US2429905A - Lubricant composition - Google Patents

Description

Patented Oct. 28, 1947 UNITED STATES PATENT OFFICE LUBRICANT COMPOSITION No Drawing. Application September 10, 1943,

Serial No. 501,855

1 Claim. (CL 252-52) The present invention relates to lubricants of improved quality. More particularly, the invention concerns improved lubricant compositions for use in certain types of service wherein operating conditions are such as to tend to cause rusting of equipment.

There are certain types of operation requiring lubrication of metal surfaces in which the service equipment is prone to rust due to the presence of water. In such operations, it is desirable, and often mandatory, that the lubricant serve not only as a lubricating agent but also asa rust preventive agent. In order for the lubricant to fulfill the latter function in satisfactory manner it must be capable preferentially of wetting the metal surfaces under prevailing operating conditions so that a protective coating of lubricant will form and prevent effective contact between the metal and water.

An outstanding example of a case where th lubricant should function as an anti-rust agent as well as a lubricant occurs in the operation of steam turbines. Due to the elevated temperatures employed in turbine operations and to the presence of water formed through condensation of the steam, steel surfaces within the turbine or gear case are prone to rust. In cases where the lubricating oil has insufilcient protective quality the metal surfaces may become so badly rusted as to scale ofi, causing scoring of bearings, sticking of governor mechanisms, plugging of oil lines, etc., often resulting in severe economic loss. A trend in turbine developments within 'recent years toward higher operating temperatures and pressures has placed increasingly greater requirementson the turbine oils, with the result that oils which were satisfactory some years ago are now unsuitable in many cases, if not generally. Oils refined in accordance with usual present-day practice generally lack preferential wetting characteristics necessary to impart the desired rust-preventive qualities.

The present invention is directed to and provides lubricant compositions which have the desired rust-preventive characteristics. In accordance with the invention the aforesaid rust-preventive quality is obtained in the highest degree by incorporating in the lubricant composition a substance comprising a relatively small amount of an oil-soluble, water-insoluble substituted 1,2-dihydroxy-benzene, preferably derivatives of pyrocatechol (1,2-benzenediol) having an alkyl group attached to the benzene ring in the para position. I have discovered that substances of this type when added to lubricating oil in relatively small proportion impart to the resulting composition the ability to prevent rusting of metallic surfaces, presumably due to preferential wetting of the surfaces by the lubricant composition.

As examples of effective rust-preventing agents of the type above set forth may be mentioned the following: 4-tertiary butyl-1,2 benzenediol; 4-tertiary octyl-1,2 benzenediol; 4-

. lauryl-l,2-benzenediol; and 4-cyclohexyl-l,2 benchains are such as to impart to the compounds the desired solubility characteristics. These compounds may be used in any effective proportion. but it is generally satisfactory to employ relatively small amounts, for example, not over 2 per cent and preferably 0.1-0.5 per cent. The stearyl derivative of pyrocatechol, which contains eighteen carbon atoms in the attached stearyl group, although having the desired solubility characteristics, is not as effective as the above named agents and therefore must be used in a greater proportion in order to afford the desired protective action. The lower efiectiveness of the stearyl derivative presumably may be due to too large a number of carbon atoms in the attached hydrocarbon group; accordingly it is preferred to use derivatlves having fewer carbon atoms in the attached group, for instance 4-12 carbon atoms.

The following examples are given by way of illustration of the invention but are not to be taken in limitation thereof since many modifications obviously are within the purview of the invention:

An acid-treated and clay-filtered turbine oil stock having the following specifications:

Gravity A. P. L- 22.5 Flash point F 335 Fire point F 380 Saybolt Universal vis. at F N. P. A. color Per cent of ggs specimen surface rusted Turbine oil stock Failed 80 Turbine oil stock +02% 4-tertiary butyl-l, Passe 2 benzenediol. Turbine oil stock +02% 4-tertiary oetyl-l, -do... 0

2 benzenediol. Turbine oil stock +02% 4-lauryi-l, 2 do.. 0

benzenedioi. Turbine oil stock +0.l% 4-cyciohexyi-l, do.. 0

2 benzenediol.

The above tabulation clearly shows that all 01 the addition agents eifectively prevent rusting. In the appended claim whenever reference is made to a substituted dihydroxy-benzene, it should be understood that this refers to a compound resulting from replacement of nuclear hydrogen in a dihydroxy-benzene by at least one hydrocarbon group.

What I claim and desire to protect by Letters Patent is:

A lubricant composition adapted for use under service conditions in the presence of water to prevent rusting due to contact between metal and water which consists essentially of lubricating oil and 0.1 %-2.0% of an oil soluble, water-insoluble 1,2 dihydroxybenzene having an alkyl group attached to the benzene ring selected from the group consisting of 4-tertiary butyl-1,2 benzenediol; 4-tertiary octyl-1,2 benzenediol; 4-lauryl-1,2 benzenediol and 4-cyclohexyl-1,2 benzenediol.

WORTLEY ANDREW WRIGHT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,793,135 Rogers Feb. 17, 1931 1,942,827 Mills Jan, 9, 1934 2,046,900 Ipatiefl July 7, 1936 2,116,220 Shoemaker May 3, 1938 2,194,312 Loane Mar. 19, 1940 2,197,833 Reifi Apr, 23, 1940 2,197,835 Reifi Apr. 23, 1940 2,298,638 Prutton Oct. 13, 1942 2,316,903 Van Ess Apr. 20, 1943 2,326,496 Reiff Aug. 10, 1943 2,339,797 Musher Jan. 25, 1944 2,352,669 Van Ess July 4, 1944 2,388,887 Weissberger Nov. 13, 1945 FOREIGN PATENTS Number Country Date 819,608 France Oct. 22, 1937