KR101080763B1 - Gasoline Engine oil composition of long-life cycle - Google Patents

Abstract

FIELD OF THE INVENTION The present invention relates to long life gasoline engine oil compositions, and more particularly, to hydrogenated-styrene-diphosphate compounds, zinc alkyldithiophosphates, monoalkyl molybdenum dithiocarbamates, polyol esters, hindered phenolic antioxidants and fixed The present invention relates to a gasoline engine oil composition containing base oil, which has improved oxidation stability and abrasion resistance, resulting in longer life, improved wear performance and fuel economy, and reduced engine oil deterioration with longer life. The present invention relates to a composition of fuel economy sustainable long life engine oil.

Engine Oil, Gasoline, Molybdenum Additives

Description

Long life gasoline engine oil composition {Gasoline Engine oil composition of long-life cycle}

The present invention relates to an engine oil composition for extending the replacement cycle of gasoline engine oil.

Engine oil life is affected by deterioration of engine oil due to oxidation of engine oil, sludge generation due to friction and wear, and engine oil deterioration. Since engine oil is used for a long time in high temperature and low temperature conditions, there is a problem of shortening the life of engine oil due to sludge generation, pyrolysis, thermal polymerization due to oxidation, and an appropriate antioxidant is used to improve oxidation stability of the engine oil.

When the engine oil has high temperature and friction at the boundary lubrication, wear and tear occurs, excessive heat is generated, the viscosity is increased, the computational value is increased, sludge is generated, and the life of the engine oil is shortened. Therefore, we try to prevent friction and wear by using anti-wear additives. However, if the engine oil is used under severe conditions, the viscosity index improver used in the engine oil will be damaged and the oil film of the engine oil will be thinned, resulting in excessive friction and wear. In addition, excessive friction and abrasion occur due to depletion of the wear resistant additive due to long time use.

Fuel efficiency improvement by engine oil can be achieved by reducing drag torque of engine oil and friction reduction of sliding part.Reducing the torque of the engine oil can reduce drag torque, but sliding friction and wear tends to increase. Therefore, fuel economy improvement through low viscosity should use additives to reduce the occurrence of friction and wear in the engine.

Generally used friction modifiers are zinc alkyldithiophosphate, and use the molybdenum-based additives at the same time, but the molybdenum-based additive alone has a problem that the effect at low temperatures and the sustained friction reduction.

It is an object of the present invention to provide a composition of an engine oil which has an improved fuel economy and a sustained oxidation stability.

The present invention relates to a gasoline engine oil composition containing a hydrogenated-styrene-dyne-based compound, zinc alkyldithiophosphate, monoalkyl molybdenum dithiocarbamate, polyol ester, hindered phenolic antioxidant, and fixative base oil. will be.

The present invention relates to a composition of a fuel-efficient, long-life engine oil with improved oxidation stability and abrasion resistance, which has a long service life, improved wear performance and fuel economy, and low engine oil deterioration according to a long service life. will be.

The present invention is 2 to 10% by weight of the hydrogenated-styrene-diyne-based compound, 0.05 to 5% by weight of zinc alkyldithiophosphate, 0.5 to 2% by weight of monoalkyl molybdenum dithiocarbamate, 0.2 to 2% by weight of polyol ester The present invention relates to an engine oil composition containing from 70 to 90% by weight of a hindered phenol-based antioxidant, and from 0.05 to 1.0% by weight of a fixing agent base oil having a kinematic viscosity of 3 to 10 cSt at 100 ° C.

The monoalkyl molybdenum dithiocarbamate is characterized in that the molybdenum content is 8 to 15% by weight, sulfur content is 10 to 12% by weight, the polyol ester is selected from neopentyl glycol, trimethylolpropane and pentaerythritol It is characterized by one or two or more kinds.

In addition, the fixing mineral oil is for the engine oil composition, characterized in that the aromatic component is 0.1% by weight or less and the viscosity index is 120 or more.

Hydrogenated-styrene-dyne-based compounds used as viscosity index enhancers are copolymerized styrene and butadiene and then hydrogenated unsaturated bond moieties. Currently, olefin copolymers (OCP) and polymethacrylates (PMA) are used in engine oils. Typical viscosity index improvers used in the present invention, the SSI (Shear Stability Index) is 5 to 10 and used as a diluent solvent of the polymer material using a fixed base oil (VHVI base oil).

The important physical properties of the viscosity index improver should be thickening, low temperature performance, shear stability, low harmful by-products, and excellent thermal and oxidative stability.

The higher the viscosity, the higher the viscosity at 100 ℃ when added 0.1% by weight of polymer, the lower the lower temperature, the better the low temperature viscosity measured by Cold Cranking Simulator, and the shear stability of Bosch injectors. The permanent viscosity decrease after 30 cycles at is expressed in%, the smaller the better.

Hydrogenated-styrene-dyne-based viscosity index improver has better thickening effect and shear stability than olefin copolymer and polymethacrylate. Therefore, the viscosity at high temperature is high even though a small amount of polymer is used due to its excellent incremental strength, which greatly helps to prevent friction and abrasion, and the excellent shear stability is excellent when the engine is operated under severe conditions for a long time. This prevents the breakage of the permanent viscosity decreases due to the breakdown of the viscosity index improver to maintain the performance of the engine oil for a long time can achieve a long service life of the engine oil.

Zinc alkyl dithiophosphate is used as an antiwear agent. At this time, zinc alkyldithiophosphate has a primary type and a secondary type according to the structure of the alkyl group, the primary type is excellent in terms of thermal decomposition temperature, and the secondary type is excellent in load resistance performance. Therefore, the ratio between primary type and secondary type is about 1: 2, and the amount of use is appropriately 0.05 to 5% by weight. If the amount of use is less than 0.05% by weight, the wear resistance is worsened, and if more than 5% by weight, sludge is generated.

Monoalkyl molybdenum dithiocarbamate used as a molybdenum-based additive reacts with metal at boundary and extreme pressure lubrication to form a molybdenum disulfide type film to act as a friction reducing agent by lowering the coefficient of friction. The molybdenum-based additive may be an organomolybdenum additive having an alkyl group having 8 to 13 carbon atoms, and a highly concentrated monoalkyl molybdenum dithiocarbamate having a molybdenum content of 8 to 15% by weight and a sulfur content of 10 to 12% by weight. The amount of use is suitably 0.5 to 2% by weight. If the amount of use is less than 0.5% by weight, the friction reducing effect is less, and if it exceeds 2% by weight, there is a problem that does not melt well when producing the engine oil and the problem that the sludge is generated at high temperatures when using.

As the ester additive, a polyol ester was used. Polyol-based esters are excellent in thermal stability and load-bearing performance and have excellent solubility in engine oil. As the polyol to be used, neopentyl glycol, trimethylol propane, pentaerythritol can be used. The amount is suitably 0.2 to 2% by weight. If the amount of use is less than 0.2%, the friction reducing effect is less, and if it exceeds 2% by weight it may cause a problem that does not melt well when producing the engine oil and swelling of the seal may occur.

Antioxidants generally include a chain terminator, a peroxide decomposer, a metal deactivator and a mixture of two or more thereof, and a chain terminator which prevents the oxidation of the initial stage may be mainly used. Examples of the chain terminator include 2,6-di-tert-butyl-para-cresol, hindered phenol-based and dioctyldi such as 4,4'-methylenebis (6-tert-butyl-ortho-cresol) Aromatic amines such as phenylamine, phenylalphanaphthalene and the like can be used. In the present invention, a hindered phenol-based antioxidant, 2,6-di-tert-butyl-para-cresol, is used in an amount of 0.05 to 1.0% by weight. If the amount is less than 0.05%, the antioxidant effect is less. If the amount exceeds 1.0% by weight, further improvement in performance is inferior.

As the base oil used in the present invention, one or two kinds of fixative mineral oils having a 100 ° C kinematic viscosity of 3 to 10 cSt were used. Fixative mineral oil refers to base oils having an aromatic component of 0.1 wt% or less and a viscosity index of 120 or more.The aromatic component is a substance that is easily oxidized at a high temperature, so that the less aromatic components, the better the oxidation stability and the viscosity index is 120 or more. The viscosity change is small, so the performance of engine oil is excellent with temperature. In the present invention, one to two kinds of fixative mineral oils were used at 70 to 90 wt%.

The present invention will be described in more detail with reference to the following Examples, which are not intended to limit the invention.

Example  1. Manufacturing of gasoline engine oil

To prepare a gasoline engine oil of the composition of Table 1.

(Unit: wt%) division Compound name Example 1 Comparative Example 1 Comparative Example 2 Base oil High Viscosity Index Base Oil 85 88.8 80.5 Viscosity Index Improver Hydrogenated-styrene-dyne 5 - - Olefin Copolymer - 3 12 Abrasion resistant Zinc Alkyl Dithio Phosphate 2 2 3 Molybdenum Monoalkyl Molybdenum Dithiocarbamate 0.8 - - Ester Polyol ester One - - Antioxidant 2,6-di-tertiary-butyl-para-cresol 0.5 0.5 0.3 Ashless dispersant Polyisobutylene Succinimide 5.0 5.0 4.0 Antifoam Polysiloxane 0.2 0.2 0.2 Corrosion inhibitor Benzotriazole 0.5 0.5 - 1) Base oil: S-Oil, Ultra-S base oil
2) Hydrogenated-styrene-dyne: Infineum
3) Zinc Alkyl Dithio Phosphate (ZnDTP): Lubrizol
4) Molybdenum dithiocarbamate (MoDTC): Adeka, SC525
5) Polyol esters: Uniqema, P-1973.
2,6-di-tertiary-butyl-para-cresol: Ciba
7) Polyisobutylene succinimide: Lubrizol.
8) Polysiloxane: Shin-Etsu Corporation
9) Benzotriazole: Lubrizol

Comparative example  One. API SM 5W-20 Gasoline Engine Oil

A commercial API SM class 5W-20 gasoline engine oil was used. The composition is shown in Table 1 above.

Comparative example  2. ACEA  A3 / B3 5W-40 Gasoline Engine Oil

A commercial ACEA A3 / B3 5W-40 gasoline engine oil was used. The composition is shown in Table 1 above.

Test Example  1. High Temperature Oxidation Stability Evaluation

Under the engine test conditions shown in Table 2, a high-temperature Deposit engine dynamo test for evaluating oxidation stability and sediment generation tendency of the engine oil was carried out, and the deficiencies thereof are shown in Table 3 below.

division Example 1 Comparative Example 1 Comparative Example 2 Piston cleanliness rating, rating (*) 8.3 6.4 8.0 Engine oil consumption,% 22.3 27.8 26.2 Epidemic, mgKOH / g Before the test 9.7 7.1 11.1 After the test 7.2 3.1 6.7 Difference (post-test) -2.5 -4.0 -4.4 Acid value, mgKOH / g Before the test 3.1 3.3 3.5 After the test 4.2 5.8 5.8 Difference (post-test) 1.1 2.5 2.3

(*) Piston cleanliness was evaluated by CEC M-02-A-78 method, and the evaluation results are expressed as 1 to 10, and the higher the value, the better the sediment performance.

The computer value was evaluated by ASTM D 664.

Total Alkaline was evaluated by ASTM D2896

In the embodiment according to the present invention, the piston deposits were greatly reduced and the engine oil consumption was also reduced compared to the comparative examples. In addition, the amount of change in infectious value and computational value was small.

Test Example  2. Fuel efficiency  evaluation

ASTM D-6837 (Seq-6B) engine test, which is an ASTM test method for evaluating fuel efficiency of engine oil, was performed, and the results are shown in Table 4 below.

ASTM fuel economy performance test results division Example 1 Comparative Example 1 Comparative Example 2 Initial fuel economy (after 16 hours), fuel efficiency improvement% (*) 0.6 1.0 -1.2 Fuel economy persistence (after 96 hours), fuel efficiency improvement% (*) 0.4 0.5 -1.7

(*) Fuel efficiency improvement rate is evaluated by measuring fuel consumption and comparing fuel consumption with reference engine oil (API SL / GF-3 5W-20).

Example 1 according to the present invention has a lower viscosity than Comparative Example 1, and a higher viscosity than Comparative Example 2, the evaluation results also showed a fuel efficiency performance in proportion to the viscosity.

However, since the viscosity grade of the engine oil used as a criterion in the fuel efficiency performance evaluation is 5W-20, the viscosity is lower than that of the viscosity grade 5W-30 of Example 1, but the fuel economy of Example 1 is equivalent to the fuel efficiency evaluation standard engine oil. As it was confirmed that it is superior to the level, fuel economy performance is excellent. In addition, it can be seen that the fuel efficiency performance of Example 1 is excellent as the fuel economy persists in terms of persistence.

Claims (4)

Hydrogenated-styrene-diyne compound 2-10 wt%, zinc alkyldithiophosphate 0.05-5 wt%, monoalkyl molybdenum dithiocarbamate 0.5-2 wt%, polyol ester 0.2-2 wt%, hindered An engine oil composition containing from 0.05 to 1.0% by weight of a phenolic antioxidant and from 80 to 90% by weight of a fixative base oil having a kinematic viscosity of 100 ° C. of 3 to 10 cSt. The method of claim 1, The monoalkyl molybdenum dithiocarbamate is molybdenum content of 8 to 15% by weight, sulfur content is an engine oil composition, characterized in that 10 to 12% by weight. The method of claim 1, The polyol ester is an engine oil composition, characterized in that one or two or more selected from neopentyl glycol, trimethylolpropane and pentaerythritol. delete