BRPI0617637A2 - Two-stroke gasoline engine oil, method for reducing the observable smoke emitted from a two-stroke gasoline engine, and use of a lubricant - Google Patents

Abstract

<B> TWO-STROKE GASOLINE ENGINE OIL, METHOD TO REDUCE THE OBSERVABLE SMOKE EMITTED FROM A TWO-STROKE GASOLINE ENGINE, AND USE OF A LUBRICANT <D> The smoke index of a two-stroke engine is improved by use with the engine lubricant of a two-stroke engine oil that comprises a larger quantity of a GTL base oil.

Description

"TWO-TIME GAS ENGINE OIL, METHOD TO STOP OBSERVABLE SMOKE ISSUED FROM A TWO-TIME AGASOLINE ENGINE, AND USE OF A LUBRICANT" Field of the Invention

This invention relates to a lubricating composition useful as a two stroke engine lubricating oil. More particularly, this invention relates to a two-stroke lubricating oil characterized by its low smoke generation characteristics.

Background of the Invention

Two-stroke petrol engines have found wide use in a wide variety of garden and recreational equipment. For example, two-stroke engines are used in lawnmowers, chain saws, rope cutters, motorcycles, paranight motor vehicles and outboard marine engines to name a few.

Two-stroke gasoline engines are operated using a gasoline mixture and a lubricant in specified proportions.

Two-stroke engine lubricants are typically formulated with a lubricating mineral oil or synthetic base oil, a variety of additives to improve performance characteristics, and a solvent to improve gasoline miscibility.

Hydrocarbon emissions from two-stroke engines, by virtue of their basic design, tend to exceed comparable four-cycle engine emissions. In addition, advances in technology to reduce emissions from four-cycle engines have not been successively adapted to two-stroke engines. As a result, there is growing concern about the emissions, such as visible smoke, produced by two-time gasoline engines.

Few smoke reducing additives are commercially available for two-stroke lubricant formulators. Some, such as those containing metals, are environmentally undesirable; and others, such as polyisobutylenes, contribute to deposits and exhaust port obstruction resulting in frictional wear and power loss. Synthetic base materials are known to reduce smoke in cost-effective two-stroke engines.

Thus there is a need for a two-stroke gasoline engine lubricant composition that meets the standard performance criteria, is cost effective and has good smoke emission characteristics.

Basically, the present invention is predicated upon the discovery that a two-stroke engine oil comprising a GTL base oil amount has a smoke index greater than about 75.

Accordingly, one embodiment of the invention is a two-stroke motor oil composition comprising a larger amount of a GTL lubricating base oil and an effective amount of at least one additive selected from the group consisting of extreme pressure additives, defoaming agents, pour point depressants. , rust inhibitors, antioxidants, detergents, dispersants and hydrocarbon solvents.

Another embodiment of the invention is a method for reducing observable fumes emitted from a two-stroke gasoline engine by the use of a lubricant comprising a GTL base oil.

These and other embodiments will become apparent from the following detailed description. Detailed Description of the Invention

GTL base oils according to the invention are lubricating viscosity materials which are generally derived from hydrocarbons, for example waxy synthetic hydrocarbons, which are themselves derived from simpler gaseous carbon-containing compounds, hydrogen-containing compounds, and / or feedstocks. GTL base oils and base materials include wax isomerates, comprising, for example, hydroisomerized or iso-removed synthesized waxy hydrocarbons, hydroisomerized or iso-removed Fischer-Tropsch (FT) material (ie, hydrocarbons, waxy hydrocarbons, waxes and oxygenated analogs), preferably hydroisomerized or iso-removable wax WT hydrocarbons, or hydroisomerized or iso-removed synthesized wax waxes, or mixtures thereof.

GTL base oils and base materials derived from GTL materials, especially base oils and base materials derived from hydroisomerized / iso-removed F-T material are typically characterized as having kinetic viscosities at 100 ° C of about 2 cSt to about 50 ° C. cSt, preferably from about 3 cSt to about 30 cSt, more preferably from about 3.5 cSt to about 25 cSt, as exemplified by an FT wax iso-removal based GTL base material, which has a kinematic viscosity of about 4 cSt at 100 ° C and a viscosity index of about 130 or greater. Reference herein to kinematic viscosity refers to a measurement made by the ASTM D445 method.

Base oils and base materials GTL derived from GTL materials, especially base oils and base materials derived from hydroisomerized / iso-removed F-T material are further characterized as having pour points of about -5 ° C or less, preferably about -10 ° C or below, more preferably about -15 ° C or below, even more preferably about -20 ° C or below, and under some conditions may have advantageous pour points around -25 ° C. or less, with useful pour points of from about -30 ° C to about -40 ° C or less. References herein to the pour point refer to the measurement made by ASTM D97 and similar automated versions.

GTL base oils and base materials derived from FT materials, especially base oils and base materials derived from hydroisomerized / iso-removed FT material are also characterized as having viscosity indices of 80 or greater, preferably 100 or greater, and more. preferably, in particular, the viscosity index of these base raw materials may preferably be 130 or greater, more preferably 135 or greater, and even more preferably 140 or greater. For example, Base oils and GTL base raw materials which are derived from GTL materials preferably F-T materials especially F-T wax generally have a viscosity index of 130 or greater. References herein to the viscosity index refer to the ASTM D2270 method.

In addition, base oils and base raw materials are typically highly paraffinic (> 90% saturated), and may contain mixtures of monocycloparaffins and multicycloparaffins in combination with non-cyclic paraffins. The naphthenic content ratio (ie, cycloparaffin) in such combinations varies with the catalyst and temperature used. In addition, base oils and GTL base raw materials typically have very low nitrogen and sulfur content, usually containing less than about 10 ppm, and more typically less than about 5 ppm each of these elements. The nitrogen and sulfur content of base oil and GTL base raw material obtained by hydroisomerization / iso-removal of F-T material, especially F-T wax is essentially zero.

Useful compositions of base oils and base materials GTL, base oils and base materials derived from F-Hydroisomerized or iso-removed wax material, base oils and wax-based hydroisomerized / iso-removed raw materials such as such as isomerates / iso-removed from wax, are cited in U.S. Patent Nos. 6,080,301 and 6,165,949 for example.

In a preferred embodiment the GTL material is an F-T synthesis process derivative material. In an F-T5 synthesis process a synthesis gas comprising a mixture of H2 and CO is catalytically converted to hydrocarbons and preferably liquid hydrocarbons. The molar ratio of hydrocarbon to carbon monoxide may vary from about 0.5 to 4, but is typically within the range of about 0.7 to 2.75 and preferably about 0.7 to 2.5. As is well known, F-T synthesis processes include processes in which the catalyst is in the form of a fixed bed, a fluidized bed or as a catalyst particle slurry in a hydrocarbon slurry liquid. The molestequiometric ratio for an F-T synthesis reaction is 2.0, but for reasons of using a different stoichiometric ratio as is known to those skilled in the art. In a cobalt emlama hydrocarbon synthesis process the molar ratio of H2 to CO feed is typically about 2.1 / 1. The synthesis gas comprising a mixture of H2 and CO is bubbled into the bottom of the slurry and reacts in the presence of the particulate FT synthesis catalyst in the slurry liquid under conditions effective to form hydrocarbons, a portion of which is liquid under reaction conditions and comprising the hydrocarbon slurry liquid. The synthesized hydrocarbon liquid is separated from the filtrated catalyst particles by means such as filtration, although other separation means such as centrifugation may be used. Some of the synthesized hydrocarbons come out on top of the hydrocarbon synthesis reactor as steam, along with unreacted synthesis gas and other gaseous reaction products. Some of these top hydrocarbon vapors are typically liquid condensed and combined with the liquid hydrocarbon filtrate. Thus, the initial melting point of the filtrate may vary depending on whether or not a few condensed hydrocarbon vapors have been combined with it. Slurry hydrocarbon synthesis process conditions may vary slightly depending on the catalyst and desired products. Effective typical conditions for forming hydrocarbons comprising mostly C5 + paraffins (eg C5 + -C20) and preferably C10 + paraffins in a slurry hydrocarbon synthesis process employing a catalyst comprising a supported cobalt component include, for example, temperatures, pressures and spatial velocities 160-454 ° C, 551-4,137 kPa and 100-40,000 V / h / N, expressed as standard CO and H2 gas mixture volumes (0 ° C, 101.3 kPa) per hour per volume. catalyst, respectively. It is preferred that the hydrocarbon synthesis reaction is conducted under conditions in which no water gas displacement reaction occurs or only limited water gas displacement reaction occurs and more preferably no water gas displacement reaction occurs during hydrocarbon synthesis. It is also preferred to conduct the reaction under conditions to achieve an alpha of at least 0.85, preferably at least 0.9 and more preferably at least 0.92, in order to synthesize more of the most desirable higher molecular weight hydrocarbons. This has been achieved in a slurry process using a catalyst containing a cobalt catalyst component. Those skilled in the art know that by alpha is meant the Schultz-Flory kinetic alpha. While suitable F-T reaction catalyst types comprise, for example, one or more Group VIII catalytic metals such as Fe, Ni, Co, Ru and Re, it is preferred that the catalyst comprises a cobalt catalytic component. In one embodiment the catalyst comprises catalytically effective amounts of Re, Ru, Fe, Ni, Th, Zr, Hf, U, Mg and La on an inorganic support material, preferably one comprising one or more metallo-refractory oxides. Preferred supports for cobalt-containing catalysts comprise particularly titanic. Useful catalysts and their preparations are known and illustrative, but nonlimiting examples can be found, for example, in U.S. Patent 4,568,663; 4,663,305; 4,542,122; 4,621,072 and 5,545,674.

Preferably, the F-T waxy material is one having an initial boiling point within the range of about 3430 ° C to 3710 ° C and preferably boils continuously to an end point of at least 565.6 ° C.

The waxy material is hydroprocessed to produce a GTL base oil. Such hydroprocessing techniques are well known in the art. In connection with this see, for example, other isomerization catalysts and processes for hydrocracking / hydroisomerization / iso-removal of GTL dematerials and / or waxy materials in base oil or base material. are disclosed, for example, in US Patents 2,817,693; 4,900,407; 4,937,399; 4,975,177; 4,921,594; 5,059,299; 5,200,382; 5,516,740; 5,182,248; 5,290,426; 5,580,442; 5,976,351; 5,935,417; 5,885,438; 5,965,475; 6,190,532; 6,375,830; 6,332,974; 6,103,099; 6,025,305; 6,080,301; 6,096,940; 6,620,312; 6,676,827; 6,383,366; 6,475,960; 5,059,299; 5,977,425; 5,935,416; 4,923,588; 5,158,671; and 4,897,178; EP 0324528 (131), EP 0532116 (BI), EP 0532118 (BI), EP 0537815 (BI), EP 0583836 (B2), EP 0666894 (132), EP 0668342 (131), EP 0776959 (A3), WO97 / 031693 ( Al), WO 02/064710 (A2), WO 02/064711 (Al), WO 02/070627 (A2), WO 02/070629 (Al), WO 03/033320 (Al) as well as in British Patents 1,429,494; 1,350,257; 1,440,230; 1,390,359; WO 99/45085 and WO99 / 20720. Particularly favorable processes are described in European Patent Applications 464546 and 464547. Processes using F-T wax feeds are described in U.S. Patent 4,594,172; 4,943,672; 6,046,940; 6,475,960; 6,103,099; 6,332,974; and 6,375,830.

GTL base oil comprises a larger amount of the total composition of the invention. Typically, it will comprise more than 55 percent by volume of the composition and preferably more than about 60 percent by volume of the composition.

In addition to comprising a larger amount of a GTL base oil, the lubricant composition includes two-time performance additives known in the art and selected from the group consisting of extreme pressure deadeners, defoamers, pour point depressants, rust inhibitors, antioxidants, detergents, hydrocarbon solvent dispersants. Such additives are used in effective amounts, typically within the range of 0.1 weight percent to about 15.0 weight percent based on the total weight of the composition.

When mixed with an effective amount of gasoline and fed to a two-stroke engine, the lubricant composition results in engine emissions having reduced observable smoke. In fact, use of the compositions of the invention will provide engine emissions having a smoke index greater than about 75 as measured by the JASO M 342-92 test. This test was established by the Society ofAutomotive Engineers of Japan (JSAE) for two-stroke engines and published by the Japan Automotive Standards Organization (JASO).

The following examples serve to illustrate the invention.

Examples

Two oils were evaluated for smoke generation properties according to the JASO M 342-92 test. In this test the result is expressed as a Smoke index and is referred to against a standard two-stroke oil with a smoke index of 100. The higher the smoke index, the greater the reduction in smoke emissions. The GTLused base oil had an IV of 142, a KV @ 40 ° C of 23.99 and> 100 ° C 5.05 and a pour point of -24 ° C.

The composition of the test oils is given in Table 1 below. TABLE 1

<table> table see original document page 10 </column> </row> <table>

The kinematic viscosities of the compositions are given in

TABLE 2

<table> table see original document page 10 </column> </row> <table>

The smoke index for the verified comparative conventional composition was 65, while that for the verified Example composition was significantly better at 78.

Claims (11)

1. Two-stroke gasoline engine oil, characterized by the understanding: a larger amount of GTL base oil; an effective amount of at least one additive selected from the group consisting of extreme pressure additives, defoaming agents, pour point depressants, rust inhibitors, antioxidants, detergents, dispersants and hydrocarbon solvents. Oil according to Claim 1, characterized in that the GTL base oil has a kinematic viscosity at 100 ° C of about 2 cSt to about 50 cSt and a VI of greater than 80. Oil according to claim 2, characterized in that the GTL base oil is derived from an F-T wax. Oil according to Claim 3, characterized in that the GTL base oil contains mixtures of cycloparaffins. Oil according to Claim 3, characterized in that the said oil has a smoke index of greater than about -75 ° C. 6. A method for reducing the observable smoke emitted from a two-stroke petrol engine, comprising: providing the engine under conditions of use with a petrol and a lubricant composition in which the lubricant composition comprises a larger amount of a GTL lubricant base. A method according to claim 6, characterized in that the GTL base oil has a kinematic viscosity at 100 ° C of about 2 cSt to about 50 cSt and a VI greater than about 80. Method according to claim 6, characterized in that the GTL base oil is derived from an F-T wax. 9. Two-stroke internal combustion engine comprises a lubricant, characterized in that it comprises: a larger quantity of a GTL base oil; an effective amount of at least one group-selected additive consisting of extreme pressure additives, defoaming agents, pour point depressants, rust inhibitors, antioxidants, detergents, dispersants and hydrocarbon solvents; and wherein the resulting smoke index of the lubricant is greater than about 75. Engine according to claim 9, characterized in that the GTL base oil has a kinematic viscosity at 100 ° C of about 2 cSt to about 50 cSt and a VI of greater than about 80. Engine according to claim 10, characterized in that the GTL base oil is derived from an F-T wax.