DE2548275C2 - - Google Patents

Description

The invention relates to dispersants which are suitable for the disperser Gourment of the dirt that occurs in the lubricating oil during use to promote zes. The properties of some of us have always been known considerable polymers, by adding a polar, mostly nitrogen-containing Group of modified compounds to disperse the dirt to hold, which occurs in lubricating oils for internal combustion engines, if in their operating conditions short, with cold engine used Routes occur that are called "cold mud" is known. The general tendency in making such connections gene goes to the property of some unsaturated, mono- or po lyfunctional carboxylic acids by condensation using olefin poly mers whose molecular weight is approximately between 500 and 2000, with or without catalysts to take advantage of alkylene-substituted Acids to be obtained, which subsequently with polyethylene polyamines to Re action to bring about the corresponding amides or imides hold. In particular, various additives are mentioned in the literature of this type and to the manufacturing processes referred to on the Reaction of amines and derivatives with substituted alkylene acids rest, the alkylene radical having a high number of carbon atoms, e.g. B. 30 to 300.

In many cases, disadvantages are found in the compounds obtained according to the known techniques above, which are related to the solubility of the dispersant in certain base oils or in particular those which are mixed with other additives having other effects, or to the incomplete fine dispersibility of certain types "cold mud", especially the more water-rich. This behavior is due to a lack of balance between the hydrophilic or polar and the lipophilic or nonpolar portion of the molecule, this balance being directly dependent on the type and above all on the length of the alkylene radical present in the molecule. It was also found that the presence of aqueous, insufficiently inhiated contaminants in the lubricating oil - especially in the presence of SO ₂ , which is generated by combustion gases seeping from the combustion chambers - causes corrosion or rust formation, especially on the immovable parts of the lubrication system.

The object of the invention is to provide a dispersant for  Lubricating oils capable of overcoming the above-mentioned disadvantages Essentially eliminate dispersants.

This object is ge by a disperser according to claim 1 solves.

Advantageous or expedient configurations of the dispersant are shown in the subclaims 2 to 9 specified.

The above-mentioned mixture of polyfunctional compounds is further characterized in that it has a typical image of the IR absorption spectrum at 1740 cm ^-1 .

The dispersants according to the invention not only have disadvantages and difficulties of those made by the prior art Lubricant additives removed, but also previously unachievable Properties and characteristics of the polyfunctional compound conferred.

According to the invention, firstly, it has been shown that it is possible above all is the balance of the hydrophilic or polar portion and lipo to significantly improve the phile or non-polar portion in that during the condensation of the polybutene with maleic acid or maleic acid anhydride a predetermined amount of a low molecular weight olefin is added, which is preferably a propylene derivative or a normal oil fin, the number of carbon atoms between 8 and 10, preferably ever yet is between 10 and 15, creating a short chain alkylene amber Acid compound arises, which attacks heavily polar dirt le promotes, as are the particularly water-rich, and second, that a good compatibility of the dispersants with the others mostly ionic or polar additives. Which the above balanced The promoting effect is also supplemented and supported by the fact that a certain amount of the alkylene succinic acid thus obtained natural fatty acid with 12 to 24 carbon atoms or a synthe table fatty acid with 9 to 20 carbon atoms is supplied. It has It has been shown that the combined effect of the fatty acid and the short chain alkylene succinic acid obtained as described above stronger is, as the single effect of corresponding amounts, only one of the two Connections, because of the diversity of the successive  beginning chemical bonds, the effect achieved as synergi can be described stisch.

The dispersant according to the invention not only exercises better dispersion effect, but also has a corrosion and rust protection, thanks to a change in the reaction process with the polyamine, which consists in the fact that the acid mixture described above with a variable amount of an alcohol with 2 to 20 carbon atoms, or a polyalcohol with 2 to 6 hydroxyl groups, or one optionally partially esterified polyalcohol with a molecular weight between 60 and 600 is brought to reaction.

The subsequent implementation of the partial ester obtained with "bottom amine" thus produces complex, essentially polyfunctional compounds (which can be determined by means of IR analysis at 1740 cm ^-1 and therefore enable an analytical differentiation between this product and those of the prior art) , such as mixed amides, imides, amido esters, mixed esters, the latter, in addition to the specific, corrosion-preventing property, also improving the oiliness properties of the product, which are not particularly pronounced in the previously known amides or imides.

It must be emphasized that it is generally possible to use IR analysis also between the compounds according to the invention and Ge mixing alkylene succinimides with those containing the ester function Establish connections precisely because of the fact that the Compounds according to the invention the ester functions in complex Mo. contain lecular structures of a not clearly defined type, since com combinations between fatty acids and alkylene succinic acids (especially de ren chains have a different molecular weight) and Verbin alcoholic beverages, individually or in particular in combination with Amine-type compounds, or also - if polyhydroxilate compounds gen use - combinations of the latter and the Ma linseic acid or maleic anhydride are statistically possible at the same time. This usually contributes to the formation of a striking IR band mechanical mixtures of alkylenesuccinimides and esters gently. According to the invention, an amine is a complex, primary, sekun amine containing där and tertiary functions with an intermediate 20 and 40% fluctuating nitrogen content used, which in compartment circles is referred to as "Restamin" or "Bottom-Amin".  

The formation of these complex polyfunctional compounds confers their use as a dispersant gives the lubricant better properties than those that are more simple monofunctional using mixtures Let connections be educated, probably because of the intramolecular Compensate for the presence of different radicals in the same Structure can be attributed, as well as mainly the simultaneous Presence of various heteroatoms (oxygen, nitrogen), which thanks to their similar but different polarity the interaction between these connections, the metal surfaces and expand the dirt particles mentioned at the beginning, whereby increased synergism and the aforementioned anti-corrosion, have a dispersing effect. The best properties of the dispersants according to the invention compared to the commercially available Succinimide dispersants, even if the latter are mixed with esters, were demonstrated in parallel engine tests, how to continue is described below in the examples.

It should be noted that the addition of esters in equal amounts as they are form directly according to the invention, no significant improvement in Performances of the pure succinimide additive bring about what the intramolecular synergetic effect confirmed. In detail, the invention Dispersant available in the following ways:

a) condensation of the polybutene with maleic acid or maleic anhydride

This stage of the process is preferred by the action of a halogen Chlorine, which catalyzes a labile bond with the polybutene and thus condensation with maleic acid (anhydride) facilitated. This can be done in such a way that in the final stage chlorination of polybutene is smaller, between 1% and 20% fluctuating amount of the olefin is added, which is among the lower polymers of propylene or butene, or among the low molecular weight Normal olefins is selected and is characterized by that it has 8 to 20, preferably between 10 and 15 carbon atoms; in particular, the use of propylene tetramer or an alpha olefin or a normal olefin with an internal double bond  and a number of carbon atoms between 11 and 14 lasts. The chlorination is best at between 80 ° and 150 ° temperature between 90 ° and 120 ° C with a chlorine content of 3% to 5%, preferably 3.5% to 4.5%. After chlorination of the olefin The excess chlorine is mixed by washing with a protection gas removed and then you go to the actual condensation step over with maleic acid or maleic anhydride at a Temperature suitably from 190 ° to 200 ° C, preferably from 220 ° to 245 ° is carried out, the molecular ratio olefin acid is essentially unit-related, at least between 0.8 and 1.1 fluctuates. At this stage, the chlorine is separated, which in the meantime has fulfilled its catalytic task, and essentially is quantitative, with the permissible proportion of residual chlorine between 0 and 0.3%.

• b) addition of fatty acid and
• c) partial esterification.

The balance of the mixed alkylene obtained as described above Succinic acid is obtained by adding 0.5% to 20%, preferably two se from 1% to 5%, based on the weight of the condensation product, a natural fatty acid with 12 to 24 carbon atoms, preferably two se of oleic acid, or a synthetic fatty acid with 9 to 20 preferably 16 to 19 carbon atoms. The acid gene obtained in this way the mono- or polyfunctional hydroxyl compound mentioned is mixed added the various functions, such as amine, amide, acid, natural or synthetic esters, contains or not and thereby ge is characterized by the fact that it contains the functional carboxyl group of the above mentioned mixture can form ester compounds. To this end become natural alcohols with 2 to 6 hydroxyl groups or polyoxyal kylene glycols with a molecular weight of 300 to 600 are preferred. The The amount of hydroxyl compound is chosen so that 0.5 to 30%, preferably 1 to 5% of the actual (like carboxyl) present as well potential (such as anhydride) carboxyl functions are esterified. The Esterification reaction is suitably carried out at a temperature of 150 to 200 ° C, preferably 160 to 190 ° C, which is forming water if you are not working with anhydrous substances  Drainage is carried off using protective gas.

• d) final reaction with polyamine and optionally dilution with oil. The partial ester obtained after performing the above steps, which Contains ester and acid (or anhydride) functions by comple Compounds of mixed acid-ester type are carried with the above "bottom amine" reacted for profit of amide, imide and especially of mixed ester-amide compounds and salt-like compounds, if the amine used too contains tertiary nitrogen. The "Restamin" or "Bottom" used Amine "preferably has a nitrogen content between 33 and 40%. The use of this "residual amine" promotes - precisely thanks to the simultaneous Presence of primary, secondary and tertiary amino groups - the bil formation of compounds with mixed amide-imide-ester-salt function, which are the important properties of Disperga already described tors compared to the known dispersants. The amount of one Amine is so high that at least 90% of the carboxyl still free groups are implemented; however, it is preferred that all Car boxyl groups are implemented, or that a small proportion of free amine up to 10% of the total nitrogen content (expressed as nitrogen) preferably up to 3%.

The reaction to form the amide bond as explained above is carried out suitably at a temperature of 100 to 250 ° C, preferably of 140 to 200 ° C, whereby care must be taken to ensure that the forming water is removed by using protective gas.

Although the reaction product can be used as it is, it is sometimes preferable to dilute it for convenience of use, preferably by using a low viscosity naphtha or paraffin solvent with a viscosity of 2.1 x 10 ^-5 to 12.95 x 10 ^-5 m ² at 37.8 ° C, in particular 3.2 · 10 ^-5 to 4.3 · 10 ^-5 m ² / s at 37.8 ° C, so that the final nitrogen content between 0.5 and 2%, preferably between 0.9 and 1.5%.

The following are some examples which illustrate the manufacture of the invention explain connections. In the accompanying drawings IR absorption spectra of dispersants shown with the verbin  were prepared according to the examples mentioned, and by Di spergators according to the prior art.

EXAMPLE 1

0.5 mole of a 1100 molecular weight polybutene was heated to 105 ° C heated and subjected to partial chlorination with 0.25 mol of chlorine.

The temperature was allowed to rise to 110 ° C, whereupon 0.05 mol of a propy lenpolymerisats (as olefin) were added, which is a distillation sinter vall from 180 to 220 ° C at 101.3 kPa and and usually as propyl entetramer is called, the added olefin with that in the poly chlorine buten is reacted.

The excess chlorine was then removed by nitrogen treatment and added 0.65 mol of maleic anhydride to the product.

The condensation was completed at 230 ° C; the surplus unreacted maleic anhydride was then together with the last Ten traces of the chlorine residue were removed by nitrogen treatment. The product obtained showed a saponification number equal to the analysis 105. The mixture of the alkenyl succinic anhydrides thus obtained 0.05 mol of oleic acid and then 0.1 alcohol equivalents of a poly Oxyethylene glycol with molecular weight 400 added, the mixture was then heated at 180 ° C for 2 hours to complete the esterification to promote. A lot of residual amine (bottom amine) was then added which contained 35% nitrogen, equal to 0.85 basic equivalents, the Condensation reaction first carried out at 140 ° and then at 200 ° and the low water residue was removed by nitrogen treatment.

The product was then diluted with a paraffin oil refined in the solvent, the viscosity of which was 3.2 × 10 ^-5 m ² / s at 37.8 ° C., to a total nitrogen content of 1.3%.

The product so obtained was used in a 2% lubricating oil diluted together with 0.75% overbased calcium sulfonate and 0.75% zinc alkyldithiophosphate in a solvent-refined SAE 30 paraffin oil. The mixture obtained in this way was subjected to a test in the Petter engine AV 1 , an average purity number 9 being achieved on the piston.

In comparative tests with those made according to the previous techniques Succinimide dispersants (which are designated A and B) an average purity number of 8.2.

In a similar experiment in which the same additives A and B with 5% polyoxyethylene glycoleate with a molecular weight of 400 ge were mixed, the same average purity number was obtained as with the the same unmixed additives.

In the accompanying FIGS. 1, 1A, 1B, 1C, 1D, a portion of the IR absorption spectrum of the above-mentioned compounds is shown, which was recorded with an INFRASCAN H-900 (Hilder and Watts) device. In particular, FIGS. 1, 1A, 1B, the IR spectra of the Zusatzstof fes according to Example 1 and the Comparison materials A and B. Fig. 1C and 1D gene zei the IR spectra thereof, mixed with one mentioned in Example 1 ester, Additives A and B. It can easily be ascertained that the graph according to FIG. 1 has a characteristic course at 1740 cm ^-1 , which differs from the corresponding spectra of 1A and 1B of the known additives as well as from those of the same Polyoxyethylene glycol oleate additives clearly stands out.

EXAMPLE 2

0.5 mol of 1100 molecular weight polybutene were heated to 105 ° C and subjected to partial chlorination with 0.25 mol of chlorine.

The temperature was allowed to rise to 110 °, whereupon 0.05 mol of a frac tion normal olefins with an internal double bond were added, the one contain between 11 and 14 number of carbon atoms and that Product of a dehydrogenation process of n-paraffins, wel che according to the process known as ISOSIV ten with the chlorine dissolved in the polybutene 30 Mi is reacted for minutes. The excess chlorine then became removed by nitrogen treatment and 0.63 mol of maleic anhydride set. The condensation was carried out at a temperature of 230 ° C carried out to the end: the excess of unreacted malein anhydride was then combined with the last traces of chlorine  Removed nitrogen treatment. The product thus obtained showed at Analyze a saponification number equal to 120. The mixture of Alken amber anhydrides were 0.05 mol of a synthetic fatty acid re added, which was produced by the known OXO process, based on a cut of inner n-olefins with 15 to 18 carbon atoms that correspond to the product of dehydration, according to the process known as ISOSIV Represent paraffins. The mixture thus obtained was washed with 0.15 alcohol equivalents of the oleic acid ester of sorbitan reacted. The The mixture was then heated to 180 ° C for four hours to form the Vere to promote stering. Then an amount of "residual amine" was added, 35% Nitrogen contained 0.8 basis equivalents, the condensation reaction first at 140 ° C, then at 200 ° C and the water residues were removed by means of nitrogen treatment.

The product was then diluted with a paraffin oil refined as a solvent with a viscosity of 3.2 × 10 ^-5 m ² / s at 37.8 ° C. until the total nitrogen content was brought to 1.3%.

The product thus obtained was used with a 2% lubricant weight percentage together with 0.75% of a zinc alkyldithiophosphate and 0.75% diluted in a solvent-refined SAE 30 paraffin oil. The mixture thus obtained was subjected to a test in the Petter engine AV 1 , an average purity number of 9.5 being achieved on the piston.

In comparative experiments with succinimide dispersants A and B dated Example 1 and an addition of 6% of the oleic diester of sorbitan was reached 9.1 as the average purity number.

In FIG. 2, 2A and 2B are the IR spectra of the compound according to Example 2 (Fig. 2) and the ester, as explained above, offset dispersants A and B (Fig. 2A and 2B) is reproduced.

In this case too, the spectrum characteristic for the di dispersers according to the invention can be clearly seen at 1740 cm ^-1 .

EXAMPLE 3

The mixture of alkenylsuccinic anhydrides obtained as in Example 1 was mixed with 0.05 mol of oleic acid and then with 0.1 alcohol equivalents of a synthetic alcohol which was derived from n-olefins by means of the OXO process and in the same amount indicated there had an average number of carbon atoms of 13. The mixture was then brought to 180 ° C for 2 hours to promote esterification. Then a lot of "residual amine" (bottom amines) containing 35% nitrogen equal to 0.85 base equivalents was added and the condensation reaction was initially carried out at 140 ° C. and then to 200 ° C., where the low water residue was removed by means of nitrogen treatment. The product was then diluted with a solvent-refined paraffin oil having a viscosity of 3.2 x 10 ^-5 m ² / s at 37.8 ° C until the total nitrogen content was 1.3%. The product so obtained was used in a lubricating oil in a proportion of 2% together with 0.75% of an overbased sulfonate and 0.75% zinc alkyldithiophosphate diluted in a solvent-refined paraffin oil of the type SAE 30. The product obtained in this way was subjected to a test in the Petter engine AV 1 , an average purity number 9.1 being found on the piston. In comparative experiments with the succinimide dispersants designated above with A and B and an addition of 4% oleic ester of lauric alcohol, the average purity number 8.5 was sufficient.

The IR spectra of FIGS. 3, 3A and 3B relate to the dispersant according to this example or to the esters designated A and B, each with the above-mentioned esters. In this case, too, the course of the IR spectrum characteristic of the compounds according to the invention can be clearly recognized.

EXAMPLE 4

The mixture of alkylenyl succinic acid obtained as in Example 1 reanhydrides were in the same amount specified there with 0.05 mol a synthetic fatty acid, which is produced using the OXO- Process based on a cut of n-olefins with an inner double bond and 15 to 18 carbon atoms was obtained, the n- Olefins result from the dehydrogenation of the corresponding n-paraffins  represent, which was obtained according to the so-called ISOSIV method the.

The mixture thus obtained was reacted with 0.15 alcohol equivalents of a commercially available OXO alcohol (C ₁₂ -C ₁₅ ) for 3 hours at 180 ° C. in order to promote the esterification. Then a quantity of "residual amine" was added which contained 35% nitrogen, equal to 0.8 base equivalents, the condensation reaction being carried out first at 140 ° C. and then up to 200 ° C. and the water residue having been removed by means of nitrogen treatment.

The product was then diluted with a paraffin oil refined in the solvent with a viscosity of 3.2 × 10 ^-5 m ² / s at 37.8 ° C. until the total nitrogen content was 1.3%.

The product so obtained was used in a 2% by weight lubricating oil together with 0.75% zinc alkyl dithiophosphate and 0.75% overbased calcium sulfonate, the latter being dissolved in a paraffin oil refined in SAE 30 solvent. The lubricating oil obtained in this way was subjected to a test in the Petter engine AV 1 , in which an average cleanliness number 9.2 was determined on the piston.

With the succinimide dispersants A and B according to Example 1 under Zuga be 4% oleic ester of the aforementioned commercially available OXO alcohol tests carried out an average purity of 8.6 was achieved.

The same conclusions of the previous examples also apply completely continuously for the dispersant of this example ( FIG. 4) and for those of the known technology ( FIGS. 4A and 4B).

Claims (9)

1. Dispersant for lubricating oils, consisting of a mixture of polyfunctional compounds, available from

• a) condensing maleic acid or maleic anhydride with polybutene having a molecular weight of 500 to 2000 in the presence of 1 to 20% of an olefin having 8 to 20 carbon atoms to a product which has a larger proportion of a long-chain alkylene succinic acid and a smaller proportion of at least one alkylene succinic acid shorter chain contains,
• b) adding from 0.5 to 20%, based on the weight of the condensation product, of a fatty acid having 9 to 24 carbon atoms to the condensation product obtained,
• c) Partial esters of the mixture with an alcohol having 2 to 20 carbon atoms, a polyalcohol with 2 to 6 hydroxyl groups or an optionally partially esterified polyalcohol with a molecular weight between 60 and 600 in an amount such that 0.5 to 30% of the present real and potential carboxyl functions are esterified, and
• d) reacting the partial ester obtained with a mixture of polyamines with primary, secondary and / or tertiary amino groups and a nitrogen content of 20 to 40% known as "bottom amine", the proportion of each group not less than 10% of the total of all amino groups present lies in such an amount that at least 90% of the still free carboxyl groups are reacted.

2. Dispersant according to claim 1, characterized in that the polybutene used in the condensation has a molecular weight between 800 and 1500 and the oil present in the condensation fin has 10 to 15 carbon atoms and a molecular weight between has 112 and 280. 3. Dispersant according to claim 2, characterized in that the Polybutene has a molecular weight between 900 and 1200 and the olefin has a molecular weight between 140 and 210. 4. Dispersant according to one of the preceding claims, characterized ge indicates that the fatty acid used under natural fatty acid with 9 to 20 carbon atoms and synthetic fatty acids is selected with 15 to 20 carbon atoms in amounts of 1 to 6%.   5. Dispersant according to claim 4, characterized in that as na natural fatty acid oleic acid is selected. 6. Dispersant according to claim 4, characterized in that the synthetic fatty acid from an olefin with an internal double bond has been won. 7. Dispersant according to one of the preceding claims, characterized ge indicates that in the partial esterification the hydroxyl compound in egg ner is used such an amount that 1 to 5% of the present Chen as well as potential carboxyl functions are esterified. 8. Dispersant according to one of the preceding claims, characterized ge indicates that the "bottom amine" used has a nitrogen content from 33 to 40%. 9. Dispersant according to one of the preceding claims, characterized ge indicates that the "bottom amine" in a to stoichiometric Amount of excess amount is mixed so that free amine up to a proportion of 10%, preferably up to 3%, of the total nitrogen moved, remains.