DE2040694A1 - Process for the production of finely divided solids - Google Patents

Description

DR.-ING. BY KREISLER DR.-1 NG. SCHDNWALD

Dft .-] NG. TH MEYER DR, FUES DIPL-CHEM. ALEK VON KREISlER DIPL-CHEMZCAROLAKELLEr DR.-ING. KLÖPSCH

COLOGNE 1, DEICHMANNHAUS

Cologne, August 14, 1970 Fu / Ax

The British Petroleum Company limited,

Britannic House, Moor Lane, London, B, C.2 (England) «

Process for the production of finely divided pesticides

The invention "relates to the preparation of oleophilic Graphite and oleophilic metal sulfides by grinding graphite or metal sulfides in an organic liquid and the production of greases containing the oleophilic graphite or the oleophilic metal sulfides are thickened.

British patent application 1,168,785 describes the manufacture of olecophilic graphite. British Patent 1,168,784 describes lubricating greases with this oleophileji graphite are thickened. Oleophilic metal sulfides and lubricating greases thickened with them can be used for similar Process are produced.

The oleophilic graphite is made by grinding graphite into a vibrating ball mill. However, ball mills consume for the production of the oleophilic Graphite has a relatively high amount of energy. The grinding takes place when the balls collide with each other and on the housing. The higher the oscillation amplitude, the more so grinding is more effective. With the more viscous milling liquids, the milling efficiency is lower, so that it is advantageous is, in liquids of low viscosity

.-10-98.09 / 1641

to grind.

When the oleophilic graphite is used as a fat thickener is to be, it is advisable to use at least part of the base oil as grinding liquid alone or with a Easily removable, miscible diluent to use diluted. This would be the case with vibrating ball mills require very high milling temperatures in order to reduce the viscosity of the milling liquid to an acceptable level to humiliate. The use of high cooling temperatures makes it difficult the problems and aggravate the troubles and may cause the lubricating oil to deteriorate. Further volatile liquids cannot form part of the grinding liquid.

The invention relates to a process for the production of finely divided solids, which is characterized is that the solid is in an agitator mill in an organic, hereinafter referred to as Mahlflüsaigkeit Liquid grinds the slurry formed of organic liquid and ground solid through a Thin film evaporator leads and removed at least part of the grinding liquid.

Milling is preferably carried out in the absence of air , for example by filling the mill with the milling liquid. An agitator mill is to be understood as a cooler in which the grinding is carried out by stirring the grinding media by rotating an axis to which projections are attached.

In the case of the agitator mills suitable for the purposes of the invention the axis is fastened in a housing on airtight bearings. The grinding media are preferably balls of high density, e.g. made of steel or zirconium, with a mean diameter of preferably less than 5 mm. The housing is made of steel.

The projections on the axis can, for example, have the shape discs, rods or pins, paddles or propellers

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or any other suitable shape. With the "preferred Mills used for the purposes of the invention are the protrusions are parallel disks.

All organic liquids come as bald liquids in question that do not react with the graphite. Preference is given to compounds or mixtures of compounds used, obtained by distillation of petroleum will. Paraffinic hydrocarbons are preferably used as grinding liquids which are above Boil 100 ° C and can be obtained in the petroleum distillation.

The thin-film evaporators suitable for the purposes of the invention generally consist of a cylinder with rotating blades, the liquid to be evaporated flowing through between the blades and the cylinder. An evaporator operating with wipers is preferably used. Suitable vaporizers are available from the company LUWA manufactured.

From. the agitator mill obtained slurry is preferably passed through a first evaporator to the Remove the bulk of the grinding liquid before it is used Thin film evaporator is performed. Distillation stills or expansion receivers are suitable as evaporators for the first stage. ·

In a preferred embodiment of the invention the bald liquid continuously through the Kütle in the closed Circulation circulated and passed to the evaporation stage after a fixed time. The closed circuit preferably contains a storage container mix quite large capacity

When working continuously or semi-continuously several cooling units can be connected in series the product from the first grinder immediately in the second row and so on to the last coolness

becomes where the final product will be removed. This will make the

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Circulation of the material avoided. The grinding liquid can be diluted by adding further liquid take place between the mills.

Agitator mills are usually designed to operate within preferred viscosity ranges. During the Grinding, the viscosity of the grinding liquid falls below, the influence of the ground solid. In order to maintain optimal grinding conditions, the grinding liquid be diluted during the ilezing3. When grinding in a mixture of oil with a volatile liquid, the dilution can be carried out by adding a further amount of a mixture of this liquid.

The viscosity of the grinding liquid is preferably measured at 85 to 1000 cP, preferably 100 to 300 cP. a shear rate of 511 sec "at 25 ° C.

If the mill and / or the grinding media are made of steel, a magnetic filter is preferably included in the circuit, to remove abrasive steel particles.

In order to allow the mill to run continuously, it is preferred to work with two vessels which contain stirrers and are connected in parallel so that only one container is connected to the circuit at a time. Any container contains grinding liquid and coarse particles of the material to be ground Materials. If the material is in the first container during has been circulated through the mill for a sufficient time to achieve the required degree of comminution of the solid reach, the contents of the first container are fed to the evaporation stage and the contents of the next container guided through the mill.

Pa the slurry is in circulation during the milling process thickened, fresh grinding liquid is preferred

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added to the circuit to increase the viscosity in the mill to hold essentially at the value at which the grinding performance is optimal. The fresh grinding liquid will preferably added immediately before entering the mill »

The method according to the invention is particularly advantageous for the production of lubricating greases with oleophilic Solids such as oleophilic graphite and oleophilic metal sulfides, e.g. sulfides of molybdenum, tin, tungsten or Lead, are thickened. In a preferred embodiment of the invention, a solid thickened with an oleophilic solid is used Grease is made by making an oleophilic solid by grinding the solid in a mixture the lubricating oil to be thickened into a grease and a more volatile organic liquid that interacts with the Lubricating oil is miscible, is formed. Pure mineral A paraffinic hydrocarbon is preferably used for lubricating oils. For polar synthetic lubricating oils volatile liquids of higher polarity, e.g. Esters or short chain alcohols are used.

If necessary, further volatiles become during the milling Organic liquid added to the grinding liquid, lim the increase in viscosity due to the thickening of the grinding liquid is to be returned by the oleophilic solid formed, to compensate. After grinding it becomes the grinding liquid is transferred to a thin-film evaporator in order to remove the volatile organic liquid, leaving the lubricating oil thickened to a lubricating grease by the oleophilic solid formed. Preferably becomes the bulk of the volatile liquid for example removed in a distillation before the Milling liquid is fed to the thin film evaporator.

Lubricating greases that have been thickened with oleophilic graphite polymers can be used to improve their hardness, i.e. to lower their penetration values. Of the

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Addition of the polymers can within the scope of the invention during after milling or after milling. Preferably they are added immediately before the end of the meal.

Polyethylenes of high density are preferred as polymers and atactic polypropylene. These polymers can be used alone or in a mixture with one another in an amount of up to 5% by weight. based on the grease. These polymers can also be used to adjust the viscosity of the Grinding liquid can be added.

Various common hinge grease additives, e.g. additives that increase the pressure absorption capacity and the load-bearing capacity * Anti-rust additives and anti-corrosion additives can also be added during or after grinding will. The formed grease can be passed through a homogenizer. If desired, usual Additives such as antioxidants and extreme pressure additives are added.

It has surprisingly been found that oleophilic graphite, which is produced by grinding graphite in an agitator mill manufactured has a higher base area to pole area ratio. As a result, the same amount that is dissolved in a lubricating oil, a thicker grease than the oleophilic graphite produced up to now. Compacts made by pressing oleophilic graphite, which is obtained by grinding in an agitator mill has been manufactured have less wear due to the abrasive action. By grinding in an agitator mill produced oleophilic graphite has better reinforcing properties in polytetrafluoroethylene.

An embodiment of the invention is shown in the accompanying flow diagram, which shows the manufacture of a with illustrates oleophilic graphite thickened grease.

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2Q40694

An agitator mill 1 is via a magnetic filter 8 with two stirred tanks 2 and 3 connected, one of which each contains a stirrer connected in parallel. The containers are connected so that only one of is connected to them in the cycle. A metering pump 4 is connected to the circuit immediately before entering the mill.

A delivery line connects the circuit after the agitator tanks with an evaporator receiver 5 and via the Pump 6 with the thin film evaporator 7

To produce the lubricating grease, the mill 1 and the containers 2 and 3 are filled with a mixture of a lubricating oil and a volatile organic liquid miscible therewith filled. The graphite to be ground is placed in the mill. The grinder, which contains its own pump, comes with operated in only one container connected to the circuit, while the graphite is being ground. When the viscosity As the grinding liquid rises, fresh organic liquid is supplied by the pump 4 x. When the liquid has the correct consistency in container 2, is more often Contents of the container of the evaporator template 5 supplied. Fresh graphite is poured into the cooler and the container 3 switched into the pump circuit. The main amount of the organic liquid is in the evaporator receiver 5 made of the consisting of Cl, organic liquid and graphite Slurry removed. The rest of the slurry is puiipt to a thin film evaporator 7, where the remainder of the organic solvent is removed and a Grease is obtained.

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Claims (20)

2Ü4069A Claims Process for the production of finely divided pesticides, characterized in that the solid is in an agitator mill of the type described in an organic Kahliquid grinds the resulting slurry of organic liquid and ground solid passes through a thin film evaporator and removes at least part of the balding liquid. 2) Method according to claim 1, characterized in that the agitator mill is kept essentially filled with the grinding liquid during grinding * 3) Method according to claim 1 or 2, characterized in that da0 ground with the exclusion of air or oxygen will. The method of claim 1 to 3, characterized in that äaü steel balls are used as grinding media * 5) The method according to claim 4, characterized in that Steel balls with a diameter of less than 5 «& ▼ can be used. 6) Method according to claim 1 to 5, characterized in that a paraffinic hydrocarbon boiling ^{above 100 0 C is used as the Kahlflüs3i £ Keit.} 7) Method according to claim 1 to 6, characterized * that iie viscosity of the organic grinding liquid between 85 and 1000 el? at 25 ⁰ C, measured with a Sebergeschwissditkeit of 511 sec., held wlii. 8 ·) Method according to · Claim f Ma 7, daiarck that the organic kah! liquid and the grist be circulated continuously through the cool. 9) Method according to claim 8, characterized in that the or-anlacheσ cooling liquid during grinding / 109809 / U41 BATH ORIGINAL 2Ü4Q694 further organic liquid is added. 10) Method according to claim 1 to 9 »characterized in that that several agitator units connected in series are and the organic mill liquor and grist are passed through each mill "before they be passed through the thin film evaporator. 11) Method according to claim 1 to 10, characterized in that that a thin film evaporator operating with Yiischern is used. 12) Method according to claim 1 to 11, characterized in that the slurry of organic grinding liquid and ground pesticide through a first evaporator is performed before it is fed to the thin film evaporator. 13) Method according to claim 12, characterized in that that bubble distillation is used as the first evaporator. 14) Method according to claim 1 to 13 »characterized in that that as a grinding fluid a lubricating oil that dilutes with a less viscous and more volatile Liquid is diluted, is used. 15) Method according to claim 14 »characterized in that a paraffinic hydrocarbon boiling ^{below 100 0 O is used as the diluting liquid.} 16) Method according to claim 1 to 15 »characterized in that that graphite or sulphides of molybdenum, tin, lead or Yfolfram are ground. 17) Method according to claim 16, characterized in that that through the evaporator essentially only the Thinning liquid is removed, whereby a lubricating grease is formed, which from the with the ground - ίο - 18) Method according to claim 1 to 17 »characterized in that that an olefin polymer is present in the semi-liquid. 19) Method according to claim 18, characterized in that that a high density polyethylene and / or atactic polypropylene is used as the polymer. 20) Method according to claim 18 or 19, characterized in that the polymer in the last quarter of the Meal is added. 10980t / ORiGfNAL INSPEGfIf