KR101080784B1 - Gasoline engine oil compositions - Google Patents

Abstract

The present invention relates to a gasoline engine oil composition, when described in more detail, the present invention is a base oil having an average kinematic viscosity of 3 ~ 10 cSt (100 ℃); Zinc alkyldithiophosphates; At least one friction modifier selected from glycerol monooleate, molybdenum dithiocarbamate and dibutylmethylene ester; Single or two or more types of clean dispersants selected from magnesium sulfonate, calcium sulfonate and calcium borate sulfonate; 3-hydroxydiphenylamine; Single or two or more viscosity index improvers selected from ethylene-propylene copolymers, polyisoprene-polystyrene copolymers, and hydrogenated styrene isoprene; And a single or two or more antifoaming agents selected from silicones and polymethacrylates. The present invention is excellent in wear resistance, friction reducing effect, very high temperature and low temperature responsiveness, excellent fuel economy improvement durability of gasoline vehicles.

Engine oil, friction reduction, fuel economy

Description

Gasoline engine oil compositions

The present invention is a base oil having an average kinematic viscosity of 3 ~ 10 cSt (100 ℃); Zinc alkyldithiophosphates; At least one friction modifier selected from glycerol monooleate, molybdenum dithiocarbamate and dibutylmethylene ester; Single or two or more types of clean dispersants selected from magnesium sulfonate, calcium sulfonate and calcium borate sulfonate; 3-hydroxydiphenylamine; Single or two or more viscosity index improvers selected from ethylene-propylene copolymers, polyisoprene-polystyrene copolymers, and hydrogenated styrene isoprene copolymers; And a single or two or more antifoaming agents selected from silicone and polymethacrylate.

In order to efficiently use energy and prevent global warming, regulations on automobile exhaust gas such as carbon dioxide are becoming more and more strict.In order to cope with such environmental regulations, each vehicle has the purpose of changing the engine structure and fuel efficiency by low friction engine oil. Development is in progress. The improvement of fuel efficiency by engine oil is the reduction of drag torque of engine oil and friction of sliding part. If the viscosity of engine oil is lowered, drag torque can be reduced, but sliding friction and wear tend to increase. . Engine friction and wear occur in cams, tappets, piston rings, cylinders and various bearings.

In order to suppress wear of sliding parts due to low viscosity, it is necessary to use an additive that lowers the friction coefficient and reduces wear. Generally, the additive most widely used in engine oil production to suppress friction and wear is zinc alkyl. Zinc dialkydithiophosphate (ZnDTP), which ZnDTP generally contains 10 to 11% by weight of zinc (Zn), 9 to 10% by weight of phosphorus (P) and 15 to 25% by weight of sulfur (S). It is common. In order to achieve a low friction coefficient, a low friction coefficient is realized by combining with an organic molybdenum additive such as highly concentrated molybdenum dithiocarbamate (MoDTC) containing 10 mol% or more of molybdenum. The ash type additives such as Mo, Zn, Ca, and Mg type are partially discharged to the catalyst during engine combustion, but ashes accumulate in the catalyst for a long time, which adversely affects the exhaust gas. It should be used minimally. In addition, MoDTC alone has a problem that it is difficult to secure a low friction coefficient, and when using a combination of MoDTC and ZnDTP has an advantage of low initial friction coefficient, but as the endurance progresses, MoDTC is rapidly consumed and the friction coefficient increases. There is. In addition, when the amount of use of MoDTC and ZnDTP increases, there is a problem in that the sludge generation is increased to shorten the replacement cycle of the engine oil. Accordingly, there is an increasing demand for the development of new or improved engine oils that can solve the above problems.

Accordingly, the present inventors have continually studied to solve the problems of the existing gasoline engine oil, and when using the ashless type additive glycerol monooleate, it is possible to continuously maintain a low friction coefficient as the durability progresses. The present invention has been completed by knowing that the viscosity change rate of gasoline engine oil can be minimized according to the selection and content of the clean dispersant component and the friction modifier component. That is, the present invention is to provide a gasoline engine oil composition having excellent fuel efficiency improvement sustainability by securing a low coefficient of friction by minimizing the rate of change of viscosity of gasoline engine oil.

Gasoline engine oil composition of the present invention for solving the above problems is a base oil having a kinematic viscosity of 3 ~ 10 cSt (100 ℃); Zinc alkyldithiophosphates; At least one friction modifier selected from glycerol monooleate, molybdenum dithiocarbamate and dibutylmethylene ester; Single or two or more types of clean dispersants selected from magnesium sulfonate, calcium sulfonate and calcium borate sulfonate; 3-hydroxydiphenylamine; Single or two or more viscosity index improvers selected from ethylene-propylene copolymers, polyisoprene-polystyrene copolymers, and hydrogenated styrene isoprene copolymers; And a single or two or more antifoaming agents selected from silicones and polymethacrylates.

Such a gasoline engine oil composition of the present invention has an effect of providing a fuel economy improvement sustainability of the gasoline vehicle because the present invention is very excellent in the wear resistance and friction reduction effect by minimizing the viscosity change rate.

Referring to the gasoline engine oil composition of the present invention introduced above as follows.

Gasoline engine oil composition of the present invention

Base oils having a kinematic viscosity of 3 to 10 cSt (100 ° C.); Zinc alkyldithiophosphates; At least one friction modifier selected from glycerol monooleate, molybdenum dithiocarbamate and dibutylmethylene ester; Single or two or more types of clean dispersants selected from magnesium sulfonate, calcium sulfonate and calcium borate sulfonate; 3-hydroxydiphenylamine; Single or two or more viscosity index improvers selected from ethylene-propylene copolymers, polyisoprene-polystyrene copolymers, and hydrogenated styrene isoprene copolymers; And a single or two or more antifoaming agents selected from silicones and polymethacrylates.

When the present invention is described by the composition ratio, the present invention

75 to 97% by weight of the base oil;

1 to 5% by weight of the zinc alkyldithiophosphate;

0.1 to 5 wt% of the friction modifier;

1 to 7 wt% of the clean dispersant;

0.05 to 3 wt% of the 3-hydroxydiphenylamine;

0.1 to 7% by weight of the viscosity index improver; And

0.1 to 3% by weight of the antifoaming agent; and it is characterized by.

Each of the compositions of the present invention will be described in more detail.

First, the base oil, which is one of the compositions of the present invention, may be one having an average kinematic viscosity of 3 to 10 cSt (centistoke) at 100 ° C. In this case, if the kinematic viscosity of the base oil is less than 3 cSt, the amount of evaporation is excessive under high temperature conditions. Since there is a problem of increasing the amount of oil used, and a problem of deterioration in viscosity at low temperatures when the viscosity is increased at a low temperature of more than 10 cSt occurs, it is preferable to use one having a kinematic viscosity within the above range. In addition, the base oil may be used a mixture of one or two selected from a fixed mineral oil and synthetic oil, the amount of the base oil is 75 to 97% by weight, more preferably 85 to 95% by weight relative to the total weight of the gasoline engine oil composition It is good to use. Here, if the base oil content is less than 75% by weight, the amount of other compositions is excessive, so that the viscosity increase and sludge generation are severe, and in particular, the viscosity at low temperatures is increased, and when the content is higher than 95% by weight, the content of the other compositions is too low. This is because there is a problem of increasing engine wear.

Next, the zinc alkyldithiophosphate (ZnDTP), which is one of the compositions of the present invention, serves as an antiwear agent in the present invention, which is 1 to 5% by weight based on the total weight of the gasoline engine oil composition of the present invention. When using less than 1% by weight can not exhibit an effective wear resistance performance, when more than 5% by weight may cause problems such as sludge generation and abrasion resistance due to competitive adsorption with a clean dispersant may be used within the above range.

Next, the friction modifier may be selected from glycerol monooleate, molybdenum dithiocarbamate and dibutylmethylene ester, or a mixture of two or more species selected from the group consisting of 0.1 to 5 based on the total weight of the gasoline engine oil composition of the present invention. Weight percent can be used. Here, when the amount of the friction modifier is less than 0.1% by weight, there is no friction reducing effect, and when it exceeds 5% by weight, the problem of metal corrosion may occur. In addition, the glycerol monooleate, which is one of the components of the friction modifier, is preferably used as represented by the following general formula (1). In the general formula (1), when the carbon number of R is less than 8, the friction effect is reduced. Since a problem may arise and a viscosity may increase when using more than 20 carbon atoms, it is preferable to use glycerol monooleate having a carbon number within the above range. Such polar groups of glycerol monooleate are densely adsorbed on the metal surface and the glycerin portion is lubricated.

In Chemical Formula 1, R is an alkyl group having 8 to 20 carbon atoms.

Next, the clean dispersant may be used a single or a mixture of two or more selected from magnesium sulfonate, calcium sulfonate and calcium borate sulfonate, preferably calcium sulfonate and magnesium sulfonate having a total infectivity of 200 or more. One kind or two kinds selected from among them can be used. The clean dispersant is preferably used 1 to 7% by weight based on the total weight of the gasoline engine oil composition of the present invention, less than 1% by weight when using less than clean, competitive adsorption and ash (ash) when used in excess of 7% by weight Problems such as generation may occur, so it is better to use the above range.

Next, the 3-hydroxydiphenylamine, which is another compositional ingredient of the present invention, serves to prevent oxidation of engine oil, and this 3-hydroxydiphenylamine is based on the total weight of the gasoline engine oil composition of the present invention. 0.05 to 3 weight percent is used. Here, if the amount is less than 0.05% by weight, there is a problem that the antioxidant performance is weakened, when used in excess of 3% by weight may cause problems such as increased wear and corrosion of metal due to competitive adsorption.

Next, in the present invention, the viscosity index improver serves to improve the viscosity index and to increase the fluidity at low temperatures, ethylene-propylene copolymer, polyisoprene-polystyrene copolymer and hydrogenated styrene isoprene air The single type or 2 or more types selected from coalescing can be used. Such viscosity index improver may be used 0.1 to 3% by weight based on the total weight of the gasoline engine oil composition of the present invention, when used in less than 0.1% by weight of the low temperature fluidity can be worsened, the problem of lowering the startability at low temperatures, 3% by weight When exceeding, the viscosity decrease due to shearing of the viscosity index improver and the viscosity increase due to oxidation may occur, so it is preferable to use within the above range.

Finally, the antifoaming agent, which is one of the compositions of the present invention, may be used by mixing one or two or more selected from silicone and polymethacrylate. Such antifoaming agent may use 0.1 to 3% by weight based on the total weight of the gasoline engine oil composition of the present invention, where the problem that can not effectively suppress the occurrence of bubbles in the lubricant when the amount of the antifoaming agent is less than 0.1% by weight. And, when it exceeds 3% by weight, the anti-foaming rather decreases, or there is a problem that precipitates in the lubricating oil, it is good to use within the above range.

Hereinafter, the present invention will be described in more detail based on examples. However, the scope of the present invention is not limited by the following examples.

Production of gasoline engine oil

Examples 1-3 and Comparative Examples 1-2

The composition shown in Table 1 was mixed under a condition of temperature 70 ℃, 400 rpm of the stirrer to prepare a gasoline engine oil.

Experimental Example

The gasoline engine oils prepared in Examples 1 to 3 and Comparative Examples 1 and 2 were SRV friction coefficient measuring equipment using a plate-type cylinder-type specimen for the new oil and the 15,000 km actual vehicle. The friction coefficient was measured at 100 ° C. and 100N load, and the results are shown in Table 2 below. And the results of the non-combustion friction test that measured the torque at the engine oil temperature 60 ℃ and 100 ℃, the engine speed 800 rpm by connecting the motor to the fly wheel of the actual engine is shown in Table 2 below.

Looking at the experimental results of Table 2, it can be seen that the gasoline engine oil of the embodiment than the comparative example, the SRV friction coefficient difference and the non-combustion friction value difference between the new oil and the used oil after the real run under the low temperature and high temperature conditions is very small. From this, it can be seen that the fuel efficiency improvement sustainability of the gasoline engine oil of the present invention is excellent.

Claims (4)

75 to 97% by weight of base oil having a kinematic viscosity of 3 to 10 cSt (100 ° C.); 1-5% by weight of zinc alkyldithiophosphate; 0.1 to 5% by weight of a friction modifier comprising a glycerol monooleate and dibutylmethylene ester represented by the formula (1); 1 to 7 wt% of discontinuous or two or more types of clean dispersants selected from magnesium sulfonate, calcium sulfonate and calcium borate sulfonate; 0.05 to 3 weight percent of 3-hydroxydiphenylamine; 0.1 to 7 weight percent of one or more viscosity index improvers selected from ethylene-propylene copolymers, polyisoprene-polystyrene copolymers and hydrogenated styrene isoprene copolymers; And 0.1 to 3% by weight of one or two or more antifoaming agents selected from silicones and polymethacrylates; Gasoline engine oil composition comprising a. [Formula 1]

In Chemical Formula 1, R is an alkyl group having 8 to 20 carbon atoms. delete delete A gasoline engine oil comprising the gasoline engine oil composition of claim 1.