoic acid, myristic acid, pentadecanoic acid, palmitic acid, margaric acid, stearic acid, isostearic acid, arachnic acid and behenic acid, oleic acid and eruk Acids, palmitoleic acid, myristoleic acid, ricinoleic acid and fatty acid mixtures obtained from natural fats and oils. Preferred fatty acid mixtures contain greater than 50 mol% fatty acids having at least 20 carbon atoms. Preferably, less than 50 mol%, in particular less than 10 mol% of the fatty acids used for esterification contain double bonds; They are especially very saturated. The esterification can also proceed from reactive derivatives of fatty acids, for example esters with lower alcohols (eg methyl or ethyl esters) or anhydrides.

In the context of the present invention, “very significantly saturated” is understood to mean the iodine number of fatty acids or fatty alcohols used in an amount of 5 g or less per 100 grams of fatty acid or fatty alcohol.

The polyols and fatty acids are based on the content of hydroxyl groups on the one hand and the content of the carboxyl groups on the other hand in a ratio of 1.5: 1 to 1: 1.5, preferably in a ratio of 1.1: 1 to 1: 1.1 and in particular equimolar amounts It is used for esterification. The acid value of the ester formed is generally less than 15 mg KOH / g, preferably less than 10 mg KOH / g, in particular less than 5 mg KOH / g. The OH number of the esters is preferably less than 20 mg KOH / g and in particular less than 10 mg KOH / g.

In a preferred embodiment, after the alkoxylation of the polyol, the terminal hydroxyl groups are converted to terminal carboxyl groups, for example by oxidation or by reaction with dicarboxylic acids. Reaction with fatty alcohols having 8 to 50 carbon atoms, in particular 12 to 30 and especially 16 to 26, likewise provides the polyoxyalkylene esters of the invention. Preferred fatty alcohols or fatty alcohol mixtures contain greater than 50 mol% fatty alcohols having at least 20 carbon atoms. Preferably, less than 50 mol%, in particular less than 10 mol% of the fatty alcohols used for esterification contain double bonds; They are especially very saturated. Esters of alkoxylated fatty alcohols and fatty acids which contain the aforementioned ratios of poly (alkylene oxides) and whose fatty alcohols and fatty acids have the aforementioned alkyl chain lengths and saturations are also suitable according to the invention.

Furthermore, the alkoxylated polyols described above can be converted into suitable polyoxyalkylene compounds according to the invention by etherification with fatty alcohols having 8 to 50 carbon atoms, in particular 12 to 30 and especially 16 to 26 carbon atoms. Preferred fatty alcohols for this purpose are straight chains and are very saturated. The etherification is preferably carried out completely or at least very fully. Etherification is carried out by known methods.

Particularly preferred polyoxyalkylene compounds are derived from polyols having 3, 4 and 5 OH groups, which contain about 5 to 10 moles of structural units derived from ethylene oxide per hydroxyl group of the polyol and are very highly saturated C _17. Very fully fully esterified with -C ₂₄ fatty acids. Further particularly preferred polyoxyalkylene compounds are polyethylene glycols which are esterified with very highly saturated C ₁₇ -C ₂₄ fatty acids and have a molecular weight of about 350 to 1000 g / mol. Examples of particularly suitable polyoxyalkylene compounds include polyethylene glycols which have been esterified with stearic acid and especially behenic acid, having a molecular weight of 350 to 800 g / mol; Neopentyl glycol 14-ethylene oxide distearate (neopentyl glycol alkoxylated with 14 mol of ethylene oxide and then esterified with 2 mol of stearic acid) and especially neopentyl glycol 14-ethylene oxide dibehenate; Glycerol 20-ethylene oxide tristearate, glycerol 20-ethylene oxide dibehenate and especially glycerol 20-ethylene oxide tribehenate; Trimethylolpropane 22-ethylene oxide tribehenate; Sorbitan 25-ethylene oxide tristearate, sorbitan 25-ethylene oxide tetrastearate, sorbitan 25-ethylene oxide tribehenate and especially sorbitan 25-ethylene oxide tetrabehenate; Pentaerythritol 30-ethylene oxide tribehenate, pentaerythritol 30-ethylene oxide tetrastearate and especially pentaerythritol 30-ethylene oxide tetrabehenate and pentaerythritol 20-ethylene oxide 10-propylene oxide tetrabehenate.

The mixing ratio of the low temperature additives of the invention with the further low temperature flow improvers IV, V, VI and VII is generally in each case 50: based on the weight of (A + B): (IV, V, VI and VII). 1 to 1: 1, preferably 10: 1 to 2: 1 (by weight).

The low temperature additives of the present invention are obtained, in particular, by distillation of crude oil, and boil, or mainly, for example, kerosene, jet fuel, diesel and heating in the range of about 150 to 410 ° C. and especially in the range of about 170 to 380 ° C. Improve the low temperature properties of the middle distillate made up of the flow path. The middle distillate usually contains about 5-50% by weight of n-paraffins, for example about 10-35% by weight, of which long chain paraffins may crystallize during the cooling process or may impair the flowability of the intermediate distillate. have. The low temperature additive of the present invention is particularly useful for middle distillates having high content of low-critical components having n-alkyl chains having carbon chain lengths of 16 or more carbon atoms. Examples of these include n-paraffins of fossil origin, as well as n-paraffins obtained by hydrogenation or dehydrogenation of animal and / or vegetable fats, and esters of saturated fatty acids with lower alcohols such as methanol or ethanol. . The low temperature additives of the present invention have been found to be particularly useful, especially in intermediate distillates having these cold-critical components in amounts of more than 4% by weight and especially in the range of 6-20% by weight, for example 7-15% by weight. The low temperature additives of the present invention are also particularly useful for oils containing only very low proportions of very long chain n-paraffins having 28 or more carbon atoms, which serve as natural nucleating agents for paraffin crystallization. The low temperature additive of the present invention has been found to be particularly useful for oils containing less than 1% by weight and especially less than 0.5% by weight, for example less than 0.3% by weight, of long chain n-paraffins having at least 28 carbon atoms. Particular advantages are exhibited by the low temperature additives of the invention, in particular in oils containing a high content of n-alkyl chains having at least 16 carbon atoms and at the same time, very low proportions of very long chain n-paraffins having at least 28 carbon atoms. The content of n-paraffins and any further cold-critical components, such as fatty acid methyl esters, is usually determined by gas chromatography. The compositions of the invention also contain intermediate distillates with low final boiling points, ie intermediate distillates with 90% distillation points below 360 ° C., in particular 350 ° C. and in particular cases below 340 ° C., and also 20 to 90% distillation volumes. It is particularly useful in intermediate distillates having a boiling point range below 120 ° C and especially below 110 ° C. The middle distillate also contains oils of animal and / or plant origin, for example fatty acid methyl esters, described in detail below, in small amounts, for example up to 40% by volume, preferably from 1 to 20% by volume, in particular from 2 to 15 % By volume, for example 3 to 10% by volume. The middle distillate preferably does not contain any residues from the distillation of mineral oil, for example residues from atmospheric distillation and / or vacuum distillation.

The low temperature additive of the present invention is likewise suitable for improving the low temperature properties of fuels (biofuels) based on renewable raw materials. Biofuels should be understood to mean animal sources and preferably oils obtained from vegetable sources or both, and derivatives thereof, which can be used as fuels and in particular as light oils or heating oils. These are triglycerides of fatty acids having 10 to 24 carbon atoms, and also fatty acid esters of lower alcohols such as methanol or ethanol, which can be obtained from them by transesterification reactions.

Examples of suitable biofuels include rapeseed oil, coriander oil, soybean oil, cottonseed oil, sunflower oil, castor oil, olive oil, peanut oil, corn oil, almond oil, palm kernel oil, coconut oil, mustard seed oil, tallow, bone oil, fish oil and use. Cooking oil. Further examples include oils derived from wheat, jute, sesame seeds, shea tree nuts, peanut oil and linseed oil. Fatty acid alkyl esters can also be derived from these oils by methods known in the art. Rapeseed oil, which is a mixture of fatty acids esterified with glycerol, is preferred because it can be obtained in large quantities and by a simple method by extrusion compression of rapeseed seeds. Likewise, a wide range of oils, like sunflowers, palms and legumes, and mixtures of these with rapeseed oil, are also preferably presented.

Particularly suitable biofuels are lower alkyl esters of fatty acids. Examples useful here are fatty acids having 14 to 22 carbon atoms, for example, lauric acid, myristic acid, palmitic acid, palmitoleic acid, stearic acid, oleic acid, oleic acid, petroleic acid, ricinoleic acid, eleostearic Commercial mixtures of ethyl esters, propyl esters, butyl esters and especially methyl esters of acids, linoleic acid, linolenic acid, eicosanoic acid, gadoleic acid, docosanoic acid or erucic acid. Preferred esters have an iodine number of 50 to 150 and in particular 90 to 125. Mixtures having particularly useful properties are those containing mainly methyl esters of fatty acids having 16 to 22 carbon atoms and having 1, 2 or 3 double bonds, ie at least about 50% by weight. Preferred lower alkyl esters of fatty acids are the methyl esters of oleic acid, linoleic acid, linolenic acid and erucic acid.

The low temperature additives of the present invention may be used alone or in addition to other co-additives, for example, other pour point depressants or deleading aids, detergents, antioxidants, cetane number improvers, antifogants, anti emulsifiers, dispersants, antifoams, dyes, corrosion inhibitors. , Lubricity additives, sludge inhibitors, fragrance and / or cloud point reducing additives.

An advantage of the low temperature additives of the present invention and methods of using them is a pronounced improvement in intrinsic fluidity under low temperature conditions, with a simultaneous improvement in efficacy, as compared to the corresponding admixtures of the prior art. For example, these low temperature additives, presented in the same active ingredient content, can also be used at lower temperatures than those of the prior art, without the need for heating. Alternatively, at the same temperatures presented, higher concentration additives can be used, thereby reducing the costs for transportation and storage. In addition, the low temperature additive of the present invention surprisingly shows improved efficacy in improving the low temperature flow properties of the intermediate distillate. This is not all expected to be much lower than for the comb polymers of the prior art, in which the side chain density of the comb polymer B) of the invention is further esterified by fatty acids (DE-A-1920849, DE-A-2451047). ). The filterability of the fuel oil treated with the low temperature additive of the present invention is also surprisingly compromised to a much lesser extent than with the addition of additives of the prior art under surprisingly identical conditions.

Example

The α-olefins used are commercially available mixtures of the specified compositions with 1-alkenes. The acid value is determined by titration of the reaction mixture mother liquor with an alcoholic tetra-n-butylammonium hydroxide solution in xylene / isopropanol. The hydroxyl value is ¹ H by quantitative measurement of the formed urethane after the reaction of the free OH group and isocyanate of the polymer. It is measured by NMR spectroscopy. Reported values are based on solvent-free polymers. Molecular weights are measured by lipophilic gel permeation chromatography in THF on poly (ethylene glycol) standards and detected by RI detector.

Polyester A)

A1) C _{20 / 24} -alkenylsuccinic anhydride (90% α-olefin and 7.5% linear internal olefins in equimolar ratios, with 43% C _20- , 35% C ₂₂ -and 17% C ₂₄ -olefin as main components industrial C _20/24 containing - prepared by thermal condensation of the olefin and maleic anhydride) and copolymers of glycerol. The reaction is heated to 150 ° C. as a 50% solution in Shellsol AB (comparative high boiling aromatic solvent mixture) with stirring until the acid value remains constant. The formed water is distilled off. The acid value of the polymer thus prepared was 7.8 mg KOH / g, the hydroxyl value was 98 mg KOH / g, and the weight-average molecular weight was 6100 g / mol.

A2), etc. The molar ratio of C _20/24 - nilseok alkenyl succinic anhydride (90% α- olefin and 7.5% has a linear internal olefins, as main _{components, 43% C 20 -, 35} % C 22 - and 17% C ₂₄ - olefin industrial C _20/24 containing - prepared by thermal condensation of the olefin and maleic anhydride), and an average condensation degree of 3 or poly conducted from glycerol example A1) copolymer is prepared in analogy to. The acid value of the polymer is 6.5 mg KOH / g, the hydroxyl value is 195 mg KOH / g, and the weight-average molecular weight is 8700 g / mol.

A3) having an equimolar ratio of C _{26 / 28} -alkenylsuccinic anhydride (85% α-olefin, 4% linear internal olefins and 9% branched olefins, as main components 57% C _26- , 39% C _28- And by thermal condensation of industrial C _{26 -28} -olefins with maleic anhydride containing 2.5% C ₃₀ -olefin and copolymers prepared analogously to Example A1) from glycerol. The acid value of the polymer is 10.4 mg KOH / g, the hydroxyl value is 68 mg KOH / g and the weight-average molecular weight is 9100 g / mol.

A4) Copolymer of C ₂₀ / ₂₄ -alkenylsuccinic anhydride, glycerol and behenic acid according to example A1) in an equimolar ratio, similar to polymer G of DE-A-24 51 047. The acid value of the polymer is 15 mg KOH / g, the hydroxyl value is 6 mg KOH / g and the weight-average molecular weight is 8300 g / mol (comparative example).

A5) Addition copolymers of equimolar ratios of maleic anhydride and C _20/24 -olefins esterified with 2 molar equivalents of behenyl alcohol. The acid value of the polymer is 9 mg KOH / g, the hydroxyl value is 11 mg KOH / g, and the weight-average molecular weight is 7900 g / mol (comparative example).

Ethylene Copolymer B)

B1) Terpolymer of ethylene, 13.5 mol% vinyl acetate and 1.5 mol% vinyl neononanoate, having a melt viscosity measured at 140 ° C. of 95 mPas.

B2) terpolymer of ethylene, 12 mol% vinyl acetate and 5 mol% propene, with a melt viscosity measured at 140 ° C. of 200 mPas.

B3) A copolymer of ethylene and 13 mol% vinyl acetate having a melt viscosity of 125 mPas measured at 140 ° C.

B4) terpolymer of ethylene, 12.5 mol% vinyl acetate and 4 mol% 4-methylpentene, having a melt viscosity measured at 140 ° C. of 170 mPas.

The melt viscosity of the ethylene copolymer B) is measured by a rotational viscometer at a temperature of 140 ° C. Prior to the measurement, all volatile components are removed from ethylene copolymer B) at 150 ° C./100 mbar.

Solvent C)

C1) Solvesso ^® 150: high boiling aromatic mixture (approximately 98% aromatic compound, 0.7% naphthalene, boiling point 175-205 ° C., flash point 65 ° C.)

C2) White spirit: mainly mixture of paraffinic and naphthenic hydrocarbons in the range of C ₁₀ to C ₁₆ (aromatic content 16%, boiling point range 182 to 212 ° C, flash point 63 ° C)

In order to measure the low temperature properties of the low temperature additive, its pour point is measured according to DIN ISO 3016. Low pour points indicate good fluidity and therefore ease of handling under low temperature conditions. The percentage reported for additives relates to the weight ratio of the additive components used. The weight ratios specified for the polymers relate to solvent-free active ingredients. Synthesis Any solvent components present in the polymer are shown as solvent C).

The efficacy of the additives was studied by lowering the CFPP value according to DIN EN 116 in low-sulfur intermediate distillates having the properties shown in Table 2. Components with n-alkyl radicals ≧ C ₁₆ and n-paraffins ≧ C ₂₈ were determined by gas chromatography.

For solubility comparison of the low temperature additive, 200 ml of Test Oil 3 (Table 2) is mixed with 1000 ppm of the additive according to Table 1 at a temperature specified in Table 6 in a 250 ml measuring cylinder. The additives are added in direct transfer pipettes, in particular in order to be able to handle the high viscosity of the comparative additives. After rotating the measuring cylinder ten times to 180 °, the undissolved additive components were visually inspected.

Claims (14)

A) a diol containing two primary OH groups and at least one secondary OH group and a C ₁₆ -C ₄₀ -alkyl radical or a C ₁₆ -C ₄₀ -alkenyl radical or an anhydride thereof or At least one comb polymer containing hydroxyl groups, which may be prepared by polycondensation of esters (OH value of the comb polymer is at least 40 mg KOH / g),
B) at least one copolymer of ethylene and at least one ethylenically unsaturated ester and
C) at least one organic solvent
Cold additives for intermediate distillates, including. The low temperature additive of claim 1, wherein the dicarboxylic acid corresponds to formula 1 below.
Formula 1

In Chemical Formula 1,
One of the R ¹ to R ⁴ radicals is a linear C ₁₆ -C ₄₀ -alkyl or alkenyl radical, the remaining R ¹ to R ⁴ radicals are each independently hydrogen or an alkyl radical having 1 to 3 carbon atoms,
R ⁵ is a CC bond or an alkylene radical having 1 to 6 carbon atoms. The low temperature additive of claim 2 wherein the dicarboxylic acid is alkylsuccinic acid, alkenylsuccinic acid or anhydrides thereof. The low temperature additive according to any one of claims 1 to 3, wherein the polyol is glycerol. The low temperature additive according to any one of claims 1 to 4, wherein the OH value of the polymer A) is 40 to 500 mg KOH / g. The polymer B) according to any one of claims 1 to 5, 8 to 21 mol% of ethylene and at least one olefinically unsaturated compound selected from vinyl esters, acrylic esters and / or methacrylic acid esters. Low temperature additive, which is a copolymer with. The low temperature additive according to any one of claims 1 to 6, wherein the solvent C) is selected from aliphatic hydrocarbons having 9 to 20 carbon atoms and aromatic hydrocarbons having 7 to 20 carbon atoms. 8. The solubilizing agent according to claim 1, wherein the solvent C) contains 4 to 24 carbon atoms and is selected from alcohols, organic acids, ethers of organic acids and esters of organic acids or mixtures thereof. Contained with, low temperature additives. The low temperature additive according to any one of claims 1 to 8, wherein 0.1 to 50% by weight of component A), 1.5 to 73.5% by weight of component B) and 25 to 95% by weight of component C) are present. 10. The method according to any one of claims 1 to 9,
There is further at least one additional cold flow improver,
The cold flow improver
III) oil-soluble polar nitrogen compounds,
IV) resins of phenol derivatives with aldehydes containing alkyl radicals,
V) comb polymers of the formula:

(In the above formula,
A is R ', COOR', OCOR ', R "-COOR', OR ';
D is H, CH ₃ , A or R ";
E is H, A;
G is H, R ", R" -COOR ', an aryl radical or heterocyclic radical;
M is H, COOR ", OCOR", OR ", COOH;
N is H, R ", COOR", OCOR, aryl radical;
R 'is a hydrocarbyl chain having 8 to 50 carbon atoms;
R ″ is a hydrocarbyl chain having 1 to 10 carbon atoms;
a is a number from 0.4 to 1.0;
b is a number from 0 to 0.6),
VI) homopolymers and copolymers of olefins having 2 to 30 carbon atoms,
VII) esters, ethers and / or esters / ethers of alkoxylated polyols containing at least one alkyl radical having 12 to 30 carbon atoms
Low temperature additive, selected from the group consisting of: The method for improving the low temperature flow characteristics of fuel oil, wherein the low temperature additive according to any one of claims 1 to 10 is added to the middle distillate. A fuel oil comprising an intermediate distillate and at least one low temperature additive according to any one of claims 1 to 10. 13. The fuel oil of claim 12, wherein the middle distillate has a content of greater than 4% by weight of components having n-alkyl chains having at least 16 carbon atoms. The fuel oil according to claim 12 or 13, wherein the intermediate distillate has a long chain n-paraffin having 28 or more carbon atoms in a ratio of less than 1% by weight.