US2931714A - Motor gasoline containing boron and hexylene glycol - Google Patents

Description

United States PatentO Moron GASOLINE CONTAINING noRoN AND HEXYLENE GLYCOL Richard J. de Gray, Shaker Heights, Ohio, assiguor to The Standard Oil Company, Cleveland, Ohio, a corporation of Ohio No Drawing. ApplicationNo'vember 4, 1957 Serial No. 694,127

3 Claims. "(CL 44-63) This invention relates to a motor gasoline containing small amounts of a boron compound from a class described hereinafter and hexylene glycol which demonstates unexpected improvement 'in octane rating. It is intended that the motor gasoline of this invention also may include tetraethyl leadand other additives commonly employedin commercial 'gasolines today, such as oxidation inhibitors, gum inhibitors, dyes, solvents, and the like.

There has been anincreasing demand, due to the recent trend of higher compression ratios in automotive engines, for gasolines exhibiting higher anti-knock qualities. This anti-knock characteristic of gasolines is commonly expressed in octane numbers wherein the fuel under consideration is compared to blends of'standard compounds, i.e., iso-octane (2,2,4vtrimethyl pentane) which is assigned anarbitrary number of 100, and n-heptane which is assigned an arbitrary number of 0.

In the race to develop such higher anti-knock qualities for motor gasoline, a diflicult problem presents itself to the refiner, requiring skillful variations in refining operations and gasoline stock blending in order to obtain the anti-knock improvement required. This pressure on refining operations can be relieved measurably by chemical additives which in part can accomplish this increase in octane rating. n

The octane number of gasoline is measured in lab'o'ratories by two independent tests referred to as the'resea'rch method and the motor method. Both'tests are performed in a single cylinder ASTM engine with the gasoline to be tested used 'as 'the'fuel. V Adevice is installed in'the cylinder head of this ASTM engine so that the pressure impulses from detonation can be detected. These are electronically amplified and their intensity indicated on a knock meter on the engine panel board. The unknown fuel is compared in knock intensity with that of various reference fuels which are blends of the two standard compounds, iso-octane and n-heptane. A blend of isooctane and n-heptane is found which produces the same knock intensity as does the unknown gasoline. The percentage by volume of iso-octane in the matching blend is designated as the octane number of the gasoline. For example, if a blend of 80% iso-octane and 20% n-heptane is required to duplicate the knock intensity of the unknown gasoline, the gasoline would then be given an octane number of 80.

Operating conditionsfor the engine vary depending upon whether a rating by the research method or the motor method is being determined. The operating conditions for this ASTM engine when running the research method determination is set forth in ASTM D 908-55. The operating conditions for this ASTM engine when runing the motor method determination is set forth in ASTM D 357-53. In general, the motor method is a more severe test than the research method. Accordingly, most gasolines will have a higher octane number by the research method than by the motor method. It is felt that the octane 'numbe'r determined by the research matter! can relates "more closely with gasoline performances in engines running at low speed, whereas the octane number determined by themotor method is felt more indicative ofgasolineperformance under conditions of high speed and hence the octane number bythis method is consid- "ered more significant as a measure of how the gasoline will performin an automotive engine in actual road operation'inftodays automobiles with automatictransmissions which generallyrunat higher speeds.

It is therefore -therobject o'f this invention to ofTe'r a gasoline which contains small 'percentagesof an additive combination which-is elfective in improving the octane rating of commercial gasolines, particularly when meastired in accordance "with the motor method.

In accordance with this invention, it has been found thathexyleneglycol, when added to a gasoline containing a boron compound from a class which is known to produ'ce beneficial effects by its incorporation into motor "fuels, 'coactswithtlie boron com ound to provide a'n'uhexpected improvement in octane rating.

Hexylene glycol as used herein is intended to mean a saturated aliphatic diol which is either a 'straight-ch'ain compound or a straight-chain compound with one branch chain, non-limiting examples of which are hexane diol- 2,5; 2-methyl pentanediol-ZA; and Z-ethyl butanedijol-2,'4. Of these examples, Z-methyIpentanediOI-ZA is preferred. 7 Patent No. 2,741,548, granted to my associates 'and'a'ssigned to my assignee, discloses a;-'class of boron-compounds which when incorporated into leaded gasolines 'and'utilized in automotive engines are effective in suppressing surface ignition, increasing spark .plug life, reducing'total combustion chamber deposits, and other advantages. Included in the compounds described in this patent are those having the formula:

(cm), i

he and Xa-on 0 Ha or the formula:

The formercompound, which -may be harmed 2-m'eth'yl pentanediol-2,4 hydrogen borate, will be referred to hereinafter as the boron ester; and the latter compound, which may be named bis-(Z-methyl pentanediol-2,4) diborate, will be referred to hereinafter as the boron anhydride.

These compounds, separately or, together in any proportlons, are used in gasolines in the amounts of 0.025 to 0.1%, based on total fuel present. The presence of such amounts of these baron compounds in gasoline is found to exhibit a positive effect on the research method rating of the fuel and a significant negative effect on the motor method rating of the fuel.

It has been determined that the presence of hexylene glycol in gasoline not containing boron does not appreciablyjalter octane number by either the research method or the motor method. The addition of small concentrations of hexylene glycol in the range of from 0.03 to 0.1%, based on the total fuel present to a boroncontaining gasoline does not diminish the octane number by the research method and demonstrates a surprising and unexpected effect in increasing the motor method octane rating of the'fuel. i

A more complete understanding of the invention will be gained from the following results in which the base fuel common to all tests had an octane rating of 99+ and the following distillation characteristics:

IBP F... 128 F-.. 144 F..- 162 F 178 F 201 F 224 F 256 F" 303 I 1 9 F' 362 an v q e P 424 Reid vapor pressur 8.75

A A Fuel F-l Effect of F-2 Effect of 0.N Hcxylene 0.N. Hexylene Glycol Glycol Base Fuel 99. 7 90. 9 Base Fuel+Hexylcne Glycol 1 (0.05 99. 6 -0.1 90. 9 0.0 Boron Fuel [Base Fuel+ Boron 2 (0.004%B)l 99. 9 90.1 Boron Fuel-l-Hexylcne Glycol (0.05%) 99.9 0.0 90.7 +0.6

efiect on the motor method octane number, increasing it 0.6 or more than one-half an octane number. At the high octane level of the boron-containing gasoline used in this test any further increase in octane number, especially by the motor method without any loss in the research method number, normally proves difiicult and hence the surprising increase obtained by this slight addition of hexylene glycol is commercially significant.

The hexylene glycol in the amounts contemplated for this invention also serves as an excellent solvent for the boron compound in the invention, eliminating the need for an extra solvent which would otherwise be required in order to stabilize the boron composition in the liquid phase and lower its viscosity so the boron compound may be readily pumped and metered in the blending-in operation with gasoline. Hence, in the application of this invention the hexylene glycol may be added to the boron compound to provide the added ratio of'these' two materials as desired in the final gasoline, and the mixture is then ata desired viscosity and adequately stabilized in the liquid phase for subsequent one-step blending into the gasoline.

I claim:

1. A motor gasoline to which has been added from 0.03 tov 0.1% by weight hexylene glycol and 0.025 to 0.1% by weight of a boron compound having the formula:

' rm, c-o

B-O-X 0:0 H CH: where X is selected from the group consisting of hydrogen and H 0-(E-CHI ll 7 (CH9: 2. A motor gasoline to which has been added about 0.03 to 0.1% by weight hexylene glycol and an amount of a boron reaction mixture consisting of an admixture of about 25% the compound of the formula:

3. The gasoline of claim 2 in which the hexylene glycol is Z-methyl peutanedio1-2,4.

References Cited in the file of this patent UNITED STATES PATENTS 2,315,957 'Hewlett Apr. 6,

2,701,754 Haworth et al. Feb. 8, 1955 2,741,548 Darling et" a1. Apr. 10, 1956 2,767,069 Fay et al. Oct. 16, 1956 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent N0 2,931,714 April 5, 1960 Richard J, DeGray In the grant, line 1, and in the heading to the printed specification, line 4, nameof'inventor, for "Richard J. de Gray", each occurrence, read Richard J. DeGray column 2, line 61, for "baron" read boron Signed and sealed t his 13th day of September 1960 (SEAL) At'fiest:

KARL H. AXLINE ROBERT c. WATSON Attesting Officer Conmissioner of Patents