US3536623A - Organic halo phosphite ester reaction products and hydrocarbon oil compositions containing the same - Google Patents

Description

United States Patent ORGANIC HALO PHOSPHITE ESTER REACTION PRODUCTS AND HYDROCARBON OIL COMPO- SITIONS CONTAINING THE SAME Shih-En Hu, Roselle, N.J., assignor to Esso Research and Engineering Company, a corporation of Delaware No Drawing. Filed Jan. 5, 1968, Ser. No. 695,893

Int. Cl. Cm 1/48 U.S. Cl. 25246.7 8 Claims ABSTRACT OF THE DISCLOSURE Organic halophosphite mono or diesters are reacted with a halide of sulfur and alkylene glycols or other polyhydric alkylene or aromatic compounds. These novel condensation products exhibit sludge inhibition, sludge dispersancy, rust inhibition, and antiwear properties when admixed at between about 0.1 and about 10.0 wt. percent, in lubricating mineral oils, middle distillate hydrocarbon fuels, and residual hydrocarbon fuels The present invention relates to organic halophosphite mono or diesters reacted with halides of sulfur and with either an alkylene glycol or other polyhydric alkylene or aromatic hydrocarbon to produce novel additives for lubricating oils, middle distillate fuels and residual fuels. These novel condensation products have been found to inhibit oxidation, inhibit sludge formation, act as sludge dispersants to a certain degree, and to be good antiwear agents. The additives are not only useful in lubricating oils but also fuels derived from mineral oils because it has been found that they have a certain degree of flowability improvement and, at the same time, they minimize wear on pumps used to transfer fuels through conduits and other types of fuel supply lines. These novel additives tend to minimize fouling and plugging difficulties in the transportation of fuels through pipes and the like where pumps are required to be the prime movers for such articles of commerce.

Various phoshite derivatives have, in the past, been produced and used as additives in both hydrocarbon fuel compositions and in lubricating oil compositions. Usually such phosphite derivatives, as employed in the past, suffer from one or more deficiencies with respect to the aforementioned properties so that it has *become a major undertaking of many persons working in the art to find novel additives which will impart additional characteristics, in one or more respects, to these mineral oil fractions by the incorporation of novel additives thereto. Such incorporation serves a combination of functions. High operating temperatures in internal combustion engines tend to accelerate the deterimental oxidative influences on lubricating oils and this, in turn, tends to result in the early breakdown of these oils with the resultant formation of acids and other sludge type materials which generally gum-up, clog and corrode bearings, pumps and the like, and deposit sludge-like materials on the internal surfaces of internal combustion engines. This, in turn, leads to excessive bearing wear, plugging difficulties in oil circulation systems, and a general fouling of the moving parts of such engines because of excessive sludge formation.

The novel organic halophosphite ester reaction products, hereinafter described, are ashless in nature which means that they tend to eliminate the formation of deposits on the internal surfaces of the combustion engines when added to lubricating oils used in those engines, Whereas, sludge inhibitors and sludge dispersants containing metal ions, upon their breakdown, tend to deposit the metals in one form or another on the internal surfaces of such engines thus leaving a residue of ash-forming deposits which is considered to be undesirable. Many of the heretofore used sludge inhibitors and sludge dispersants not only are ash forming but tend to be too corrosive for practical purposes when coming in contact with the conventionally used copper-lead bearing employed in automotive and diesel engines. The heretofore employed dispersants oftentimes do exhibit certain desirable properties but they may lack suflicient antioxidant and antiwear properties thus making it necessary to employ still other additives in association with these dispersants in order to impart additional desirable properties to the fuels and lubricating oils. The organic halophosphite mono and diesters herein employed in producing condensation products are, for the most part, not new in and of themselves but the resultant condensation reaction products are believed to be novel and are designed to impart antioxidant, rust preventive, antiwear, sludge inhibiting and sludge dispersing characteristics to the fuels and lubricating oils to which they are added to a much greater degree than has heretofore been thought possible The novel condensation products which offer enhanced utilities in connection with their use in lubricating oils and mineral oil fuels are produced by reacting organic halophosphite mono or diesters with a halide of sulfur and with an alkylene glycol or other polyhydric alkylene or aromatic hydrocarbon. Alternatively, these halophosphite esters may be reacted with a preformed reaction product of a halide of sulfur with an alkylene glycol or with another polyhydric alkylene or aromatic hydrocarbon. The final condensation product appears to be substantially the same regardless of whether or not the halides of sulfur and the polyhydric compounds are reacted sequentially with the phosphite esters, are first reacted with each other, or are simultaneously added to the phosphite ester reactants.

The organic halophosphite esters used as reactants are represented by the formula:

wherein R is selected from the group consisting of alkyl, chloro and bromo alkyl, aryl, chloro and bromo aryl, aralkyl, chloro and bromo aralkyl, cycloalkyl, chloro and bromo cycloalkyl, alkenyl, chloro and bromo alkenyl, alkaryl, and chloro and bromo alkaryl; X is selected from the group consisting of chloro and bromo and CR and X is selected from the group consisting of chloro and bromo. The polyphosphite prepared from polyhydric compounds may be used as well.

Phosphite ester compounds, as defined, are reacted then with a halide of sulfur followed by a reaction with a polyhydric organic compound or they are reacted simultaneously with an admixture of the halide of sulfur and the polyhydric compound. As before stated, these phosphite esters may also be reacted with the reaction product of a halide of sulfur with a polyhydric compound of the type more fully described hereinafter. Typical phosphite esters which may be employed are as follows:

nonylphenyl, dichloro phosphite normal propyl dichloro phosphite isopropyl, butylhexyl chloro phosphite cyclohexyl dichloro phosphite decyl dichloro phosphite lorol dichloro phosphite cetyl dichloro phosphite phenyl dichloro phosphite cresyl dichloro phosphite tolyl dichloro phosphite 3 dinonylphenyl chloro phosphite diphenyl chloro phosphite dicresyl chloro phosphite ditolyl chloro phosphite dicyclohexyl chloro phosphite ethylbenzyl dichloro phosphite nonyl, phenyl chloro phosphite dioctadecyl chloro phosphite polyisobutenylphenyl dichloro phosphite dipolyisobutenyl chloro phosphite diethylbenzyl chloro phosphite chloroctyl dichloro phosphite chlorbenzyl dichloro phosphite chlorpolyisobutenyl, nonylphenyl chloro phosphite Each of the above named specific compounds may have the chlorine atom substituted with a bromine atom and serve equally as well as the reactant. The lorol radicals mentioned above in connection with the specific phosphites named are derived from the corresponding primary alcohols obtained by the reaction of carboxylic acid mixtures obtained from coconut or palm kernel oils. They are largely composed of lauryl alcohol together with minor amounts of octyl, decyl, and myristyl alcohols. Typically, this alcohol mixture boils between about 140 C. and about 190 C. at 50 mm. mercury pressure. The phosphite ester compounds are conventionally prepared by reacting the corresponding phenol or alcohol with the desired phosphorus trihalide, i.e., phosphorus trichloride or phosphorus tribromide. The particular method of preparation is immaterial since the mono and dihalo phosphite esters are, for the most part, old and well known and for the purposes of the present invention they are simply employed as one of the reactants to produce the novel additive compounds.

Any halide of sulfur will be suitable for use as the second reactant employed in effecting the production of the novel condensation products, for example, sulfur monochloride, sulfur dichloride and sulfuryl chloride may be employed as a reactant.

The final reactant is an organic compound containing two or more hydroxyl groups attached to carbon atoms, i.e., the final reactant employed may be an alkylene glycol or other polyhydric alkylene or aromatic hydrocarbon. Specific compounds which are suitable examples of polyhydric reactants in the instant invention are as follows:

ethylene glycol propylene glycol 1,2 trimethylene glycol Z-methyl propylene glycol 2-methyl butylene glycol catechol glycerol pentaerythritol diethylene glycol resorcinol hydroquinone para, para-dihydroxy diphenol methyl hydroquinone 4-methyl catechol triethylene glycol polyethylene glycol polypropylene glycol The reaction of the organic halo phosphite mono or diester with the other reactants is carried out in liquid phase either in the presence or absence of inert solvents such as normally liquid hydrocarbon petroleum solvents, petroleum ether, hexane, cyclohexane, heptane, benzene, toluene middle distillate fractions, residual fuel oils or lubricating oil fractions. The last named solvent is particularly desirable for example, in cases where the final product is to be used in lubricating oils because the reacted mixture, upon purification, serves as a concentrate containing any-where from 50% to 75% of the active 4 phosphite sulfurized condensation product as the active ingredient and constitutes a convenient method of marketing the novel additive compound.

The reaction is carried out in a temperature range between about 0 C. and about 100 C., preferably between about 20 C. and about C. The reaction time varies depending upon the reaction temperature employed. Generally, for the addition of the polyhydric compound, from between about 1 and about 10 hours, preferably between about 3 and about 6 hours are used. In any event, a sufficient length of time of reaction is maintained so that the evolution of hydrogen halide has completely ceased. The end of the evolution of the hydrogen halide is an indication of the completion of the reaction. The residual traces of hydrogen halide are stripped from the reacted mixture by means of an inert carrier gas stream, such as nitrogen. During this stripping operation, if desired, a slight vacuum may be applied in order to hasten the stripping operation.

In general, the mole ratio of reactants is as follows: the ratio of the halide of sulfure to the phosphite ester will range between about 2:1 and about 1:2 moles, in the case of a monoester being used, and between about 2:1 and about 1:4 moles in the case of a diester being used.

In the case of the amount of polyhydric compound employcd per unit of phosphite ester employed, this will usually be about one equivalent of hydroxyl per halide attached to a phosphorus or sulfur atom. It is also possible to use larger amounts of polyhydric compounds, particularly if a chloro or bromo-substituted constituent for R is used. Also, if a polyphosphite ester is used, up to 4 times the number of moles of polyhydric compound may be employed over that used in the case of the corresponding phosphite ester as represented by the foregoing structural formula. In the case of the pre-reaction of a halide of sulfur with the polyhydric compounds, a temperature of between about 10 and about 40 C. is used and an equi-molar amount of sulfur halide per hydroxyl compound is used.

Many of the halophosphite mono and diesters above mentioned are available commercially. For those enumerated above which are not available commercially, it is a simple matter to effect a reaction between phosphorus trichloride or tribromide and the corresponding monohydric alcohol or phenol or between the phosphorus trihalides and the corresponding polyhydric alkylenes or aromatic hydrocarbons in which the molar ratios of the alcohol to phosphorus compound are maintained at between about 111 and about 2:1 depending upon whether or not it is desired to produce a mixture predominating in mono or diphosphite ester. In the case of the polyhydric compounds, the molar ratio of phosphorus trihalide to glycol or to polyhydric aromatic hydrocarbon is between about 2:1 and about 4:1, also depending upon whether diesters or monoesters are desired to be the predominant component of the resultant reactant mixture. Preferably a mole ratio of alcohol to phosphorus trihalide of be tween about 0.75:1 and about 2.5 :1 is maintained and preferably a mole ratio of glycol or other polyhydric alkylene or aromatic hydrocarbon to phosphorus trihalide of between about 1.511 and about 5:1 is maintained. Any solvents which are employed in effectuating the reaction are distilled off at atmospheric pressures or under slight vacuum.

The novel sulfurized phosphite-polyhydric condensation products are useful in lubricating oil compositions of the type customarily employed in internal combustion engines of either the gasoline or diesel fuel type as well as in the lubrication of heavy duty gas engines. The amounts incorporated into such lubricating oils range between about 0.01 and about 10.0 wt. percent, preferably between about 0.1 and about 5 .0 wt. percent. As before stated, the novel additives are also useful in middle distillate fuels and residual fuel oils because they impart antirust, anti-1 corrosive and sludge inhibiting properties to such materials into which the additives are incorporated. Specifically, these hydrocarbon compositions include gasoline, jet feul, kerosene, heating oil, heavy residual fuels such as Bunker C, and the like. When used in these particular petroleum fuel fractions, the additives are incorporated into amounts ranging between about 0.01 and about 5.0 wt. percent, preferably between about 0.05 and about 2.0 wt. percent, all percentages being based on the total weight of the composition.

The fuels and lubricating oil compositions described may also include other conventional additives present in like or smaller amounts. For example, they may contain oxidation inhibitors such as phenyl alpha naphthylarnine; rust inhibitors such as the over-based alkaline earth metal petroleum sulfonates; detergent additives such as overbased calcium petroleum sulfonate, zinc dialkyl dithiophosphates, phosphosulfurized polyisobutylene, barium phenate sulfide, phenol sulfonates; viscosity index improvers such as the polymers and copolymers of long chain alkyl acrylates and methacrylates, the polymers and copolymers of long chain alkyl fumarates, polyisobutylene, the aryl and alkyl phosphates; the four point depressants such as wax-alkylated naphthalenes, and the like. In addition, they may contain other ashless dispersants such as polyisobutylene-substituted succinic anhydride condensation reaction products with polyethylene polyamine such as tetraethylene pentamine.

A typical lubricating oil fraction of the SAE 10W30 grade is representative of automotive lubricating oils conventionally available. This was employed in carrying out certain of the tests described in the examples. The base oil was composed of about 90% of a solvent-extracted, dewaxed, neutral oil from Mid-Continent paraffinic crude. It had a viscosity of 105-115 SUS (Saybolt Universal Seconds) at 100 F. and a pour point of about F. The remaining of the base oil blend was the same type of oil but had a viscosity of about 450-500 SUS at 100 F. The oil also contained, in all tests, approximately 10% of a viscosity index improver, namely, polyisobutylene and about 3.75% of an ashless dispersant, i.e., the polyisobutenyl succinic anhydride imide of tetraethylene pentamine. Minor amounts, i.e., less than 1%, of over-based calcium petroleum sulfonate and wax-alkylated naphthalene were also present. The amount of novel additive employed in the base oil for test purposes was, in all cases, about 1 wt. percent based upon the total weight of the composition.

Two types of tests were carried out to test the efficacy of the herein described novel additives. In one test known as the Falex wear test, a Falex wear test machine was operated with the test oils for minutes under 500 lbs. per square inch direct pressure gauge reading on a hearing having a rotating steel pin and then determining, at the end of this time, the milligrams of wear on the steel pin used in the test. The test was conducted for the purpose of measuring the amount of wear which the bearings would encounter under extremely severe conditions and while using the test oil compositions.

Another test was carried out known as the cyclic temperature sludge test which evaluated the sludge-handling ability of the tested lubricating oil compositions. In this test the temperature of the oil was cyclically raised and lowered over a period of stated hours in order to determine the oxidation stability and the sludge inhibiting or sludge forming tendencies of the novel additives in the oil compositions. A 6 cylinder Ford engine was used which employed a standard carburetor. It was operated at a standard speed of 1,500 r.p.m.::15 r.p.m. under a constant load of 140:2 foot lbs. of torque. The oil sump temperature was maintained in the cold phase at 150 F.i-'5 F. and in the hot phase at 215 F.i5 F. The cold phase operation was for a period of 5 hours and alternated with a hot phase operation of 2 hours.

The invention will be more completely understood by reference to the following examples but it is not intended that the invention be limited to these examples since they are only representative in nature. All percentages given are in terms of weight percent of the total composition.

EXAMPLE 1 600 grams of nonylphenol were gradually added to 414 grams of phosphorus trichloride at ambient or room tem perature. The admixture (after 3 hours) ceased evolving hydrogen chloride gas. An aliquot constituting 158 grams of the nonylphenol dichloro phosphite ester was then mixed with about 51 grams of sulfur dichloride. After the addition of the sulfur dichloride, the mixture was then gradually added to about 62 grams of ethylene glycol. After completion of the addition, the reaction temperature of the reacting mixture was increased from ambient temperature to about C. and kept at this temperature for about 3 hours with stirring and agitation. In the final stages of the final 3-hour period, the mixture was stripped with a stream of nitrogen gas for about 2 hours. The product had a phosphorus content of about 7.95 wt. percent and a sulfur content of about 9.33 wt. percent.

EXAMPLE 2 About 400 grams of nonyl phenol was added, dropwise, to 137 grams of phosphorus trichloride at room temperature. The mixture was stirred constantly until all evolution of hydrogen chloride gas had ceased. This took about 3 hours.

An additional 200 grams of nonylphenol was added, dropwise, to about 103 grams of sulfur dichloride at room temperature and the mixture was constantly stirred until the evolution of all hydrogen chloride gas had ceased. This again took about 3 hours.

An admixture of the foregoing mixtures of nonylphenolphosphorus trichloride reaction product and the nonylphenol-sulfur dichloride reacted mixture was prepared. This admixture was added, dropwise, to 62 grams of ethylene glycol at room temperature and was stirred for 3 hours followed by stripping with a stream of nitrogen gas at room temperature for an additional 2 hours. The final product had a phosphorus content of 3.49 wt. percent and a sulfur content of 4.41 wt. percent.

EXAMPLE 3 200 grams of nonylphenol was added, dropwise, to 137 grams of phosphorus trichloride at room temperature. The mixture was stirred constantly until evolution of hydrogen chloride gas had completely stopped. This reaction mixture was then admixed, dropwise, with about 76 grams of sulfur monochloride and the resultant mixture added, dropwise, to about 62 grams of ethylene glycol while maintaining the mixture at about room temperature. The reaction mixture was stirred for 3 hours and was then stripped with a stream of nitrogen gas for 2 hours at room temperature. The product showed a phosphorus content of about 4.16 wt. percent and a sulfur content of about 4.48 wt. percent.

EXAMPLE 4 Each of the products of each of the preceding examples were subjected to either the Falex test or the Cyclic Temperature Sludge Test, both tests having been hereinbefore described. The data obtained are set forth in the hereinafter set forth table.

The base oil employed, in the tests set forth in the table, was previously described as an SA-E l0W-30 oil blend. It contained about 1.2 wt. percent of zinc di-(C C alkyl)-dithiophosphate, which additive was omitted from the base oil when the additives prepared in accordance with Examples 1, 2 and 3 were employed. A test carried out on the base oil but containing no zinc di-(C -C alkyl)- dithiophosphate and no additive resulted in a broken pin Falex test,

brorno cycloalkyl, alkenyl, chloro and bromo alkenyl, alkaryl, and chloro and brorno alkaryl; X is selected from the group consisting of chloro, brorno and CR and X is selected from the group consisting of chloro and bromo,

Cyclic temperature sludge test demerit rating, hours 500 p.S.l., Wt. percent 30 min., bearing Number Additive of additive wt. loss, mg. 63

None F ZDDP l 1 Zinc di-(Ci-Cs alkyl) dithipl10sphate.

It is readily apparent, from the foregoing data, that the novel additives exhibit marked antiwear and sludge inhibition characteristics when used in lubricating oils.

A comparison of the results of the Cyclic Temperature Sludge Test (Run A vs. Run B) shows that the base oil above exhibited excessive sludge formation at 105 hours whereas use of the sulfurized-phosphite ester condensation product of Example 1 was still better than the control even after 168 hours. Also in the Falex test, the novel additives were superior to the conventional antiwear additives of Run F.

Having now thus fully described and illustrated the nature of the invention, what is desired to be secured by Letters Patent is:

I claim:

1. A mineral lubricating oil composition containing a sludge inhibiting amount of the reaction product of:

X2 wherein R is selected from the group consisting of alkyl, chloro and brorno alkyl, aryl, chloro and bromo aryl, aralkyl, chloro and bromo aralkyl, cycloalkyl, chloro and bromo cycloalkyl, alkenyl, chloro and brorno alkenyl, alkaryl, and chloro and brorno alkaryl; X is selected from the group consisting of chloro, brorno and 0R and X is selected from the group consisting of chloro and brorno, with a halide of sulfur and with a polyhydric hydrocarbon selected from the group consisting of polyhydric alkylene hydrocarbons and polyhydric arylene hydrocarbons.

2. A mineral lubricating oil composition containing a sludge inhibiting amount of the reaction product of:

chloro and brorno alkyl, aryl, chloro and brorno aryl, aralkyl, chloro and bromo aralkyl, cycloalkyl, chloro and with the reaction product of halide of sulfur and a polyhydric hydrocarbon selected from the group consisting of polyhydric alkylene hydrocarbons and polyhydric arylene hydrocarbons.

3. A mineral lubricating oil composition containing a sludge inhibiting amount of the reaction product of claim 1 wherein the phosphite ester is mono nonylphenyl dichloro phosphite ester and the polyhydric compound is ethylene glycol.

4. A mineral lubricating oil composition containing a sludge inhibiting amount of the reaction product of claim 3 wherein the sulfur halide is sufur dichloride.

5. A mineral lubricating oil composition containing a sludge inhibiting amount of the reaction product of claim 3 wherein the sulfur halide is sulfur monochloride.

6. A mineral lubricating oil composition containing a sludge inhibiting amount of the reaction product of claim 2 wherein the phosphite ester is mono nonylphenyl dichloro phosphite ester and the polyhydric compound is ethylene glycol.

7. A mineral lubricating oil composition containing a sludge inhibiting amount of the reaction product of claim 6 wherein the sulfur halide is sulfur dichloride.

8. A mineral lubricating oil composition containing a sludge inhibiting amount of the reaction product of claim 6 wherein the sulfur halide is sulfur monochloride.

References Cited UNITED STATES PATENTS 2,242,260 5/1941 Prutton 25248 2,506,344 5/1950 Cleary 260-985 X 3,240,704 3/1966 Nelson et a1. 25246.6 3,245,979 4/1966 Nelson et al. 25246.6 3,435,097 3/1969 Bottomley et al. 260-985 X DANIEL E. WYMAN, Primary Examiner W. H. CANNON, Assistant Examiner US. Cl. X.R.