DE2714752A1 - LUBRICANT - Google Patents

Description

p. \ tekta :: väi ~ e

DR. E. WIEGAND DIPL-ING. W. NIEMANN DR. M. KÖHLER DIPL-ING. C. GERNHARDT Munich Hamburg // I H /

TEIEFON: 555476 ⁰ ^ 8000 MUNICH 2,

TELEGRAMS _: KARPATENT MATH I LD EN STR A3 SE 12 TfLEX: 5 29 368 CARPD

W. 42 827/77 7 / RS l. April 1977

Mobil Oil Corporation New York, N.Y. (V.St.A.)

lubricant

The invention relates to lubricant compositions, particularly those for use under High speed conditions are determined in which misting of the lubricant base oil in Comes into consideration.

In metalworking, especially operations such as high-speed cutting, grinding or deforming, a lubricant is used to prevent tool wear. However, if the

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working or cutting surface flooded with a lubricant a considerable amount of oil mist is generated. Oil mist obscures the view, creates possible fire hazards and generally leads to less desirable working conditions. Methacrylate copolymers are currently used to create anti-fog properties in lubricants. However, they must be used in amounts of at least 1 to 2% by weight to ensure effectiveness. It is therefore Purpose of the invention to provide lubricant compositions create which is a means of regulating or combating evil contained, which is present in much smaller quantities than was previously possible.

Atactic polypropylene has previously been used as viscosity improvers for lubricating oils. In the US PS 3 3Ao 194 describes a non-staining rolling oil which Contains 1 to 3o% by weight of atactic polypropylene in a base oil. The US-PS teaches that staining in dan rolled metal that is present when heavier oil is used to bring the base oil to the desired viscosity bring, is eliminated when the base oil is brought up by the addition of a substantial amount of atactic polypropylene the desired viscosity is brought.

In GB-PS 1 422 2o4 certain polymers and copolymers, which are not atactic polypropylene are reported as mist control agents.

In accordance with the invention, lubricant compositions are provided with improved anti-fog properties through the use of an extremely small amount of an atactic polypropylene additive. This additive can be used in an amount of from 0.5 to 0.5% by weight, but is preferably present in an amount of from 0.05 to 0.3% by weight.

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The use of amounts greater than those specified above leads to unsatisfactory products due to haze and excessive increases in viscosity. The additive is suitable for use with all types of lubricant bases where fog formation occurs Problem can be. Basics or basic materials used for Use according to the invention are suitable include paraffinic, naphthenic, paraffinic-naphthenic mixtures, Solvent-refined or -sulphurized mineral bases as well as synthetic lubricants. The latter include polyisobutylene, polybutenes, hydrogenated Polydecene, polypropylene glycol, polyethylene glycol, trircethylolpropane ester, Neopentyl and pentaerythritol esters, di- (2-ethylhexyl) sebacate, Di- (2-ethyihexyl) adipate, dibutyl phthalate, fluorocarbons, Silicate esters, silanes, esters of phosphorus-containing acids, liquid ureas, ferrocene derivatives, hydrogenated mineral oils, chain-like polyphenyls, siloxanes and silicones (polysiloxanes), alkyl-substituted diphenyl ethers, for example butyl-substituted bia (p-phenoxyphenyl) ether, phenoxyphenyl ether, etc. a.

The base material, which comprises a predominant proportion of one or more of the above-mentioned lubricants, functional additives such as lubricity agents, antiwear agents, corrosion inhibitors, antioxidants, Detergents or the like. can be added. They are known in the art.

Atactic polypropylene is a substantially amorphous, solid hydrocarbon polymer that is an arbitrary one Has chain formation so that the methyl groups are arranged arbitrarily with respect to the plane of the carbon atom chain available. It has a molecular weight of 3,000 to Aoooo

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and a specific gravity of about 0.86. This material is used as a by-product in the production of isotactic Polypropylene and can be obtained commercially. Other forms of polypropylene such as isotactic polypropylene (the methyl groups are on the same side of the carbon chain) and syndiotactic polypropylene (The methyl groups are alternately on opposite sides Sides of the plane of the carbon chain) are in no way satisfactory in terms of prevention the IT mist formation as a result of poor tolerance with the mineral oil.

The tendency for a lubricant to fog up can can be measured using the iicrgren fog test. Of the In short, test uses a Norgren Micro Fog Lubricator (Type I0-0I5) that comes with an air filter and a pressure regulator is equipped so that a test liquid is atomized into a compressed air stream of about 0.5 at (7 PSI) compressed air. This Lubricator is placed about 75 am (3 inches) up from a condensation nozzle. The nozzle empties into the side an empty jug or can of about 1/4 1 (1/2 pint), which holds back the condensed oil droplets. Of the Air flow then goes through a can of about 1/2 1 (1 pint) content that is made with absorbent cotton and active charcoal packed and in which the remaining oil is stripped from the air. The total fog generated is called the condensed mist that collected in the empty 1/4 liter can plus the "excessive" fog (excess fog), which is sorbed by the cotton and charcoal in the filled can, defines excessive mist (overmist) is commonly expressed as a percentage of the total fog generated and is the amount of fog that can be minimized wishes.

The tapping effectiveness of a lubricant is

measured by means of a tapping efficiency test, and

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In general, the operation of this test involves a measurement of the internal threading operation developed torque when using a hot-rolled steel (SAE lo2o) 3o torque values obtained with the test fluid and compared with 3o reference fluid values to obtain the percent tapping efficiency, i.e.

average 3o reference fluid torque- % tapping efficiency = values χ loo

average 3o test fluid torque values

to determine.

The reference fluid used in the foregoing test comprised 9k weight percent sulfurized mineral oil, 3% corrosive sulfurized fat, and 3% oxidized Ca / P ₂ Sc cutting fluid additive.

In general, the ability of a cutting oil to heat effectively is measured by the tapping test. The threading test involves making a series of holes in a test metal such as 3. drilled hot rolled steel (SAE Io2o). The holes have been drilled in a drill press fitted with a table that is freely rotatable about the center of a ball bearing. A torque arm is attached to this "floating table" and the arm in turn actuates a spring scale so that the actual torque during the threading operation with the oil to be determined is immediately measured. The same conditions when testing the test oil are used when threading with a strong Ul, the arbitrary

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borrowed an effectiveness of loo% has been applied. The average torque for the test oil is compared with that of the standard and a relative effectiveness is calculated on a percentage basis, e.g .:

Torque with standard

reference oil 19.3

Torque with test oil 19 »8

relative effectiveness of the

Test oils

19.3 / 19.8 χ loo 97 Λ

This exam is from CD. Flemming and L.H. Brewing wood in "Lubrication Engineering", Vol. 12, No. 3, May-June 1956, Pp. 1-99-2o3, and also described in U.S. Patent 3,278,432.

It should be noted that in the above thread cutting effectiveness test, when the test fluid torque readings exceed the reference value, the thread cutting efficiency is below loo #. Criteria for acceptability of the product are determined as follows:

Thread cutting

effective remarks

^ loo% The liquid is said to be excellent

considered and should be superior to the reference products for heavy cutting operations be.

8o - loo # Acceptable range for cutting fluids for medium or moderate performance.

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Thread cutting

effectiveness remarks

<8o96 All products with thread cutting

efficiencies below 80% are considered considered unacceptable. The torque values are erratic or irregular, often due to sticking in the hole and / or breakage.

The invention is explained in more detail below with the aid of examples.

Examples

A metal cutting oil is prepared by blending of atactic polypropylene in a base oil selected from a sulfurized, solvent refined paraffinic oil having a viscosity of 15o SUS at 37.8 ⁰ C (loo ° F) together with functional additives: oleyl alcohol, polypropylene glycol, and non-corrosive, sulfurized Fat, in the proportions shown in the table. The blends were prepared by heating the polymer and base oil to Ho ⁰ C (23o ° F) until the polymer was dissolved therein and then cooling to room temperature, excessive mist (overnist) as described above, and product quality measured and is reproduced in the table.

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TABEL

Composition and properties of the cutting oil

composition

Component, Cev.% Atactic polypropylene oleyl alcohol polypropylene glycol (2,000 molecular weight) non-corrosive, sulfurized fat, sulfurized, refined paraffin oil solvent

15o SUS at 37.8 ⁰ C (loo ° F)

properties

Viscosity, SUS excessive at 37 "C 8 ⁰ (loo ° F) fog, haze% threading effectiveness

*) Average molecular weight estimated at 22,000

Example 1 Example 2 Example 3 Example 4 O o, 25 X.0 Io Ι, ο Ι, ο l, o l.o 1.0 Ι, ο l.o l, o Ι, ο Ι, ο l, o 97, ο 96.75 96, oo 87 149 161 1311 11.2 1.37 o, 8o - 1ο5 Ic4 - —_ clear very lighter veil cloudy, Veil- cloudy

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From the table above it can be seen that the addition of atactic polypropylene in an amount in the range from o, ol Oev ».% to o, 5 Ge \ v. & stark den excessive fog (overniist) diminishes.

It is noted, however, that the use of atactic polypropylene on I; "a compositions obtained, which are too viscous i'ür metal Bear ^ aitungszv / corner example, causes an addition of lo '/ ό of atactic ¹ polypropylene to mineral oil of!. 149 SU5 (Example 1) a viscous: actual increase of 1162 Saybolt seconds (Example 4). The heat transfer capacity of this liquid is impaired; the oil is difficult to pound and it is not possible to pull it out on chips. Ferrer gives the use of ataktis chem polypropylene in amounts such as $ 1 and above, obscuring and cloudy products.

There are also Oewindeschneid-Prüfimgsergebnisse which the Schmiennittel-Schneiaviirksarnkeit measure included to show that the use of atactic polypropylene s in the given here lien% does not adversely affect these properties of the lubricant.

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Claims (5)

Claims Lubricant for metalworking purposes with a reduced tendency to form mist, characterized in that it is not a base for metalworking lubricants and atactic polypropylene in an amount of 0.5% by weight excessive amount included. 2. Lubricant according to claim 1, characterized in that the amount of atactic polypropylene is o, ol to o, 5 wt. % . 3. Lubricant according to claim 1 or 2, characterized in that the amount of atactic polypropylene o, o5 to 0.3% by weight. 4. Lubricant according to one of claims 1 to 3, characterized in that the atactic polypropylene is a Has a molecular weight between 3,000 and 4,000. 5. Use of a lubricant according to any one of claims 1 to 4 in metalworking operations. 709842/0819