US2947697A

US2947697A - Lubricant composition

Info

Publication number: US2947697A
Application number: US541295A
Authority: US
Inventors: Ernest R Vierk; Theodore J Karr
Original assignee: Sinclair Refining Co
Current assignee: Sinclair Refining Co
Priority date: 1955-10-18
Filing date: 1955-10-18
Publication date: 1960-08-02
Anticipated expiration: 1977-08-02

Description

United States atent O LUBRICANT COMPOSITION Ernest R. Vierk, Lansing, 111., and Theodore J. Karr,

East Chicago, Ind., assignors to Sinclair Refining Company, New York, N.Y., a corporation of Maine No Drawing. Filed Oct. 18, 1955, Ser. No. 541,295

3 Claims. (Cl. 252-55) This invention relates to a new protective lubricant composition and more particularly relates to a lubricant composition especially useful for application in conjunction with wire ropes, flexible metallic strands and similar metallic articles.

Lubricants suitable for use as a protective lubricant must have a series of properties which are essentially inconsistent. For example, the lubricant should have a high softening point to avoid dripping over a great range of temperature and still possess good flexibility at low temperatures so that brittleness resulting in cracking, peeling and chipping does not occur. The problems presented by these essentially inconsistent properties has resulted in the development of numerous lubricants characterized as useful under a particular series of conditions but possibly not of general use. Additives have been employed in attempts to adjust certain properties of these lubricants. This, of course, is expensive and wasteful of the additives because they should be used to obtain properties which cannot be otherwise economically obtained.

In the course of our investigations of lubricants, especially those adapted for use as protective lubricants,

we have discovered a new composition of matter which is characterized by outstanding properties in each of the extremes to which the lubricants normally are subjected. In accordance with our invention a lubricant can be produced which is characterized by case of application, the action of a plastic solid after solidification and which has a high flow or drip temperature and good flexibility at low temperatures.

The novel compositions constituting our invention in protective lubricants employ a specially blown asphalt, polyethylene and a viscosity reducing mineral oil as the essential constituents. While many different combinations of the various materials are effective in producing lubricants we have found that considering functional properties in relation to the cost of the material produced, compositions containing about 2 to weight percent polyethylene, about 55 to 75 weight percent blown asphalt and substantially the balance a mineral lubricating oil, have highly satisfactory properties. Preferred compositions contain about 3 to 6 percent polyethylene, about 60 to 70 percent blown asphalt and substantially the balance oil.

The effect of varying the compositions, for example, by changing the quantity of polyethylene can best be seen in the data in the following table. To conduct these tests a solvent refined Mid-Continent neutral oil having a viscosity of about 155 S'US at 100 F. was employed. Blown asphalt having a penetration of 7 at 77 F. (100 gram needle) obtained by air blowing an asphalt having a viscosity of 1000 furol seconds at 210 F. to a softening point (R and B) of 210 F. and a polyethylene having a molecular weight of about 2000 were employed. The data are:

2,947,697 Patented Aug. 2, 1960 TABLE 1 Composition, Parts:

Oil

Asphalt. Polyethylene." Laboratory Tests: Flow (Drip) Temperature, F. Softening Point gfi ing & Ball),

Flexibility at '-5 F1, Wire Rope Coated with Lubricant.

Brittle Point,

F. Metal Strip Coated with Lubricant.

Few tiny cracks Few tiny cracks Few tiny 0 cracks cracks.

These data evidence the surprising properties of our compositions; that is, improved high temperature characteristics are obtained without simultaneously experiencing a detrimental effect on the low temperature characteristics of the resulting compositions, an undesirable effect which frequently occurs upon making additions to a base composition. It is also apparent that high resistance to flow and a sufliciently high softening point are obtained with compositions containing 2 or more percent polyethylene. To obtain optimum flexibility of the lubricant as evidenced by applying the lubricant to a wire rope strand, cooling to 5 F. and flexing, larger quantities of the polyethylene, for example about 5 percent, are needed to result in a product without any cracks. It will thus be apparent that within the ranges above established there will be an optimum concentration of the various components depending upon the functional property most desired.

Compositions of the present invention may be prepared by blending the polyethylene and blown asphalt in the oil component separately in any order or viscous blends of blown asphalt and polyethylene may be preformed and the oil added as needed to obtain the final composi= tion. An advantageous method involves simply heating the blown asphalt and polyethylene at an elevated temperature above the melting point of both components for example above about 275 or 300 F. The melted components are then stirred to insure homogeneity. Such oil as is needed for specification viscosity can then be incorporated, with stirring, and the mixture then permitted to cool to room temperature, preferably without the use of cooling means. If desired, compositions can be prepared and stored for subsequent use or the com= positions can be prepared at the time that application to the material to be protected is desired. By employing the latter procedure a heat economy is obtained since the melted composition can be applied directly to the object without intervening solidification and its attendant remelting to obtain the necessary fluidity. This is possible since application of lubricants of this nature normally is brought about by melting a lubricant and painting or otherwise applying it to the surface. Where a wire rope comprised of a plurality of strands is to be coated with the lubricant, suflicient fluidity to penetrate to all surfaces is, of course, required. When the lubricant is applied to each strand separately as during the, manufacture of a wire rope, surfaces, crevices and the like being extremely small, fluidity of a lubricant again is highly important. Other methods of application can be used at the option of an operator.

The invention will be described further in conjunction with the following specific example. It is to be under- Example About 61 pounds of blown asphalt having a softening point of 210 F. (R. and B.) .and a penetration of 7 at 77 F. with a 100 gram needle were melted by heating to a temperature of about 275 to 300 F. About pounds of polyethylene having a molecularweight of about 2000, a specific gravity of 0.92, a melting point of about 100 C. and a viscosity of 185 furol seconds at 140 C. were added to the melted asphalt and the mixture was stirred until the polyethylene was melted and blended throughout the asphalt; stirring for about one-half hour was needed. About 34 pounds of a Mid- Continent solvent refined neutral oil having a viscosity of about 155 SUS at 100 F. were added while stirring the mixture of blown asphalt and polyethylene. Stirring was continued until the mixture was homogeneous and the composition was then permitted to cool to room temperature. Samples of the resulting composition were tested to determine various properties; the results are as follows:

TABLE II Laboratory Tests: 1

Specific Gravity (SO/60 F 0.9582. Flash, F 440. Furol Viscosity at 250 F Furol Viscosity at 275 F Penetration at 77 F., 100 g. Ne Softening Point (R & B), F

Flow (Drip) Temperature, F 170. Flexibility at -5 F., Wire Rope Coated with Lubri- No cracks.

cant. Brittle Point, F. Metal Strip Coated with Lubricant. 40. Salt Spray Rust Test, Days Pass.

4-Ball EP Test, Kg. Load to Incipient Weld The functional data of the above table were obtained by various commercial tests. For example, dripping point is determined by dip coating a test panel with lubricant preheated to250 F. The panel is then put into an oven at 80 F. and the oven temperature elevated 10 every 24 hours until dripping occurs, the temperature of dripping being reported. To determine low temperature flexibility a wire rope strand is coated with lubricant preheated to 250 F., the coated strand is then cooled to 5 F. and flexed. Visual observation is then made and the presence or absence of'any cracking or break in the lubricant film is noted and recorded. Brittle point is determined by coating a metal strip with lubricant preheated to 250 -F. The coating strip is then placed in a cold cabinet in which the temperature is progressively lowered. At 10 intervals the strip is flexed and ob- :served for cracking and other evidence of brittleness in the lubricant film with the temperature of faulting being noted and recorded.

The polyethylene used in the example is preferred and has a molecular weight of about 2000. Other polyethylenes which can be employed in the present invention :are normally solid at room temperature and range in molecular Weight from about 1000 to 23,000 or more, and preferably about 1000 to 5000 to take advantage of ease of handling. The polyethylenes may, if desired, be those which contain so-called terminal hydroxyl groups, that is a hydroxyl radical attached to one of the last few carbon atoms, for example, one of the last five carbon atoms. Polyethylenes including those containing terminal hydroxyl groups are commercially available and the commercial products are employed in the present invention.

, The blown asphalt component of the present invention is present in amounts varying from about 55 to 75 weight percent. .The blown asphalt is prepared by a procedure consisting of air blowing a suitable charge stock, for example, one having a viscosity of about 900 to 1100 furol se sn sat 210 u t h Swelling P in of the blown asphalt is within the range of about 200 to 225 F. The resulting blown asphalt will normally evidence a penetration of less than about 15 for example, from about 3 to 15 (100 gram needle at 77 F.). Air blowing to produce blown asphalts is conducted according to known procedures at elevated temperatures, for example, 500 F. with or without the use of conventional catalysts.

The mineral oil component of the compositions of the present invention is present in an amount suificient to render the composition of a viscosity determined pri: marily by specifications. Normally this amount will range from about 20 to 45 or more percent by weight. The oil can be a Mid-Continent, naphthenic, or paraffinic base lubricating oil fraction, for example a neutral oil, and can be conventionally refined or preferably solvent refined by conventional refinery procedures. The amount and viscosity of the oil employed is adapted to characterize the product composition with a viscosity of about 150 to 300 furol seconds at 250 -F. It is preferred to employ neutral oils having viscosities within the range of about to 450 SUS at F. v

While the compositions of the present invention have been described as containing as the essential constituent blown asphalt, polyethylene and a viscosity reducing mineral oil it should be understood that other components such as antioxidant and extreme pressure additives and the like may be included so long as they do not deleteriously affect the functional properties of the composition. On the other hand, an outstanding advantage of the present invention is that its functional properties are such that additives such as lead naphthanate, an extreme pressure agent, may not be necessary to meet the usual specification. Also in the data in Example I it can be seen that our composition successfully passed the salt spray rust test without the necessity of employing an anti-rust additive.

In the foregoing we have described compositions which are especially useful as protective lubricants for wire ropes, flexible metallic strands and similar metallic articles. These compositions are particularly advantageous in that they possess superior properties at the extrem of conditions encountered in use.

We claim:

1. A protective lubricant consisting essentially of about 2 to 10 percent by weight of a normally solid polyethylene having a molecular weight of about 1000 to 23,000, about 55 to 75 percent by weight of blown asphalt, said blown asphalt having a softening point of about 200 to 225 F. and having a penetration at 77 F. (100 gram needle) of less than about 15, and a mineral lubricating oil fraction suflicient to characterize the lubricant with a viscosity of about to 300 furol seconds at 250 F.

2. The protective lubricant of claim 1 in which the polyethylene content is about 3 to 6 percent by weight.

3. The protective lubricant of claim 1 in which the polyethylene content is about 5 percent and has a molecular weight of about 2000.

References Cited in the file of this patent Manufacture and Application of Lubricating Greases, by Boner. Copyright October 20, 1954. Reinhold Publishing Corporation, New York. Pages 795-798 perti- Bent.

r in

Claims

1. A PROTECTIVE LUBRICANT CONSISTING ESSENTIALLY OF ABOUT 2 TO 10 PERCENT BY WEIGHT OF A NORMALLY SOLID POLYETHYLENE HAVING A MOLECULAR WEIGHT OF ABOUT 1000 TO 23,000, ABOUT 55 TO 75 PERCENT BY WEIGHT OF BLOWN ASPHALT, SAID BLOWN ASPHALT HAVING A SOFTENING POINT OF ABOUT 200 TO 225*F. AND HAVING A PENETRATION AT 77*F (100 GRAM NEELDE) OF LESS THAN ABOUT 15, AND MINERAL LUBRICATING OIL FRACTION SUFFICIENT TO CHARACTERIZE THE LUBRICANT WITH A VISCOSITY OF ABOUT 150 TO 300 FUROL SECONDS AT 250*F.