FI64381C - FOERFARANDE FOER FRAMSTAELLNING AV EN SAMMANSAETTNING SOM INNEHAOLLER POLYALKENYL-BIS-BAERNSTENSSYRA ELLER POLYALKENYL-BIS-BAERNSTENSSYRAANHYDRID - Google Patents

Description

1 64381

A process for preparing a composition comprising polyalkenyl-bis-succinic acid or poly-alkenyl-bis-succinic anhydride.

The present invention relates to a process for preparing a composition comprising polyalkenyl bis-succinic acid or polyalkenyl bis-succinic anhydride by reacting a polyolefin with a greater than equimolar amount of maleic acid or raw acidic acid in a catalyst catalyzed at elevated temperature. Polyalkenyl-bis-succinic acid or their anhydrides are abbreviated herein as PABSA. Derivatives of these compounds are used in lubricating oil compositions. GB patent 1,356,802 describes the use of a catalyst-15. in a reaction using iodine as a catalyst.

The reaction of maleic acid or its anhydride with a monoolefinic polymer to produce polyalkenyl succinic acid or its anhydride is well known. In this case, poly-20 isobutylene succinic anhydride, hereinafter referred to as PIBSA and widely used in the form of its ester or imide as a dispersant in lubricating oil applications, is prepared by reacting polyisobutylene with maleic anhydride. The reaction can be represented by the following equation: CH3 CH, - (C - CH „HC = CH, + 3 i 2. n | 2 CH3 CH3 polyisobutylene -V Λ CH-CCL CH, \. 3 Ό —p CH, .— (- C - CH _—) - C - CH, - CH - CO.

^ 3, 2 n „2 I N.

CH-CO 2 CH 3 CH 2 No ch 2

maleic acid PIBSA

anhydride from U.S. Patent 4,012,438 is also known that can be prepared from the formula I1 2 64381 OR1 R1 ff? I If x-c-c c-c-x

I pi I I I I

H— - Cn - C ~ - C-, - C, - —H

. . ± «2, 3, 4

Y-C-C Lr2 R · 3 J C-C-Y

Il I 1 I 1 It 5 l 0 R J LR 0-

A B C

alkyl or cycloalkyltetracarboxylic acid compounds wherein A and C are monovalent succinic acid-10 groups attached to the group B by one of the two carbon atoms of the groups A and C having unsaturated valencies and the second unsaturated carbon atom attached to the second unsaturated carbon atom; and wherein B is a connecting alkane or cycloalkane group having 4 to 30 carbon atoms, including the two aforementioned monovalent groups A and C, which may be the same or different, attached to carbon atoms 1 and 2 or carbon atoms 1 and 3 and, if desired, carbon atom 1 and carbon atom 4 is connected by a 1-8-carbon-methyl bridge; the other unsaturated valencies of said divalent hydrocarbon group 20 are attached to 1 2 3 hydrogen atoms; and wherein R is H and R and R are hydrogen atoms or identical or different hydrocarbon groups: X and Y together form a group -O- or X and Y are the same or different groups having the structure -OR, wherein R is hydrogen or similar or a different alkyl or cycloalkyl group containing 1 to 8 carbon atoms. An alkyl or cycloalkyl tetracarboxylic acid compound represented by the above formula is prepared by hydrogenating a corresponding compound wherein B is an alkenyl group having 4 to 30 carbon atoms.

It is theoretically possible to prepare polyalkylene-bis-succinic acid or anhydride thereof by reacting monomeric succinic acid or its anhydride prepared by the reaction of maleic acid with PIBSA to react with maleic anhydride as shown above.

? H2 ίΗ3 CH - CO

.OC - CH - CH- - C - (- CH „- C -f- CH-. + ||

| 2 ^ | n 3 ch _ cO

OC - CH-CH- s / 5 polyisobutylene monomeric succinic anhydride

OC - CH - CH- - C - CH- - CH - CO

0 I 2 2 I ^ 0

OC - CH, CH - CO

10 h3c - C - ch3 2 ch3 (H2C - ch3 polyisobutylene-bis-succinic anhydride 15

However, such a polyalkenyl-bis-succinic acid or anhydride thereof has not been shown and in practice it has not been found possible to even prepare monomeric succinic acid or its anhydride as a 100-20% conversion of an olefin polymer. For example, when administering one mole of polyisobutene having an average molecular weight of 1,000, i. average molecular weight per mole of olefin as determined by measuring the number of bromine, react with one mole of maleic anhydride to form polyisobutylene monomeric anhydride having a PIBSA number of about 102 (PIBSA number is the amount of 1 mg of potassium hydroxide required, . In practice, it has not been found possible to exceed a PIBSA number of about 90 in non-catalyzed maleination, which corresponds approximately to a molar conversion of polyisobutylene of about 85%. One reason for this is assumed to be that the polyisobutene contains about 15% unreacted impurities.

It has now surprisingly been found that polyalkenyl-35-bis-succinic acid or its anhydride in which the polyalkenyl group is derived from a polyolefin having an average molecular weight (mp) in the range of 500 to 2,100 can be prepared by changing the process conditions and especially using a nickel salt as a catalyst.

Thus, the present invention provides a polyalkylene-bis-succinic acid or anhydride thereof, wherein the polyalkylene group is derived from a polyolefin having an mp in the range of 500 to 2100.

The polyalkylene groups may suitably be derived from a polyolefin such as polyethylene, polypropylene and polybutylene or an olefin polymer. Preferably, the polyalkylene group is derived from polyisobutylene.

In the process according to the invention, a polyolefin having an average molecular weight, mp, in the range from 500 to 2100 is reacted with more than an equimolar amount of maleic acid or maleic anhydride at elevated temperatures at either normal atmospheric pressure, reduced pressure or overpressure, the gas stream being reacted with reactants. A nickel salt is used as a catalyst in the reaction.

Preferably, maleic acid or its anhydride is reacted with polyalkylene in a molar ratio of 1: 1 to 3: 1. Although all of the maleic acid or maleic anhydride may be added in a single dose at the beginning of the reaction, it is preferable to add it either periodically or continuously during the reaction.

Preferably, the elevated temperature is higher than 150 ° C and is especially in the range of 200-260 ° C. Even more preferably, the reaction is performed by programming a temperature rise over the range of 230-150 ° C.

The pressure used in the process depends on whether or not a gas stream is passed through the reactants. In this case, the pressure can be normal air pressure, vacuum or overpressure when the gas stream is passed through the reactants. The gas may be an inert gas such as nitrogen or an "entrainer" gas such as carbon dioxide or a lower hydrocarbon. If no gas is used, the pressure must be vacuum during all or part of the reaction time. Although the reaction can be carried out completely under reduced pressure, it is preferable to use overpressures in the early stages of the reaction and to reduce the pressure below normal atmospheric pressure at some point during the reaction, preferably in the final stages of the reaction.

5 64381

It is assumed that directing the gas flow or applying a vacuum will facilitate the removal of volatile contaminants. The use of an inert gas flow is recommended when using the method on a factory scale due to the long operating times 5 required to significantly change the pressure.

The reaction time is suitably at least four hours and is preferably 6 to 12 hours.

With respect to the catalyst, it has been found that nickel salts and especially nickel iodide are effective catalysts in the preparation of polyalkenyl bis-succinic acid or its anhydride independently of the alkenyl substituent.

In the process, in addition to PABSA, polyalkenyl monomeric succinic acid or its anhydride is formed. If nickel iodide is used as a catalyst, it is possible to increase the PIBSA number to at least 120, which corresponds to a conversion of about 40% to PABSA material.

The PABSA or composition of the invention may be suitably converted to an ester or ester composition by reaction with an alcohol under known esterification conditions or may be converted to an imide or midi composition by a reaction of formula

H-N (CH 2 CHNH) H

L · fa I X

R

wherein x is an integer and R 1 is a C 1 -C 4 alkyl radical or hydrogen, for example according to the method disclosed in GB Patent 2 ib 992 831. Both ester and imide can be used in lubricating oil compositions. It has been found that the succinic acid amide derived from the PABSA-containing composition of the invention is less required to form the same concentration of functional groups as when the succinic acid amide derived from the corresponding monomeric succinic acid or its anhydride is used without significant deterioration in dispersion properties. In practice, this is due to a decrease in viscosity in lubricating oil preparations containing succinic acid amides prepared from the PABSA-containing compositions of this invention.

This gives a lubricating oil composition containing lubricating drilling oil and imide or as a dispersant. ester derived from either PABSA or a PABSA-containing 64381 \ composition as described above.

In addition to the dispersant of succinic acid imide or ester, the lubricating oil composition may also contain one or more conventional lubricating oil additives.

The invention is further illustrated by the following Examples.

Preparation of polyisobutylene-bis-succinic anhydride Example 1

Polyisobutene (400 g, mp 1,000), maleic anhydride (64 g) and nickel iodide (0.64 g) were added to a stainless steel Magnedrive autoclave (1 liter) and the mixture was heated to 230 ° C with stirring. 2 bottles using a nitrogen pressure of 2.1 kp / cm. Nitrogen was also continuously introduced into the reaction mixture at a flow rate of about 3 l / h. The reaction temperature was gradually raised from 230 ° C to 240 ° C over two hours. Maleic anhydride (33 g) was added over a further two hours at 240-250 ° C and 2.1 kp / cm and the reaction mixture was

the thio mixture was further heated at 250-260 ° C for four hours

2 temperature and 2.1 kp / cm pressure. The reaction product (484 g) was cooled to 150 ° C and then removed from the autoclave. The reaction product contained 1.1% by weight of unchanged maleic anhydride, 30% by weight of unchanged polyisobutene and the remainder being polyisobutenic succinic anhydride. The total PIBSA of this product was 25 mg KOH-eq / g after correction for its maleic anhydride content. This high PIBSA number indicates that a significant amount of polyisobutylene has been substituted for bis-succinic anhydride.

Example 2 Polyisobutene (400 g, mp 1,000) was added to a stainless steel Magnedrive autoclave (1 liter capacity) and heated to 230 ° C with stirring and blowing nitrogen (gas rate about 3 1 / h) using 2 nitrogen pressures 2 , 8 - 3.1 kp / cm. Maleic anhydride (63 g) was then pumped into the reactor over two hours while raising the temperature of the reaction mixture from 230 ° C to 240 ° C. Maleic anhydride (32 g) was further pumped into the reaction mixture for 2 hours at 240 ° C and 2 at 2.8-2.2 kp / cm and the temperature of the reactants was then raised from 240 ° C to 250 ° C over a further four hours. . The reaction mixture was then cooled to 150 ° C and removed from the reactor. The product was equilibrated at 215 ° C / 100 mbar to remove unreacted maleic anhydride as a front vessel distillate. The distillation residue was then filtered to remove the resin formed from maleic anhydride, and the total PIBSA number of the filtrate product was 115 mg KOH eq / g.

Preparation of succinic acid imide for use as a dispersant from polyisobutylene-bis-succinic anhydride

Example 3

The PIBSA reaction product of Example 1 (220 g) with a PIBSA number of 120 was mixed with an equal amount of lubricating oil and heated to 190 ° C at one bar. Triethylenetetramine (15.78 g) was then added with stirring over 15 minutes and the mixture was further heated at 190 ° C for three hours.

The PIBSA imide product contained 1.3% by weight nitrogen, 0.5% by weight basic nitrogen and had a viscosity of 76.3 cSt at 100 ° C.

The PIBSA imide derived from conventional PIBSA material had a total PIBSA of 95 mg KOH eq / g and typically contained 1.4% by weight nitrogen, 0.58% by weight basic nitrogen and had a viscosity of 495%. cSt. 100 ° C.

The viscosity of the imide derived from polyisobutenyl bis-succinic anhydride is lower (76.3 cSt) than that of the imide derived from polyisobutenyl monomeric succinic anhydride (495 cSt).

30 Engine test

Example 4

The Petter AV.1 engine test was performed using a standard preparation using a lower than usual amount of the imide of Example 3 (i.e., 95/120 x standard 35 addition) to obtain the same concentration of imide functional groups in the test mixture and the same good engine test values (as determined by measuring the amount of sooting on the surface of the piston) than that obtained with a conventional preparation containing an imide derived from polyisobutenyl monomeric anhydride.

Effect of pressure 5 Example 5

Polyisobutene (1 mole, mp 1,000) and maleic anhydride (1.6 moles) were added to a stainless steel Magnedrive autoclave (1 liter capacity) and the mixture was heated with stirring to 238 ° C using 2 nitrogen at 0.7 kp / cm . After two hours under these conditions, the total PIBSA number was determined. The pressure was further reduced to normal atmospheric pressure for two hours and the PIBSA number was re-determined. Finally, the pressure 2 was reduced to -0.7 kp / cm for four hours and the PIBSA number was determined after this time. The results are shown in the attached table.

Benchmarking test 1

The procedure of Example 5 was repeated except that the pressure was maintained at 0.7 kp / cm throughout and the PIBSA-20 reading was measured after four and eight hours. Benchmarking test 2

The procedure of Comparative Test 1 was repeated, except that the pressure 2 was maintained at 1.4 kp / cm at all times and the PIBSA number was measured after only four hours.

Comparative tests 1 and 2 are not examples according to the invention and are included for comparison only. Example 6

Example 5 was repeated except that the pressure was maintained at 1.4 kp / cm at all times and nitrogen was blown through the reactants at a rate of four volumes of nitrogen per volume of reaction mixture for one hour. Total PIBSA was measured after six hours.

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E P p E P P E

p ρ oi p P 01 P

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Pd> p w> p w 10 64381

The results shown in the table show that in control grid 1, the PIBSA number 85 was reached after four hours at 238UC and 0.7 kp / cni pressure and that this value does not increase during the next four hours of the reaction.

In Example 5, equilibrium was reached after 2 hours at 238 ° C and 1.75 kp / cm 2, but reaction 2 continued and the pressure dropped from 1.75 kp / cm to 2 1.05 kp / cm to give a PIBSA of 87, which further increased 2 to 95 when the pressure was reduced to 0.35 kp / cm. In Example 10, a similar PIBSA number was obtained by operating at constant pressure by simply blowing nitrogen gas into the reaction mixture.

Claims (4)

A process for preparing a composition comprising polyalkenyl-bis-succinic acid or polyalkenyl-bis-succinic anhydride by reacting a polyolefin with a greater than equimolar amount of maleic acid or maleic anhydride as a catalyst at elevated temperature, in the presence of a catalyst, in the presence of a catalyst. 1 1 64381 Process according to Claim 1, characterized in that the nickel salt is nickel iodide. Process according to Claim 1 or 2, characterized in that the reaction is carried out under reduced pressure, normal pressure or overpressure while introducing an inert gas into the reaction mixture. Process according to Claim 1 or 2, characterized in that at least part of the reaction is carried out under reduced pressure.