DD298262A5 - LUBRICANTS FOR FOUR-STICK OTOT AND DIESEL ENGINES - Google Patents

Abstract

The invention relates to lubricating oils for four-stroke petrol and diesel engines for year-round use in highly loaded engines of passenger cars and commercial vehicles. The lubricating oil compositions according to the invention are characterized by the use of alkaline earth sulfonates and phenolates as well as zinc dithiophosphates in certain equivalence ratios to one another. In terms of performance, they correspond to the API performance class SE / CC and have a good detergent-dispersant and antioxidant behavior {lubricating oil composition; Four-stroke spark ignition engines; Diesel engines; Year-round use; Erdalkalisulfonate; Erdalkaliphenolate; API performance class SE / CC; Antioxidansverhalten; Detergent-Dispersantverhalten}

Description

Field of application of the invention

The invention relates to lubricating oil compositions for year-round use in highly loaded four-stroke gasoline engines and diesel engines of passenger cars and commercial vehicles.

-2- 298 262 Characteristic of the known state of the art

It is known that the operation of efficient and current state-of-the-art diesel and four-stroke Otto engines requires lubricating oils which have a high degree of aging resistance under operating conditions, as well as a number of other properties, such as protection against wear, rusting and corrosion of nonferrous metals, low tendency to cold sludge formation, good flow behavior at low temperatures as well as first priority, the ability to keep under changing operating conditions, the Motoronteile free of debris and particles from combustion soot and oil-insoluble aging products of the lubricating oil in Dispersin ^r IEM state.

This complex of properties is circumscribed in motor oils in the definition of quality grading by means of specifications, i. H. Testing requirements requiring the existence of one or more tests in engines or model testing machines under standardized test conditions.

Internatinal is most commonly referred to the classification system of the American Petroleum Institute (API classification). At present, with respect to the aforementioned field of application of the invention, multigrade oils corresponding to the API performance classes SE / CC and SF / CC determine the state of the art.

Dig mentioned requirements are met in detail by an age-stable base oil, z. B. a Solventoder Hy 'roraffinat suitable for adjusting the required viscosity-temperature behavior Vl improvers and the performance veau determining additives such as ash-containing detergents, ashless dispersants, oxidation, wear and corrosion inhibitors and possibly other additives are added.

The added additives may well have multiple or complex effects (so-called multifunctional additives). So z. B. known that the predominantly used Zn salts of acid Dialkyldithiophosphorsäureestern act both as an aging inhibitor and as a wear reducer, on the other hand, for. For example, basic alkaline earth salts of natural or synthetic alkylarylsulfonic acids mainly as detergents / dispersant additives, but also as rust inhibitors. Individual additives can mutually reinforce each other in their effect so that the effect is far greater than can be expected from the concentration of the individual components (synergism). So z. As the enhancer effect of azoxy compounds of alkylphenols and / or other ethoxyl compounds with respect to the activity of basic alkaline earth sulfates as rust inhibitors known in principle (/ 1 /).

Finally, additives that are used to achieve different effects, by their side effect attenuate other additives and thus lead to (mostly partial) antagonisms.

Thus, it is known that the addition of certain polymers necessary for the production of multigrade oils to flatten the viscosity-temperature curve requires a higher concentration of additives with detergent for the compensation of dadurocane-increased tendency to form residues, especially in the cylinder-piston complex / dispersant effect.

Also to be considered are the possible interactions with the fuels used, so that, for example, for use in diesel engines sufficient neutralization capacity, expressed by the Total Base Number (TBN) must be present.

The additive packages (detergent-inhibitor-inhibitor combinations) used in practice to meet the performance requirements according to the abovementioned API specifications, which are commercially available in a variety of designs, attempt to achieve optimum technical and economical results by exploiting the properties of the components. Thus, it is known that the Ca sulfonate detergents according to the prior art, although good DD properties, but not the requirements of aging resistance at high temperatures with additional load by catalytic influences z. B. finely divided Eisenabriab or of Fe ions, so that it comes to disturbing deposit formation in the engine and oil thickening, especially in long-term operation.

On the other hand, the also known alkaline earth metal salts of alkylphenols, especially those with sulfur bridges in the molecule, because of their pronounced side effect as antioxidants Although improved high-temperature aging resistance, but their DD behavior is not sufficient to ensure optimum engine cleanliness. Even the obvious combination of the two types of detergents mentioned, which can also be realized in the form of their co-production as phenolate-containing alkaline earth sulfonate (for example according to DD 219187, DD 219188 and DD 220305), with ashless dispersants, e.g. of the succinimide type, and zinc dithiophosphate type of oxidation and wear inhibitors commonly used in motor oils obviously does not automatically meet the performance requirements of modern gasoline and diesel engines (see Table 1), so that the additional use of ashless antioxidants in the literature The type of sterically hindered phenols and alkylated diphenylamines in high-performance engine oils is described (Schmiertechnik and Tribologie 29 [1982) p.92-97).

However, such components are often difficult to obtain or significantly increase the cost of producing the lubricating oils alloyed therewith.

A further disadvantage with respect to the known prior art is that special raw materials are often required of the raw materials used to produce the detergents used for high-performance engine oils. In particular, in the production of sulfonic acids required for the production of sulfonates, special mineral oil fractions of certain crude oil origin and stabilized sulfur trioxide generally have to be used for the sulfonation, which in turn leads to restrictions in the availability or price increases in the production of the finished products. Overall, the commercially available additive packages for the performance levels mentioned are very complex and are used according to the manufacturer in significant concentrations (about 7-12% by weight) in the corresponding lubricating oils, with respect to the individual components contained no detailed information is known.

The aim of the invention is to develop, cost-effective and on the basis of readily available components, in particular without additional use of special ashless antioxidants of the type sterically hindered phenols and / or alkylated diphenylamines, lubricating oils for four-stroke petrol and diesel engines of passenger cars and commercial vehicles, which have a very good detergent-dispersant and antioxidant behavior and in the performance properties of at least the API performance class SE / CC correspond.

Explanation of the essence of the invention

The object of the invention is to provide lubricating oils for year-round operation of powerful four-stroke petrol and diesel engines, which meet at least the API performance class SE / CC, so that the synergis .. '. The properties of available additive components or additives produced in a new way are maximally utilized, opposing side effects are minimized, and the complex performance parameters of the lubricating oils are fully guaranteed by a balanced recipe design in accordance with the requirements of the applications. According to the invention, this object is achieved in that for a generally conventional manner from 70 to 97Ma .-% age-stable lubricating oil raffinates, 2 to 10Ma .-% of a detergent-inhibitor composition, 1 to 8Ma .-% ash-free dispersant Siccinimidtyp, and, if necessary up to 2% by weight of a rust inhibitor and up to 10% by weight of a Vl pretreater, such a composition has been found to consist of ash-containing detergents, oxidation and wear inhibitors, which allows maximum exploitation of the synergistic effects of the components.

The composition is characterized in that are used as components alkaline earth metal salts of technical alkylbenzenesulfonic acids, technical alkylphenols, the latter being at least 30% in sulfurized form and are used from free alkylphenols and / or alkylphenol sulfides and zinc salts of Dialkyldithiophosphorsäuren in such concentrations that in the finished lubricating oil with a minimum content of 5 meq / kg sulfonate groups, an equivalence ratio of sulfonate groups to phenolic groups of 1: 5 to 1:13, a proportion of free phenols of 5 to 50% of the phenolic compounds and an equivalence ratio of phenolic groups to zinc dialkyldithiophosphates of at least 2: 1 ,

In this case, the molar concentrations of the sulfonate groups or phenolic groups required for adjusting the equivalence ratios are determined, for example, by potentiometric step titration of the sulfonate-containing additive for the preparation of the sulphonate-containing additive and the determination of the OH number of the alkylphenol in the preparation of the or phenol-containing additive on the other hand. The molar concentration of the technical Zinkdialkyldithiophosphates is obtained in a simple manner from the zinc content, while the proportion of present in sulfurized alkylphenol, based on the theoretical formula (RC ₆ H ₄ -OH) ₂ S, for example, from the attack of hydrogen sulfide in the sulfurization the alkylphenol used can be determined. Furthermore, it has been found that the synergistic effect is particularly pronounced and thus the object of the invention is very inexpensive and effectively achievable if in the detergent-grain gap position next Zinkdialkyldithiophosphat only a detergent component in the form of a prepared in a continuous process phenolate Erdalkalisulfonates or a sulfonate Erdalkaliphenolates is used, in their preparation based on technical Aikylbenzensulfonsäure and technical, at least partially sulfurized alkylphenol, the presentation of the components and promoters and the reaction carried out so that the equivalence ratio of sulfonate according to the invention to phenolic groups and the inventive proportions of sulfurized and free phenolic groups at the production of this detergent are set from the outset.

Thus, a low-cost Varianto of the formulation according to the invention, if in the detergent-inhibitor composition at least one prepared in a continuous process phenolate-containing alkaline earth sulfonate with equivalents of sulfonate groups of 100 to 300mval / kg and phenolic groups of 500 to 1400mval / kg is used at least 30% of the phenolic groups in sulphurized form and from 5 to 50% as free alkylphenols or alkylphenol sulphides. A particularly favorable overall engine behavior at an optimal TBN sulfate ash ratio was achieved by using at least one medium or high basic calcium sulfonate as phenolate-containing alkaline earth sulfonate, in the preparation of which a promoter combination of a technical, at least 30% sulfurized alkylphenol, an aliphatic alkenol and an alkanolamine used and the carbonization at temperatures of 35 to 80 ⁰ C is performed so far that the molar ratio of calcium carbonate to calcium hydroxide at least 3: 1 and at the same time the molar ratio of phenolate to free phenol is at least 1: 1.

It is particularly advantageous that for such sulfonate detergents used in the formulation of the invention also technical sulfonic acids are used, which are prepared in a simple manner by Friedel-Crafts alkylation of benzene with chlorinated paraffins and subsequent reaction with oleum.

If pure sulfonate detergents are used in the formulation or if the equivalence ratio of sulfonate groups to phenolic groups required according to the invention is not attained by said phenol-containing alkaline earth sulfates, this is advantageously achieved by adding a medium containing phenolic groups of 1100 to 1900 meq / kg. or highly basic sulfurized calcium phenate containing a maximum of up to 200mg / kg sulfonate groups in the form of an alkaline earth sulfonate. With suitable reaction procedure in the preparation of the sulfonate-containing phenolate and its sole use as a detergent together with a Zinkdialkyldithiophosphat in the detergent-inhibitor composition of the invention is possible, provided that the proportions of free phenols or phenol sulfides according to the invention are achieved.

Very good results in terms of thermal capacity of the lubricating oil and a cost, low total content of alkylphenol within the limits of the invention are achieved when a product is used as sulfurized calcium phenolate, in its preparation, the reaction in the common presentation of technical alkylphenol, a

Erdalkalisulfonat, a mixture of high molecular weight aliphatic alcohols, diluent oil and sulfur in only one reaction vessel and is run continuously and the carbonization in the presence of a promoter combination consisting of

2 to 8% by weight of the alkaline earth sulfonate,

4 to 15% by weight of the mixture of high molecular weight saturated aliphatic alcohols,

0.005 to 0.7% by weight of a dimethylpolysiloxane,

based on the total mixture takes place.

Within o'er recipe according to the invention, the Detergent Inhltibor combination in the form of the individual components or as a package, optionally also with the inclusion of further formulation ingredients, are added.

The performance of the lubricating oils composed according to the invention is demonstrated, in particular, in engine test methods, the test method standardized in TGL 32429 representing a high-temperature deposition test in a four-stroke Otto engine and thus being particularly relevant for the field of application of the invention. As Table 1 shows, comparable or better deposit behavior is achieved with products of the international market of the performance classes SE / CC or SF / CD with lubricating oils added according to the invention based on readily available and effectively producible components (see embodiments). Based on the comparative formulations which are prepared on the basis of the same additive components but in a composition outside the solution according to the invention, a significantly improved deposition behavior of the lubricating oils according to the invention results. The invention will be explained in more detail below with reference to some embodiments.

embodiments

example 1

To 82.7 kg of a base oil, which consists of a brightstock prepared in the usual way and a lubricating oil raffinate produced according to DD 113768, are added and mixed thoroughly:

7.0 kg of a commercially available polymethacrylate-based dispersing VI improver, 3.6 kg of a commercial dispersant of the bissuccinimied type,

0.3 kg of a rust inhibitor based on a multiply ethoxylated alkylphenol and 6.4 kg of a detergent-inhibitor combination consisting of 2.5 parts by weight of a medium-basic phenol-containing calcium sulfonate (TBN: 160 mg KOH / g) with an equivalence of sulfonate groups of 230mg / kg and to phenolic groups of 610 meq / kg, the latter to 50% in sulfurized form and 20% in the form of free phenols or phenolsulfides, 1.5 parts by mass of a highly basic Ca-phenolate detergent prepared by a one-step process (TBN : 220mg KOH / g) with equivalents of phenolic groups of 1320mval / kg and sulfonate groups of 20mval / kg, the former being sulfurized at stoichiometric ratio, and 2.4 parts by mass of a technical grade zinc dialkyldithiophosphate with a zinc content of 4.0 Ma. -Divide. This gives a lubricating oil for four-stroke petrol and diesel engines of the SAR viscosity class 15 W40 with a sulfate ash content of 1.1 parts by mass and a TBN of 8.1 mg KOH / g, which, as the results in Table 1 shows an excellent high-temperature deposition behavior a.ifweistt meets all requirements for use in highly loaded four-stroke gasoline engines and can be successfully used in diesel engines with sulfur contents of diesel fuel to about 1%.

Example 2

To 82.8 kg of the base oil used in Example 1 are added and mixed thoroughly:

7.0 kg of a commercially available dispersing VI improver,

3.6 kg of an ash-free dispersant,

0.2 kg of a commercial alkoxylate as a rust inhibitor and

6.4 kg of a detergent-inhibitor combination consisting of 2.4Ma parts of an approximately 50% solution of a technical Zinkdialkyldithiophosphates in a diluent oil with a zinc content of 3.9 parts Ma and 4.0 Ma parts of a Specially prepared phenolate-containing barium sulfonates having an equivalent content of sulfonate groups of 180 meq / kg and phenolic groups of 1200 meq / kg, the latter being about 55% in sulfurized form and about 12% in the form of free phenols or phenol sulfides.

A high-performance lubricating oil of SAE viscosity class 15W40 having a sulfate content of 1.4% by mass and a TBN of 6.2 mg KOH / g with excellent high-temperature deposition behavior for use in modern four-stroke engines of passenger cars and commercial vehicles (see Table 1) ).

Example 3

The production method of a lubricating oil according to the invention for four-stroke petrol and diesel engines is modified in that, instead of the highly basic Ca phenolate in the detergent-inhibitor combination, a medium-basic Ca phenolate prepared in a one-stage process (TBN approx. 150 mg of KOH / g), which has an equivalent amount of phenolic groups of 1 μMal / kg and sulfonate groups of 25 meq / kg, the former being sulfurized again in the stoichiometric ratio, so that in the overall composition the theoretical degree of sulfurization of the alkylphenol used exceeds 75 % and the equivalence ratio of sulfonate groups to phenolic groups is about 1: 6.3.

This gives a thermally highly durable lubricating oil for internal combustion engines with a sulfate ash content of 1.0 wt .-% and a TBN of 7 mg KOH / g, which also in the modified metal strip test to Wolf with the addition of 50 ppm Fe at 250 ° C over 12h has a very good high-temperature aging stability and ensures excellent protection against deposits during engine operation.

Example"

Instead of the barium sulphonate used in Example 2 within the detergent-inhibitor combination, 3.5 .mu.% of a medium-basic Ca detergent (TBN 170 mg KOH / g) is used which, according to a special one-step process, is based on equal fractions of a Friedel-Crafts Alkylation and sulfonation with oleum-derived sulfonic acid and a 50% sulfurized technical Nonylphenoles was generated. In this case, in the finished detergent an equivalence of sulfonate groups of 160mval / kg and of phenolic groups of 1760mval / kg, i. an equivalence ratio of 1:11 is set and the reaction is terminated with a Gohalt to free phenol sulfides of about 10% of the phenolic compound. Again, there is obtained a lubricating oil with a TBN of about 6.7 mg KOH / g and a sulfate ash content of 0.9Ma, which is very well suited for use in thermally highly stressed four-stroke petrol and diesel engines of passenger cars and commercial vehicles. %.

Table 1

Results of the motor test in the high-temperature deposition test according to TGL 32429 (score: 100 = clean)

Comparative Inventive Comparative Inventive Lubricating Oils

recipe recipe Example Example Example Example

Technology * 1 ·· 2 · * · 12 3 4

Charcoal filling I.Ringnut 31 34 17 41 40 40 54

Lacquer, 2nd u. 3. annular groove 66 65 43 71 73 72 78

Paint, webs 43 33 21 45 45 52 57

* Mean value for 8 reference oils of the international market with the same field of application

** Formulation contains as Detergentkompsnente 3.5Ma .-% of the moderate basis phenolathaltigen Ca sulfonate from Example 1, whereby in the lubricating oil, a content of sulfonate groups of about 8mval / kg and an equivalence ratio sulfonate groups to phenolic groups of 1: 2.6 is set (Zn content: 0.09% by mass, content of ashless dispersant: 3.6% by mass)

* * · Formulation contains as detergent component sulfonate-containing phenolates, whereby a content of sulfonate groups of about 2 meq / kg and a equivalence ratio sulfonate groups to phenolic groups of 1:22 is set in the lubricating oil (Zn content: 0.09Ma .-% , Content of ashless dispersant: 4.0% by mass)

Claims (6)

1. Lubricating oils for four-stroke petrol and diesel engines of passenger cars and commercial vehicles, consisting of 70 to 97% by mass of a mixture of lubricating oil raffinates, 2 to 10% by mass of a special detergent inhibitor composition, 1 to 8 ma. % of a siccinimide ash-free dispersant, up to 2% by mass of a rust inhibitor, and up to 10% by mass of a VI improver, characterized in that the detergent-inhibitor composition is comprised of alkaline earth salts of alkylbenzenesulfonic technical technical alkylphenols the latter are presented to at least 30% in sulfurized form, and from free phenols or phenol sulfides and zinc salts of technical dialkyldithiophosphoric acids, wherein in the finished lubricating oil, a content of at least 5 meq / kg sulfonate groups, an equivalence ratio of sulfonate to phenolic groups of 1: 5 to 1:13, a proportion of free phenols or phenol sulfides from 5 to 50% of the phenolic compounds and a set 1: quivalenzverhältnis phenolic groups of at least zinc dialkyldithiophosphates. 2 2. lubricating oils according to claim 1, characterized in that in the detergent-inhibitor composition in addition to Zinkdialkyldithiophosp, ~> n only a detergent component in the form of a prepared in a continuous process phenolate Erdalkalisulfonans or sulfonate Erdalkaliphenolates is used in their preparation based on technical alkylbenzenesulfonic acid and technical, at least partially sulfurized alkylphenol the presentation of the components and promoters and the reaction carried out so that the equivalence ratio of sulfonate groups and phenolic groups according to the invention and the inventive proportions of sulfurized and free phenolic groups in the preparation of this detergent are set from the outset. 3. Lubricating oils according to claim 1 or 2, characterized in that in the detergent-inhibitor composition at least one produced in a continuous process phenolate-containing alkaline earth sulfonate with equivalent proportions of sulfonate groups of 100 to 300mval / kg and phenolic groups of 500 to 1400 meq / kg is used , the latter being at least 30% in sulfurized form to 5 to 50% as free alkylphenols or alkylphenol sulfides. 4. lubricating oils according to claim 1 to 3, characterized in that as phenoiathaltiges alkaline earth sulfonate at least one medium or highly basic calcium sulfonate is used in its preparation a promoter combination of a technical, at least 30% sulfurized alkylphenol, an aliphatic alkanol and an alkanolamine used and the carbonization at temperatures of 35 to 80 ⁰ C is performed so far that the molar ratio of calcium carbonate to calcium hydroxide at least 3: 1 and at the same time the molar ratio of phenolate to free phenol is at least 1: 1. 5. lubricating oils according to claim 1,3 or 4, characterized in that in the detergent-inhibitor composition in addition to at least one alkaline earth sulfonate at least one medium or highly basic, sulfurized calcium phenolate with an equivalent amount of phenolic groups from 1100 to 1900 meq / kg is used in that it contains up to a maximum of 200 meq / kg of sulfonate groups in the form of an alkaline earth sulfonate. 6. Lubricating oils according to claim 1 and 5, characterized in that as sulfurized calcium phenolate, a product is used in the preparation of the reaction in common template of technical alkylphenol, an alkaline earth sulfonate, a mixture of high molecular weight aliphatic alcohols, Verdünnungsöi and sulfur in only one reaction vessel and consistently and the carbonization in the presence of a promoter combination consisting of 2 to 8 wt .-% of Erdalkalisulfonates, 4 to 15 wt .-% of the mixture of high molecular weight saturated aliphatic alcohols, 4 to 10Ma .-% of a polyhydric alcohol and 0.005 to 0.7 Ma .-% of a dimethylpolysiloxane, based on the total mixture, takes place.