DE19723460A1 - Lubricant use to inhibit particulate emission from internal combustion engine, especially diesel engine - Google Patents

Abstract

A lubricant which inhibits the emission of particle mixtures from an internal combustion engine, especially a diesel engine, comprises: (a) 2-25 wt.% additives; (b) 0-20 wt.% polymer to improve the viscosity index, and (c) a base containing (1) oil-soluble esters, (2) oil-soluble copolymers of unsaturated esters and olefins, (3) oil-soluble polyglycols and/or (4) hydrocarbons selected from (4a) oligomers of internal, linear, branched or cyclic olefins and/or alpha -olefins and (4b) hydrogenated, optionally isomerised mineral oil base, and (5) 0-85% mineral oil base with respect to the total amount of products (1) to (5). The lubricant preferably contains 5-15 wt.% additive and 1-12 wt.% viscosity index-enhancing polymer. The base contains 0-40, especially 0 wt.% mineral base oil. The esters (1) are carbonates and esters of polyols. The polyglycol (3) is polypropylene glycol. The lubricant especially contains 10-20, more especially 14-18, wt.% neopentyl polyol esters, 3-7, more especially 4-6, wt.% viscosity index-enhancing polymer and 12-18, especially 13-16, wt.% additives, and the rest C10 poly- alpha -olefins.

Description

The present invention relates to lubricants that contributes little to the exhaust particle emissions of an internal combustion engine carry.

During the operation of an internal combustion engine, esp special of a diesel engine, fuel and ge amount of lubricant consumed. By scorching inhalation gases (e.g. stick substance, water, carbon dioxide, oxygen), gaseous ver dirt (especially carbon monoxide, unburned carbon hydrogen, nitrogen oxides and sulfur oxides) and particles shaped pollution (mainly unburned oil, koh particles containing len, unburned fuel and anor ganic material).

The proportion of inhalable gases and dirt (gaseous and particulate) is generally around 99.9% and 0.1%, respectively.

Many attempts have been made to both gas to reduce moderate as well as particulate contamination.

The applicants have surprisingly found that a considerable reduction in the amount of particulate Substances used by internal combustion engines, especially diesel engines gates, are given through the use of special Lubricating oils can be achieved.

Accordingly, the present invention relates to Ver use of a lubricant comprising

• (a) 2 to 25 percent by weight, preferably 5 to 15 Weight percent, additives;
• (b) 0 to 20 percent by weight, preferably 1 to 15 Weight percent, viscosity index improver polymer;
• (c) a base in an amount such that the percentage of the sum (a) + (b) + (c) is 100, the base, individually or mixed, of at least one of the following components:
  • (1) oil-soluble esters, preferably carbonic acid esters and polyol esters;
  • (2) oil-soluble copolymers between unsaturated esters and olefins;
  • (3) oil-soluble polyglycols, preferably polypropylene glycol;
  • (4) hydrocarbons selected from (4a) oligomers derived from the polymerization of internal, linear, branched or cyclic olefins and / or from α-olefins, (4b) hydrogenated, optionally isomerized, mineral oil bases;
  • (5) mineral base oils in an amount of 0 to 85 percent, preferably 0 to 40 percent, before 0 percent is selected, based on the sum of the products (1) to (5),

to reduce the amount of particles from a Internal combustion engine, especially a diesel engine, ejected will eat.

The term additives means all those substances different functions that are normally used to formulate lubricating oils.

Of the additives should be dispersants, preferably Ashless, to be highlighted, whose job is to all other substances not belonging to the lubricant, whether now gets into the oil from outside or from thermal or oxide tive changes in the oil itself, dispersed by half ten.

The dispersants generally used are ge usually nitrogen-containing derivatives, esters, anhydrides, as well as salts of mono- and dicarboxylic acids with a hydrocarbon chain containing 50 to 400 carbon atoms. Under The preferred dispersants should be anhydrides from amber acids with aliphatic substituents that have a high molecular weight Lar lar have, or esters of these acids with mono- and Polyalcohols, phenols, naphthols or amides or imides of these acids with polyethylene amines.

With regard to the possible aliphatic substitutes High molecular weight alkenyl chains are preferred,  as in the case of, for example, isobutenyl succinic acid deri dads.

Another group of additives that normally present in lubricating oils are wear reduction compounds conditions that contribute to the wear resistance of the engine. Typi Wear-reducing compounds are zinc dicarbonates serstoffdithiophosphat, where the substituents are the same or can be different, and alkyl, alkenyl, aryl, alkyl can represent aryl or cycloalkyl groups.

Another group of additives consists of Deter gents, d. H. Substances that impurities and residues before keep the deposit on the metal surfaces. The usual The most common detergents are neutral sulfonate of calcium and Magnesium, overbased calcium and magnesium sulfonate, Phe n (ol) ate, sulfophen (ol) ate of calcium, magnesium and barium, Calcium and magnesium alkyl salicylates and naphthenates.

Another group of additives consists of corro sion inhibitors, d. H. Substances that are able to construction of metal parts that come into contact with the lubricating oil men to diminish. Examples of corrosion inhibitors are phosphorus-sulfurized hydrocarbons and the reaction products of these phosphorus-sulfurized hydrocarbons Oxides or hydroxides of alkali metals, preferably in Presence of an alkylated phenol and also preferred wise in the presence of carbon dioxide.

Other connections normally in the group of the additives are antioxidants. Typical verb Applications that belong to this category are steric other phenols, sulfurized phenols, arylamines, nitrogen containing heterocyclic compounds, compounds the base of copper (e.g. copper thiophosphates, Copper oleate and naphthenate).

Additives with other functions can also be used lie, like anti-foaming agents, friction modifiers and pour point depressant.

The above additives show in the finished formulation oil a total proportion of 2 to 25 percent by weight preferably 5 to 14 percent by weight.  

Furthermore, the viscosity index improvers bindings Substances that change the viscosity with the tem keep temperature within a more limited range, than would be the case with an additive-free oil. Compounds with this effect are oil-soluble polymers, un ter them ethylene-propylene copolymers, polyisobutenes, styrene Diene copolymers, polyacrylates and polymethacrylates.

As indicated above, these have viscosity index improver (V.I.T.) in the fully formulated product a proportion of 0 to 20%, preferably 1 to 15% by weight percent, on.

There are also chemicals that have more than one Have function, for example viscosity index improvements rer with dispersing and / or detergent properties, such as Copolyacrylates, which are also basic units, preferably Nitrogen, contained in the polymer structure. Typical examples are copolyacrylates made by copolymerization of acrylates and / or methacrylates with nitrogen-containing monomers, for example heterocyclic N-vinyl compounds and di alkylaminoacrylates can be obtained.

The basis for reducing the emissions Particles containing emissions can be used can be selected from different connection groups.

The first group is that of oil-soluble esters. To (1a) oil-soluble esters of dimeric acid belong to this group ren or esters of C₃-C₂₀ alcohols and unsaturated dicar bonic acid by codimerization of a molecule of oleic acid and a molecule of linoleic acid is obtained; (1b) oil soluble Esters of linear and / or branched dicarboxylic acids for example sebacic acid, azelaic acid, adipic acid esters of C₃-C₂₅ alcohols (linear, branched or cyclic), gege optionally alkoxylated, especially isobutyl, neopentyl, 2-ethylhexyl; (1c) oil-soluble esters consisting of alcohols of the neopentyl type (for example neopentyl glycol, Trimethy lolpropane, pentaerythritol), esterified with linear or ver branched C₃-C₂₅ acids; (1d) Oil-soluble esters of coal acid, for example carbonic acid esters of C₃-C₂₅ alcohols, linear, branched or cyclic, as such or alkoxylated;  (1e) Oil-soluble esters of polyglycols and ethoxylated and / or propoxylated alcohols, for example esters of Polyethylene and / or polypropylene glycol, esterified with li middle or branched C₃-C₂₅ acids; (1f) polyvinyl ester of C₁₀-C₃₀ acids, for example polyvinyl stearate, Polyvi nylsebacate; (1g) oil-soluble ester complexes obtained from mono and / or polyfunctional acids, esterified with mono- and / or polyhydroxy alcohols.

Typical examples of group 2, i.e. H. oil-soluble co polymers between unsaturated esters and olefins, are Co polymers between C₈-C₂₄-α-olefins and esters of unsaturated took dicarboxylic acids with C₂-C₈ alcohols (for example those described in EP-A-429 123).

To group 3 or to the oil-soluble polyglycols hear polypropylene glycol, mixtures of polyethylene glycol and Polypropylene glycol, polyalkylene glycols in which the alky lengruppe has more than 3 carbon atoms, two-block Po lyglycols, which are described in US-A-4,793,939 (one block consists of C₂- C₄ units and the other consists of C₆-C₄₀ units) so as in EP-A-355 977 (one block is predominantly a C₂-C₄- Block and the other a C₆-C₃₀ block) are described and Tripod polyglycols, which are from the same applicant filed patent application IT-A-MI 95 / A 001 652 (corresponding EP-A-0 755 978).

Partially and completely etherified polyglycols naturally also belong to this group.

The polyglycols that can be used have at 100 ° C a viscosity between 1 and 100 cSt.

Group (4a) includes oligomers derived from the poly merization of internal olefins (linear, branched, cyclic) and / or α-olefins, in particular PAO (poly-α-olefi ne) and PIO (inner polyolefins). PAO come from the oligo merization of α-olefins, especially 1-decene and 1-dode cen, whereas PIO from linear or oligomerization branched internal olefins, usually of C₁₂-C₂₀ polyiso butenes, e.g. B. with a molecular weight between 300 and 2500.  

The basis ver in the present invention can also be used, may also contain mineral base oils. It However, these mineral base oils require that they not more than 85 percent by weight, preferably not more than 40 percent by weight based on the entire base or the sum of the products from (1) to (5). In the more preferred embodiment, the mineral base is do not oil before.

The following examples illustrate the present Invention more precisely.

EXAMPLES

The procedure and the assessment in the exhaust Emissions of particles contained in a diesel engine are in pending patent application filed in the name of the same application which was submitted.

The device described in the pending application filed by the same applicant includes:
an internal combustion engine (1) to which an air intake line (2) and a fuel line (3) are connected, a one-nozzle injector (4) connected to the air intake line, the injector with almost constant flow rate of lubricating oil to the foregoing feeds, wherein the above-mentioned injection device (4) by pump (5), which sucks the lubricant from a reservoir (6), with lubricating oil, and the filter (7), suitable for collecting the particles contained in the the combustion in the engine generated exhaust emissions (8) are included.

1) TEST PROCEDURE

The vessel with the product to be tested is filled and the temperature to be reached with a heat controller posed, the engine being among those related to the type of Motors selected conditions is operated. The first one temperature is based on the viscosity curve of the product to be tested with the aim that at the  Injector before a viscosity of about 40 cSt lies.

The flow rate of the metering pump becomes flat if so regulated that a set amount (under those conditions about 5% of the flow speed of gas oil) and the attempt to includes a sequence of different sampling, be fine.

The first sampling takes place without injecting Lubricants take place to provide reference values for exhaust emissions to find out, whereas in the second sampling the Do Sierpump put into operation for the product to be tested to measure the effect of the injection.

The sample to be tested is placed in the air intake line from which it reaches the motor. At the end of Combustion gas samples of exhaust emissions are taken and analyzed.

The exhaust emissions reach the mixing duct where they are after suitable mixing with air on a Teflon filter of 90 mm for the particles sampled and then weighed out using a high-precision balance, in accordance with the European emissions legislation (CEE 91/441 and 88/77).

The gaseous contaminants, on the other hand, are taken directly fresh as a sample, dehumidified and fed to the CO, HHC and NO _x analyzers, non-dispersive infrared, flame ionization and chemiluminescence sensors.

The entire experiment is repeated three times to complete the Being able to evaluate repeatability and reliable results win from a statistical perspective.

2) APPLICATION OF THE TEST PROCEDURE

The procedure described was carried out using two single-cylinder diesel engines, the first is a two-valve Ruggerini RW 120 and the second is a four- Valve hydra is HSDI with central injection.  

The tests were under high and low loads executed at 28 Nm and 6 Nm. The tests with the Hydra engine were always carried out at high loads at 28 Nm times under conditions of constant fuel consumption of 1.9 kg / h and then with a constant output of 7 kW.

Table 1 shows the chemi cal properties and the kinematic viscosity at 100 ° C in cSt.

In particular, "alkyl." disubstituted Al kylbenzene with predominantly para position and with one molecule lar weight of 480, obtained by alkylation of benzene becomes; PIB is a polyisobutene with a molecular weight of 440; PAO is a poly-α-olefin with a molecular weight of 1300 obtained by oligomerization of α-decene; PIO is an inner polyolefin with a molecular weight equal to 490, obtained by oligomerizing a mixture of ren olefins, predominantly C₁₄-C₁₆; Ester 1 is the ester (Mo molecular weight 950) between dimeric acid obtained from egg nem moles of oleic acid and one mole of linoleic acid, and iso-C₁₃-Al alcohols; Ester 3 is an ester (molecular weight 550) from left near saturated C₈-C₁₀ carboxylic acids and trimethylolpropane; Ester 4 (molecular weight 470) is the carbonic acid ester of predominantly C₁₄-C₁₅ alcohols; Ester 5 is carbonic acid esters of trimethylolpropane; "Polygly." means a poly propylene glycol with a molecular weight of 1000; Is NC3 a copolymer between the ester of an unsaturated dicar bonic acid and α-olefin.  

TABLE 1

Table 2 shows the changes in exhaust particulate emissions sions of two diesel engines (Hydra and Ruggerini) with one spraying of the basics listed in Table 2. The percentage changes only refer to the Injection of gas oil. The percentages relate to the percentage change in the amount of particles in the presence of Basics, based on the data with pure gas oil.

The particulate exhaust emissions (injection of pure gas oil) is 0.634 g / kWh for the Ruggerini engine at high load, 1.97 g / kWh for the Ruggerini engine low load, 0.38 g / kWh for the Hydra engine at con constant consumption and 0.47 g / kWh for the Hydra engine at con constant performance.

For comparison, the table shows alkylate (alkyl.) and listed the two mineral base oils.  

TABLE 2

The percentages of Table 2 were in Ver equals with a value of 1 for the polyglycol and one Converted zero value for the alkylate (see Table 3).  

TABLE 3

The data from Table 2 and Table 3 show that Products belonging to the group of polyglycols, polyisobutenes, Esters, isomerized bases, copolymers between dicarboxylic acid reesters and olefins, poly-α-olefins, internal polyolefins hear particularly effective in reducing particles are. The most effective are polyglycols.

Table 4 then shows the exhaust emission data of two lubricants, one as a reference and a second ge according to the present invention. The reference wording is a SAE 15 W 40 oil, which consists of 76.5% mineral base oil, 8.8% viscose index of improver polymer and 14.7% of a group of anti corrosion additives for a quality according to API SH CCMCG4 / PD2 be stands.

The lubricant used in the invention, which in is able to produce a small amount of particles  an SAE 5 W 30 oil (grade equal to the above oil) and around according to the present invention, a basis consisting of 15% Esters of neopentyl glycols, 65.5% C₁₀-poly-α-olefins, 4.8% Viscosity index improvers and 14.7% of them in the loading tensile formulation used additives.

The two lubricating oils were used as lubricants in three various diesel engines, especially Ricardo Hydra Die sel (test cycle: 90% max. coupling), Iveco 8460 (test cycle: ECE49), VM Turbotronic (test cycle: ECE15 + EUDC) under nor paint conditions used. The particulate exhaust emissions ions were then measured.

The results are shown in Table 4.

Table 4

The data in Table 4 confirm the benefits that with the use of the lubricant according to the invention Reduction of particulate exhaust emissions associated are. In fact, the positive effects can be the first mentioned lubricants both for engines with low as well as with high loads for engines in the street simulated operating conditions can be observed.

Claims (9)

1. Use of a lubricant comprising

• (a) 2 to 25 weight percent additives;
• (b) 0 to 20 weight percent viscosity index improver polymer;
• (c) a base in an amount such that the percentage of the sum (a) + (b) + (c) is 100, the base, individually or mixed, of at least one of the following components:
  • (1) oil-soluble esters;
  • (2) oil-soluble copolymers between unsaturated esters and olefins;
  • (3) oil-soluble polyglycols;
  • (4) hydrocarbons selected from (4a) oligomers derived from the polymerization of internal, linear, branched or cyclic olefins and / or α-olefins, (4b) hydrogenated, optionally isomerized, mineral oil bases;
  • (5) mineral base oils are selected in an amount of 0 to 85 percent in terms of the sum of the products (1) to (5),
    to reduce the amount of particles which is expelled from an internal combustion engine, in particular a diesel engine.

2. Use of a lubricant according to claim 1, comprising 5 to 15 weight percent additives. 3. Use of a lubricant according to claim 1, comprising 1 to 12 weight percent viscosity index improvements rer polymer. 4. Use of a lubricant according to claim 1, with the base 0 to 40 percent by weight mineral base oils includes.   5. Use of a lubricant according to claim 4, the base contains no mineral base oils. 6. Use of a lubricant according to claim 1, the oil-soluble esters (1) from carbonic acid esters and Esters of polyols are selected. 7. Use of a lubricant according to claim 1, the oil-soluble polyglycols (3) polypropylene glycol are. 8. Use of a lubricating oil agent according to claim 1, consisting of
10 to 20 weight percent esters of neopentyl polyols;
3 to 7 weight percent viscosity index improver polymer;
12 to 18 weight percent additives,
the replenishment to 100% consists essentially of C₁₀-poly-α-olefins. 9. Use of a lubricating oil agent according to claim 8, consisting of
14 to 18 weight percent esters of neopentyl polyols;
4 to 6 weight percent viscosity index improver polymer;
13 to 16 weight percent additives,
the replenishment to 100% consists essentially of C₁₀-poly-α-olefins.