DE1806899C3 - lubricant - Google Patents

Description

The present invention relates to an improved lubricant which is particularly useful for such Motors that work without lubricating oil coating are suitable.

Heavy fuel oils are usually burned in large ship engines, while relatively large ones are often used for soft ones Contain amounts of sulfur. When burning, therefore, sulfur dioxide and / or sulfur dioxide are formed as acidic products of combustion, which alone or together with other products of combustion can cause serious corrosion problems in such marine engines. To the thereby To remedy the difficulties caused or to keep them as low as possible, one has to deal with the problem Lubricating oils already have basic naphthenates of metals from Group II of the Periodic Table of the Elements added, which neutralize the acidic combustion products. Such lubricants correspond but not yet all practical requirements, especially with regard to the rust protection effect, the thermal stability and the basic properties.

The lubricant of the invention enables these disadvantages to be remedied.

The lubricant according to the invention from

1) a mineral lubricating oil and / or a synthetic hydrocarbon lubricating oil,

2) an oil-soluble basic salt of a metal of the group derived from a naphthenic acid II of the Periodic Table of the Elements with an atomic number from 12 to 56,

3) an oil-soluble basic salt of a metal derived from an aromatic carboxylic acid of group II of the periodic table of the elements with an atomic number from 12 to 56, optionally

4) 0.01 to 2.0 percent by weight of common antioxidants, in particular zinc dialkyldithiophosphate and / or 2,6-di-tert-butyl-4-methylphenol, and if necessary

ίο 5) usual additives

is characterized in that it is used as components 2 and 3 in combination 0.5 to 3 percent by weight of at least one of a naphthenic acid and 1 to

»5 6 percent by weight of at least one oil-soluble basic derived from an aromatic carboxylic acid Salt of a metal from group II of the Periodic Table of the Elements with an atomic number of 12 to 56, the potentiometrically determined

so total base number of lubricant 5 to 12 mg KOH / g, in particular 8 mg KOH / g.

Ice was known, both oil-soluble basic salts of a naphthenic acid and oil-soluble basic salts a petroleum sulfonic acid or a hydroxybenzoic acid

zs acid, such as salicylic acid, and such products to be used as lubricating oil additives. However, the cheap naphthenates are not sufficient Effect in relation to z. B. the total piston purity of engines, while on the other hand in the relative expensive salicylates the neutralization effect, expressed as a potentiometrically determined total base number, not satisfied.

With this fact it was extremely surprising that when the above is used in combination marked components 2) and 3) in certain proportions a synergetic Effect is achieved which leads to a particularly favorable behavior of the lubricant according to the invention in engines without oil circulation. This also results in economic advantages, because now a Part of the expensive salicylate can be replaced by the cheaper naphthenate, which, however, unexpectedly an increase in quality is associated.

The basic salts of naphthenic acid and the aromatic carboxylic acid are preferably in such Amounts in the lubricant suggest that the potentiometrically determined total base number is 8 mg KOH / g. The total potentiometric base number, which is abbreviated as TBNE below, can be determined according to ASTM method D 664-58 or according to the method of the Institute of Petroleum No. 177/64.

The hydrocarbon lubricating oil used as the base oil can be of mineral or synthetic origin

Be leaps. It can be a single oil or a mixture of oils. For example, a mixture of mineral lubricating oils can be used as the base oil like a mixture of a distillate lubricating oil and a »bright slock«. On the other hand, can as a base lubricating oil but also a mixture of a mineral lubricating oil and a synthetic hydrocarbon lubricating oil be used. The mineral lubricating oil can, but can, have an essentially paraffinic and / or naphthenic character one with considerable proportions of aromatic hydrocarbons can also be used. very well usable miners?! lubricating oils are made from highly Parairtine Obtain crude oils. In this case one is

Distillation and / or dewaxing treatment sufficient for the production of the mineral lubricating oil. Mixed basic or highly aromatic oils can also be used Crude oils containing paraffinic hydrocarbons through refining operations well usable mineral lubricating oils are worked up. As a useful synthetic hydrocarbon lubricating oil a polyolefin, for example a polyisobutylene, can be used. The viscosity the basic cutting oils can vary within wide ranges, and lubricating oils can be produced which meet the SAE classes 5V /, 1OW, 2OW, 20, 30, 40, 50, 60 or 70.

The basic salts of naphthenic acid are expediently used in such an amount that they give the lubricating oil a potentiometrically measured total base number in a concentration of 1 percent by weight impart from 1.5 to 3 mg KOH / g.

The naphthenic acids concerned can have an average molecular weight from Z. B. 150 to 750 have. The excess basicity of the basic naphthenic acid salts is generally more than 400% compared to the corresponding neutral salts, preferably more than 600% and especially more than 800% up to the highest practically attainable Value. Barium, calcium, magnesium, or strontium are very suitable for the purposes according to the invention Zinc salts, with calcium salts being preferred.

The excess basicities of the inventiveQ used Basic salts of naphthenic acids and aromatic carboxylic acids can be according to the determine the following equation:

Excess basicity in

100.

In this equation, M is the number of equivalents of the metal from group H and E is the number of equivalents of naphthenic acid or aromatic carboxylic acid per 100 g of the basic salt. The values for M and £ are chosen so that the lubricating oil at a salt concentration of 1 percent by weight has a potentiometrically determined total base number between 1 and 1.5 mg KOH / g.

Barium, calcium, magnesium, strontium or zinc salts are expediently used as the basic salts of the aromatic carboxylic acids, the calcium salts being preferred. The aromatic carboxylic acids can be hydrocarbon-substituted benzoic acid, salicylic acid, dihydroxybenzoic acid. Act as anthranilic acid or naphthoic acid. Examples of such acids are ₂ -Alkylb <C ₃ -C »: nzoesäuren, C ₃ -C _i2 -Alkylsalicylsäuren and C ₃ -C _2g -AIkylnaphthoesäuren, for example Laurylsalicylsiiuren, Stearylsalicylsäuren or mixtures of C ₈ -C ₃₀ -Alkylsalicylsäuren. In the context of the invention, preference is given to using salts of C ₁₄ -C ₁₈ - or C ₁₄ -C _2J -alkylsalicylic acids. Such acids are very conveniently used in the preparation of mixtures of basic salts of C _u -C _ia - or C ^ -Qa monoalkyl and dialkyl salicylic acids. A mixture of basic calcium salts of C ₁₄ -C ₁₈ monoalkyl and dialkyl salicylic acids is particularly preferred. Such a salt mixture is referred to as salt "A" in the examples below. Such salts expediently have excess basicities of 50, 200 or 600%.

The lubricants according to the invention preferably also contain 0.01 to 2.0 percent by weight, in particular 0.05 to 1 percent by weight of a conventional antioxidant, for example calcium

S or zinc dialkyldithiophosphates, especially those thiophosphates which are the alkyl groups are amyl and / or butyl groups. Also alkylphenols, for example di- and trialkylphenols, preferably 2,6-di-tert-butyl-4-methylphenol, and Alkyl bisphenols, such as bis (3,5-di-tert-butyl-4-hydroxyphenyl) methane, are suitable for this purpose. A third class of antioxidants are arylamines, such as phenyl-alpha-naphthylamine or phenylbeta-naphthylamine.

Other customary additives can also be incorporated into the lubricants according to the invention be e.g. B. anti-wear agents, such as phosphorus-containing esters, antifoam agents, such as. B. Silicone polymers, viscosity index improvers, e.g. B. polymeric acrylic acid esters, extreme pressure additives, such as dibenzyl disulfide, rust inhibitors, for example condensation products from maleic anhydride and long-chain olefins, agents to improve oiliness, such as acid-free sebum and / or surfactants, such as with Peroxyden bell made aromatic extracts.

The invention is illustrated by the following lubricants, some of which are merely serve for comparison.

30 Lubricants A
(for comparison)

Weight percent

Basic calcium naphthenate (800%

Excess basicity) 5.0

An antioxidant containing sulfur and phosphorus 0.2

2,6-di-tert-butyI-4-methylphenol 0.2

Mineral cutting oil with a medium viscosity index and a viscosity of
41 cSt at 6O ⁰ C rest

Lubricant B
(for comparison)

Calcium basic alkyl salicylates
(Salt "A") (200% excess basicity) 4.0

Zinc amylbutyldithiophosphate as an antioxidant 0.2

Mineral lubricating oil with a medium viscosity index and a viscosity of
41 cSt at 6O ⁰ C rest

Lubricant C
(according to the invention)

Calcium basic alkyl salicylates
(Salt "A") (200% excess basicity) 3.0

Basic calcium naphthenate (800%
Excess basicity) 2.0

Zinc amylbutyldithiophosphate as an antioxidant 0.2

Mineral lubricating oil with a medium viscosity index and a viscosity of
41 cSt at 6O ⁰ C rest

Table I.

Rust protection Emulsifying ass ;, ' Oxidation effect until capital, oil stability, 10% of the % W O _t -On- lubricant surface in the 16 hours nahraein from the rust 2.5 Minutes infested, 2 hours. 1.0 in hours 4.5 1.0 110 A (comparison) 70 3.5 730 B (comparison) 168 3.0 710 C (invention) 168

Test to determine the anti-rust effect

The percentage of the rusted surface of the specimen is determined according to the ASTM method D 665 using a 20 percent saturated saline solution as corrosive Medium determined.

Test to determine the emulsifying power

The oil to be tested is stirred in an apparatus according to ASTM method D 665 at 6O ⁰ C and 10 volume percent water, and then allowed to settle at the same temperature under the influence of gravity. Samples are taken from the upper layer after 2 or 16 hours and their water content is determined.

Determination of the oxidation stability

It is here to SCOT test at 16O ⁰ C using an oil-soluble iron catalyst.

From Table I it can be seen that a lubricating oil mixture which contains both basic calcium naphthenates as well as basic calcium alkyl salicylates, a particularly good anti-rust effect and good behavior when testing the emulsifying capacity and the oxidation stability.

Lubricant D
(for comparison)

Weight percent

Calcium basic alkyl salicylates
(Salt »Α«) (Λ00% excess

basicity) 5.0

Mineral lubricating oil with a medium viscosity index and one viscosity
of 41 cSt at 60 ° C rest

Lubricant E.
(according to the invention)

Calcium basic alkyl salicylates
(Salt "A") (200% excess basicity) 3.5

Basic calcium naphthenates
(800% excess basicity) 1.65

Zinc amylbutyldithiophosphate as
Antioxidant 0.2

Mineral lubricating oil with a medium viscosity index and one viscosity
of 4IcSt at 60 ° C rest

Lubricant F.
(according to the invention)

Basic calcium alkyl salicyates
(Salt "A") (200% excess basicity) 4.0

Basic calcium naphthenates
(800% excess basicity) 1.4

Zinc amylbutyldithiophosphate as
Antioxidant 0.2

Mineral lubricating oil with medium
Viscosity index and a viscosity of 41 cSt at 6O ⁰ C remainder

Table II

Evaluation of the piston cleanliness completely pure) a coat TRNF ** lubricant (10 = ring
webs 5.8 1 DlIC ) Grooves 1.05 9.8 mg
KOH / g A (comparison) 0.5 4.9 8.9 10.0 B (comparison) 5.0 4.3 8.8 5.0 D (comparison) 5.8 4.0 9.7 6.25 C (invention) 3.7 3.4 9.7 7.8 E (invention) 5.1 5.9 8.0 F (invention) 6.4 8.0

*) Potentially determined total base number.

From Table II it can be seen in particular that the values for the total base number for lubricants C, E and F are greater than would be expected when considering the total base number for lubricants A, B and D. Lubricants B and D correspond to a total base number of 1.25 mg KOH / g for a concentration of 1 percent by weight of basic calcium alkyl salicylates, and lubricant A corresponds to a total base number of 2 mg KOH / g for a concentration of 1 percent by weight of basic calcium naphthenates. This would give a total base number for lubricants C, E and F of 7.75, 7.675 and 7.8 mg KOH / g, respectively.
In fact, however, Table II shows that the experimentally determined total base numbers are 7.8, 8.0 and 8.0 mg KOH / g, respectively.

Furthermore, it can be seen from the above numerical values that the comparative lubricant A, which contains only basic naphthenate, only a total piston purity of 7.35, while the inventive lubricants C, E and F give total piston purities of 16.5, 18.2 and 22.0 respectively.

Claims (5)

Claim: lubricant, consisting of 1) a mineral lubricating oil and / or a synthetic hydrocarbon lubricating oil, 2) an oil-soluble basic salt of a metal derived from a naphthenic acid Group II of the Periodic Table of the Elements with an atomic number from 12 to 56, 3) an oil-soluble basic salt derived from an aromatic carboxylic acid Metal of group II of the periodic table of the elements with an atomic number from 12 to 56, if applicable 4) 0.01 to 2.0 percent by weight of conventional antioxidants, in particular zinc dialkyldithiophosphate and / or 2,6-di-tert-butyl-4-methylphenol, and if necessary 5) usual additives, characterized in that it is used as components 2 and 3 in combination 0.5 to 3 percent by weight of at least one of a naphthenic acid and 1 to 6 weight percent of at least one derived from an aromatic carboxylic acid Oil-soluble basic salt of a metal from group II of the Periodic Table of the Elements with an atomic number of 12 to 56, the potentiometrically determined total base number of the lubricant 5 to 12 mg KOH / g, in particular 8 mg KOH / g.