US2477356A - Turbine oil - Google Patents

Description

Patented July 26:,

U I ED TURBINE 'oiLf p p, sens-1 J. wmwmeng, has

Befi ning Company, New Yorlt, N. Yap;

corporation of Maine N6 basin. ,fnp t n bcember 3, 19

Serial No. 632,596

My invention relatesfto an improved lubricating composition especially adapted for use in the lubrication, of steam turbines, such as marine steam turbines.

In the operation of-steam turbines it is not pos sible to entirely avoid seepage of water into the oiling system from the steam sealing glands which surround the turbine shaft. For this reason it is necessary to add to turbine lubricating oils in order to prevent corrosionofmetal parts within the oiling system, a materialgfiective as a rust inhibitor. Such material; to be satisfactory, must not be capable of promoting the formation of a stable oil-water emulsion. i

The improved lubricating composition of my invention is characterizedin that it depends iorits rust-inhibiting effect on the presence therein of an alkylmercaptoacetic acidand an a1kylsu1finy1- acetic acid.= I

The alkylmercapto and alkylsuliinyh acids adapted for use in my-composition re those in which the alkyl group contains amass 12 carbon atoms. Thus, the alkylmercaptoacetic acidmay be, for example; hexadecylmercaptoacetic acid or ocetadecylmercaptoacetic acid, while thealkyls-ulfinylacetic acid. 1 may be; for example, hexadecylsulfinylacetic acid or ocetadecylsulfinylacetic acid. Other suitable combinations include do decylmercaptoacetic"acid and dodecylsulfiiiyh acetic acid; hep'tadecylmercaptoacetic acid and heptadecylsulfinylaceticacid, etc. Although preferable, it is not" essential that the alkyl group of the mercapto acid contain the same number of carbon atoms as the alkyl group of the sulfiny-l acid.

The total weight of the acids in my composition can be varied depending uponthe degree of pro tectionrequired but in the composition as I ordinarily prepare'it, the weight of the acids is equiva lent to from about 0.025 to about 1.0% oithe weight of the base oil. Therelative proportion of mercaptc-acid and sulfinylracid may also vary and within a wide ranigecbut the mercaptoeacid should alwa s predominate; It is generally, advantageous to limit the amount of sulfinyl-acid to 15-20% on the total weightof the acids.

It is my usual practice to add the two acids to the base oil in admixture and since the sulfinylacids represent oxidation products of the mercanto-acids, it is convenient to prepare the mixture by the partial oxidation of the particular mercapto-acid it is desired to use. The partial oxidation is with advantage carried out using hydrogen peroxide as the oxidizing agent and in the presence of a suitable solvent. The following Claims. (01. 252--48.6)

. mixtuiierepresented a. thin slurry.

laboratory .run is .zillustrativez 4.1 gms. (0.012 mollof crude'octadecylmercaptoacetic acid were added to 150cc. ofiacetoney andthe mixture heated to boiling (1381-7140 F.) Thereafter 0.22

the abo drum was preparedin accordance with The procedure employed was as followsi An aqueous potassiu-m hydroxide solution, previously prepared 'by adding 12.3 g-ms. of potassium hydroxid'e to '75 0050f water, was added to 500 cc. of methanol. Tot-his mixture was added, withstirring, 57.2 gms. (0.20 mole) of octa-decylmercetritan. Partial precipitation of the potassium mercaptide took place and the temperature of the .mixture rose from F. to 98 F. A previously prepared aqueous sodium monochloroacetate solution was then added, with stirring. Reaction was rapid, a precipitate.- forming in1;l=2.minutes and increasing in bulk until, in 1.0 15 minuteathe Thisoonsist ency was.mainta1ned throughout the. reaction which was continued for? Onehoun, .Atthe end of the ,hour durifig whichla maximum temperature of 106. F.. w.as.r.eached the mixture was aci'di fiedlwith hydrochl ric :a o n the methanol distilled. .lheoltenresl ue-was washed with hot water lilie -L852 F.) until the wash water was neutrall-to, methyl drange'. product was then ll wed t st u t suspend Wat r hi ee tled, after which itwa's allowed tocool and solidify. The recovery of crude octadecylmercaptm acetic acid was 70.5 gms, slightly above theoreti cal.

It is not to be understood from theforegoing that my invention is predicated on any particular method of preparing the mercapto or sulfinylacid as any suitable method may be used.

, The suitability of a compounded oil for application as a marine turbine oil is now conventionally gauged by testing it according to (a) a procedure prescribed. by the American Society of Testing Materials and identified as specfication D605-42T, frRust-preventing characteristics of steam turbine oil in the presence of water, and (b) a procedure commonly known as the f-Navy emulsion test which will be found described in section IV, part 5, of thelf'ederal Standard StockCatalog, being designated therein as Emulsion test for lubricating oils. Of late it has loeen the practice to substitute synthetic sea water for the disstilled water called for by the A. S. T. M. testy in fact this is required by United States Navy Turbine oil specification 14-0-15 (INT) of March acetic acid, the alkyl group of each of the acids 1, 1943. The Navy formula for syntheticseawater I is as follows, the proportional-being 'per liter-of distilled water:

i Grams NaCl mgcizen oh .1 -'11.o CaClz 1.2 Na2SO4. .1 1 4.0

My lubricating composition prepared to contain from 0.04 to 0.05% on the base oil of a mixture of "octadecylmercaptoacetici and octadecylsulfinyla'ceti'c acids containing "from 10-15% of the sulfinyl-acid or from 0.05 to 0.06% on the base oil of a mixture of hexadecylmercaptoacetic and hexadecylsulfinylacetic acids containing from 10-15% of the 'sulfinyl-acid successfullyjpassed each of the above tests, including the modified A. S. T. M. test. In these tests I used as the base oil a neutral'distillate having the following properties: 1 1

API gravity 2712 Flash 460 Fire 520 F. Saybolt viscosity; l. 1

@ 100 F- ;1 431.0 see. 130 F 190.3 sec.

' F 57.16sec.

-1. +5 /2- Conradsen carbon 0.03% Ash -1 0 Acid V j..' 0 V Sulfur 2 0.13% Specific dispersion 111.4 Navy emulsion: V v r H 'NaCl 0K1 min.

1 Calculated from kinematic viscosity.

Each of the test samples gave an A rating in the modified rust test i. e., there was no detectable corrosion of the test strip. Moreover, there was no coating or etching of the strip; In the'emulsion test, the period required for clear settling varied but the result was satisfactory in every instance. The result on a blend prepared by adding to the base oil 0.045 %"of the mixture of acids produced as described supra by the oxidation of octadecylmercaptoacetic acid was OK- minutes for distilled water andOK-llminutes for salt water. On a blend prepared by adding to the containing at least-12 carbon atoms, the acids being present-in an amount sufiicient to impart a corrosion inhibiting' property to the composi= tion but not over 1% on the weight of the oil.

2. improved lubricating composition adapted for use as a turbine oil comprising a petroleum oil having compounded therewith from file of this patent:

0.025 to 1.0% on the Weight of the oil of a mixture of an alkylmercaptoacetic acid and an alkylsulfinylacetic acid the latter acid being present in. an effective, though relatively smaller, proportion than the alkylmercaptoacetic acid,the alkyl group of each of the acids containing at least 12 carbon atoms. I

3. An improved lubricating composition adapted for use as a-turbine 011- comprising a pctroleum oil having compounded therewith from 0.025 to 1.0% on the -weight of the Oil of a mixture of an aikylmercaptoacetic acid and the corresponding alkylsulfinylacetic acid containing from 5-20%;by weight of the sulfinyl-acid, the taining at least 12 alkyl group of the acids con carbon atoms. H a V 4. An improved lubricating composition adapted for use as a turbine oil comprisinga petroleum oil having compounded therewith from 0.04 to 0.05% on the weight of the oil of a mixture of octadecyclmercaptoacetic acid and octadecylsulfinylacetic acid containing from 10-15% by weight of the sulfinyl-acid.

5. An improved lubricating adapted for use as a turbineoil comprising a petroleum oil having compounded therewith from 0.05 to 0.06% on the weight of the oil of a'mixture of hexadecylmercaptoacetic acid and hexadecylsulflnylacetic acid containing from 10-15% by weight of the sulfinyl-acid;

STEPHEN J. WAYO.

REFERENCES CITED V The following referen ces are of record in the UNITED STATES PATENTS 2,371,207 Zublin et a1 Mar. 13, 1945 composition