US2150400A - Lubricating oil composition - Google Patents

Description

Patented Mar. 14, 1939 UNITED STATES LUBBICA'I'ING on. comrosrnon Raphael Boson, Craniord;N. 3., assignor to tandan! Oil Development Company, a corporation of Delaware No Drawing. Application octobcr 4, 1934, Serial No. 748,844

It has been known for some time that hydrocarbon and other lubricating oils deteriorate by oxidation, and especially the more highly relined oils, particularly hydrocarbon oils which consist essentially of parafiin hydrocarbons. Such deterioration by oxidation maybe con trolled by the addition oi substances known as oxidation inhibitors, of which the best known are.

phenols or naphtholssnd naphthyl'amines, although a great many others are known.

The present application deals with a new class of oxidation inhibitors particularly useful for lubricating oils, including hydrocarbon lubricating oils, and these may be generally described as those containing an iso-cyanic radical which is represented by the formula XCN, where X represents either an oxygen or a sulphur atom. It is preferred to use esters of iso-cyanic and isothio-cyanic acids. The alkyl esters may be used, for example those of the lower alcohols, such as methyl, ethyl, the propyl and butyl alkyl esters, either straight chain or with branch chain structures, such as isopropyl and secondary butyl isocyanates. Higher alkyl esters may also be used as well as the esters oi. unsaturated alcohols such as allyl iso-cyanate, vinyl iso-thio-cyanate and the corresponding propargyl esters,'and the like. 134- and polyhydric alkyl esters of these acids may beused and these may be fully esterified or,

if desired, only one of the two ormore hydroxy groups need be esterifled.

Besides the alkyl iso-cyanates and iso-thiocyanates aryl esters may also be employed, such as the phenyl or naphthyl esters of the acids specified above, and of particular interest are the alkylated phenolic and naphtholic esters of such acids, which are more soluble in the oils than the corresponding unalkylated esters. 1

The esters may be added in relatively small amounts; for example as little as .1% is efl'ective, although more is generally used, say from 2% to .5%. On the other hand, as muchas 1% is generally unnecessary. These compounds may be added to the oil as such and dissolvul in some solvent such as benzol or toluol and. dispersed through the heavier oil. I i

The oils in which the present class of inhibitors may be used are generally described as well refined lubricating oils. Petroleum lubricating oils may be obtained from any desirable crude source, such as paraflin, asphalt or mixed base crudes, and may be refined by ordinary methods, such as distillation, acid'and clay treatment, or by special methods including hydrogenation, de-- structive hydrogenation, solvent extraction and heavy acid treatment with concentrated or fuming acid or olenm such as is used for the preparation or white oils for medicinal or technical purposes.

Whiie cyanides and cyanates and cyanuric acid compounds have been used for various purposes in conjunction with hydrocarbon and other oils, it will be understood that the iso-cyanates and the iso-thio-cyana'tes are a quite different class of compounds and in general are much more efiective for the. present purposes than the cyanocompounds known hitherto. As examples of the action of the present class of compounds, the fol lowing may be considered:'

Example 1 to a circulatory path and at fifteen-minute intervals the volume of oxygen absorbect was measured bydifierence. The result of these tests is included inthe following table:

Oxygen absorption cc. of oxygen 10 Oilsample cc. sample 15- minute intervals at 200 C.

Lubricating oii (blank) 190-80-83 Same containing .2% allyl iso-thiocyanate-.." 18-100 Same containing 2% ethyl-thio-cyanate 171-94 The above quoted results indlcatethat the thiocyanate produced little, if any, reduction in oxidation rate while the iso-thio-cyanate greatly reduced the rate.

Example 2 Samples of the oils used above were then subiected to a cone deposit test, which measures the tendency of oils to deposit sludge at elevated I itiehiperialtfiresp these-I testjs the 201 1 was passed I I I {of the 611 has passed threugh :thezco'ne theznaph the insoluble; residue: adhering w the cone? and I I v cb'ziteine d in the 011 ilsgcdllatted an recorded;

- g :In these tests the biank sample showed a value, i ,Oif ES; 98 0; of Ithe oil against; for; 1

' included in the fol lbwing table: 5

DISCLAIMER QLUBRICATINGIOIL Gomrosrrlou Patent -1 I I I I I datedIVIai'ch14f-1939;

{0 Gazette'July 2, 1 9.40.]

, I atfajfixedf rate thmugha grooveeut; in; the inner 1 I j I :eurfa'ee at a steel cone org-standardized dimensions; 5 Z I l i :Which, isfhatd tq 250: C 1 After; 9; Med ivmume 3 l I I I i namerf sa le :or a mineral: lubricating on I 8.5 A; E5 50 grade was subjected .130 the; oxidaticgm test along: with two Samples containing .-2 bi i I pheny'l 1so -cyanate'andpheny1 1so+thic+cyanatm l f respectively. I "The oxidation rat s Obtained: are I l i .1 *1; Composition according to claim; 2 o! xygen/IO: I

sampla!15- I I the added s'ubstaheeis en alklvl e'ster oriswmoe; cyanicaeidi y The lubnc-ating oils described above, may con-=;-. q ,5 tain'additional ingredlentsysuchaszdyes:for'cast; I

or l thic eners, y ur i h b tors oap 1 11s i I I persinig agents; and the 111m; 1 y

oune: amen 01- m oxidetiong inhibitm snnr m. g;

g'iany particulaeoi li nor to any; perticular mhibitory I I i but; only to the following} claims in which it isj I j l I i desired} to, iclaim ,9,1! novelty f1iheIBIit in th 6 111+; l I I I vention i I j .j

, g I -1.iCompo'sition of matter eampnsmg a jviscQusQ I minerallubricating oil and e-smjall: amount of an, I g

I i s'q-cyanic cbmpound selected from the class can I I sistlng of acids and esters; soluble therein; 7 I I 2, Cumpositiongo f matter comprising; a, vl'seouis' Q 3 i imirierallubricatinepifandafimall amount; Qf Iester selected from the; class iOf alkyl end aryl; estershof'iso cyanicaclds. {.ff i I 3.?Composition aceordlnggto claim: 2 in :whieh I the ester is an ester of iso thio-cyanic :acid. I

in whien I 5. Cemposition according to; claim 2 in which i i a i I I a, Compasition incoming: to claim; 2 1m which;

lithe adgledeubstance isanalwl ester pf isqi 'WM a d-Jf 'entersthi s d isclaimerto 1a" iqfsai LettersBatent jfjjmf