DE1279267B - Stabilization and increase of the electrical conductivity of liquid hydrocarbons or their mixtures - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY GERMAN FILW PATENT OFFICE Int. Cl .:

ClOl

EDITORIAL

German KL: 23 b-1/05

Number: 1 279 267

File number: P 12 79 267.5-44 (S 68679)

Filing date: May 25, 1960

Open date: October 3, 1968

The low electrical conductivity of light hydrocarbons, such as gasoline and kerosene, leads to in practice often to difficulties, since z. B. when pumping through narrow pipes and hoses accumulate electrostatic charges as a result of the associated friction on the container walls, which give rise to explosions. The presence of water increases this danger significantly increased.

It is known from German Auslegeschrift 1 050 338 that the electrical conductivity of hydrocarbons, halogenated hydrocarbons and other organic liquids with low electrical conductivities, which have a dielectric constant of less than 8 and an average of 12 carbon atoms, can be increased by 10 ~ ^{7 each} to 10 ~ ² mol per liter of a salt of a polyvalent metal with a molecular weight of over 200 and a compound with a molecular weight of over 200 and a product value of the molecular weight times the specific conductivity, measured at 25 ⁰ C in benzene at a concentration of 1 g each Liters, dissolves at least 10 ~ ¹⁰ in the organic liquid, whereby this second additional compound can also be a salt, the anion and cation of which, however, must be different from those of the first salt.

A chromium alkyl salicylate in combination with the calcium salt is particularly suitable for this purpose a sulfosuccinic acid dialkyl ester.

It has been shown, however, that the conductivity of hydrocarbon mixtures containing such additives contained, decreases again over time, especially in the presence of water or alkali. The effect of the known additives is also in a freshly refined mineral oil fraction less than one previously treated with an adsorbent such as silica has been. A scientific explanation for these phenomena could not yet be found being found.

Surprisingly, it has now been found that these disadvantageous phenomena by Have the use of certain oil-soluble copolymers remedied.

Accordingly, the invention relates to the use of an oil-soluble copolymer with a molecular weight of 5,000 to 2,500,000 and a nitrogen content of 0.1 to 8.0 percent by weight of a) N-vinyl-2-pyrrolidone or vinylpyridines, b) esters of Acrylic acids and / or -substituted acrylic acids of alkanols with stabilization and increase in electrical
Conductivity of liquid hydrocarbons
or their mixtures

Applicant:

Shell Internationale Research Maatschappij N.V., The Hague

Representative:

Dr. E. Jung, patent attorney,

8000 Munich 23, Siegesstr. 26th

Named as inventor:

f hurston Skei, East Alton, JIl .;

James Edward Douglas, Godfrey, JlI. (V. St. A.)

Claimed priority:

V. St. v. America May 27, 1959 (816 039)

at least 8 carbon atoms and optionally c) (meth) acrylic acid esters of alkanols with a maximum of 6 carbon atoms to stabilize and increase the electrical conductivity of liquid hydrocarbon mixtures that contain a small amount of an oil-soluble salt with a molecular weight of at least 200 and an alkylated salicylic acid of a metal of atomic number 21 to 29 and optionally an oil-soluble calcium salt of a sulfosuccinic acid dialkyl ester, the weight ratio of the oil-soluble salt of the alkylated salicylic acid (calculated as the metal) to the oil-soluble copolymer being 1:20 to 1: 5000 and the concentration of the oil-soluble salt being 1 10 ⁹ to 1 x 10- ³ gram-atom of metal and the calcium salt of the dialkylsulfosuccinic ester 1 × 10 ⁹ to 1 x 10 ^"4 gram atom of metal per liter amounts of the liquid hydrocarbons.

The copolymers used as additives according to the invention not only have a stabilizing effect Effect from so that the means of the from the alkylsalicylic acid derived salts achieved increased electrical conductivity lasts longer, but one has even observed an increase in them in some cases.

The copolymers used as additives preferably have a molecular weight between 50,000

809 619 '' «4

and 1,000,000, determined by the light scattering method, on. Their nitrogen content is preferably 1 to 5 percent by weight.

The oil-soluble, nitrogen-containing copolymer can be derived from N-vinyl-2-pyrrolidone and at least one alkyl ester of an acrylic acid, the proportion of N-vinyl-2-pyrrolidone being 5 to 30% based on the weight of the copolymer, amounts to. Such a mixed polymer is described in Belgian patent 550,422. A _ϊ0 N-vinyl-2-pyrrolidone can also be copolymerized with a mixture of alkyl esters of acrylic acids, the alkyl groups of the mixture containing an average of at least 8 carbon atoms. Particularly preferred copolymers of this type are derived from N-vinyl-2-pyrrolidone and a mixture of alkyl methacrylates from primary alkanols having 12 to 18 carbon atoms in a weight ratio of 1: 5 or 1: 6.

A particularly preferred class of interpolymers is disclosed in U.S. Patent 2,839,512 described. These copolymers are derived from vinylpyridine a), a mixture of different long-chain (Meth) acrylic acid esters in which the alcohol residues differ by at least 4 carbon atoms and wherein the molar ratio of the esters is 1:10 to 10: 1, b) and at least one low molecular weight (methacrylic acid ester with an alcohol residue of no more than 6 carbon atoms c) from, wherein the molar ratio of a) to b) + c) is 1:15 to 2: 1 and c) 10 to 75 mol percent of b) + c).

The vinyl pyridines used in the preparation of these special interpolymers are for example 2-vinylpyridine, 3-vinylpyridine, 4-vinylpyridine, 2-methyl-5-vinylpyridine, 4-methyl-2-vinylpyridine, 5-ethyl-2-vinylpyridine and 2-butyl-5-vinylpyridine.

Specific examples of the long-chain acrylic acid esters include decyl acrylate, lauryl acrylate, Stearyl acrylate, decyl methacrylate, lauryl methacrylate, cetyl methacrylate, stearyl methacrylate, Eicosanyl acrylate, docosanyl acrylate and mixtures thereof.

Examples of mixtures of long-chain acrylate esters whose alcohol residues are at least 4 carbon atoms differ are among others. Dodecyl methacrylate - octadecyl methacrylate, Tetradecyl acrylate - octadecyl methacrylate, decyl methacrylate - octadecyl methacrylate, Tetradecyl acrylate - octadecyl methacrylate and dodecyl methacrylate - eicosanyl acrylate. Particularly excellent results are achieved when one of the acrylic acid esters has a 10 to 14 carbon atoms, the other being one having 16 to 20 carbon atoms.

Examples of the low molecular weight acrylic acid esters include the acrylic acid and methacrylic acid esters of methanol, ethanol, butanol, hexanol, isobutyl alcohol and Propanol.

The low molecular weight acrylic acid ester is preferably used in amounts of 15 to 60 mole percent of the entire ester mixture used.

A mixed polymer of stearyl methacrylate, lauryl methacrylate, Methyl methacrylate and '2-methyl-5-vinylpyridine (Copolymer I) can be used in the following Way are produced, for which, however, no protection is claimed within the scope of the invention.

A mixture of 2.52 moles of stearyl methacrylate, 5.04 moles of lauryl methacrylate, 0.83 moles of methyl methacrylate and 1 mole of 2-methyl-5-vinylpyridine and 0.2 percent by weight of α, α'-azodiisobutyronitrile, the latter Acetate is dissolved in a smaller amount for better solubility and is placed in a reaction vessel and over the course of 24 to 48 hours at 65 ° C with stirring in a nitrogen atmosphere implemented. The polymer is then dispersed in the same volume of benzene and then with 5 to 10 volumes of a mixture precipitated from acetone and methanol. If it is repeated, a stearyl methacrylate-lauryl methacrylate is obtained - methyl methacrylate - 2 - methyl - 5 - vinyl pyridine copolymer with a nitrogen content of 0.60 percent by weight and a molecular weight of over 750,000.

Further interpolymers are made in essentially the same manner as for the interpolymers I prepared, from mixtures of monomers, the molar proportions in the following Table I shows:

Table I.

Mixed
polymer SMA LMA MMA BMA MVP EPP II 2.24 4.48 1.86 * 1 III 2.24 4.48 1.86 1 IV 2.05 3.92 2.43 1 V 2.05 3.92 2.43 1 VI 1.68 3.36 3.36 1 VII 1.68 3.36 3.36 1 ■ VIII 1.40 2.80 4.2 1 IX 1.40 2.80 4.2 1 X 1.12 2.24 5.04 5.04 1 XI 1.12 2.24 1 XII 2.52 5.04 0.83 1 XIII 2.24 4.48 1.86 1 xrv 2.05 3.92 2.43 1 XV 2.05 3.92 2.43 1

SMA = stearyl methacrylate.

LMA = lauryl methacrylate.

MMA = methyl methacrylate.

BMA = butyl methacrylate.

MVP = 2-methyl-5-vinylpyridine.

EVP = S-EthyW-vinylpyridine.

A stearyl methacrylate-lauryl methacrylate-methyl methacrylate-methyl vinyl pyridine copolymer (Copolymer XVI) can be prepared in the following manner, for which in the context of Invention but no protection is claimed.

29.3 percent by weight stearyl methacrylate, 49.7 percent by weight lauryl methacrylate, 16 percent by weight Methyl methacrylate and 5.0 percent by weight methyl vinyl pyridine are made in an autoclave stainless steel of about 11001 content introduced. A mixture is then made into the autoclave Parts of benzene and neutral petroleum, added so that one part of the mixture to 3 parts of all the monomer came. 0.25 percent by weight of di-tert-butyl peroxide is then added, whereupon the mixture for about 7 hours

at 12O ⁰ C is heated. When the reaction is complete, the benzene is ^{removed at 120 °} C. and 10 mm Hg by blowing in nitrogen. The benzene-free product is then diluted with a neutral oil 'to a mixed polymer content of about 30 weight percent and filtered at 100 to 120 ⁰ C. The pure mixed polymer has a molecular weight of 500,000 and a nitrogen content of 0.65 percent by weight.

Specific examples of particularly effective oil-soluble salts of an alkylated salicylic acid according to the invention are chromium (III) diisopropyl salicylate, iron (III) diisopropyl salicylate, titanium (III) salts of Cu- to Cis-alkylsalicylic acids and the manganese (II) salts of Cu- to Cis-alkylsalicic acids.

The chromium salts of alkyl salicylic acids which have at least one alkyl substituent are particularly preferred containing at least 8, preferably 10 to 22 carbon atoms, in particular one Chromium (III) salt, which can be either neutral or slightly basic.

To protect the concentration of Alkylsalicylsäuresalzes necessary a liquid hydrocarbon from static electricity is very low, are particularly suitable concentrations of about 1 ■ 10 ~ ⁵ to about 1 x ΙΟ- ⁷ gram atom of metal per liter of the liquid hydrocarbons.

The beneficial effect of these metal salts with regard to the increase in conductivity can be further improved by using the calcium salt of the dioctylsulfosuccinic acid ester. These salts are advantageously also used in such amounts that the hydrocarbon mixture contains 10 ^-7 to 10 ^-5 gram-atom of the respective metals per liter.

Suitable hydrocarbon mixtures to which the active ingredients according to the invention are advantageously added normally boil in a temperature range of -40 to 375 ° C, i.e., they are generally hydrocarbon distillates. The invention is particularly applicable to petroleum distillates in the boiling ranges of light gasoline and kerosene, such as B. Gasoline for automobiles and airplanes, fuels for the gas turbines of aircraft types JP-I, JP-4 and JP-5. The invention is also applicable on directly blended xylenes and non-aromatics that are in the xylene range or close to it boil, or similar toluene or benzene blends and obtained from such fractions Extracts and raffinates (e.g. from extraction with SO2 or furfural).

example 1

To two samples of this test fuel is placed 0.0000385 weight percent of chromium-Cu-Cis-alkyl salicylate (Cr content: 5.9 per cent by weight), which is 3.5 x ΙΟ- ⁷ gram atom of chromium or 1.8 x IO ⁵ g chromium per Liters of the fuel and 0.0001 percent by weight calcium dioctyl sulfosuccinate, ie 9 · ΙΟ " ⁷ gram atom calcium per liter of the fuel (fuel A). Two additional samples of the same test fuel were added in addition to the chromium Ci4-Ci8 -Alkyl salicylate and calcium dioctyl sulfosuccinate add 0.001 percent by weight of the copolymer XVI, ie 0.008 g "of the copolymer per liter (fuel B with a weight ratio of copolymer to metal

[here so chromium] of about 450: 1).

Each sample was shaken with water to avoid the important influence of the usual presence of a mimicking the aqueous phase in the treatment of liquid hydrocarbons. The conductivities the fuel samples were measured both initially and after aging for 16 hours. the The results are shown in the table below:

Table II

fuel

Fuel A
Duplicate ...
Fuel B
Duplicate ...

Electrical conductivity in units (1 unit = 1 (T ¹⁴ Ohm- '■ cnr ¹ )

at the start

190
190
210
210

after aging

40
50

.120
100

After aging, fuel B had 2 to 3 times the conductivity of fuel A without the mixed polymer content.

B e i s ρ i e 1 2

The experiment of Example 1 was repeated with samples containing the same chromium-Cw-Cis-alkyl salicylate and mixed polymers but not containing calcium dioctyl sulfosuccinate (Fuel C). Even though the measured conductivities both too

Onset as well as after the 16 hour aging were lower, you could after aging determine the same high percentage of remaining conductivity as in the case of fuel B.

The test fuel had the following properties:

Example 3

Specific gravity at 15.6 ° C 0.8095 g / ml

Saybolt color 28

Flash point in the closed
Crucible (Tagliabue) 62 ⁰ C

ASTM distillation:

Start of boiling 175 ° C

10% go over at 191 ⁰ C '

50% go over at 213 ° C

90% go over at 242 ° C

95% pass at 264 ° C

End of boiling 273 ⁰ C

In another test series, a gasoline (boiling range: 80 to 110 ⁰ C) was the same

Amount of calcium dioctyl sulfosuccinate and chromium-Cw-Cig-alkyl salicylate added as in Example 1, with and without the same amount of copolymer XVI. In this case it was only a subset of each sample with water

shakes. The conductivities were measured several times over the course of a longer storage period. the Measurement results are given in the table below:

Table III

Electrical conductivity in units with water
shaken With polymer with water
shaken (1 unit = 1 (T ¹⁴ Ohm " ¹ ■ cm" ¹ ) 400 dry 450 storage time 150 450 500 in days - 500 600. Without polymer 80 600 - O dry - 6th 400 30th 200 33 - 130

The above data show; that in this case the mixed polymer not only the loss of conductivity prevented during storage, but even increased the conductivity somewhat.

Example 4

A gasoline having an initial boiling point of 80 ⁰ C and a final boiling point of 110 ⁰ C was added an amount of a xylene solution of a chromium-CM-Cie-alkyl salicylate, Cw-Cie-alkyl phenol containing, added with a content of 2.10 percent by weight chromium, that the chromium content was 4 x 10 ^-7 gram atom of chromium per liter of gasoline.

No copolymer was added to one gasoline sample, the other gasoline sample was mixed with a copolymer of stearyl methacrylate and N-vinyl-2-pyrrolidone with a molar ratio of the monomers of 5.5: 1, a molecular weight of 850,000 and a nitrogen content of 0.93 percent by weight in an amount of 2 · 10 ^-3 grams per liter added. The electrical conductivity of each sample was determined immediately afterwards and after intimate mixing with 1 percent by volume of water after 10 and after 35 days.

The results summarized in the table below were obtained:

Table IV

Gasoline with 4 × 10 " ⁷ gram-atoms of Cr
per liter

Amount of mixed polymer in g / l

dry

Electrical conductivity in units
(1 unit = 10 " ¹⁴ ohm- '■ cm" ¹ )

after thorough mixing with water
after 7 days after 10 days after 35 days

Without mixed polymer
With mixed polymer ..

2-10-3

270
600

115

108
470

130

Example 5

Further experiments were carried out with a gasoline with an initial boiling point of 85 ° C. and an end boiling point of 115 ° C. This gasoline was mixed with such an amount of a xylene solution of a trivalent iron salt containing Ci i-Cin-alkylphenol with Ci i-Cm-alkylsalicylic acid with a calcium salt of the dioctyl ester of sulfosuccinic acid with a content of 2.30 percent by weight iron and a content of 2. (X) percent by weight calcium added that the iron content and the calcium content in the gasoline 4 K) ' gram atom iron or 5 x 10 "Gram atom of calcium per liter of gasoline. The electrical conductivity of this gasoline mixture was measured immediately afterwards.

A portion of this mixture was then intimately mixed with 1 percent by volume of water. To The electrical conductivity of the gasoline layer was determined for 11 days.

Another part of the gasoline mixture was added a mixed polymer, which is referred to below as E, in an amount of "10 x 10 ³ grams per liter. This mixed polymer contains stearyl methacrylate, lauryl methacrylate and methyl vinyl pyridine in a molar ratio of 0.4: 0.9 : 1; it has a molecular weight of 84,000 and a nitrogen content of 2.9 percent by weight The portion of the gasoline mixture containing the mixed polymer E was also intimately mixed with 1 percent by volume of water, and the electrical conductivity of the gasoline layer was determined after 11 days.

The results are summarized in the table below:

Table V

Gasoline with 4 · IO ' ⁷ gram-atom

Fc je Liier
and 5 · JO ' ⁷ gram-atom Ca per liter

Electrical conductivity in units
(1 unit = 10 " ¹⁴ Ohm" ¹ ■ cnT ¹ )

after thorough mixing
dry with water

after 11 days

Without mixed polymer
With mixed polymer.,

720

52
105

This table shows that the electrical conductivity of the gasoline mixtures, which a salt other than the chromium salt of an alkyl salicylic acid contained in the presence of water

decreases after some time and that this decrease is due to the addition of nitrogen-containing copolymers is inhibited according to the invention.

Claims (3)

Patent claims: 1. Use of an oil-soluble copolymer with a molecular weight of 5,000 to 2,500,000 and a nitrogen content of 0.1 to 8.0 percent by weight of a) N-vinyl-2-pyrrolidone or vinylpyridines, b) esters of acrylic acids and / or α-substituted acrylic acids of alkanols with at least 8 carbon atoms and optionally c) (meth) acrylic acid esters of alkanols with at most 6 carbon atoms to stabilize and increase the electrical conductivity of liquid hydrocarbon mixtures that contain a small amount of an oil-soluble salt a molecular weight of at least 200 of an alkylated salicylic acid and a metal with atomic number 21 to 29 and optionally an oil-soluble calcium salt of a sulfosuccinic acid dialkyl ester, the weight ratio of the oil-soluble salt of the alkylated salicylic acid (calculated as metal) to the oil-soluble copolymer being 1:20 to 1: 5000 and the concentration of oil-soluble salt is 1 · IO ⁹ to 1 · 10 ³ gram atom Me tall and from the calcium salt of the sulfosuccinic acid dialkyl ester 1 · IO- ⁹ to 1 · ΙΟ " ⁴ gram atom of metal per liter of the liquid hydrocarbons. 2. Use of copolymers according to claim 1, characterized in that the mixed polymer of N-vinyl-2-pyrrolidone and a mixture of alkyl methacrylates primary alkanols with 12 to 18 carbon atoms in a weight ratio of 1: 5 or 1: 6 derives. 3. Use of copolymers according to claim 1, characterized in that the mixed polymer of vinyl pyridine a), a mixture of different long-chain (methacrylic acid esters, in which the alcohol residues differ by at least 4 carbon atoms and where the molar ratio of the esters is 1:10 to 10: 1 is, b) and at least one low molecular weight (methacrylic acid ester with an alcohol residue derived from not more than 6 carbon atoms c), the molar ratio of a) to b) + c) is 1:15 to 2: 1; and c) is 10 to 75 mole percent of b) + c). Considered publications:
German interpretative document No. 1 050 338.