US2785111A

US2785111A - Protective lubricant composition

Info

Publication number: US2785111A
Application number: US438292A
Authority: US
Inventors: Ernest R Vierk; Theodore J Karr
Original assignee: Sinclair Refining Co
Current assignee: Sinclair Refining Co
Priority date: 1954-06-21
Filing date: 1954-06-21
Publication date: 1957-03-12
Anticipated expiration: 1974-03-12

Description

United States Patent 6 PROTECTIVE LUBRICANT COMPOSITION Ernest- R. Vierk, Lansing, 111., andTheodore J. Kan, East Chicago,lnd., assignorsto Sinclair-Refining Company, 'New"Yoi-k, N. Y., a corporation -of.Maine No Drawing. Applicationiune 21, 1954, Serial No. 433,292

3' Claims. or. 196-149) bility at low temperatures so that brittleness resulting in cracking, peeling and chipping or" the lubricant film is not a characteristic. The lubricant must'be sutficiently adhesive to metal to avoid being pulled or peeled off by contacts normally encountered, and still be sufficiently resistant to adhesion to avoid picking up contaminants which could pierce the lubricant film nullifying part of its lubricant and corrosion prevention characteristics. The problem presented by these essentially inconsistent properties has resulted in the development of numerous protective lubricants each being characterized as useful under specially limited conditions but no more than partially useful for the total range of conditions normal- 1y encountered by the flexible metallic articles. Additives have been employed in attempts to adjust the properties. This, of course, is expensive and wasteful of the additives because they should be used to impart properties to the lubricant which cannot otherwise be economically obtained by modifying properties characteristic of the base materials.

In the course of our investigations of lubricants we have discovered a new composition of matter especially suitable as a protective lubricant for use with wire ropes, metallic strands and similar metallic articles. In accordance with our invention, a lubricant can be produced which is characterized by case of application, rapid solidification after application, the action of a plastic solid after solidification, adhesiveness to flexible metallic articles yet possessing film firmness sufflcient to avoid picking up contaminants, being capable of complete and continuous coverage of the flexible metal thereby providing corrosion protection and being very flexible at low temperatures.

The novel compositions constituting our invention in protective lubricants employ high melting microcrystalline wax, a specially blown asphalt, and a viscosity adjusting mineral oil as essential constituents. The microcrystalline wax is used in amounts of about 5 to 20 percent by weight with about to percent by weight, especially 14 to 15 percent, being preferred. Microcrystalline waxes which we have found to be satisfactory are characterized by melting points ranging from about 140 F. to about 165 F. We prefer to employ petroleumderived microcrystalline waxes having melting points ranging from about 150 to 155 F. The higher melting point characteristics are desirable fromthe standpoint of performance of the lubricant on the metal to be protected; however, plant handling facilities, such as pumps and heating. equipment, may, make it desirable .to'use waxes having-the lower melting points.

Microcrystallinewaxes suitable for. use in our :invention can be obtained by any known process. One satisfactory process which can be employed uses a Mid-Continent cylinder stock. Theeylinder stock is subjected .to a propane deasphaltingprocedure and is then dewaxed with methyl ethyl-ketonesolvent. The rnicrocrystalline wax product thus obtained can be further refined as 'desiredto adjust the properties of the wax.

The asphalt content of our novel-microcrystalli'ne wax specially blown asphalt mixture is present in amountsof about 50 to'70 percent by weight with about 55-,to 65 percent by weight being preferred. The asphalt is prepared by a procedure consisting of airblowing a charge stock having a viscosity of about 900 to 1100 furol seconds at 210 F. until the softening point ofthe blown asphalt comes within the range of about 200 to 220 .F. The resulting product will normally permit the penetration of a gram loaded needle at 77 F. of about 11 to 15 (0.01 cm./unit). The'air blowing is conducted'according to known procedures at elevated temperatures, for example, about 500 F.

The final lubricant containing the wax and blown asphalt has added thereto a mineral lubricating oil sufficient to characterize the lubricant with a viscosity of about 140 to .200 furol seconds .at 250 F. The exact amount of oil needed toproduce the desired viscosity will, of .course, dpendupon the amount of wax and asphalt employed and their characteristics. However, it is essential that the oil be added to afford the desired viscosity, and the amount'to .be added is a matter of simple and routine testing.

Compositions'within the. scope of our invention which we have found to be,eminently suited as; protective lubricants for wire ropes contain'microcrystalline wax in amounts of about 14m 15 weight percent. These compositions are characterized by a hardness equivalent to such indicated by a penetration of a IOOgram needle at 77 F. of about 160 to 230 (0.01 cm./unit), asoftening temperature (Rand B) of about to F., and a flash point of at least 455 F. Compositions with these characteristics can be used for applications other than as lubricants for wire ropes, though as pointed out above, we have obtained highly satisfactory results employing them in conjunction with wire ropes.

The essential constituents of our new lubricant are rni-t crocrystalline wax, blown asphalt, and the viscosity ad-- justing lubricating oil. The lubricant can be used without additives of any sort. to be used on a wire rope, or similarly flexible metallic articles which are subjected to high stress as localizedi points, extreme pressure additives such as lead naph-. thenate can be employed to enhance chemical afiinity'forthe surfaces of the metallic articles thereby aiding in the prevention of galling, scoring and and scufiing whicln would promote excessive wear and premature rope failure, The composition can contain corrosion inhibitors such: as sodium sulfonate; other additives such as wetting agents. and foam inhibitors can also be employed. Since the: vast majority of applications for our new lubricant would; encounter the broadest range of general conditions of weather, friction, contacting, atmospheres, etc., the invention will be described hereinafter in a form containing several of the more common additives characteristic of this field.

Our protective lubricant compositions can be produced by mixing the blown asphalt and microcrystalline wax atanelevated temperature, for example, about 250 to 350 F., to render the asphalt and wax sufficiently fluid to mix. A mineral lubricating oil, such as a solvent refined Mid-Continent oil having a viscosity of about However, when the lubricant is.

155 SUS at 100'F., is blended into the asphalt-wax mixture until a product is obtained having a viscosity of about 140 to 200 furol seconds at 250 F. The point at which this viscosity is obtained can be determined by simply making spot control tests during the addition of the oil and ceasing such addition when a test shows the viscosity to be within the range. When the viscosity test discloses the product to be within the range, such additives as desired are added. At this point the product i can be used by dipping therein the metallic strand, wire rope or similar flexible metallic article, removing the coated article and permitting the protective lubricant to set. Where the metallic article is composed of a plurality of strands, the lubricant can-be applied to the individual strands prior to joining them, in addition to, or in lieu of a coating on the finished article. Another desirable method of application of our lubricant entails the application of several layers to the metallic article. Multiple layers can be obtained by dipping, painting, or spraying lubricant on the metallic article, cooling to set the lubricant, and then repeating the coating and cooling steps a plurality of times to obtain the number of coats or layers desired. Painting and spraying followed by a cooling step facilitates protection of the articles by relatively thin layers of lubricant. The coated flexible metallic articles can then be employed for any purpose where such articles are presently used, with advantages accruing by use of our coated article which are demonstrated hereinafter. I

The invention will be described further by means of a specific example demonstrating a method of preparing the novel lubricant. It is to be understood that the invention is not to be limited by the details of preparation disclosed therein.

EXAMPLE I About twenty-three pounds of a propane precipitated asphalt of a Mid-Continent crude oil showing a 77 penetration of about 50 (0.01 cm./unit) were added to about 77 pounds of reduced Mid-Continent crude asphalt showing a penetration of about 275 (0.01 cm./unit) at 77 F. in a reaction pot. This blend had a viscosity of about 1000 furol seconds at 210 F. Heat was applied until the temperature reached about 500 F., and the blend then was air blown until the pot mix tested at a softening point between 200 and 210 F.

About fifty-nine pounds of the jblown asphalt were mixed at a temperature of 300 F. with about 14.2 pounds of a microcrystalline wax having a melting point of 151.5 F. A solvent refined Mid-Continent oil having a viscosity of 155 at 100 F. was added to the wax-asphalt and stirred until the oil-wax-asphalt mixture obtained a viscosity of 179 furol seconds at 250 F. About 16.6

, pounds of oil had been added at the time the final viscosity resulted. About 8.1 pounds of lead naphthenate, 2.0 pounds of sodium sulfonate and 0.005 pound of DCF (an anti-foam agent being a silicone polymer with a viscosity of about 100 centistokes'at 25 C.) were added. Stirring was continued until the mass appeared homogeneous, at which time the lubricant was considered finished. Portions of this lubricant were tested in the laboratory to determine its properties; the results are tabulated in Table I:

Table I Flash, F. 470 Viscosity, furol at 250 F. 179 Penetration at 77 F., 100 g. needle 213: Softening point (R 8: B), F. 121.0 Lead, percent 2.03 Sodium, percent ""0071 Lubricant prepared in accordance with the procedure of Example I was applied to various sections of wire rope. This was accomplished by heating the lubricant to 250 F. and then dipping the wire rope in the lubricant; the lubricant coated wire rope was removed from the lubricant vat and permitted to stand at room temperature for several minutes until the lubricant had set. The coated specimens were subjected to various conditions to demonstrate the efiectiveness of the lubricant.

Several specimens were suspended in a storage room maintained at about 80 F. to simulate conditions en countered during storage or non-use of the lubricant coated wire rope. While a commercial'lubricant begins to drip at about 48 hours, our lubricant showed no tendency to drip; in fact, a specimen stored for weeks at 120 F. has shown no tendency towards dripping. The ability to resist dripping at this extreme temperature shows the characteristic of our lubricant of being a plastic solid. As a plastic solid our lubricant has a rather high 7 flowing temperature which is not reached until the melting point is approached. V

Generally wire rope and similar flexible metallic articles come into contact with'themselves when wound on drums or subjected to normal use. It is necessary that a lubricant employed to protect the metallic article resist the peel-off and pull-oflf conditions of normal service. In testing our new lubricant, coated specimens of a Wire rope were rolled over one another at right angles. Visual observation of the specimens disclosed the superior nature of our lubricants film surface and of its adhesivenelss and chemical aflinity for the wire'rope as-the speciment remained completely coated and protected.

'Another important characteristic of a protective lubricant is its flexibility at low temperatures. A simple test of this characteristic can be made by flexing a coated flexible metallic strand maintained at a temperature of about 10 F. If the flexing can be accomplished without cracking, peeling or chipping the lubricant film, the lubricant has satisfactory flexibility at low temperature.

Lubricants prepared in accordance with our invention which were applied to flexible metallic strands demonstrated superior flexibility at low temperatures when tested inaccordance with the above procedure because there were no cracks, peels or chips in the lubricant film.

In' the foregoing description we have described novel lubricant compositions useful as protective lubricants for wire ropes, flexible metallic strands and similar applications. Our lubricants are especially useful since they have properties which are superior under the extremes of conditions generally encountered by wire ropes and other flexible metallic strands or articles.

We claim:

1. A protective lubricant containing about 5 to 20 percent by weight of microcrystalline wax melting in the range from about 140 to 165 F.,'about 50 to 70 percent by weight of blown asphalt, said blown asphalt being obtained by air blowing asphalt having a viscosity of about 900 to 1100 furolseconds at. 210 F. until. the softening point is about 200 to 220 F., and a mineral lubricating oil suflicient to characterize the lubricant with a viscosity of about.140 to 200 furol seconds at 250 F.

2. The protective lubricant of claim 1 in: which the microcrystalline wax content is.10 to 15 percent by weight and the blown asphalt is present in amounts of about 55 to 65 percent by weight. V

3. The lubricant of claim 2 in which the microcrystal line wax is present in an amount of 14 to 15 percent by weight. 7

References Cited in the file of this patent UNITED STATES PATENTS 1,396,527 Richter et al. Nov. 8, 1921 2,291,905 Koenig Aug. 4, 1942 2,492,843 Crouch et al Dec. 27, 1949 2,501,149 Yellott .Mar. 21, 1950 Anderson Aug. 18, 1953

Claims

1. A PROTECTIVE LUBRICANT CONTAINING ABOUT 5 TO 20 PERCENT BY WEIGHT OF MICROCRYSTALLINE WAX MELTING IN THE RANGE FROM ABOUT 140 TO 165*F., ABOUT 50 TO 70 PERCENT BY WEIGHT OF BLOWN ASPHALT, SAID BLOWN ASPHALT BEING OBTAINED BY AIR BLOWING ASPHALT HAVING A VISCOSITY OF ABOUT 900 TO 1100 FUROL SECONDS AT 210*F. UNTIL THE SOFTENING POINT IS ABOUT 200 TO 220*F., AND A MINERAL LUBRICATING OIL SUFFICIENT TO CHARACTERIZE THE LUBRICANT WITH A VISCOSITY OF ABOUT 140 TO 200 FUROL SECONDS AT 250*F.