Organic compounds -- part of the class 532-570 series – Organic compounds – Carboxylic acids and salts thereof
Patent
1996-11-25
1998-09-15
Gibson, Sharon
Organic compounds -- part of the class 532-570 series
Organic compounds
Carboxylic acids and salts thereof
508525, C07C 6501
Patent
active
058081453
DESCRIPTION:
BRIEF SUMMARY
This application is a 371 of PCT/FR95/00299, filed Mar. 14, 1995.
The present invention relates to new detergent-dispersant additives for lubricating oils of the sulphurised and superalkalised, alkaline earth alkylsalicylate-alkylphenate type having improved properties in terms of foaming, compatibility and dispersion in oils and stability towards hydrolysis, and to a process for the preparation thereof.
It is already known from the patent U.S. Pat. No. 3,036,971, published on 29 May 1962, to prepare detergent-dispersant additives based on sulphurised alkylphenates of high basicity alkaline earth metals by sulphurisation of an alkylphenol, neutralisation of the sulphurised alkylphenol with an alkaline earth base, then superalkalisation by carbonation of the alkaline earth base dispersed in the sulphurised alkylphenate; this type of product has the disadvantage of being relatively unstable towards hydrolysis, with the formation of a precipitate of crystalline calcium carbonate, particularly if said type of product is highly superalkalised, which leads to risks of blockages in the filters of marine engines.
It is also known from the French patent 1.563.557 published on 11 Apr. 1969 to prepare detergent additives based on sulphurised calcium alkylsalicylates by carboxylation of a potassium alkylphenate, exchange with calcium chloride, then sulphurisation of the calcium alkylsalicylate obtained with sulphur in the presence of lime, a carboxylic acid and an alkylene glycol or alkylether of alkylene glycol; such a process has the disadvantage of requiring an exchange reaction.
Under these circumstances, the applicant described in French patent application 2.625.220 published on 30 Jun. 1989 a process for the preparation of superalkalised detergent-dispersant additives based on alkylphenates and alkylsalicylates, which comprises the following steps: substituents by an alkaline earth base in the presence of a C.sub.1 to C.sub.8 acid and of a solvent forming an azeotrope with the water of reaction at a temperature corresponding to the reflux temperature of the azeotrope; alkylphenate to alkylsalicylate; base in the presence of glycol and a third solvent, followed by carbonation;
However, this process developed by the applicant and the products obtained by said process have several disadvantages.
Firstly, in the neutralisation step, the use of a solvent giving an azeotrope with water is needed to obtain a sufficient degree of conversion of alkylphenol to alkylphenate.
The carboxylation step takes place at elevated pressures generally between 5 and 15.10.sup.5 Pa in order to convert the alkylphenate to alkylsalicylate.
Moreover, the sulphurisation and superalkalisation step is dangerous from an industrial point of view because it gives rise to a sudden release of hydrogen sulphide which could not be controlled.
Finally, the products obtained by this former process have properties of dispersion and compatibility with lubricating oils that are inferior to those of alkylsalicylates having the same alkaline earth metal content and, in particular, exhibited poor stability towards hydrolysis, requiring frequent changes of the filters used in the lubricating circuits of marine engines.
The applicant has now found that he was able to improve substantially the performance of said additives, particularly in the tests relating to foaming, compatibility and dispersion in a new oil and in the tests of stability towards hydrolysis, by preparing them by a process comprising the following steps: 85 wt. % of linear alkylphenol in which the linear alkyl radical contains 12 to 40 and preferably 18 to 30 carbon atoms, in mixture with a maximum of 65 and a minimum of 15 wt. % of branched alkylphenol in which the branched alkyl radical contains 9 to 24 and preferably 12 carbon atoms, using an alkaline earth base, in the presence of at least one carboxylic acid containing from 1 to 4 carbon atoms, said neutralisation operation being carried out at a temperature of at least 215.degree. C., the pressure in the reactor in which the neutralisa
REFERENCES:
patent: 4902436 (1990-02-01), Hori et al.
patent: 5030687 (1991-07-01), Leone
patent: 5035816 (1991-07-01), Leone
patent: 5529705 (1996-06-01), Small et al.
patent: 5538650 (1996-07-01), Goto
Cazin Jacques
Coent Jean-Louis Le
Triconnet Thierry
Willis, Jr. William W.
Gibson Sharon
Schaal Ernest A.
Toomer Cephia D.
LandOfFree
Detergent-dispersant additives for lubricating oils of the sulfu does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Detergent-dispersant additives for lubricating oils of the sulfu, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Detergent-dispersant additives for lubricating oils of the sulfu will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-89943