DE1769124A1 - Continuous process for the production of lubricants - Google Patents

Description

PATENT LAWYERS

DR.-ING. BY KREISLER DR-ING. SCHÖNWALD 1769124 DR.-ING. TH. MEYER DR. FUES

COLOGNE 1, D.EICHMANNHAUS

Cologne, 2.4 »1968 Fu / Ax

^f i ^! he British Petroleum Company Limited, British annicHouse, Ho or lane, Io ndon, E, Q. 2 (England).

Continuous process for the production of lubricants

The invention relates to the production of lubricants, in particular the continuous or semi-continuous production of greases with oleophilic solid lubricants are thickened "

Some work has already been done on making dispersion lubricants and also to produce soap-thickened greases continuously, but it is common to produce dispersion lubricants and lubricating greases in batches «,

It has now been found that lubricants containing oleophilic solid lubricants can be carried out in a single step can be produced continuously or semi-continuously by passing a solid lubricant and a grinding liquid through a high-energy mill (high-energy grinding mill), any abrasion formed by passing the resulting slurry through a Filter removed, the slurry exposed to a base oil and the grinding fluid is removed.

The invention accordingly relates to the production of Lubricants which contain an oleophilic solid lubricant according to a method which is characterized is that a solid lubricant and a grinding liquid

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by a high-performance mill to the exclusion of Air passes, the solid lubricant grinds to form an oleophilic solid lubricant, the resulting Passes slurry of oleophilic solid lubricant and milling liquid through a magnetic filter which Slurry of a mineral or synthetic base oil admixed and the grinding liquid removed.

The grinding liquid can consist of the mixture of oleophilic solid lubricant, grinding liquid and base oil Evaporation, e.g. sudden evaporation or film drying, can be removed.

The milling liquid preferably also contains a mineral oil or synthetic lubricating oil. That "oil" decreases the amount of milling fluid that must be present and aids in dispersing the oleophilic solid lubricant in the base oil with the formation of the lubricant. The lubricating oil that is added to the grinding liquid is expedient The same base oil is used as the slurry added from milling liquid and oleophilic solid will.

The amount of lubricating oil that is added to the milling liquid depends on the viscosity of lubricating oil from · The G _e obtained mixture must not be so viscous that it prevents the formation of an oleophilic solid lubricant, although in certain cases the mill can be heated to reduce the viscosity to lower the grinding liquid.

When the oleophilic solid lubricant is stored for a period of time before the formation of a fat or dispersion is to be, the slurry of oleophilic solid lubricant and milling liquid becomes a lot Lubricating oil base oil added after the grinding liquid has been removed by the oleophilic solid lubricant is fully adsorbed, forming a "dry" solid oleophilic lubricant.

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The filtered lubricant is optionally added to a other treatment device, preferably a homogenizer, guided

The lubricant formed by the process according to the invention can be a fat or a dispersion. When a Dispersion is formed in the form of a slurry, this can be subjected to further treatment, for example by homogenization to be subjected to the formation of a fat » If necessary, the filtered slurry or fat can be returned to the mill for further grinding will.

An oleophilic solid lubricant is a graphite or a metal sulfide which has a ratio of the heat of adsorption of n-dot triacontane from n-heptane to the heat of adsorption of n-butanol from n-heptane of at least 1 si:, preferably of at least 2: 1 " The heat of adsorption can be measured with a flow microcalorimeter, as described in "Ghemistry and Industry" of 20 "3 ₆ 1965, pages 482-489,"

As a solid lubricant for grinding, is preferred natural or synthetic graphite is used. Further suitable solid lubricants are metal sulfides, in particular molybdenum sulfide and also tin sulfides and tungsten disulfide and intimate mixtures of graphite with sulphurous materials, e.g. graphite and lead sulphides be able to add lubricants, e.g. enhancing additives to be added in the milling stage of the process.

The grinding liquids used, the oleophilic graphite, the grinder, the magnetic filter and the base oil are shown below described in detail. '**.

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Grinding liquid

1719124

As milling liquids of the invention, organic liquids are used for the purposes boiling below 500 C, .a viscosity less than 600 cS at 38 ⁰ C and a surface tension below 72 dynes / cm at 25 C have "Preferably, the fluids have a surface tension of 10-40 dyne / cm at 25 ° 0 and a viscosity of less than 30 cS, preferably less than 3 ATS, in particular less than 1 cS at 38 ⁰ C.

Low molecular weight liquids are suitable as organic liquids Hydrocarbons, namely straight-chain or branched, saturated or unsaturated aliphatic compounds, saturated or unsaturated, substituted or unsubstituted cycloaliphatic compounds and substituted or unsubstituted aromatic compounds.Examples of such compounds are n-heptane, octene-2, 2,2,4-trimethylpentane, Cyclohexane, benzene and toluene. Particularly preferred are branched alkyl compounds, suitable as Organic liquids are also compounds that contain fluorine, chlorine or phosphorus and chlorine, e.g. carbon tetrachloride.

Further suitable organic liquids are the polar oxygen compounds, for example isopropyl alcohol and liquids Silicones can also be used. Low molecular weight hydrocarbons, e.g. propane, butane and pentane, can be used as grinding liquids under pressure

It is important that air be excluded from the mill as much as possible so that the grinding of the graphite takes place below the surface of the grinding liquid takes place.

For best results, the amount should not exceed of the solid lubricant in the mixture of solid lubricant and organic liquid 50 wt .- #, and preferably 2 to 20 wt. ~ ^V be jo.

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The grinding can be carried out in any suitable mill or device and is expediently carried out until an oleophilic solid lubricant with the largest possible surface (determined by nitrogen adsorption) has been obtained. This can usually be achieved by grinding at normal temperatures for the required time, but the temperature of the mixture can optionally be artificially increased to, for example, 400 ^° C. In this case, liquids may be used, the viscosities up to 600 cS at 38 ⁰ C habeno

Oleophilic graphite

The production of oleophilic graphite is described in the German patent _{o «0 0} ...... (patent application B 89 777 IVa / 12i) of the applicant, preferably has a heat of adsorption of n-dotriacontane from n-heptane of at least 700 millicalories / g and a heat of adsorption of n-butanol from n-heptane of less than 200 millicalories / g.

Natural and synthetic graphite is well known and readily available, the synthetic material is for example made of petroleum coke by heating to 1000 to 3Ö00 ° C under vacuum or inert gas, "generally contains 95 to 100 percent by _e ~ ^c / £ carbon" The natural material may have a slightly lower carbon content and usually consists of larger crystals

Oleophilic graphite can be obtained by grinding natural or Synthetic graphite can be made in most organic liquids, however, one will be useful organic liquid used, for the most part! can be easily removed from the oleophilic graphite. It is It is advisable to grind until a surface (determined by nitrogen adsorption) of at least 20, pre-

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1763124

ο
preferably 30 Ms 800 m / g is obtained

mill

A vibrating mill is preferably used. According to the invention is preferably a vibrating mill, in particular . a vibrating ball mill is used in which the balls and the grinding chambers are made of steel, preferably hard, ferromagnetic Made of steel,

A high-performance vibratory mill is preferably used in which the amplitude of the vibration is at least 2 mm and the vibration frequency is at least 1500 / minute, e.g. ₀

a vibrating ball mill in which the balls have a diameter of 50.0

from 6.4 to 57Θ8 mm, preferably from 9.5 to 25.4 mm,

A suitable mechanically driven ball mill is commercially available under the name "Megapact" (manufacturer Pilamec Limited). In one embodiment, the grinding chambers are steel cylinders 31.8 mm inside diameter and 38.1 cm length that goes to at least $ 50, preferably 80-95 / 6 des total possible volume are filled with steel balls »The mill is equipped with a 1/8 or 1/4 HP electric motor and the vibration amplitude can be adjusted from 1 to 5 mm «

A suitable electromagnetically powered vibratory ball mill is available from General Electric Company Limited manufactured. This mill has a grinding chamber that has a capacity of about 170 1 has.

A visual swing amplitude that is as large as possible is preferred of about 4 mm, for example, is applied.

The grinding speed of a mill is a measure of its performance, the grinding speed of a ball mill depends not only on their visual swing amplitude, but also on the dimensions of the grinding chamber »

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Magnetic filter

A suitable magnetic filter is manufactured by the company H _{0 VoPhilips Gloeilampenfabrieken.} When the slurry from the mill runs through the filter, "the iron particles formed during milling stick to the rings of the permanent magnet material"

One or more magnetic filters * can be used one after the other or in parallel. A filter connected in parallel can be switched off and cleaned while a second filter continued to remove the iron particles. If only a magnetic filter is used and the slurry exiting the mill contains 3 to 6 wt Gew _e - ^ 4 iron in the slurry, further filters increase the efficiency of the iron removal

Grundö1

Mineral oils or synthetic oils can be used as base oils for the lubricant. Refined mineral oils obtained from petroleum are suitable as mineral oils, ζ _β Β _β those which at 99 ° C have a viscosity in the range from 2 to 50 cS, preferably from 4 to 40 cS have _o

Synthetic lubricating oils include organic esters, Polyglycol ethers, polyphenyl ethers, fluorinated hydrocarbons, Silicate esters, silicone oils and their mixtures. The most important class of synthetic oils are the organic ones liquid polyesters, especially the neutral polyesters, the viscosity of which at 99 ° C. is in the range from 1 to 30 cS. The term "polyester" is used to denote esters which contain at least two ester bonds in the molecule. The term "neutral" is used to denote a fully esterified product. Examples of suitable poly-

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Esters are the liquid diesters of aliphatic dicarboxylic acids and monohydric alcohols (z _e B "dioctyl sebacate, dinqyyl sebacate, octyl nonyl sebacate and the corresponding azelaic and adipic acid esters), liquid diesters of aliphatic dicarboxylic acids and" phenols (z, B _o those in the German patent "." ο <, ο (Patent application B 85 IYC / 23c) and in British patents 1,044,550, 1,044,883, 1,058,906 and) and 1059955 described more complex polyesters (e.g., B _t in British patent specifications 666 697, 743 571, 780 034, 861 962, 933 721, 971 901 and 986 068 and in British patent application 4059/65 ™ and in German patent specification ,, ... ο <, ».. (patent application B 85 398 IYc / 23c) described by the applicant) »

The invention is explained on the basis of the figures, which represent flow diagrams »

FIG. D shows a flow diagram of a method according to FIG Invention in which the graphite is ground in a petroleum ether and a mineral lubricating oil as grinding liquid will. Fig. 2 shows a flow diagram for the production of "dry" oleophilic graphite.

In the method shown in FIG. 1, graphite is mixed with Wk of the grinding liquid in mixer 1. The slurry is fed through a three-way cock to a vibrating mill 2, through a circulating pump 3 and a magnetic filter 4, and then to another three-way cock. The resulting slurry is mixed with any necessary additives in a mixer 6 inserted in the line to a base oil. The mixture is passed through an injection pump 7 and the grinding liquid is removed in a flash evaporator or film dryer 8. The grinding liquid is condensed and recycled using a cooler 9 connected to a vacuum pump. The lubricant is passed through the homogenizer 5 to form the finished lubricating grease.

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In the process shown in Figure 2, there is no lubricating oil The added in the mixer 6 present in the grinding liquid Lubricating oil is completely adsorbed on the oleophilic graphite, so that after removal of the petroleum ether a "dry" oleophilic graphite powder from the flash evaporator or film dryer 8 is withdrawn ,,.

The "dry" graphite is fed to the homogenizer 5, where an additional amount of base oil is added to form a grease.

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Claims (9)

Claims 1) Process for the production of lubricant mixtures that Containing an oleophilic solid lubricant, characterized in that a solid lubricant is continuously used and passing a grinding liquid through a high performance mill in the virtually absence of air, herein that Solid lubricant milled to form an oleophilic solid lubricant, the resulting slurry passes the oleophilic solid lubricant in the grinding liquid through a magnetic filter, then the slurry is added to a synthetic or mineral oil based base oil and the milling fluid removed from it. 2) Method according to claim 1, characterized in that the solid lubricant is graphite or molybdenum disulfide used and converted into their oleophilic forms. 3) Method according to claim 1 and 2, characterized in that an organic liquid phase is used as grinding liquid which ^{boils below 500 0} C, has a surface tension below 72 dynes / cm at 25 ° C and a viscosity below 600 cS at 38 ⁰ C. , wherein preferably organic liquids are used having a surface tension in the range of 10 to 40 dyn / cm at 25 ° C and a viscosity below 1 cS at 38 ⁰ C. 4) Method according to claim 3, characterized in that a paraffin liquid phase is used as grinding liquid. 5) Method according to claim 1 to 4, characterized in that a Schwingartihle with 3in oscillation amplitude of at least 2 mra and an oscillation frequency of at least 1500 cycles per minute is used as a high-performance mill. 109839/13 42 - "- 176912A 6) Method according to claim 1 to 5, characterized in that a mineral lubricating oil or synthetic lubricating oil is added to the grinding liquid for the grinding process, the base oil preferably being used, to which the slurry of the oleophilic solid lubricant is then added. 7) A method according to claim 1 to 6, characterized in that the solid lubricant in the mixture of solid lubricant and grinding liquid less than 50 wt -.%, And preferably makes up 2 to 20 wt -% by.. 8) Method according to claim 1 to J, characterized in that the grinding liquid is removed from the mixture of substances obtained in the final stage by evaporation. 9) Method according to claim 1 to 8, characterized in that lubricants are produced in a lubricant consistency will. 1098 39/13 42 ORIGINAL INSPECTED