DE2753569A1 - METHOD FOR PRODUCING A SUCCINIMIDE DERIVATIVE AND LUBRICANT OIL CONTAINING THE SAME - Google Patents

Description

DR. GERHARD SCHUPFNER

PATENT ASSESSOR AT DEUTSCHE TEXACO AO

About jerlng 4O SOOO Hamburg βθ Telephone (ΟΊΟ) 63 TO 27 23 For "rn" chr "lb" r O2 17OOS

Hamburg, November 25, 1977 726-po

T 77 037

TEXACO DEVELOPMENT CORPORATION 135 East 42nd Street New York, N.Y. 10017 UNITED STATES.

Process for the preparation of a succinimide derivative and lubricating oil containing the same

809827/0626

The invention relates to the production of a succinimide derivative of copolymers consisting of ethylene and an alpha-olefin, in particular propylene, and relates also refer to a lubricating oil that contains the new succinimide derivative as an additive.

It is known that lubricating oils for motor vehicles consist of a lubricating oil., usually a mineral oil distillate, and usually contain small proportions of various additives or additives that affect their properties and their Improve utility value. There are a large number of additives which give the lubricating oil increased shear stability, higher viscosity index and better cleaning action (dispergancy). known and with the process for their production, e.g. in the ÜS-PS 3.179.716; 3,316,177; 3,329,658; 3,413,104; 3,449,250; 3,471,458; 3,496,249 and 3,513,095.

Copolymers consisting of ethylene and alpha-olefin, in particular propylene, are also known and will be used in lubricating oils as ashless, shear stable viscosity index improvers. Such copolymers impart however, the lubricating oil has no appreciable dispersing effect.

The invention was based on the object of creating a derivative of such ethylene / alpha-olefin copolymers which gives them the previously missing cleaning effect when they are added to lubricating oils as an additive.

The subject of the invention is that in the claims characterized process for the preparation of a succinimide derivative of copolymers of ethylene and a alpha-olefin, especially propylene.

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The invention also relates to a lubricating oil which contains the new succinimide derivative as an additive.

It has been found that succinimide derivatives of copolymers of ethylene with an alpha-olefin, in particular propylene, are excellent shear-stable viscosity index improvers and dispersants for lubricating oils, in particular mineral oil lubricating oils for motor vehicles. Particularly suitable is the N- (3-dimethylaminopropyl) - _s uccinimid such olefin copolymers. According to the invention, these succinimide derivatives are obtained by reacting an ethylene / alpha-olefin copolymer in a diluent and in the presence of a free radical initiator with maleic anhydride.

Particularly suitable initiators are dibenzoyl and dicumyl peroxide and like peroxides.

The olefin copolymer used is deposited during this reaction to the double bond of maleic anhydride and the maleic anhydride derivative is obtained copolymer used. After a low-volatility diluent has been added to the reaction mixture and has separated off the excess maleic anhydride, the maleic anhydride derivative of the copolymer becomes reacted further with a polyamine to form the succinimide derivative of the copolymer. After this implementation is complete, the excess polyamine is distilled off and leaves a solution of the succinimide derivative in the non-volatile diluent.

In a preferred embodiment of the invention Procedure, a solution is first prepared,

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the approximately 10 to AO% by weight of a largely amorphous ethylene / propylene copolymer with a narrow molecular weight distribution in a suitable solvent. Benzene and chlorobenzene are suitable solvents and similar aromatic compounds, but also saturated, aliphatic or cycloaliphatic hydrocarbons, such as cyclohexane. Maleic anhydride is added to this solution in excess and heated in the presence of small amounts a free radical initiator, such as dibenzoyl or dicumyl peroxide, to a temperature of 80 to 130 C. The resulting reaction product contains the succinic acid or succinic anhydride derivative of the copolymer used. A non-volatile, inert diluent, such as mineral oil, is added to this reaction mixture. and removes the excess maleic anhydride and the solvent used in the first stage Vacuum distillation. The remaining succinic anhydride derivative of the copolymer is in a second stage by heating with an excess of a polyamine, in particular 3-dimethylaraino-1-propylamine, into the succinimide derivative, in particular the N- (3-dimethylaminopropyl) succinimide derivative of the copolymer is reacted further. After this reaction is complete, the excess polyamine is distilled off and the resulting reaction product filtered.

As already mentioned, it is preferred in the process of the invention from ethylene and especially propylene use prepared copolymers which are known to be shear stable. As was found, they are Succinimide derivatives of such copolymers prepared according to the invention are also highly shear-stable.

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So that the new succinimide derivatives a Schrderöl the Can give the highest possible cleaning effect, it is advisable to increase the proportion of the peroxide initiator choose that the resulting succinimide derivative of the copolymer contains about 0.15 to 0.4 wt.% nitrogen. The influence of the nitrogen content in one according to the invention produced succinimide derivative added as an additive to a lubricating oil is exemplified by the following Experiments, the results of which are summarized in Table I. In these experiments the sludge formation of the lubricating oil with the "Bench Sludge Test 11" (BSII) and the resinification with the "Resin Inhibition Test" (RIT), which both indicate the minimum necessary nitrogen content in the additive:

Table I. "BSII" "RIT" Weight% N in the additive % By weight additive in lubricating oil mixture 2.2 30th 0.09 1.5 1.5 27.5 0, 1 1 1.5 1.7 29 0, 15 1.5 0.9 16 0, 19 1.5 0.8 13th 0.29 1.5 1.0 50 0, 19 1.0 1.5 47 0.29 1.0 1," ·· 0.37 1.0

As Table I shows, the lowest "RIT" and "BSII" values are obtained with a nitrogen content of 0.19 to 0.29% by weight in the additive.

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The cleaning effect of succinimide derivatives prepared according to the invention in mineral lubricating oils was also shown in Engine tests checked. These tests of multigrade lubricating oils, which are the only additive to improve Viscosity index and cleaning effect of the dimethylaminopropyl succiniraid of a ethylene / propylene copolymer gave excellent results. The examined In addition to those produced according to the invention, multigrade oils were also contained Succinimide derivative, an additive to lower the pour point, an overbased calcium sulfonate as Detergents, a zinc dialkyldithiophosphate as an oxidation / Corrosion inhibitor and a defoaming additive, with the remainder of the multigrade oil consisting of mineral lubricating oil.

This multigrade oil was tested using the "MS-VB" engine test, which is described in the "ASTM Special Technical Bulletin No. 315-D." Engine Test Sequences for Evaluating Automatic Lubricants for API Service MS "published by the American Society for Testing Materials, 1916 Race Street, Philadelphia, Pa. 19103. This ¹¹ MS-VB" engine test consists of a low temperature and low temperature Cyclical test run carried out at speed, in which the ability of the lubricating oil _/ the deposition of sludge and the formation of paint in Otto engines, which are provided with a closed overpressure ventilation of the crankcase, is to be investigated. The test run is cyclical in that it alternates between operation and standstill of the motor. At the end of the test run, the completely disassembled engine is inspected in the usual manner and the results obtained with different lubricating oils are compared with one another.

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The following were made with the lubricating oils of the present invention Get results:

Table II

Weight% M in additive 0.2 0.3 Weight% additive in lubricating oil mix 1.4 0.9 Viscous range 10W-40 10W-30 mud 48.5 47.7 paint 39.8 36.7 Piston skirt paint 7.8 7.4

In the preparation of the succinimide derivatives according to the invention, the first stage, in which the copolymer used is reacted with maleic anhydride, should be carried out in the presence of a solvent. It is also useful, if not necessary, to use a large excess of maleic anhydride in this first stage. In the second stage of the process, too, in which the maleic anhydride derivative is converted into the succinimide derivative with a polyamine, in particular 3-dimethylaminopropylamine, it is advantageous, if not necessary, to use an excess of polyamine. An excess of maleic anhydride and polyamine is particularly necessary when a saturated cycloaliphatic hydrocarbon, such as cyclohexane, is used as the solvent, since considerable side reactions take place between the cyclohexane and maleic anhydride and polyamine.

However, it has been found that the excess maleic anhydride can be used and also reduce polyamine considerably if benzene, chlorobenzene or a solvent are used

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similar aromatic solvent is used. In this case one does not need more than of the polyamine about 110% of the stoichiometrically necessary amount for complete conversion of the succinic anhydride intermediate product use. This relatively small excess of the polyamine can strip off the unreacted Polyamine from the end product is omitted, so that the production costs are reduced. It also contains the final product much less non-polymeric nitrogen compounds. Will however, the polymeric succinimide derivative prepared using, e.g., cyclohexane in the first stage can be found in the reaction product of the second stage there are considerable amounts of by-products from the cyclohexane and maleic anhydride and the polyamine. Such by-products, when used as a lubricating oil additive, can cause severe corrosion if the lubricating oil is tested, for example, in the "CLR L-38" bearing corrosion test is checked.

The beneficial influence of using aromatic solvent in the first stage of the process of the invention can also be seen from the following table III:

Table III Influence of the solvent (1st stage)

feed

(per 100 g mixed

polymer) cyclohexane chlorobenzene

Maleic anhydride, g 8 2.7

Dicumyl peroxide, g 0.3 0.43

3-dimethylaminopropylamine, g 8 1,2

Stripping off No stripping

Amine excess of amine excess

at 215 ° C and shot 20 Torr

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The invention is further illustrated by the following example.

example

AOO g of a commercially available solution, which consists of 31% by weight a ethylene / propylene copolymer (with a molecular weight range suitable for improving lubricating oil) and hexane existed as a solvent, 550 g of chlorobenzene were added. The resulting mixture became 330 g Solvent distilled off. A solution remained which contained 20% by weight of the copolymer in chlorobenzene. After this solution had cooled to about 130 ° C., 3.35 g of maleic anhydride and 0.53 g of dicumyl peroxide were added to it. The resulting mixture was kept at 130 ° C. for 6 hours. Like the IR spectroscopy of a sample of the polymer that was precipitated by pouring into boiling acetone, would be a polymer if converted to the succinimide with 0.30% nitrogen was to be expected. 1,116 g of a high-boiling, inert, neutral were added to the resulting solution Hydrocarbon oil added as a diluent, and the chlorobenzene and excess maleic anhydride were removed by stripping at a temperature of 180 ° C under an absolute pressure of 0.08 torr. Then, 500 g of the obtained oil solution was added at a temperature from 125 C 0.605 g of 3-dimethylaminopropylamine with stirring added. The stirred reaction mixture was held at 125 ° C for 2 hours. An analysis of the polymer obtained Succinimide product gave a nitrogen content of 0.033%, which corresponded to the theoretically expected nitrogen content based on the amine used.

The polymeric succinimide product was made with a similar product but made using cyclohexane instead Benzene was produced as a solvent ...

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compared. The results of these comparative tests are shown in Table IV below. Like these Test values show that both products are in terms of properties, shear stability and cleaning effect Lubricating oils equivalent.

Table IV

Additive manufactured in test values chlorobenzene cyclohexane

Original viscosity, SUS ³⁾ 426 397 at 37.8 ° C 69.0 68.6 at 98.9 ° C Shear stability test FISST (MS-103, 20 passes) 65.2 63.3 Viscosity at 37.8 ⁰ C 3.8 5.3 at 98.9 ° C

Thickening,%

Loss of power at 98.9 ° C ²⁾ 14 20

Pour point, ° C -42.8 -42.8

CCS test, cP 1580 1600

Laboratory sludge test I 0.4 0.4

"" (BS) II 0.4 0.9

With 1.5 wt.% Pure additive in the one described above Lubricating oil

² * The viscosity of the base lubricating oil at 98.9 ° C would be assumed to be 42.3 SUS in this calculation.

'SUS = Saybolt Universal Seconds

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In another experiment, the above example was used instead of chlorobenzene with benzene as the aromatic solvent for the first stage and also using dicumyl peroxide as initiator. The implementation was at about 130 to 132 C under the autogenous pressure and with similar mixing ratios of the reactants as in performed in the example above. How was found was the obtained polymeric succinimide in terms of oil solubility, Shear stability and dispersing effect when using product made from chlorobenzene is at least equivalent.

A copolymer of ethylene and propylene is preferred as the starting material for the process of the invention. These Copolymers are known to be suitable as lubricating oil additives for improving the viscosity index. For this Purpose, copolymers of this type usually have a molecular weight of greater than 2,000, usually in the range of 5,000 to 50,000 or higher. For the process of the invention, copolymers of ethylene with a other alpha-olefin, such as butene-1, pentene-1, hexene-1 or 4-methylpentene-1 and the like can be used, however ethylene / propylene copolymers are preferred because of their shear stability. They usually consist of 10 to 90, in particular 30 to 70 mol% of ethylene and 90 to 10, in particular 70 to 30, mol% of propylene units.

Starting materials which are particularly preferred for the process of the invention are the amorphous ethylene / propylene copolymers described in US Pat. No. 3,522,180. you will be in a hydrogen-mitigated reaction at medium temperatures and pressures in the presence of a soluble one Ziegler-Natta catalyst produced. After the IR analysis they have 20 to 70 mol% propylene units

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■ - »te.

Number average molecular weight from 10,000 to 100,000 and a very narrow molecular weight distribution of smaller than 5 as measured by gel permeation chromatography. For the method of the invention is also used as a polyamine component the 3-dimethylamino-1-propylamine preferred, it however, other polyamines are also suitable.

Suitable polyamines include compounds that conform to the following formulas:

(A) R ₁

NR ₃ - NH ₂ ,

^R 2

xT N and

ΧΙ N - R- - NH.

d y J d

^B 7

in which R ₁ and R _? , identical or different, a C ₁ -C ^ - alkyl group, R, R, and R_, identical or different, a C to C, - alkylene group, R. and R, identical or different, a C ₁ to C ^ - alkylene group , X. either 0, N, S or a CH group if R ^ and R are methylene groups, or a CH group if R and R are methine groups, and X _{2 is} either 0, N, NR ₁ , S or a Represent CH ₂ group. ...

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Examples of polyamines corresponding to formula A are: 3-dimethylamino-i-propylamine; 2-dimethylamino-i-ethylamine; 4-dimethylamino-1-butylamine and 3-dimethyl-1-isopropylamine. Examples of polyamines according to formula B are: 2-aminopyridine and aminopyrazine. Examples of polyamines of the formula C are: N- (3-aminopropyl) -morpholine, N- (3-aminopropyl) -imidazole and N- (2-aminoethyl) pyrrolidine. Other suitable polyamines are described in U.S. Patents 3,329,658 and 3,449,250.

As already mentioned, the first stage of the invention Process carried out in the presence of a preferably aromatic solvent at approximately 80 to 130.degree will. The further reaction of the intermediate product obtained in the first stage with the polyamine can also be carried out at a temperature of about 80 to 130 C, but also above or below, take place. The reactions run in both stages until the respective polymeric feedstock has been completely converted. In the second stage, the low-volatility diluent is preferably a high-boiling diluent Mineral oil or especially lubricating oil fraction added so that a solution of the polymer is used as the reaction product Succinimide derivative in this lubricating oil is used as an additive concentrate for the production of lubricating oil molds can be used immediately.

As has also already been described, aromatic solvents are preferred in the first stage of the process, since cycloaliphatic solvents such as cyclopentane, methylcyclohexane and cyclohexane have proven to be too reactive. Halogenated aromatics, such as chlorobenzene, are particularly preferred for the first stage.

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The polymeric succinimide derivatives prepared by the process of the invention can, in particular, be mineral Lubricating oils of motor vehicles in proportions of 0.05 to 10% by weight are added as additives. Proportions of this Additives in the range from 0.5 to 2.5 up to about 3 to 4% by weight in the lubricating oil are usually sufficient to provide the lubricating oils with shear stability, improved viscosity index and increased To give cleaning effect. In the additives produced according to the invention, the nitrogen content should be 0.02 to 1.0, preferably 0.2 to 0.3 wt.%.

For more convenient preparation of ready-to-use lubricating oil formulations however, the polymeric succinimide derivatives obtained according to the invention can also initially be used to produce concentrates in a lubricating oil, such as a light lubricating oil with a viscosity of 75 to 300 SUS (Saybolt Universal Seconds) at 37.8 ° C. Such additive concentrates can contain 5 to 30, in particular about 10 to 15% by weight of the polymer Succinimide derivative included.

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Claims (10)

Claims / r. Process for the production of a succinimide derivative from copolymers of ethylene with an alpha-olefin, characterized in that the copolymer of ethylene and the alpha-olefin with maleic anhydride in the presence of a free radical initiator and in the presence of a diluent a succinic anhydride derivative of the copolymer is reacted and this derivative after the addition of a low-volatility, inert, liquid diluent and after Separation of residual maleic anhydride and diluents from the reaction mixture of the first Stage with a polyamine of the formula ^R 1 N - R_ - NH ₅ , , or R ₆ ^ NR- NH ₂ 809827/0626 , in which R and R, identical or different, a C ₁ - C ^ - alkyl group, R, R, and R, flat or different, a C ^ - C ^ - alkylene group, R and R, identical or different, a C to C ^ -alkylene group, X ₁ either 0, N, S or a CH group if R and R are methylene groups, or a CH group if R and R are methine groups, and X _? represent either 0, N, NR ₁ , S or a CH group, is further reacted to the succinimide derivative of the Λ ethylene / alpha-olefin copolymer. 2. The method according to claim 1, characterized in that that a copolymer of ethylene with propylene is used. 3. The method according to claim 1 or 2, characterized in that that the reaction of the copolymer used with maleic anhydride in the presence an aromatic solvent, especially benzene or chlorobenzene. 4. The method according to any one of claims 1 to 3, characterized in that the reaction of Mischpoiymerisats used is carried out with the maleic anhydride at 80 to 130 ⁰ C. 5. The method according to any one of claims 1 to 4, characterized in that the reaction of the copolymer with the maleic anhydride in the presence of a peroxide initiator, in particular dibenzoyl or dicumyl peroxide, takes place. 6. The method according to any one of claims 1 to 5, characterized in that in the first 809827/0626 Step reaction mixture obtained as an inert diluent is a high-boiling petroleum or lubricating oil fraction is added. 7. The method according to any one of claims 1 to 6, characterized characterized in that the polyamine is 3-dimethylamino-1-propylamine, 2-aminopyridine or N- (3-aninopropyl) morpholine is used. 8. The method according to any one of claims 1 to 7, characterized in that the copolymer derivative is reacted with the polyamine in such a ratio that the succinimide derivative 0.02 to 1.0, in particular 0.2 to 0.3% by weight nitrogen content. 9. Lubricating oil, which consists of a lubricating oil, in particular a petroleum distillate, as the main component and optionally consists of small proportions of conventional additives and additives, characterized in that it the succinimide derivative prepared according to claims 1 to 8 contains. 10. Lubricating oil according to claim 9, characterized by a proportion of 0.05 to 10, in particular 0.5 to 2.5% by weight of the succinimide derivative.