US 3275668 A
Description (OCR text may contain errors)
United States Patent 3,275,668 .ORGANOMETALLIC ORTHOPHUSPHATES Anthony J. Revukas, Cranford, N..l., assignor to Cities Service Oil Company, a corporation of Delaware No Drawing. Filed July 31, 1961, Ser. No. 127,840 8 Claims. (Cl. 260---429.3)
This application is a continuation-in-part of my application S.N. 27,294, filed on May 6, 1960, now abandoned.
This invention relates to novel metallic orthophosphate compounds and to gasolene compositions including such compounds.
The use of lead compounds to increase the octane rating of gasolene is extremely common. Unfortunately, the addition of lead, while substantially increasing the octane ratings of gasolenes to which it is added, at the same time has several drawbacks. Of these drawbacks the most serious is probably the tendency of the lead to increase undesirable surface ignition in the combustion chambers of the internal combustion engines in which the leaded gasolene is used. It has been the practice previously to utilize various phosphorous compounds in an attempt to reduce or prevent such surface ignition, but the use of such compounds has generally led to additional difiiculties such as lead deposits on cylinder heads and valves.
It is an object of the present invention to provide novel metallic orthophosphate compounds adapted for use in improved gasolene compositions.
It is another object of the invention to provide an improved gasolene composition especially adapted to resist surface ignition.
The novel compounds of the present invention are orthophosphates of titanium or zirconium. Preferred orthophosphates of these metals may be represented by the general formula RO\(? M PO] R O X wherein M represents zirconium or titanium, X is a number equal to the valence of the metal M and R and R each represent a hydrocarbon radical having from 2 to 30 carbon atoms. In such compounds titanium and zirconium each have a valence of either 3 or 4 depending upon the starting material used. Preparation of these compounds is discussed in greater detail below. R and R may represent identical or different hydrocarbon radicals. While any hydrocarbon radicals having between 2 and about 30 carbon atoms and soluble to the required extent in gasolene may be used, at least one of R and R preferably represents a branched chain hydrocarbon radical. Such radicals are generally more soluble in gasolene than other hydrocarbon radicals, thereby facilitating the use of the novel compounds of the present invention as gasolene additives. Since chains of more than about 30 carbon atoms are generally difiicult or impossible to dissolve in gasolene compositions, it is preferred that the hydrocarbon radicals of the orthophosphates of the present invention each have been 2 and about 30 carbon atoms.
Compounds of the present invention having branched chain alkyl hydrocarbon radicals include for instance the following:
titanium tetra (bis(Z-methylpropyl) orthophosphate) Zirconium tetra (bis(3-butyloctyl) orthophosphate) titanium tetra (bis(S-pentylhexadecyl) orthophosphate) titanium tetra (bis(Z-ethyl-S-butyltridecyl) orthophosphate) zirconium tetra (bis(Z-propyldecyl) orthophosphate) titanium tetra (bis(2,4-diethyloctyl) orthophosphate) titanium tetra (bis(Z-methyloctyl) orthophosphate) zirconium tetra (bis(methylethyl) orthophosphate) titanium IV di(2ethylhexyl), tributyl orthophosphate titanium tetra (bis(methylethyl) orthophosphate) titanium tetra (Z-methylpropyl, methylethyl orthophosphate) titanium tetra (Z-methyloctyl, 2-propyldecyl orthophosphate) titanium IV di(2-ethylhexyl), di(methylethyl), di(2- methylpropyl) di 3-butyloctosyl) orthophosphate titanium tri (bis(Z-ethylhexyl) orthophosphate) zirconium tetra (bis(Z-ethylhexyl) orthophosphate) zirconium tri (Z-ethylhexyl, Z-methylpropyl orthophosphate) Compounds of the present invention having alkylaryl hydrocarbon radicals include for instance, the following:
titanium tetra (bis(octylphenyl) orthophosphate) zirconium tetra (bis(methylphenyl) orthophosphate) titanium tetra (bis(tricosylphenyl) orthophosphate) zirconium tetra (bis(pentylphenyl) orthophosphate) titanium tetra (octylphenyl, pentylphenyl orthophosphate) titanium tri (bis(methylphenyl) orthophosphate) zirconium tri (bis(hexylphenyl) orthophosphate) Compounds of the present invention having both alkyl and alkylaryl hydrocarbon radicals include, for instance, the following:
zirconium tetra (Z-ethylhexyl, methylphenyl) orthophosphate titanium IV di(2-ethylhexyl), diQoctylphenyl), 2- propyldecyl, methylethyl, di(2-methyloctyl) orthophosphate Compounds of the present invention having straight chain hydrocarbon radicals include for instance the following:
zirconium tetra (bis(octyl) orthophosphate) titanium tetra (bis(ethyl) orthophosphate) titanium tetra (methyldecyl orthophosphate) zirconium IV dibutyl, diheXyl, ethylhexyl, dipentyl orthophosphate titanium tetra (octylphenyl, hexyl orthophosphate) zirconium tetra (2-ethylhexyl, butyl orthophosphate) zirconium tetra (pentacosyl, hexadecyl orthophosphate) titanium tri (bis(ethyl) orthophosphate) zirconium tri (Z-ethylhexyl, butyl orthophosphate) The novel compounds described above are especially useful as gasolene additives in forming novel gasolene compositions adapted to resist surface ignition. In addition to resisting surface ignition, these additives generally inhibit rust and carburetor icing. In accordance with a preferred embodiment of the present invention a gasolene composition is provided which comprises a major proportion of a leaded hydrocarbon base fuel boiling in the gasolene range and containing between about 0.001 and about 5.0 theories of a titanium or zirconium orthophosphate. Such metallic orthophosphate preferably is of the type described above having the general formula RO (H) M[ so] RO 1 By the term leaded gasolene, leaded hydrocarbon base fuel boiling in the gasolene range and similar terms is meant a petroleum fraction boiling in the gasolene boiling range (e.g., between about and about 450 F.) to which has been added a small amount, such as between about 0.1 and about 6.0 cc. per gallon, of a metalloorganic antiknock compound such as tetraethyl lead (TEL), tetramethyl lead (TML), tetraisopropyl lead, etc. Lead is frequently present in gasolene compositions of the present invention in the form of TEL, TML or mixtures of the same which may be present in suitable amounts such as between about 0.1 and about 6.0 cc. per gallon of gasolene composition, more usually between about 0.5 and about 4.0 cc. per gallon.
The novel metallic orthophosphates described above for use in leaded gasoline compositions in accordance with the present invention are present in suitable amounts such as between about 0.001 and about 5.0 theories, preferably between about 0.02 and about 2.0 theories. The term theory is intended in this context to designate the amount of additive required for the metal in the additive to react stoichiometrically with the lead in the compound such as TEL to produce the appropriate compound such as lead metatitanate.
In addition to the above described titanium and lead compounds, gasolene compositions contemplated by the present invention may include one or more other ingredients such as lead scavengers, gum inhibitors, lubricants, rust inhibitors, metal deactivators or other special purpose additives.
Lubricants suitable for use in the above described gasolene compositions may include, for instance, light hydrocarbon lubricating oils having viscosities at 100 F. of between about 50 and about 200 Saybolt Universal seconds (SUS) and viscosity indexes (VI) of between about 30 and about 120 with oil having a viscosity of about 100 SUS being preferred. Such oils may be present in suitable amounts such as between about 0.1 and about 1.0 volume percent of the gasolene composition.
When using lead compounds such as TEL, it is frequently found desirable to include with the lead a suitable lead scavenger for reducing the deposit of lead compounds within the combustion chamber. Such lead scavengers include for example halohydrocarbon compositions such as ethylene dibromide and ethylene dichloride.
Gum inhibitors suitable for use in the above described gasolene compositions include conventional gum inhibitors such as 2,6-ditertiary-butylpara cresol. Such gum inhibitors may be present in suitable amounts such as between about 0.001 and about 0.006 volume percent of the gasolene composition. Likewise, a suitable metal deactivator is for example N,N'disalicylidene-1,2-diaminopropane.
An especially valuable titanium compound of the type described above for use in gasolene compositions of the type described above is titanium tetra (bis(2-ethylhexyl) orthophosphate) having the formula Ti OP(O) OOHz.OH
and hereinafter referred to as TIP.
Gasolene compositions of the present invention may be illustrated by the following examples. In most of these examples the gasolene compositions of the present invention are described as containing TIP. While TIP and the corresponding zirconium compound are preferred additives for use in such gasolene compositions, it should be understood that any of the other novel additive compounds contemplated by the invention, such as those described above, may be used in such gasolene compositions in place of or in addition to the TIP.
Example 1 A gasolene composition having excellent surface ignition characteristics may be prepared by adding the following ingredients to a suitable base gasolene:
TEL2.2 cc. per gallon TIP-0.05 theory The base gasolene used in blending this and other gasolene compositions of the invention may be a gasolene having the following characteristics:
Another suitable gasolene composition is prepared by adding the following ingredients to a suitable base gasolene:
T EL2.2 cc. per gallon TIP0.l theory Example 3 Another suitable gasolene composition is prepared by adding the following ingredients to a suitable base gasolene:
T EL-0.5 cc. per gallon TIP0.25 theory Example 4 Another suitable gasolene composition is prepared by adding the following ingredients to a suitable base gasolene:
TEL-4.0 cc. per gallon TIP-0.5 theory Lubricating oil 1.0 volume percent (100 SUS, VI)
Example 5 Another suitable gasolene composition is prepared by adding the following ingredients to a suitable base gasolene:
TEL6.0 cc. per gallon TIP-50 theory Example 6 Another suitable gasolene composition is prepared by adding the following ingredients to a suitable base gasolene:
TEL-0.1 cc. per gallon TIP-0.005 theory Example 7 Another suitable gasolene composition is prepared by adding the following ingredients to a suitable base gasolene:
TEL1.5 cc. per gallon TIP0.01 theory Lubricating oil 0.1 volume percent SUS, 95 VI) Example 8 Another suitable gasolene composition is prepared by adding the following ingredients to a suitable base gasolene:
TEL3.0 cc. per gallon Zirconium tetra bis (octylphenyl) orthophosphate 2.0 theory Example 9 Another suitable gasolene composition is prepared by adding the following ingredients to a suitable base gasolene:
TEL2.0 cc. per gallon Titanium tetra bis(octylphenylorthophosphate- 0.5 theory Example Another suitable gasolene composition is prepared by adding the following ingredients to a suitable base gasolene:
TEL-22 cc. per gallon TIP-0.1 theory Lubricating oil 0.25 volume percent (100 SUS, 95 VI) Novel additive compounds of the type described above may be prepared in any suitable manner. According to one method of preparation, a suitable organic hydrogen phosphate or a mixture of such phosphates is placed in a reaction flask together with about half its volume of a suitable solvent such as dry toluene. The reaction flask is preferably equipped with a mechanical stirrer, thermometer, gas inlet tube, reflux condenser and a pressure equalizing funnel with its long stem dipping into the solution. The temperature in the reaction flask is raised to between about 110 and about 130 C. while stirring vigorously and titanium or zirconium tetrachloride with an equal volume of the solvent is added in spurts by means of the pressure equalizing delivery funnel. The tetrachloride is preferably introduced in amounts of about 1.1 moles of tetrachloride for each 4 moles of the organic hydrogen phosphate. Hydrogen chloride is evolved copiously by the reaction. Stirring and heating under reflux to 130 C. is continued until evolution of hydrogen chloride stops. Removal of by product hydrogen chloride is promoted by flushing the reaction flask with dry nitrogen by means of the gas inlet tube. The solvent is removed by distillation at reduced pressure such as 10 to 80 millimeters, the final temperature being about 130 C. The yield of product is usually between about 85 and about 95% of theory based on hydrogen phosphate.
In compounds prepared as described immediately above, the titanium or zirconium has a valence of 4. Similar compounds in which these metals have a valence of 3 may be prepared in a similar manner, e.g., by using titanium or zirconium trichloride rather than tetrachloride as a starting material.
Example 11 In the production of TIP by means of the above procedure 2000 grams of commercial di(2-ethylhexyl) hydrogen phosphate (6 moles) and 330 grams (1.7 moles) of titanium tetrachloride were brought into reaction. The resulting solvent-free crude product was washed with water to remove acidic materials, taken up in half its volume of normal pentane, and dried over anhydrous sodium sulfate. After filtering, the pentane was removed by distillation with the final temperature being 130 C. at 20 millimeters pressure. The yield of dark, amber colored liquid TIP was 1900 grams or 95% of theory based on acid phosphate. Percentages of titanium and phosphorous obtained on analysis were as follows:
Theory: Titanium, 3.59%; phosphorous, 9.29%. Actually found: Titanium, 3.70%; phosphorous, 8.94%.
This TIP had a viscosity at 100 F. of 1337 SUS and at 210 F. of 180 SUS. The density of this TIP at 20 C. was 1.055.
In forming the TIP as described above the reaction is formulated as follows:
Example 12 In order to demonstrate the usefulness of novel compounds of the type described above which include alkylaryl radicals as gasolene additives, titanium tetra (bis- 0 (octylphenyl) orthophosphate) was prepared in accordance with the general method of preparation described above. This compound was solid but was moderately soluble in gasolene and is, therefore, suitable as a gasolene additive.
Example 13 Another titanium orthophosphate containing branched chain hydrocarbon radicals was prepared by reacting 0.2 mole each of mono'butyl hydrogen phosphate, dibutyl hydrogen phosphate and di(2-ethylhexyl) hydrogen phosphate with 0.22 mole titanium tetrachloride in the manner described above. A 92% yield based on titanium tetrachloride was obtained of titanium IV di(2'e-thylhexyl)- tributyl orthophosphate having the formula:
This compound was a resinous amber colored solid which was soluble in gasolene. An analysis for titanium yielded the following results:
Theory: 6.56%. Actually found: 6.55%.
Example 14 Zirconium orthophosphate was prepared according to the general procedure described above by reacting 0.11 mole of zirconium tetrachloride with 0.40 mole of di(2- ethylhexyl) hydrogen phosphate in the presence of 300 milliliters of toluene. The product was zirconium tetra (bis (Z-ethylhexyl) orthophosphate) having the formula:
In order to evaluate the characteristics of gasolene compositions of the present invention, three separate gasolene compositions (A, B, and C) were prepared. These gasolene compositions contained metallic orthophosphate additives of the present invention as indicated in Tables I and II below.
Gasolene compositions A and B used the base gasolene described above in connection with Example 1 with 2.2 cc. per gallon of TEL added. Gasolene composition C also used a base gasolene having the same properties as the base gasolene of Example 1. The base gasolene of Example C also contained 2.2 cc. per gallon of TEL but had been stored for a shorter period of time .prior to the tests described below than had the base gasolenes of gasolene compositions A and B. The base gasolenes of gasolene compositions B and C also contained 0.25 volume per percent of SUS (95 VI) light lubricating oil. The base gasolenes of gasolene compositions A, B and C thus differed from the compositions A, B and C respectively only in the presence or absence of the metallic orthophosphate additives of the present invention. The gasolene compositions A, B and C, as well as their respective base gasolenes were subjected to both single cylinder and multi-cylinder engine deposit tests as described below.
The single cylinder engine deposit tests were run in CPR engines having L head assemblies and compression ratios of 7 to 1. Each test consisted of alternating periods of operation under idling conditions for 50 seconds followed by operation under full load conditions for 150 seconds. These cycles were continued for a total test time of at least 40 hours for each test. During these tests the engine air intake temperature was maintained at F. while the oil temperature was maintained at 160 F. and the coolant temperature at F. During the idling portions of the tests the engines were operated with an air to fuel ratio of 12 to 1 at 600 r.p.m. while during 7 the full load portions of the tests the engines were operated with air to fuel ratios of 13 to l and at 900 r.p.m. During the test, the number of wild pings (indicating preignition) was counted by an Erwin Instrument Co. Wild dicates clearly that the addition of the zirconium or titanium orthophosphate substantially reduced the octane number increases due to engine deposits as well as the LIB requirements. For instance, with TIP in the gaso- TABLE IL-MULTICYLINDER ENGINE DEPOSIT TEST Octane Requirement LIB Requirements Increase RI) Base Base Gasolene Gasolcnc Theories of Gasolene Composi- Orthophosphate Additive Additive tion Without With Without With additive additive additive additive TIP 0.05 14. 5. 5 85 55 TIP 0.10 14. 5 4. 5 C Zirconium tetra (bis (Z-ethyl- 0.20 24.8 5.2 100+ 60 hexyl) orthophosphate).
Ping Counter. At the end of the test the average of the wild pings per hour was determined by plotting the total wild pings versus time and taking the slope of the curve. This measurement served as a reliable indication of the surface ignition characteristics of the fuel being tested.
The multi-cylinder engine deposit tests were run in 1958 Oldsmobile Rocket engines having compression ratios of 10 to 1. The total time of each of these tests was 120 hours of operation 'in cycles of 50 seconds operation under idling conditions followed by 150 seconds operation under load conditions to develop twelve brake horsepower. During the idle portions of the cycle the engines were operated with an air to fuel ratio of 12 to 1 at a speed of 600 r.p.m. and with a coolant temperature of 160 F. During the load portions of the test the engines were operated with an air to fuel ratio of 14 to 1 at 2000 r.p.m. and with a coolant temperature of 160 F. Oil temperature was not controlled during these tests. At intervals of 16 to 24 hours the octane requirement increase (ORI) was obtained by full throttle operation at 1000 r.p.m. using primary reference fuels and varying spark advance for trace knock. At the end of the test the LIB requirement (leaded isooctane-benzene reference fuel with 3 cc. per gallon TEL to yield trace rumble) was obtained. The LIB requirement was obtained at 1500 r.p.m. and was the LIB fuel needed to prevent rumble at wide open throttle.
The results of the single cylinder engine deposit test on the gasolene compositions A, B and C and their respective base gasolenes described above are given in Table I below while the results of the multicylinder engine deposit tests are given in Table II.
Table I shows clearly that the addition to the titanium or zirconium orthophosphate to the base gasolenes resulted in gasolene compositions having remarkably good surface ignition characteristics as evidenced by a decrease in wild pings as compared with the base gasolenes which did not contain these additives. Likewise, Table II inlene the Oldsmobile engines tolerated a three times greater amount of the surface ignition inducing aromatic benzene than did the base gasolene, thereby further attesting to the high surface ignition resistance quality of the gasolene compositions containing the metallic orthophosphates of the present invention.
In order to evaluate the ability of TIP to inhibit carburetor icing, carburetor icing tests were conducted in a standard six cylinder Chevrolet engine having a displacement of 216.5 cubic inches and rated at 86 horsepower at 3400 r.p.m. The following test conditions were employed.
Intake air 38 to 40 F.
Relative humidity 100% Engine load 10 horsepower Engine speed 1500 r.p.m.
Idle speed 450 to 500 r.p.m.
Temperature of fuel entering carburetor 48 to 50 F. Air to fuel ratio 12.3 to 12.5
Carburetor icing tendencies of gasolenes are measured by this test when the engine is operated under the constant severe icing conditions outlined above. The engine run is started with the throttle late at 34 F. The ice forming characteristics of the test gasolene normally control the engine operating cycle. During the test the engine is run at 1500 r.p.m. for 1 to 2 /2 minutes. At the end of the 1500 r.p.m. operating cycle the throttle is returned to the idle speed of 450 to 500 r.p.m. The engine is idled for 30 seconds and if stalling does not occur the idle speed r.p.m. is observed. A reduction in idle speed of more than 100 r.p.m. is considered a partial stall.
The base gasolene used in the carburetor icing had the following volatility characteristics:
tests Gravity API" 60.0
Reid vapor pressure lbs 10.9
I.B.P. F 81 5% evaporated F 102 10 F 112 30 F 146 50 F 188 70 F 250 F 315 F 335 BR F 359 Recovery percent 97.4 Residue percent 1.1 Loss percent 1.5
A total of 12 test runs were made. In four of these runs the base gasolene contained no additive except 2.2 cc. per gallon TEL. In another series of four runs the base gasolene used contained 0.024 theory TIP while in the remaining four runs the base gasolene contained 0.096 theory TIP. The results of these carburetor icing tests are shown in Table III below.
TABLE IIL-STALLING CHARACTERISTICS OF GASOLENE WITH AND WITHOUT TIP S indicates stalling occurred. N indicates no stalling occurred.
The results show clearly that when TIP was not used the engine stalled within /2 to 1 minute after the throttle was returned to the idle position. Stalling is attributable to ice formation around the periphery of the throttle plate when it was nearly closed at idle. During these runs the ice was observed to build up, particularly in the throttle plate swivel area, thereby restricting the air flow. Such icing is especially prevalent in the wintertime because the more volatile winter grade gasolenes aggravate icing tendencies due to their greater tendency to evaporate with resulting cooling. Also, weather conditions frequently introduce enough moisture to create icing problems when relative humidity of the atmosphere is above about 85% and the temperature between about 35 and about 47 F. In contrast to the poor stalling characteristics displayed by the base gasolene under the test conditions described above, the gasolene containing TIP prevented ice build up in the throttle plate zone as observed visually during the test and also as demonstrated by the absence of stalling during 3 /2 minutes of engine operation with the throttle in idle position during the above described test. It is, therefore, apparent that the addition of TIP to the base gasolene served to eliminate the stalling tendencies of the base gasolene. TIP is thus shown to be a superior gasolene additive in that it not only reduced preignition problems as described above, but also reduces or eliminates carburetor icing and prevents rusting as determined by ASTM Method D665-54 Test for Rust-Preventing Characteristics of Oil, when performed at ambient temperature.
While the invention has been described above with respect to certain preferred embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention and it is intended to cover all such changes and modifications in the appended claims.
1. A liquid compound having the formula:
wherein M is a metal selected from the group consisting of titanium and zirconium and each of R and R is a branched chain alkyl having up to about 30 carbon atoms.
2. A liquid compound having the formula:
wherein M is a metal selected from the group consisting of titanium and zirconium, X is a number equal to the valence of the metal M and each of R and R is a branched chain alkyl having up to about 30 carbon atoms.
3. A compound of claim 2 in which R and R are identical branched chain alkyls.
4. Titanium tetra (bis(2-ethylhexyl) orthophosphate).
5. Zirconium tetra (bis(2 ethylhexyl) orthophosphate).
6. Titanium tri (bis(2-ethylhexyl) orthophosphate).
7. Zirconium tri (bis(2-ethylheXyl)i orthophosphate).
8. A compound of claim 1 wherein the metal is titanium.
References Cited by the Examiner UNITED STATES PATENTS 2,228,659 1/1941 Farrington et al. 252-35 2,346,155 4/1944 Denison et al 25232 2,480,673 8/1949 Reitf et al 260-429.5 XR 2,881,062 4/1959 Bishop 4469 2,885,417 5/1959 Heyden 260429.5 XR 2,913,469 11/1959 Russell 260429.5 2,926,183 2/1960 Russell 260--429.5 2,948,599 8/1960 Orloft et al. 4469 3,055,925 9/1962 Hartle 260--437 TOBIAS E. LEVOW, Primary Examiner.
JULIUS GREENWALD, ABRAHAM H. WINKEL- STEIN, Examiners.
M. WEINBLATT, W. J. VAN BALEN, H. M. S. SNEED,
UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,275,668 September 27, 1966 Anthony J. Revukas It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.
Column 4, line 74, for "(0ctylphenylorthophosphate-" read (octylphenyl)orthophosphate column 5, lines 67 to 70, the
formula should appear as shown below instead of as in the patent:
column 6, line 15, the formula should appear as shown below instead of as in the patent:
Signed and sealed this 29th day of August 1967.
ERNEST W. SWIDER EDWARD J. BRENNER Attesting Officer Commissioner of Patents