US2989466A - Oxyalkylated-carbonated phenates in lubricating oils - Google Patents

Description

United States Patent i 2,989,466 OXYALKYLATEDFCARBONATED PHENATES IN LUBRICATING OILS Andrew Doyle Abbott, Ross, Califi, assignor to California Research Corporation, San Francisco, Calif., a corporation of Delaware No Drawing. Filed Oct. 6, 1959, Ser. No. 844,621 4 Claims. (Cl. 252-417) This invention pertains to improved metal salts of alkylphenols particularly useful as lubricating oil additives; more particularly, this invention is directed to lubricating oil compositions having incorporated therein as detergents certain particular modified metal alkylphenates.

This application is a continuation-in-part of patent application Serial No. 685,07 3, filed September 20, 1957, and now abandoned.

It is well known that metal salts of alkylphenols are useful as detergents and as acid neutralizers in lubricating oils compositions. Because of their excellent detergent characteristics and acid neutralizing properties, lubricating oils containing metal phenates have been partcularly effective in heavy duty oils used for lubricating high speed diesel and gasoline engines.

crankcase lubricants in internal combustion engines are exposed to extremely severe conditions of operation, particularly in diesel engine service, wherein the lubrieating oil compositions encounter temperatures as high as 650 F. and higher, and pressures of 1000 psi and higher. Under such conditions of operation, the lubricating oil compositions have a tendency to deteriorate, forming gummy deposits on the piston rings, the piston lands, and the skirts of the pistons. Such deposit formation has been inhibited by the use of metal phenates as detergents.

The effectiveness of the metal salts of alkylphenols as detergents is modified by storage conditions, particularly when lubricating oil compositions containing such metal alkyl phenates are exposed to water. Water may become admixed with the lubricating oil composition simply by the normal breathing of the container in which the lubricating oil compositions are stored. That is,

during changes in temperature, the air may be sucked into the bulk containers, and the water vapor in the air will condense in the oil container, gradually becoming admixed with the oil. This water sensitivity of alkyl phenates has been reduced by known treatment of alkyl phenates with carbon dioxide; that is, when metal phenates are treated with carbon dioxide, this water sensitivity is minimized. However, even though the water effect on phenates has been reduced by this carbon dioxide treatment, such lubricating oil compositions still break down prematurely.

' It is not only water sensitivity which effects the benefi-cial characteristics of metal salts of alkylphenols in lubricating oil compositions. Other factors which must be considered are color stability and viscosity stability during storage, and the characteristic which permits a metal phenate to blend in an-oil containing other additives without forming an undesirable .haze.

j Therefore, it is an object of the present invention to prepare lubricating oil compositions having incorporated therein a storage stable metal salt of an alkylphenol.

.In accordance with the present invention, it has been discovered that. improved lubricating oil compositions areobtained by incorporating therein oxylakylated-carbonated metal alkyl phenates. Thus, the lubricating oil 7 Patented June 20, 1961 use of lighter oils reduces the overall mileage obtainable by such a composition. However, by the use of the oxylkylated-carbonated metal phenates of the present invention, heavier base oils can be used in the blending of lubricating oil compositions useful for internal conibustion engines. Therefore, since heavier base oils give better oil mileage in engine operation, the oil compositions described herein give better oil mileage than that previously obtainable With untreated metal alkyl phenates.

As used herein, the term "oxyalkylated-carbonated metal phenate means the product obtained by first reacting a metal salt of an alkyl .phenol, including sulfurized metal salts of alkyl phenols, with an alkylene oxide, followed by reaction with carbon dioxide. Alkylene oxides condense with active hydrogen atoms of the phenates, and the subsequent reaction with carbon dioxide converts the phenate metal to a partial bicarbonate. The reaction products thus prepared are not described in the art wherein it is known to alkylate an alkyl phenol'with ethylene oxide, then form the salt of the thus alklated product, using this tmcarbonated product as a lubricating oil additive. It is not meant herein to describe any theory in the formation of oxyalkylated-carbonated metal phenates which are described herein as useful additives for lubricating oil compositions.

The alkylene oxides which are useful herein in the reaction with metal salts of alkyl phenols are the alkylene oxides containing from 2 to 3 or more carbon atoms,

preferably 2 to 3, and as ethylene oxide, propylene oxide, etc., as exemplified by the formulas: I

OH2-CH2 CHE-037C112 MAOL Mi ly wherein A is an essentially hydrocarbon aromatic radical, such as a naphthalene radical and a benzene radical, preferably a benzene radical; R is a cyclic, straight-chain or branched-chain, saturated or unsaturated, essentially hydrocarbon radical (e,g., an aliphatic radical) having from 4 to 30 carbon atoms, 0 represents oxygen, a is a number having a value from 1 to 5, M is a polyvalent metal, x is a number from 1 to the valence of the metal M, and y is a number equal to the difference of x and said valence.

Examples of suitable hydrocarbonaceous radicals (that is R radicals in'the above formula) include alkyl radicals such as butyl, hexyl, octy-l, decyl, dodecyl, hexadecyl, eicosyl, triacontyl radicals, etc.; radicals derived from petroleum hydrocarbons, such as white oil, wax, olefin polymers (e.g., polypropylene and polybutylene), etc.; aryl radicals such as phenyl, naphthyl, etc; aralkyl radicals such as phenyloctyl, phenyldecyl, phenyloctadecyl,

etc.; alkaryl radicals such as amylphenyl, cetylphenyl,

; etc.

Examples of the metal M include lead and the metals of Group II of Mendeleefs Periodic Table, particularly the alkaline earth metals, for example, calcium.

In the lubricating oil compositions of this invention, it is particularly preferred that the metal salts of the so-called basic sulfurized metal alkyl phenatm are used in the reaction with oxyalkylenes and carbon dioxide. Thus, as used herein, the term basic sulfurized metal phenates refers to sulfurized metal phenates wherein the mol ratio of the metal to phenol derivative is greater than that of the normal sulfurized metal phenates. That is, in the normal sulfurized calcium phenates, the mol ratio of metals to alkyl phenol is 1:2.

In the lubricating oil compositions herein containing oxyalkylated-carbonated metal phenates, it is preferred that in the final product the average mol ratio of alkylene oxide to metal alkyl phenate (based on the metal) has a value no greater than about 4 (i.e., a maximum value of about 4) with a minimum value of about 0.05. It is preferred that the average mol ratio value is from 0.3

. In the carbonation step in the preparation of the phenates of this invention, it is preferred that the average mol ratio of carbon dioxide to oxyalkylated metal alkyl phenate ranges from 0.1 to 1.0.

The metal salts of alkyl phenols as used herein include the sulfurized metal salts of alkyl phenols such as described in US. Patents Nos. 2,680,096 and 2,680,097.

Suitable base oils useful in the composition of this invention include a wide variety of lubricating oils such as naphthenic base, parafiin base, and mixed base mineral oils, other hydrocarbon lubricants, e.g., lubricating oils derived from coal products and synthetic oils, e.g., alkylene polymers (such as polymers of propylene, butylene, etc.) alkylene oxide type polymers, dicarboxylic acid esters, liquid esters of acids of phosphorus and silicon, polysiloxanes, etc. Synthetic oils of the alkylene oxide type polymers which may be used include those exemplified by the alkylene oxide polymers and derivatives, including alkylene oxide polymers prepared by polymerizing alkylene oxides, e.g., propylene oxide, in the presence of water or alcohols (e.g., ethyl alcohol, and esters of alkylene oxide type polymers).

Synthetic oils of the dicarboxylic acid ester type include those which are prepared by esterifying such dicarboxylic acids as adipic acid, azelaic acid, suberic acid, sebacic acid, alkenyl succinic acid, fumaric acid, maleic acid, etc., with alcohols such as butyl alcohol, hexyl "alcohol, 2ethyl hexyl alcohol, dodecyl alcohol, etc.

Examples of dicarboxylic acid synthetic oils include dibutyl adipate, dihexyl adipate, di-Z-ethyl-hexyl sebacate, etc.

Synthetic oils of the alkyl benzene type include those which are prepared by alkylating benzene (e.g., dodecyl benzene, etc.). Synthetic oils of the type of the liquid esters of silicon and polysiloxanes include those exemplified by tetra (2-ethyl hexyl) silicate, polymethylphenyl siloxane, polymethyl siloxane, etc.

The oxyalkylated-carbonated metal alkyl phenates herein may be used in lubricating oil compositions in amounts sufficient to impart improved detergency characteristics, that is, in amounts of about 0.1% to about 25%, by weight, to as high as 50%, preferably 0.5% to 5%, by weight. Their unique physical characteristics make the phenates particularly suitable for lubricating oil concentrates containing up to 75% of phenate.

The immediate examples hereinbelow describe a method of preparing basic sulfurized metal phenates which are preferably used according to this present invention in the further reaction with alkylene oxides of carbon dioxide.

Example 1.--Preparation of alkyl phenol A mixture consisting of 300 parts by weight of phenol, 555 parts by weight of olefin polymers having average 4 molecular weights of 170, and 45 parts by weight of acidtreated clay was heated at 300 F. for a period of 12 hours, after which the mixture was filtered. The remaining reaction was heated to 530 F. to remove unreacted phenol, olefin polymers, and low molecular weight alkylphenols.

Example 2.Preparation of sulfurized metal alkyl phenate A mixture of 600 parts, by weight, of an alkylphenol having a boiling range of 560 F. to 700 F., parts, by weight, of calcium hydroxide, 55 parts, by weight, of sulfur, and 300 parts, by weight, of ethylene glycol was heated at 300 F. with agitation at an absolute Pressure of 300 mm. of mercury. After the water of reaction had been distilled off, the pressure was reduced to 60 mm. of mercury and the temperature raised to 380 F., at which temperature and pressure the ethylene glycol was removed. During the period when the glycol was being removed, 400 parts, by weight, of petroleum lubricating oil were added. When substantially all of the ethylene glycol had been removed, the mixture was cooled and 200 parts, by weight, of a petroleum thinner were added and the mixture was filtered. The filtrate was heated at reduced pressure to remove the petroleum thinner. The final lubricating oil composition contained 2.85% sulfur and 5,63% calcium; the basic sulfurized calcium alkyl phenate containing 92% more calcium than that present in the corresponding normal alkyl phenate.

Example 3.Preparati0n of sulfurized metal alkyl phenate A mixture of 300 parts, by weight, of an alkylphenol having a hydroxyl number of 155, 40 parts, by weight, of calcium hydroxide, 19 parts, by weight, of sulfur, 50 parts, by weight, of ethylene glycol and 200 parts, by weight, of petroleum lubricating oil was slowly heated up to a temperature of 375 F. at an absolute pressure of 60 mm. of mercury. The temperature of 375 F. was maintained for 3 hours to remove substantially all of the ethylene glycol, after which time the reaction mixture was filtered. The lubricating oil solution of normal sulfurized calcium alkyl phenate contained 3.83% calcium and 1.67% sulfur.

Example 4--Preparati0n of sulfurized metal alkyl phenate A mixture of 110 pounds (0.325 mol) of an alkylphenol having a hydroxyl number of 166 (and wherein the alkyl radical was derived from propylene polymers having an average of 12 carbon atoms), 24 pounds (0.325 mol) of hydrated lime, and 12.5 pounds (0.389 mol) of sulfur was heated to F. with constant agitation until a uniform mixture was obtained. The mixture was then heated to 260 F. at 500 mm. of mercury absdlute, after which 45 pounds (0.725 mol) of ethylene glycol and 106 pounds of Mid-Continent neutral oil having a viscosity of about 100 SSU at 100 F. (which had been previously heated to about 225 F.) were added. The water of reaction was removed and the heating was continued. The ethylene glycol was distilled oil by heating to 380 F. at 45 mm. of mercury.

Example 5-Preparation of oxyalkylaIed-carbonated sulfurized metal phenate STEP A Ethylene oxide was charged to the final reaction mix ture of Example 4 hereinabove at 300 F. The ethylene oxide was injected at the bottom of the reaction vessel so that the ethylene oxide pressure never exceeded 5 p.s.i.g. until 6.5 pounds (0.147 mol) of ethylene oxide had been added to the reaction mixture during a period of 25 minutes. Moderate cooling was required to maintain the reaction temperature at 300 F. After all of the ethylene oxide had been introduced, the reaction was stirred for an additional 30 minutes, followed by purging with nitrogen to remove any excess ethylene oxide; that is, the

unreacted ethylene oxide.

STEP B The reaction vessel was then pressured to 75 p.s.i.g

proximately 12 pounds (0.252 mol) of carbon dioxide were introduced into the reaction. The whole reaction mixture was maintained at a temperature of 300 F. under 75 p.s.i.g. carbon dioxide pressure with constant agitation for a period of one hour.

Filter aid (e.g., Hyflo-Super-Cel) was added to the reaction mixture and the product was filtered through a filter-press." Table I hereinbelow sets-forth the analysis ofai the products obtained.

Table I hereinbelow presents analyticalidata obtained by'ana'lysi's of the products of Examples 4 and 5 hereinabove.

- TABLE II Unmodified I Finished Phenate Product of Produce of Product of Step A Step B Example 4 Percent Calcium 4. 25 4. 19 4. 10 Percent Sulfur 2. 49 2. 40 aseN m Hme KO lz-L 112 1 106 Percent 4 2.3 Percent Sulfated Ash 14.1 l3. 9 13.5 ASTM Color, Dilute 3 2. 2. 5 Viscosity, SSU' For the purpose of ascertaining that an oxyalkylated phenate was obtained in-Step A of Example 5 hereinabove tl1e product was fractionated by precipitation with acetone. The phenate was then purified by reprecipitating several times from acetone. The resulting solid oxyalkylated .alkylphenate contained 13.1% calcium and 5.5%

"sulfur; and the color .was chalky white. Upon analysis "with .the infrared spectrometer; it was ascertained that an oxyalkylated phenate had been obtained.

The data of Column 2 of Table I hereinabove markedly show the undesirable viscosity effects obtained by the oxyalkylation of phenates. On the other hand, the viscosity characteristics of the finished oxyalkylated-carbom' ated phenate as shown in Column 3 of Table I were similar to those of the unmodified original phenate.

Table II hereinbelow presents data which illustrate further the undesirable viscosity efiects obtained by oxyalkylation only of metal phenates. A sulfurized metal alkyl phenate was oxyalkylated with ethylene oxide similarly as described in Step A of Example 5 hereinabove.

TABLE H Unmodlfied Phe- Oxyalkylated Phenates nate Mol Ratio, Ethylene Oxide/Ca 0.0 0.55 0.78 1.06 Viscosity, SSU:

1 Calcium of the calcium phenate.

Table III hereinbelow summarizes reaction conditions and analytical data of further preparations of oxyalkylated-carbonated sulfurized metal alkyl phenates.

The sulfurized metal alkyl phenate (noted in the tables as reactant SMAP) was a 45% petroleum oil solution of a sulfurized calcium alkyl phenate containing 4.21%, by weight, calcium, and 2.72% sulfur, and wherein the alkyl radical was derived from propylene polymers having an average of 12 carbon atoms.

TABLE III Experiment No 1 2 3 4 5 6 -I. Reaetants (STEP A):

BMAP (Wt. Percent) 100 94.7 94.9' 92. 9 97.5 98.1 Ethylene Oxide (Wt. Percent) 5. 3 5. 1 7. 1 2. 5 l. 3 Mel Ratio, SMAP Ethyu lene Oxide 1.21 1.17 1.6 0.5 0.3

' Reactionlemp F 380 300 350 -350 200 Percent Calcium. 4. 21 3. 99 4. 04 3. 95 4.11 3. 8 'Percent'Sulfur- 2.72 8.36 2. 58- 2.51 2.57 2.8 Viscosity (SSU): 1 100]? 2,690 5,316 5,942 5,645 4,267 4,060

210! 13 16 V 18 17 166 160 II. Reactants (STEP B) (Car- 'bonation Step): 7 7

Pressure Temperature, F 380 300 350 350 200 III. Analysis Final Product:

, Percent Calcium 3. 98 4.03 3. 97 4.02 3.77 Percent Sulfur. 2. 46. 2. 30 2.35 2.68 Viscosity (SSU) I 100 F 1, 428 1, 870 1, 572 1, 708 2, 998 210 F 81 y 84 94 134 Atmos. 3 2.5 Hg.

described as follows:

(a) The engine used'for the L-1 test was a Caterpillar single-cylinder, 5%" bore diesel engine; it was run for hours at 100 r.-p.m. at a load of 19.8 brake horsepower, oil temperature of F. to F., jacket temperature of F. to F., using a fuel containing 1% sulfur. (b) The engine used in the Ir-4 test was a stock Chevrolet engine, wherein the normal Babbitt bearings where replaced with copper-lead bearing inserts, which were weighed before being assemblied in the engine. The Chevrolet engine was operated at 3150 r.p.m., the engine jacket temperature was maintained at 200 F., the crankcase oil temperature was maintained at 280 F., and the engine was operated for a period of 52 hours, at which time the bearing inserts were weighed.

(0) The engine used for the l-G test was a Caterpillar single-cylinder engine having a 5%" bore and a 6%" stroke; operating at 1800 r.p.m. with 42 brake horsepower; an oil temperature of 205 F.; an inlet air temperature of 255 F.; supercharged to 53 inches of mercury absolute; for a period of 120 hours, using a fuel with a minimum sulfur content of 0.35%.

The groove deposit ratings noted in Table II as GD Rating refers to the amount of deposit in the top ring groove as a percent of the total possible. That is, a rating of 0 means that there was no deposit in the groove, and a rating of 100 means that the groove was completely filled with deposit.

The sulfonate used in the oil composition was a calcium petroleum sulfonate.

The sulfide was a sulfurized diparatlin sulfide.

The thiophosphate was a zinc salt of a mixed diester of dithiophosphoric acid, wherein one of the ester radicals was derived from butyl alcohol and the other ester radical was derived from methylisobutylcarbinol.

Phenate A was a sulfurized calcium alkyl phenate as described in Example 4, hereinabove.

Phenate B was an oxyethylated-carbonated sulfurized calcium alkyl phenate as described in Example 5 hereinabove.

TABLE IV Oil Composition mM. g3 p [K Whole Engine Test Bearing GD Test Duration Phenate- Weight Rating (hours) Sulfonate Thiophos- Percent Loss phate Sulfide (mgs.) A B l-G 120 as s1 s L-l 120 17.5 28.6 7 0.35 i 12 120 17. 5 28. 5 7 0.35 1 I-4 62 7 16 6 0. 25 846 oil composition.

an alkylphenol, followed by reaction with from 0.1 mol to 1 mol of carbon dioxide per mol of metal alkyl phenate, wherein said alkylphenol contains from 4 to 30 carbon atoms in the alkyl radical and said metal is a metal selected from the group consisting of lead and the metals of Group II of Mendeleefs Periodic Table.

2. A lubricating oil composition comprising an oil of lubricating viscosity, and from 0.1% to 25%, by weight,

of an oxyalkylated-carbonated sulfurized metal alkyl phenate, wherein said oxyalkylated-carbonated sulfurized metal alkyl phenate is obtained by reacting from 0.05

mol to 4 mol of an alkylene oxide per mol of sulfurized 'metal alkyl phenate, with subsequent reaction with 0.1

mol to 1 mol of carbon dioxide per mol of sulfurized metal phenate, wherein said alkyl radical of said phenate contains from 4 to 30 carbon atoms and said metal is a metal selected from the group consisting of lead and the metals of Group II of Mendeleefs Periodic Table.

' 3. A lubricating oil composition comprising an oil of lubricating viscosity, and from 0.5% to 5%, by weight,

of an oxyalkylated-carbonated sulfurized metal alkyl phenate, wherein said oxyalkylated-carbonated sulfurized metal alkyl phenate is obtained by reacting from 0.05 mol to 4 mol of an alkylene oxide per mol of sulfurized metal alkyl phenate, with subsequent reaction with 0.1 mol to 1 mol of carbon dioxide per mol of sulfurized metal phenate, wherein said alkyl radical of said phenate contains from 4 to 30 carbon atoms and said metal is a metal selected from the group consisting of lead and the metals of Group II of Mendeleefs Periodic Table.

4. The lubricating oil composition of claim 1, wherein said metal is a metal of Group II of Mendeleefs Periodic Table, and said alkylene oxide is ethylene oxide.

References Cited in the file of this patent UNITED STATES PATENTS 2,402,448 Richards June 18, 1946 2,406,041 Schneider et al Aug. 20, 1946 2,659,696 Netf Nov. 17, 1953 2,680,096 Walker et a1. June 1, 1954 2,736,701 Neff Feb. 28, 1956 2,762,774 Popkin Sept. 11, 1956 2,781,403 Kane et a1 Feb. 12, 1957

Claims (1)

1. A LUBRICATING OIL COMPOSITION COMPRISING A MAJOR PROPORTION OF AN OIL OF LUBRICATING VISCOSITY, AND, IN AN AMOUNT SUFFICIENT TO IMPART DETERGENCY CHARACTERISTICS TO SAID LUBRICATING OIL COMPOSITION OF AN OXYALKYLATEDCARBONATED METAL ALKYL PHENATE, WHEREIN SAID OXYALKYLATED-CARBONATED METAL ALKYL PHENATE IS OBTAINED BY REACTING, PER MOL OF METAL SALT OF ALKYLPHENOL, FROM 0.05 TO ABOUT 4 MOLS OF AN ALKYLENE OXIDE WITH A METAL SALT OF AN ALKYLPHENOL, FOLLOWED BY REACTION WITH FROM 0.1 MOL TO 1 MOL OF CARBON DIOXIDE PER MOL OF METAL ALKYL PHENATE, WHEREIN SAID ALKYLPHENOL CONTAINS FROM 4 TO 30 CARBON ATOMS IN THE ALKYL RADICAL AND SAID METAL IS A METAL SELECTED FROM THE GROUP CONSISTING OF LEAD AND THE METALS OF GROUP II OF MENDELEEF''S PERIODIC TABLE.