US2644794A - Hydrocarbon oil compositions - Google Patents

Description

Patented July 7, 1953 sauteGhemical flompany ,stkllnuismMit, stem:

n rationv-of Delaware No Drawing. Application Niwemben I5; 1951 Serial No. 1.9558981 This invention relates: toanti-foaming hydrQ carbon oils: and deals more particularly within!- drocarbon oils containing smail amounts of" oer-- tain. ketonie epoxid'ecompounds as. anti-foaming agents. l

The problem. of foam inhibition is one of major importance to all. industries employing. hydro,

carbon oils under foam-inducing conditions. While most oil's will toam tosome extent. due. to vigorous agitation and aeration in a. running engine, foaming becomesa problem only when; loss of oil: occurs by foam seepage. or when. so many air bubbles are: present: in. the oil that proper lubrication of bearing. surfaces. isv impeded.

oil by the use of additives is made only at the expense: of increasing its susceptibility to foam. Thus; while the demands of modem engine design for extreme-pressureresistinglubricants; for anticorrosive' lubricants, for lubricants of" inz creased. viscosity law' pour-point: and good; detersrve. properties have been met: by-the formu latlon; and: use at numerous; chemicals; which. give these desirable properties to; oils; when. admixed:

therewith the; use: of such; additives: makes: the" treated oils? particularly susceptible to: foaming; While light. graded-laces.- L0 grad-e oils are: almost non-foamingj under the most. severe: conditions, when. there are: employed; with these. oils one, or more: additivessueh as viscosity index 1m.

proverts, extreme-qoressure.- resisting; improversg. pour-point; depressors; e.tc.,,, the, resulting? improved oils do not retain;v their non-foaming characteristics.v andate. frequently: even-more sus- Foaming: is often experienced it dry sump enee-ptible. tofoaming; than-arertheheavy grade'oils. m in which th is. employed: a scavenger Hencetwith thedevelopmentoof newhighesbeed pumpfor'collecting oil fromvarious engine parts engines and the? provision. of the; new.- additive-- and returning it to: the lubricant reservoir. Heretype 1ubrieants, the, problem-.of foaming; has asair: may be: con-acted along-with 1 31 and desumed mama-importance; Attempts to sulvethe posited: in: thereservoin. The: design and opera-- problemby: defoaming existingoils; e; g;, by ubtionyof aircraft engines is. suchthat foaming ocmitting oilsv to;.heat-treatment,, absorption; proccurs more readily in: this. type of engine than; it esses, filtering; stepa, etm. have provedofr'but little doesgin. a utomotivgengines, value The; most practical? solution. to; this. prob Foam andfroth inhydrocarbon oil's, however, y Iem. has been made by the use of anti-foamad isnotdue solely toengine design-i Althoughl'ocaditivesi. tiona-nd design of the oil pump, oil sumpandoili A number of anti-4509,1111. additives;. L e=, anti-- lines t smodification of other engineer foamingagents foam depressing: agentsu foam ing featuresmay. retard" foam development, when depressants, antifrothersor foam suppressors. certain. oils. are emp yed with high: sp ed are known; but. in prior art their use; has been. gines, mechanical control, alone, does, not sufn attendedwithnumerous diflicultiesi Among disfice; Here; the. nature of the crankcase oil is O advantageaof sucir.knownadditivesi'areehemical often the: prime factor in foaming difficulties reactivity-*with; the lubricant or. other oiladdi- Theheavier the grade of the oil or the higher tivest corrosive efizect susceptibility to decom? the viscosity of the oil, the more difil'cult it to position; upon; hea-ting,, instability when; ex d; avoid foaming; Heavy grade oils, such as those 35; for longperiods of; time.- to; ordinary atmospheric: employed high-speeddiesel and-sparks ignition conditions hightcostretez. engines operating" under severeconditions are Now-I have found that; foaming; off hydrocarparticularly susceptible to; foaming; The heavy bonoilsisefiiciently retarded andzevencomplete oilsholdbubbles very firmly'sothat when foam'i's 1y inhibited when; there is. added; t s h; 11 a. formed, itis very persistent. small: quantity, say,. up to;1.0 pen centby weight developments in engine construction, of. a-liquid mixture of. adducts of. one. moleof. a have constantly demanded lubricants having saturated1-aldehydeof. from 1 to lg atoms properties not'possessed by crudehydrocarbon with,mor thanonemole otbutadienemonoxide. 02%;, Such pr p rties are now gener ly- CQII- Addition products. of this kindpare described. in. ferred to lubricants by the use of additives. For the. copending application. of. Tracy M. Patrick, example, in order to sat sfy h lubrication Jr". Serial. No... 195,914. nleanovember. 15,1950. quirements of hypoid gears, materials which-oim- They are readil'y'obtainedi'by a free-radicalrcatapart extre -p r r stin pr p r ies are lyzed' addition... reaction substantially according now generally added to gear lubricants. In most t th scheme; cases, however, the improvement attained: in an 3 in which R is an alkyl radical of from 1 to 17 carbon atoms and n is an integer of from 2 to 20.

Saturated aldehydes which may be employed for the preparation of the present adducts are, for example, acetaldehyde, propionaldehyde, nbutyraldehyde, isobutyraldehyde, n-valeraldehyde, isovaleraldehyde, methylethylacetaldehyde, n caproic aldehyde, isohexaldehyde, 2-ethylhexaldehyde, octaldehyde, capric aldehyde, undecaldehyde, lauric aldehyde, palmitic aldehyde, stearic aldehyde, etc.

The liquid mixture of adducts is obtainable by contacting butadiene monoxide with the saturated aldehyde in the presence of a free-radical liberating agent, e. g., a peroxidic compound as catalyst, allowing the resulting mixture to stand at ordinary or increased temperatures until formation of the liquid mixture of adducts has occurred, and removing from the resulting reaction product any initial unreacted material and 1:1 molar adduct. The residue is a liquid mixture of a series of adducts having the above formula.

The present aldehyde-butadiene oxide adducts are effective anti-foaming agents only'when they are employed in very low proportions, i. e., in amounts of up to 1.0 per cent by weight, based on the weight of the total hydrocarbon oil composition. From .01 per cent to .05 per cent of the adducts is preferred, depending upon the nature of the oil. Heavy oils and oils containing foaminducing adjuvants require more of the present anti-foaming adducts than do base oils of good viscosity characteristics.

The anti-foaming effect of the aldehyde-butadiene oxide adducts is not materially affected by the presence of other adjuvants in the oil. The present adducts are stabl ketonic epoxides which can be hydrolyzed only with difficulty, and since they are present in the oils in only very small quantities, the use of even very acidic or very basic additives in the oil has substantially no effect on the adducts. Hydrocarbon oils containing the present anti-foaming agents are stable when stored over long periods of time and also when subjected to heat and pressure conditions of engine and motor operation.

While the anti-foaming effect of the aldehydebutadiene oxide adducts is obtained only when they are employed in concentrations of up to 1.0% by weight, the adducts may be incorporated into hydrocarbon oils in much higher proportions, e. g., in amounts of up to per cent or even 50 per cent of the weight of the hydrocarbon oil to give concentrates. Oils containing such high proportions of the adducts may be manufactured and sold for use as lubricant additives. Addition of small amounts of such concentrate to hydrocarbon oils may be made so as to supply an oil containing suitable quantities of the adducts.

Hydrocarbon oils which are rendered substantially anti-foaming by incorporation therein of quantities of up to 1.0 per cent of the present adducts are synthetic or petroleum stocks of varying viscosities such as lubricating oils for internal combustion engines and motors, diesel fuels and lubricants and pressure transfer media, e. g., industrial lubricants, process oils, hydraulic oils, turbine oils, cutting oils, fluid greases, gear oils, shock absorber oils, spindle oils, journal bearing oils, pneumatic tool lubricants, etc. They may be synthetic or natural hydrocarbons of any type, i. e., parafiinic, naphthenic or blended.

The invention is further illustrated, but not limited, by the following example.

Example The anti-foaming properties of lubricants may be determined according to the procedure generally described in Designation L-12-445 of the Coordinating Lubricants Research Committee of the Coordinating Research Council, New York. Briefly this procedure involves bubbling air or an inert gas such as nitrogen through the hydrocarbon oil to be tested, employing standard apparatus and standard conditions.

The oil was placed in a standard -ml. graduated cylinder in the top of which was inserted a two-hole rubber stopper. An air-inlet tube extended through this stopper, to the bottom of which was attached a gas diffuser or porous stone sphere. The length of the inlet tube was adjusted so that when the apparatus was assembled. the sphere just touched the bottom of the cylinder. The sphere was attached to the inlet tube by means of litharge Or glycerine, or by a copper tube soldered to the diffuser-stone coupling. The oil bath used was capable of controlling temperature at 200-J:1 F., (93.3i0.6 C.) large enough to permit the cylinder to be immersed at least to the 90-ml. mark, and arranged to permit the visual observation of the graduations on the cylinder.

Dry nitrogen was supplied at the rate of 0.2 cubic feet per hour, employing a calibrated flowmeter. The sample was heated to F. (48.9" C.), and then cooled, before testing, to 75i5 F. (23.9:2.8 C.) in a constant temperature room. 25 cc. of oil was used for each test.

With the air hose disconnected between the fiowmeter and the delivery tube to th diifuser stone, the stone was allowed to soak in the oil for 5 minutes, at the end of which time the air flow (0.2 cu. ft. per hour) was started through the stone. Zero time Was noted when the nitrogen bubbles started to rise from the stone. Readings of the top and bottom foam levels were taken at the end of a 5-minute period. The volume of foam was calculated from the two readings.

Employing the testing procedure described above there was determined the anti-foaming effect of a liquid mixture of n-butyraldehydebutadiene oxide adducts when added to a Champlin SAE base oil in concentrations of from 0.2% to 0.5% by weight of the oil. The liquid mixture of adducts, B. P. above 81 C./l0 mm. consisted of adducts of one mole of n-butyraldehyde with from 2 to 20 moles of butadiene oxide and'were prepared by maintaining at a temperature of about 74 C. for a time of 68.5 hours a mixture consisting of 216 g. (3.0 moles) of n-butyraldehyde, 70 g. (1.0 mole) of butadiene monoxide and 2.0 g. of benzoyl peroxide, and removing from the resulting reaction mixture material which boiled below 81 C./10 mm., as described in the previously cited copending application. The following results were obtained:

Concentration of adduct. weight percent 0 02 Foam cc 10 0.025 cc 2 0.03 none 0.05 none In the absence of an additive, the Champlin 30 SAE oil gave 71 cc. of foam under the same testing conditions.

Nonfoaming hydrocarbon oil compositions may be obtained by incorporating into such oils in a quantity of up to 1.0% based on the weight of the composition, other liquid mixtures of adducts of one mole of a saturated, aliphatic aldehyde with from 2 to 20 moles of butadiene oxide. Thus, instead of the butyraldehyde-butadiene oxide adducts employed in the above example there may be used, e. g., adducts of one mole of acetaldehyde, of octaldehyde or of stearaldehyde, with from 2 to 20 moles of butadiene oxide. The present adducts impart anti-foaming properties to hydrocarbon oils, generally, in the presence or absence of other customarily employed additives such as extreme-pressure resisting additives. detergent additives, etc.

What I claim is:

1. A substantially foam-resisting hydrocarbon oil composition containing up to 1.0 per cent by weight based on the weight of the composition of a liquid mixture of adducts having the formula in which R is an alkyl radical of from. 1-1'7 carbon atoms and n is an integer of from 2-20.

2. A lubricant composition containing a hydrocarbon oil and up to 1.0 per cent by weight based on the weight of the composition 01 a liquid mixture oi. adducts having the formula I I ROO[OH2-CH.CH.CH1. H

I CHaCHnCHzC O[-CHz-CH.CH.CH20]H in which n is an integer of from 2-20.

JOSEPH E. FIELDS.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,528,465 Borsoif Oct. 31, 1950 2,528,466 Borsofi Oct. 31, 1950 OTHER REFERENCES Foaming of Aircraft-Engine Oils as a. Problem in Colloid Chem. NACA Report ARR. No. 4 I O 51944 -McBain et a1.

Claims (1)

1. A SUBSTANTIALLY FOAM-RESISTING HYDROCARBON OIL COMPOSTION CONTAINING UP TO 1.0 PER CENT BY WEIGHT BASED IN THE WEIGHT OF THE COMPOSITION OF A LIQUID MIXTURE OF ADDUCTS HAVING THE FORMULA