DE1444878C3 - Use of an oil-soluble copolymer as a mineral oil additive - Google Patents

Description

CH ₂ = C (RO-COOC _n H _2n NR ² R ³

contains where R ^{1 is} hydrogen or a methyl radical, η 2 or 3, and R ² and R ^{3 are} each lower alkyl radicals or together the radicals

CrL, CH ₂ CH ₂ CH ₂ ,

The production of lubricating oils with improved properties by adding a copolymer is known a polymerizable heterocyclic basic nitrogen compound such as vinyl alkyl pyridine and an optionally substituted acrylic acid or an acrylic acid ester. In contrast, has the invention set itself the task of finding an additive to mineral oil that has the pour point in waxy oils, furthermore the dispersion of occurring in the course of use Promotes dirt and contributes to improving the viscosity index.

The invention relates to the use of one from 5 to 30 percent by weight of N-vinyl-2-pyrrolidine and several acrylic or methacrylic acid esters consisting of an oil-soluble copolymer, whose ester groups are partly a methyl,

*> CH ₂ -CH ₂ -O-CH ₂ -CH ₂ -,

which form a ring with the nitrogen atom mean, as a mineral oil additive. Preferably contains the Alkyl part of the higher acrylic acid or methacrylic

² S acid esters in the copolymer up to 18 carbon atoms. R ² and R ³ are usually methyl or ethyl, but can also be propyl or butyl groups.
The use of a copolymer according to the invention has the advantage that it is also resistant to oxidation at relatively high operating temperatures and is compatible with other additives. However, since it fulfills a number of functions in the mineral oil, the number of otherwise usual additives, e.g. B. to improve the viscosity index or lower the pour point.

For the copolymer used according to the invention it is essential that it contains a mixture of acrylic acid or methacrylic acid esters, the are matched so that the average of the total alkyl portion is at least 8 carbon atoms results. On average, the alkyl moiety should have sufficient chain length to achieve solubility to ensure in the mineral oil. If the copolymer is units of an N-vinylpyrrolidone contains in an amount between 5 and 30 percent by weight, it has a dispersing effect against asphaltones, gums, petroleum resins and sludge components that form in oils. the preferred content of N-vinylpyrrolidone in the copolymer is between 6 and 15%, and the best content between 8 and 12 percent by weight.

The N-vinylpyrrolidones recognized as useful are N-vinylpyrrolidones themselves, 3-methyl-1-vinylpyrrolidone, 4-methyl-l-vinylpyrrolidone, 5-methyl-l-vinylpyrrolidone, 3-ethyl-l-vinylpyrrolidone, 3-butyl-1-vinylpyrrolidone, 3,3-dimethyl-l-vinylpyrrolidone, 4,5-dimethyl-1-vinylpyrrolidone, 5,5-dimethyl-1-vinylpyrrolidone, 3,3,5-trimethyl-l-vinylpyrrolidone, 4-ethyl-l-vinylpyrrolidone, S-methyl-S-ethyl-l-vinylpyrrolidone, 3,4,5-trimethyl-3-ethyl-l-vinylpyrrolidone and others substituted with lower alkyl radicals N-vinyl pyrrolidones. It is known that these vinyl compounds are produced by reacting acetylene with the corresponding pyrrolidone accessible in the presence of a strong base as a catalyst.

The vinyl pyrrolidones can be represented by the following structural formula:

R ³
R ⁴ —C-

R ⁶ -C

R ^a

-CR ¹
C = O

CH = CH ₂

wherein the groups denoted by R are lower alkyl groups. The preferred N-vinyl pyrrolidones have no more than about 10 total carbon atoms.

While the ester units in the alkyl group can contain up to 18 carbon atoms, is at Use e.g. B. as an additive to a heating oil a considerable proportion, up to about 50 percent by weight permissible on butyl acrylate or methacrylate, while the rest of the copolymer is then off consists of a mixed monomer which contains dodecyl, myristyl, cetyl or stearyl groups. For the production mixed polymers with good oil solubility can use a little more hexyl, heptyl or octyl acrylate or methacrylate are used than on butyl esters and accordingly somewhat less Methyl, ethyl or propyl acrylate or methacrylate. With dodecyl acrylate or methacrylate as mixed monomers the copolymers are usually soluble in all types of liquid petroleum products. This is also the case when using higher alkyl groups.

Even if mixed polymers containing alkyl acrylate or methacrylates with 4 to 8 carbon atoms are preferred, are used in the alkyl groups, similar can also be used in small proportions Alkyl esters with smaller or larger alkyl groups can be used. The copolymer can therefore contain a small amount of ethyl, methyl or propyl acrylate or methacrylate, provided that the ester mixture has the required solubility in the mineral oils to be treated, namely both heating and lubricating oils. The reliable proportion of such lower alkyl groups depends on the size and proportion of the higher alkyl substituents and the mineral oil in which the copolymer is to be dissolved.

Alkyl acrylates or methacrylates with alkyl groups of more than 18 carbon atoms can also be used in the polymer such as tricosyl acrylate or methacrylate or tetracosyl acrylate or methacrylate being. However, these are not as easily accessible as the cetyl and / or stearyl esters.

It should also be mentioned that smaller proportions of other polymerizable monoethylenically unsaturated Compounds in the copolymer can be included, provided that they do not allow the usability of the copolymer, for example due to a lack of solubility.

Some typical mixed monomers that are used in the inventive Copolymers may be contained in smaller quantities, are dibutyl itaconate, Dioctyl itaconate, didodecyl itaconate, dicetyl itaconate, octadecyl butyl itaconate, didodecyl fumarate, vinyl laurate, Vinyl stearate, vinyl octoate, vinyl dodecyl ether, vinyl tetradecyl thioether, vinyl butyl thioether, butoxyethyl methacrylate, Dodecyloxyethyl methacrylate and dodecylthioethyl methacrylate.

The aminoalkyl esters give the copolymer a basic character. You can expediently make up about 0.5 to 10% of the copolymer. The presence of groups from the aminoalkyl esters in the copolymer improves the dispersing effect, especially at high temperatures, but without showing the disadvantages of copolymers which consist only of the aminoalkyl acrylates (or methacrylates) and alkyl acrylates and / or methacrylates exist. These latter copolymers are not compatible with various additives commonly used in oils. In particular are they incompatible with petroleum sulfonates, which are used as high-performance and high-temperature cleaning agents

ao medium are effective. They are also sensitive to oxidation. If, however, the aminoalkyl esters in the copolymers described above consist of one Contain N-vinylpyrrolidone and an acrylic acid ester these disadvantages do not arise. The copolymers of acrylic acid ester, N-vinylpyrrolidone and tertiary aminoalkyl acrylate or methacrylate have a very good dispersing effect for asphaltenes.

The average length of the alkyl groups will of course be on a group or mole basis calculated. The alkyl ester can have a single alkyl group with 8 or more carbon atoms, or a mixture of acrylates and / or methacrylates can be used, provided that this required average carbon number in the alkyl radical is achieved.

Any initiator which forms free radicals can be used as initiators for the polymerization - including of peroxidic and azo catalysts - use. A particularly effective system exists from a hydroperoxide and a quaternary ammonium salt. On the weight of the polymerization mixture based, one usually uses 0.05 to 5% of hydroperoxide. The relationship from hydroperoxide to quaternary ammonium salt can be between 100: 1 and 2.5: 1 and is preferably 10: 1.

example

A mixture of 30 parts of stearyl methacrylate, 35 parts of a lauryl myristyl methacrylate, 25 parts n-butyl methacrylate, 2 parts of dimethylaminoethyl methacrylate and 8 parts of N-vinylpyrrolecline copolymerized. The yield of copolymer is over 90%. A 30% solution of the same in Toluene has a viscosity of 412 cSt at 37.8 ° C.

This copolymer is introduced into a light oil and in an amount of 1.5%> a solvent-cleaned, mid-continental neutral 170-S. U. S oil incorporated. Furthermore will 0.65 ° / »zinc dialkyldithiophosphate inhibitor and 4.2 percent by volume of alkaline earth oil sulfonate (commercially available High-performance cleaning agent) added. During a Coordinating Research Council FL-2 study this mass gives a value of 90 +. Without the addition of this copolymer, the result is oil with the other additions the value 60.

During a 36 hour FL-4 exam

Corrosion at high temperatures and oxidation resistance under SAE-30 conditions are associated with Copper-lead storage observed the following weight loss: No. 1 0.05 g; No. 6 0.023 g. The value is 95.5.

When tested in a single cylinder compression combustion engine This mixture shows a 3% filling of the upper ring groove in 50 hours, 4.5% in 75 hours and 6.5% in 100 hours. The Oil with the same inhibitor and the same commercial detergent but with 1.5% of one Acrylic ester copolymer to improve the viscosity index instead of the above copolymer results in a filling of 8.5% in 25 hours and 15% in 50 hours and also a 2% filling the second ring groove, whereupon the investigation was discontinued because of the seizing of the rings could be.

The dispersing effect of the copolymers according to the invention is about 0.001 in heating oils up to 0.1 percent by weight or more of one or more of the copolymers according to the invention achieved. Concentrations above 0.1% are effective but are usually uneconomical because they are unnecessary.

In lubricating oils, the dispersing effect begins at fairly low concentrations, however the copolymer is usually in practice under the conditions of use of these oils in

ίο Concentrations between 0.1 and 20 percent by weight used, with 0.5 to 5% being preferred. A copolymer of lauryl myristyl methacrylate, Dimethylaminoethyl methacrylate and N-vinyl-3,3,5-trimethylpyrrolidone, made using diisopropylbenzene hydroperoxide and diisobutylphenoxyäthyldimethylbenzylammoniumchlorid as an initiator, also has good dispersing properties for asphaltenes, promotes the rate of oxidation and acts as a dispersant for in heating oils

ao forming gums.

Claims (2)

Patent claims: 1. Use one of 5 to about 30 weight percent N-vinyl-2-pyrrolidone and more Acrylic or methacrylic acid esters and, if appropriate, smaller proportions of other polymerizable monoethylenically unsaturated compounds existing oil-soluble Copolymer, some of whose ester groups are methyl, ethyl, propyl, butyl, Hexyl or heptyl group and in part - um for the number of carbon atoms of the whole Alkyl content of the acrylic acid or methacrylic acid ester components an average value of at least 8 and to ensure the solubility of the copolymer contain higher alkyl groups and an ester of the general as a polymer component formula = C (RO-COOC _n H _2n -NR ² R ³ contains in which R ^{1 is} hydrogen or a methyl radical, η 2 or 3 and in which 2 ² and R ^{3 are} each lower alkyl radicals or together the radicals —CH ₂ —CH ₂ —CH ₂ —CH ₂ -, r> u r-Ίτ r ^ tr <~ tj <-u * ⁱ - ^{Δ J} ° the CH CH ₂ O CH, CH, which form a ring with the nitrogen atom mean, as an additive to mineral oil. 2. Use one of N-vinyl-2-pyrrolidone and several acrylic or methacrylic acid esters existing oil-soluble copolymer according to claim 1, some of its ester groups a methyl, ethyl, propyl, butyl, hexyl or heptyl group and in some cases higher alkyl groups with up to 18 carbon atoms. Ethyl, propyl, butyl, hexyl, or heptyl group and partly - um for the number of carbon atoms of the total alkyl content of the acrylic acid or methacrylic acid ester components an average value of at least 8 and to ensure the solubility of the copolymer - contain higher alkyl groups and an ester of the general formula as a polymer component