DE960756C - lubricant - Google Patents

Description

The invention relates to lubricants which are ashless, polyfunctional and in particular with a strong cleaning effect, increasing the resistance to oxidation and lowering the pour point Supplements included.

Additives with such properties are very desirable components of lubricants because they Foreign substances that penetrate the lubrication system, as well as the harmful products that are in the Lubricants are formed in suspension under the various working conditions of the engine keep. Lubricants that do not have these properties allow sludge to form and paint on the engine parts as well as excessive corrosion and wear.

Such undesirable sludge deposits and paint formations occur particularly frequently in engines that work at low temperatures and under low loads. Precisely such decomposition products however, the common oil additives are difficult or impossible to prevent. For example, we already have a wide variety of metal-containing organic compounds because of them Cleaning action used as lubricating oil additives.

However, because of the resulting metal-containing ash, these are not suitable for engines that use have to work at low temperatures. In addition, these known means are relatively exhausted rapid in their action and / or they cause the formation of degradation products that are insoluble in oil, which clog the filters and increase corrosion.

The present invention provides improved lubricants which are particularly useful are for use in engines operating within a wide temperature range and in particular work at low temperature, and which also prevent corrosion and wear or push back and at the same time have favorable cleaning properties. According to the invention in Contemplated additives are non-metallic and retain their effect during use practically unchanged at.

The new lubricants consist of a suitable lubricating oil and a smaller amount of one or more copolymers with a molecular weight above 1000, which are obtained from α-olefins with at least 10 carbon atoms in the molecule and another unsaturated, polymerizable compound, the latter being a substituent alcoholic OH group, an SH group, SCN group, CN group, CONR ₂ group or NR ₂ group, where R is a hydrogen atom or a hydrocarbon radical. The amount of the copolymer added is preferably about 0.01 to 10 percent by weight and in particular 0.1 to 5 percent by weight, based on the total lubricant mixture. As mentioned, the molecular weight of the additives according to the invention should be at least 1000. However, molecular weights between 1,500 and 50,000, in particular between 4,000 and 15,000, are preferred.

The molar ratio between the α-olefin and the unsaturated polymerizable compound having polar Substituents in the copolymer can vary within wide limits, preferably between ι: 5 and 5: 1 and in particular between 1: 2 and 2: 1. It should also be mentioned that mixtures of additives can also be used.

The additives according to the invention can be prepared in a suitable manner by copolymerization of cc-olefins, especially a-alkenes, with an unsaturated polymerizable compound which contains the polar substituent, that one wishes to have in the finished additive. But you can also use an unsaturated polymerizable Use compound that contains a different polar substituent, which is then in the finished copolymer is converted into one of the specified special polar substituents, e.g. by hydrolysis, oxidation, reduction, amidation, dehydration or any other known Reaction. In the unsaturated polymerizable compound, the polar substituent should preferably be used be bonded to one of the ethylene carbon atoms, or to such an ethylene carbon atom via only a single carbon atom.

The α-olefins suitable for the reaction should at least 10 and preferably up to 40 carbon atoms contain. Examples of particularly suitable α-olefins are tetradecene, hexadecene and octadecene. These olefinic compounds can, for example, by splitting solid paraffins in a known manner can be obtained.

The α-olefins can, for example, be copolymerized with acrylonitrile and acrylamide as well as homologues of these substances, such as methacrylonitrile, a-ethyl acrylonitrile, a-propyl acrylonitrile, 2-butyl-2-hexenenitrile, 2-propyl-2-pentenenitrile, α-Isopropyl- ^ cyclohexyl acrylonitrile and the corresponding amides.

Suitable additives can also be prepared by copolymerizing the α-olefins with hydrolyzable or alcoholizable vinyl compounds, such as vinyl halides and vinyl esters, among subsequent conversion of the hydrolyzable or alcoholizable group (halogen or ester groups) in hydroxyl groups. Examples of suitable vinyl compounds are vinyl chloride and the vinyl esters low molecular weight organic acids such as vinyl acetate, vinyl propionate, vinyl butyrate and vinyl benzoate.

The interpolymerization is generally carried out in the presence of a catalyst, e.g. various organic peroxides such as sodium bisulfite, diethyl sulfoxide, ammonium persulfate, Alkali perborates, etc.

The working methods for the interpolymerization, which as such or after appropriate modification lead to the additives according to the invention are in the USA. Patents 2,421,971, 2,467,774, 2,436,926, 2,486,241 and 2,551,643. The examples below serve to provide further explanation the invention.

example 1

Hydrolysis product of an α-octadecene-vinyl acetate copolymer ■

A small amount of benzoyl peroxide was added to a mixture of 1 mole of vinyl acetate and 1.2 moles of α-octadecene, and the mixture was then introduced into a glass bomb from which the air had been displaced by nitrogen. The bomb was then placed in a water bath held at about 80 ° for 24 hours. The product was ^{topped at 170 0} and 2 mm Hg. Analysis of the residue gave an ester value of 0.491 gram equivalent ester groups per 100 g of the sample.

This product was in 1800 ecm methanol, to which 1 g of metallic sodium was added, subjected to alcoholysis. The mixture then became Purpose- removal of a methyl acetate azeotrope with iao Excess methanol distilled. The product was then dispersed in heptane and topped. That the product obtained was an alkane polyol with a molecular weight of about 8,000. It was oil-soluble and, as will be shown below, had excellent cleaning properties.

Example 2

Hydrolysis product of an α-hexadecene vinyl acetate

Mixed polymer

This copolymer was prepared in the manner described in Example 1 with the change that α-heptadecene was used. The hydrolyzed copolymer was oil-soluble, had a molecular weight of about 6000 to 8000, contained an average of 2 units of vinyl alcohol per 1 unit of heptadecene and showed good cleaning properties. Other suitable polyol products are the hydrolyzed (alcoholized) copolymers with molecular weights between 6,000 and 12,000, which are derived from the following copolymers: α-heptadecene-vinyl acetate; α - tetradecene - vinyl acetate; α-eicosene vinyl acetate; α-octadecene vinyl propionate; α-octadecene vinyl butyrate; α-octadecene vinyl benzoate; Mixture of tetradecene and octadecene vinyl acetate; _{Mixture of C 8} to C ₁₄ α-olefin mixtures obtained from split paraffin and vinyl acetate; α-docosen vinyl acetate.

Example 3
Copolymer of α-octadecene and acrylonitrile

This copolymer was prepared by reacting 4 moles of α-octadecene with 1 mole of acrylonitrile in the presence of 2,2-bis- (tert-butyl) -peroxybutane as a catalyst in a bomb (from which the air had been displaced by nitrogen) by heating it for 10 hours in an oil bath iio °. The product was filtered and washed with heptane, an oil-soluble copolymer being obtained became.

From this copolymer, other products, which are used as additives in the inventive Lubricants suitable are prepared by converting part of the CN groups - e.g.

from 25 to 75% of the same - in CH ₂ NH ₂ groups by means of hydrogenation. The mixtures of polycyanopolyaminomethylalkanes thus obtained give a lubricating oil improved properties with regard to wear.

Example 4

Copolymer of α-octadecene and acrylamide

To a mixture of 4 moles of α-octadecene and one Catalyst (2,2-bis- [tert-butyl] -peroxybutane) was added to a solution of 1 mol of acrylamide in acetone. The mixture was placed in a sealed steel bomb, from which the air was displaced by nitrogen had been; heated to 100 ° in an oil bath for 16 hours. The acetone was then distilled off removed, the product filtered and washed with heptane. The heptane was removed by distillation separated at 170 ° and 2 mm Hg.

It is also possible to prepare other polycyan or polycarbamylalkanes which can be used in the mixtures according to the invention, such as, for example, the copolymers given below with molecular weights of 6,000 to 12,000: α-heptadecene-acrylonitrile; α-tetradecene acrylonitrile; α-octadecene methacrylonitrile; α - octadecene - a - ethyl acrylonitrile, ci-eicosene acrylonitrile; α-tetradecene acrylamide.

In the lubricants according to the invention, a natural or a synthetic lubricating oil or a Mixture of such oils can be used. So the base oil can be a hydrocarbon oil that consists of a paraffinic, naphthenic, asphaltic or a mixed-basic crude oil as well as from Mixtures of such oils have been obtained. The viscosity of these oils can be within a wide range fluctuate, e.g. from 50 Saybolt sec. at 37.7 ° up to 100 Saybolt sec. at 99 °. The hydrocarbon oils can also be blended with fatty oils such as castor oil, bacon oil and the like. Suitable synthetic Lubricating oils are the polymerized olefins, polyalkylene glycols, e.g. copolymers of alkylene glycols and alkylene oxides, organic esters, especially polyesters such as 2-ethylhexyl sebazate, Dioctyl phthalate and trioctyl phosphate, polymeric tetrahydrofuran and polyalkylpolysiloxanes (siliconicones), e.g. dimethyl silicone polymer.

In order to demonstrate the beneficial properties of the lubricants according to the invention, some Samples subjected to the tests specified below.

Test method description
the test method I. Pour point ASTM - D 396-39 T II. High temperature Oxidation residue .. Ing. And Eng. Chem., Vol. 44, 1834, 1952 III. High temperature Cleaning test see the following Be writing IV. Chevrolet test on mud lower tempera door see the following Be writing

The cleaning power at high temperatures is determined by measuring the electrical resistance of dispersions which contain 15 percent by weight of carbon black dispersed in a test oil. The "degree of flocculation" is calculated as the ratio of the resistance of the tested system to the resistance of an unmixed oil which contains the same amount of soot (at the same temperature [150 ⁰ ]).

The Chevrolet sludge test is carried out with the Chevrolet ■ car engine (Personenwagen) executed 1942-47, the has a cooling jacket around the oil pan and with a coolant pump is provided. The purpose of the sludge build-up is the crankcase not ventilated. In place of the dipstick there is a thermocouple up to the same height in the crankcase oil immersed. The engine is also connected to a dynamometer.

The engine works under for the first 15 hours Circulation conditions with each cycle lasting 2 minutes and consisting of an idle period of 1 minute

(Engine speed 500 to 550 rpm, dynamometer load = 1.25 braking horsepower) and an equally long working period (engine speed = 1600 rpm dynamometer load = 10.5 braking horsepower). Before the start of the actual test, the engine is ^{idled for 1 to} ₂ hours in order to adapt it to the test conditions, with a cooling jacket temperature of -17.8 ° and an oil temperature, measured by the thermocouple, of -6.7 °. When ^{the temperature of the Kühhnanteltelt has risen to 65.6 to 71.1 ° and the oil temperature to 71.1 to 76.7 ° about 1} Z ₂ hours after the start of the actual experiment, the working cycle is interrupted and fresh coolant is pumped around by means of the pump until the temperatures of the cooling jacket and oil have dropped to the initial values (duration approx. I ¹ I ₂ hours). The experiment is then continued under the same conditions until the working cycle is a total of 15 hours. Then, after placing a cooling coil cooled with tap water in the cooling tank, the engine is operated for a further 3 hours at constant speed and load (engine speed = 1600 rpm, dynamometer load = 10.5 brake horsepower, maximum oil temperature = 85 °, maximum temperature of the coolant at the outlet = 73.9 °). The working method of the first 15 hours is then repeated for a further 6 hours and then another 3-hour operation at constant load and speed follows. At the end of the test, the total amount of sludge formed is checked. A mineral oil without additive with a pour point of -6.7 °, determined according to the ASTM method, showed a pour point of -17.8 ° with the addition of 0.5% additive according to Example 2, and with the addition of 0.5 ° / q of the additive according to a pour point of -20.6 ° and addition of i ° / ₀ Extension example 3 (non-hydrogenated) example 1 according to a pour point of

20.6 °.

The mixtures given below were tested according to the high temperature oxidation test; the results are summarized in the table.

Time for the on acquisition of 250 ecm. composition Oxygen at 260 ⁰ without a catalyst Minutes mineral oil 26th Mineral oil + 1.5% SA *) Ca salt of octylphenol formaldehyde Condensation product 43 Mineral oil + 1.5 SA basic Ca- Petroleum sulfonate 21 Mineral oil + 1 percent by weight Addition according to example 3 (not hydrogenated) 70.5

*) SA = sulfated ash

After the high temperature cleaning test, the following mixtures were tested. The results are also given in the table.

High temperature mixture Cleaning test
Degree of Aus flocculation Mineral oil + 1.5% SA Ca-SaIz of octylphenol formaldehyde Condensation product 20th Mineral oil + 0.2% / ₀ SA basic Ca petroleum sulfonate: 8th Mineral oil -f 2 percent by weight Addition according to example 1 .... 2000 Mineral oil 4- 2 percent by weight Addition according to example 3 (not hydrogenated) 1600

The following blends were made from the Chevrolet Sludge Test tested for low temperatures. The results are summarized below.

Chevrolet Mud test at composition lower temperature Gram of mud mineral oil 400 Mineral oil + 1.5 _{% / 0} SA Ca-SaIz of octylphenol formaldehyde Condensation product 460 Mineral oil + 2 percent by weight according to example 1 49

The mineral oil used in experiments II, III and IV had the following properties:

Pour point

Flash point

Viscosity (SUS) at 100 ° F

- 12.2 °

240.6 ° 194.4 °

Compound lubricating oils according to the present invention can also contain other additives known per se contain, such as additional corrosion inhibitors, high-pressure additives, means for generating and increase in fluorescence, viscosity regulator, etc.

These auxiliary additives can be used in amounts from 0.05% to about 5% by weight.

The lubricating mixtures can be replaced by a soap or an inorganic colloid such as silica gel, thickened to the consistency of the grease. In the last-mentioned form of greases the additives of the present invention can also act as waterproofing agents.

Claims (7)

Patent claims: i. Lubricant consisting of a lubricating oil and a small amount, preferably 0.01 . up to 10 percent by weight, based on the total iao mixture, one or more copolymers with a molecular weight over. 1000, preferably between 1500 and 50,000, made from an α-01efin with at least 10 carbon atoms and another, unsaturated, polymerizable compound which, as a substituent, is a alcoholic OH group, SH group, SCN group, CN group, CONR _a group or NR ₂ group, where R is a hydrogen atom or a hydrocarbon radical, or contains such a polar group that is formed in the finished copolymer by hydrolysis , Alcoholysis or other known measures can be converted into one of the specified special groups. 2. Lubricant according to claim i, characterized in that that the molar ratio between the α-olefin and the unsaturated polymerizable Compound with a polar substituent in the copolymer between ι: 5 and 5: ι lies. 3. Lubricant according to claim 1, characterized characterized in that the α-olefin has up to 40 carbon atoms contains and is preferably a-tetradecene, ct-hexadecene or a-octadecene. 4. Lubricant according to claim 1 and 2, characterized in that the unsaturated poly ao merisable compound is acrylamide, acrylonitrile or a homologue of these compounds. 5. Lubricant according to claim 1 and 2, characterized in that the unsaturated polymerizable compound is a vinyl halide or a vinyl ester, ζ. Β. Vinyl acetate, is. 6. Lubricant according to claim 1 to 5, characterized in that the lubricating oil by addition a soap or an inorganic colloid such as silica gel, thickened to the consistency of grease is. 7. Lubricant according to claim 1 to 6, characterized in that there are minor amounts other known additives such as corrosion inhibitors, viscosity regulators or fluorescence contains substances. © 509 «18/446 5.5S (609 845 3.57)