Lubricant compositions containing ester-substituted hindered...

Details Lubricant compositions containing ester-substituted hindered... Lubricant compositions containing ester-substituted hindered...

2002-10-30

2004-09-07

Howard, Jacqueline V. (Department: 1764)

Organic compounds -- part of the class 532-570 series

Organic compounds

Carboxylic acid esters

C508S186000

Reexamination Certificate

active

06787663

ABSTRACT:

BACKGROUND OF THE INVENTION
The present invention relates to compositions suitable for use as lubricant additives which contain an ester-substituted hindered phenol antioxidant and other additives suitable for lubricants such as a detergent or a dispersant. The present invention provides an economical antioxidant which has good performance properties when used in lubricant formulations especially for heavy duty diesel engines and passenger car crankcase.
U.S. Pat. No. 5,523,007, Kristen et al., Jun. 4, 1996, discloses a lubricant oil composition comprising a diesel engine lubricating oil and, as antioxidant, a compound of the formula
X can be —CH
2
—CH
2
—C(═O)—OR and R is a straight chain or branched alkyl radical of the formula —CH
n
H
2n+1
wherein n is an integer from 8 to 22.
U.S. Pat. No. 3,285,855, Dexter et al., Nov. 15, 1966, discloses stabilization of organic material with esters containing an alkylhydroxyphenyl group. The ester can have the structure
in which x has a value of from 0 to 6, inclusively, and y has a value of from 6 to 30, inclusively. The “lower alkyl” groups can be t-butyl. Organic materials which can be stabilized include, among many others, lubricating oil of the aliphatic ester type, and mineral oil.
U.S. Pat. No. 5,206,414, Evans et al., Apr. 27, 1993, discloses a process for the preparation of compounds of the general formula
A can be —OR
4
where R
4
can be C
2
-C
45
alkyl.
The present invention provides, among other advantages, a convenient method for obtaining a certain class of hindered phenolic ester antioxidants having particularly useful properties. In particular the antioxidants (shown below), that is, those having an R
3
group of 2 to 6 carbon atoms, can be conveniently prepared in a single step. In a preferred synthesis, no trans-esterification reaction is necessary, resulting in a simplified process which leads to fewer byproducts. The antioxidants thus prepared impart excellent thermal and oxidative stability to lubricant formulations and show excellent performance in seal durability tests.
SUMMARY OF THE INVENTION
A composition comprising;
(A) at least one antioxidant of the formula
 wherein R
3
is an alkyl group containing 2 to 6 carbon atoms; and
(B) at least one component selected from the group consisting of dispersants and detergents.


REFERENCES:
patent: 3247240 (1966-04-01), Meier et al.
patent: 3285855 (1966-11-01), Dexter et al.
patent: 3364250 (1968-01-01), Dexter et al.
patent: 3657322 (1972-04-01), Dexter et al.
patent: 4085132 (1978-04-01), Park et al.
patent: 4228297 (1980-10-01), Haeberli et al.
patent: 4322303 (1982-03-01), Rosenberger
patent: 4529809 (1985-07-01), Irving et al.
patent: 4536593 (1985-08-01), Orban et al.
patent: 4659863 (1987-04-01), Burton
patent: 5081280 (1992-01-01), Takee et al.
patent: 5089656 (1992-02-01), Yu
patent: 5130465 (1992-07-01), Kovasy et al.
patent: 5177247 (1993-01-01), Brogli et al.
patent: 5206414 (1993-04-01), Evans et al.
patent: 5264612 (1993-11-01), Evain et al.
patent: 5354486 (1994-10-01), Evans
patent: 5453210 (1995-09-01), Bardasz et al.
patent: 5523007 (1996-06-01), Kristen et al.
patent: 5563291 (1996-10-01), Kleiner
patent: 5658865 (1997-08-01), Yoshida et al.
patent: 5696281 (1997-12-01), Evans
patent: 5916851 (1999-06-01), Hosonuma et al.
patent: 5965495 (1999-10-01), Goto et al.
patent: 6310009 (2001-10-01), Kocsis et al.
patent: 6559105 (2003-05-01), Abraham et al.
European Publication EP 0 620 267, Oct. 19, 1994, equivalent to US 5,460,741.

Affiliated with

Also associated with

Rating

Lubricant compositions containing ester-substituted hindered... does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Lubricant compositions containing ester-substituted hindered..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Lubricant compositions containing ester-substituted hindered... will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3227857