CA2097828C

CA2097828C - Fluorocarbon seal protective additives for lubrication oils

Info

Publication number: CA2097828C
Application number: CA002097828A
Authority: CA
Inventors: Anatoli Onopchenko; Edward T. Sabourin
Original assignee: Chevron Research and Technology Co
Current assignee: Chevron USA Inc
Priority date: 1991-10-08
Filing date: 1992-08-25
Publication date: 2003-07-08
Anticipated expiration: 2012-08-25
Also published as: CA2097828A1; EP0562062A4; EP0562062B1; DE69223942T2; EP0562062A1; WO1993007242A1; DE69223942D1; JP3231322B2; JPH06505526A; SG48193A1

Abstract

Certain borated aromatic polyols, such as catechol borate, are found to be effective lube oil additives to compatibilize the oil with the flourocarbon polymer seals when the lube oil contains basic nitrogen.

Description

This invention relates to a discovery that a borated 6 aromatic polyol having at least one aromatic ring and at 7 least two hydroxyl groups and wherein at least two of the 8 hydroxyl groups are on adjacent carbon atoms on the aromatic 9 ring can serve to inhibit fluorocarbon engine seal deterioration in the presence of basic nitrogen.
1i 14 The most important automotive lubricating formulations are based on using dispersants as additives. One of the most 16 effective dis~persants in use today is based on succinic 17 anhydride with a long polyisobutylene alkyl chain in the 18 alpha position, i.e.:

H H
21 H-C C~ R
I I
22 ~C\ /C~

where R is a polyisobutylene.

27 These succinic anhydrides are then reacted with a polyamine, 28 such as tetraethylenepentamine (TEPA) or 29 triethylenetetramine (TETA), in a certain mole ratio to give predominantly either a mono- or bis-succinimide, i.e.:

4 ~ O + HZN- ( CHZCH2NH) 3-CHZCHZNHZ ->
TEPA

R
1l ~ N- (CHZCHZNH) 3-CH2CHZNH2 MONO-SUCCINIMIDE

l~
and/or 18 R ~ R
19 ~ N- ( CHZCHzNH) 3-CH2CH2-N BIS-SUCCINIMIDE

2~ These, and other additives, such as Mannich bases, have basic nitrogen (Total Base Number (THN) of 28-45, generally 26 measured as mg KOH/g sample), and are used to protect the 27 metallic parts of the engine while in service from acidic 28 components formed as the result of the oxidation of oil and 29 fuel, and to keep the high molecular weight oxidation 3o products and sludge precursors dispersed in the oil, and 31 thus minimize their agglomerization.

33 While basicity (as evidenced by TBN) is an important 34 property to have in the dispersant additive, ~.t is also believed that the initial attack on the fluorocarbon 2097g2g :.

1 elastomer seals used in some engines involves attack by the 2 basic nitrogen which leads to the loss of fluoride ions, and 3 eventually r~asults in cracks in the seals, and loss of other 4 desirable physical properties in the elastomer. One approach towards solving the elastomer problem is to use a 6 bis-succinim:ide instead of mono-succinimide, in essence, 7 diluting the basic nitrogen content level of the dispersant.
8 However, as will be shown later in the Examples, even the 9 bis-succinimides a:Lone will not serve to pass the fluorocarbon seal bench test.

12 In practice, a mixture of mono- and bis-succinimides is 13 used, usually predominating in the latter. Thus, additional 14 means are necessary to inhibit the deterioration of the fluorocarbon seals in the presence of additives containing 16 basic nitrogen.

18 U.S.P. 4,873,009, issued October 10, 1989, to 19 Ronald L. Anderson and entitled, "Borated Lube Oil Additive", i~; also concerned, in part, with the use of 21 succinimides as lube oil additives. Anderson recognizes in 22 Col. 2, lines; 28 et seq. that Tube additives prepared from 23 "long chain aliphatic polyamines", i.e.,succinimides "are 24 excellent lube oil additives." However, Anderson teaches such succinia~ides are "inferior to additives where the 26 alkylene polyamine is hydroxylated" (Col.2, lines 31 - 32).
27 Such hydroxyl.ated polyamine based succinimides "have the 28 drawback that. they tend to attack engine seals particularly 29 those of the fluoracarbon polymer type" (Col. 2, lines 35-37).

32 Anderson solves his fluorocarbon polymer seal compatibility 33 problem by directly borating his hydroxylated polyamine 34 based succinimides. Anderson fails to teach or suggest any solution to the fluorocarbon seal compatibility problem when 2pg7g28 1 using unhydroxylated polyamine based succinimides. In fact, 2 Anderson teaches that boration of the unhydroxylated 3 succinimides failed to solve the problem (Col. 3, lines 3 to 4 5). What is desired and needed is a separate additive to use with other lube oil additives containing basic nitrogen 6 which will serve to~ inhibit the deterioration of engine 7 seals of the fluorocarbon polymer type.

SUMMARY OF THE INVENTION
11 In accordance with the invention, an additive has now been 12 discovered which will improve the compatibility of 13 lubricating oils containing basic nitrogen towards 14 fluorocarbon engine seals. More specifically, an additive comprising a borated aromatic polyol having at least one 16 aromatic ring and at least two hydroxyl groups and wherein 17 at least two of said hydroxyl groups are on adjacent carbon 18 atoms on said aromatic ring, has been discovered for use in 19 lubricating oils containing basic nitrogen, the borated 2o aromatic polyol being used at an effective amount to improve 21 the compatibility of the lubricating oil towards 22 fluorocarbon engine seals.

24 Thus, in one aspect, this invention relates to a lubricating oil composition suitable for use in engines containing 26 fluorocarbon seals comprising a major amount of an oil of 27 lubricating viscosity which has basic nitrogen and an 28 effective amount to compatibilize the oil and the 29 fluorocarbon seals of a borated aromatic polyol having at 3o least one aromatic ring and at least two hydroxyl groups on 31 adjacent carbon atoms on said aromatic ring. Usually the 32 basic nitrogen content of the lubricating oil is provided 33 through the use of an oil soluble alkyl or alkenyl mono- or 34 bis-succinimide. The borated aromatic polyol, such as borated catechol, is believed to complex with the basic nitrogen.

5 The complexation of-.oorated long-chain alky]. catechols with succinimic~es (,which contain basic nitrogen) is described in U..S.P. 4,629,578 to T. V. Liston. Liston teaches in Col.. l, lines 21 et seq., that the use of borated alkyl catech~~ls in Tube oils is known for anti-oxidation purposes. But, the borated alkyl catechols are sensitive to moisture and hydrolyze readily. Liston teaches complexing tze borated alkyl catechols with succinimides to stabi7_ize the catechols against hydrolysis (Co=L. 1, lines 32-35).
The borated alkyl c;atechols of Liston are those where the alkyl group has from 10 to 30 carbon atoms (Col. 2, lines 22 et seq.).
Other additives may ~~lso be present in the lubricating oil in order to obt:a.in a proper balance of properties such as disper:~ancy, corrosion, wear and oxidation inhibition whi<:h are critical for the proper operation of an internal corlbust:i~~n engine.
In still another asp(=ct of this invention, there is provided a method fo:r improving the compatibility of a lubricating oi=_ cont~~s_ning basic nitrogen to fluorocarbon seals in engines whi~~h comprises adding to said lubricating oi=_ a c:ompatibilizing amount of the borated aromatic polyo=_s of -this invention.
In accordance with an aspect of the invention, a Tube oil composition for_ use in an engine containing fluorocarbon ;,,,,, ~ 35 polymer seals which ~zomprises a maj or amount of a ;x. ~<

_5a_ lubricating oil having basic nitrogen and a sufficient amount of a borated aromatic polyol to improve the compatibility of said lubricating oil towards said fluorocarbon engine seals, said aromatic polyol having at least one aromatic ring and at least two hydroxyl groups and wherein at least two of said hydroxyl groups are on adjacent carbon atoms on the aromatic ring.
In accordance with another aspect of the invention, there is provided a lubricant composition comprising a major proportion of a lubricating oil; a minor proportion of at least one compound containing basic nitrogen and a minor but effective compatibi:Lizing amount of a borated aromatic pol.yol as an additive to passiv,ate fluorocarbon polymer seals, said aromatic polyol having the formula:
OH
OH
where R"' is selected from the group consisting of H; OH;
or an alkyl group having from 1 to 8 carbon atoms.
In accordance with a further aspect of t:he invention, a method to improve the compatibility of a lubricating oil containing basic nitrogen to fluorocarbon seals in engines which comprises adding to said lubricating oil a compatibilizing amount of a borated aromatic polyol having at least one aromatic ring and at least two hydroxyl groups and wherein at least two of said hydroxyl groups are c>n adjacent carbon atoms on said aromatic ring.
In accordance with another aspect of the invention, there is provided a method to improve the compatibility of a lubricating oil containing basic nitrogen to fluorocarbon -5b-seals in engines which comprises adding to said lubricating oil a compatibilizing amount of a borated aromatic polyol having at least one aromatic ring and at least two hydroxyl groups and wherein at least two of said hydroxyl groups are on adjacent carbon atoms on said aromatic ring, the aromatic polyol having the formula:
OH
R
OH
R, where R' is H and R" is selected from H, OH or an alkyl group having from 1 to 8 carbon atoms.
BRIEF DESCRIPTION OP THE FIGURE
The Figure is a graphic representation o:E the change in ..1, .-..-.~...-.., ~..~. "r., i-r, ~~ ~ ro~arorwo rvi ~ r,r~rW-~ i r~ nrt ~

_6_ 20 97828 1 alkylcatechol borate versus the number of carbon atoms in 2 the a~.kyl group of the alkylcatechol borate.

6 The additive for use in the compositions of this invention 7 is a borated aromatic polyol having at least one aromatic 8 ring and at least two hydroxyl groups and wherein at least 9 two of said hydroxyl groups are on adjacent carbon atoms on an aromatic ring. Preferably the aromatic polyol is a 11 single ring aromatic having from 2 to 3 hydroxyl groups and 1Z wherein two of the hydroxyl groups are on adjacent carbon 13 atoms on the aromatic ring.

More preferably the aromatic polyol has the following 16 formula:
1~ OH
18 R~
i9 OH
2 0 R..

22 where R~ and R." can be the same or different and are selected 23 from the group consisting of -OH; hydrogen; alkyl group 24 having from 1 to 40 carbon atoms, preferably 1 to 30 carbon atoms.

27 One subclass of preferred aromatic polyols are those having 28 the formula:

3 0 R.

33 where R"' is sE:lected from the group consisting of H; OH; or 34 an alkyl group having from 1 to 8, preferably 1 to 6 and more preferably 1 to 4 carbon atoms.

-7- 2p 87828 1 While all catechol borates, as the data later show, can be 2 expected to compatibilize the oil with the fluorocarbon 3 polymer seals, catechol borates without any alkyl groups, or 4 those carrying a short chain alkyl group of 1-8 carbons, were unexpectedly found by the dispersancy blotter spot 6 test, to be discussed later, to be effective in enhancing 7 the overall dispersancy, while alkylcatechol borates 8 carrying long alkyl groups surprisingly showed a loss in the 9 overall dispe:rsancy.
11 Also, mixtures of aromatic polyols as described above can be 12 employed, the higher carbon number alkylated catechols 13 tending to so:lubilize the lower molecular weight catechols 14 in the lubricating oil.
16 For example, one of the shortcomings of using catechol 17 borate is that its solubility in the reference oil 18 formulation at roam temperature is limited, in spite of its 19 excellent dispersancy characteristic. It has now been discovered that alkylcatechol borates having an alkyl group 21 of ten carbon atoms or longer can be used effectively to 22 enhance the solubility of catechol borate in a reference 23 oil, and the overall loss in dispersancy of the higher alkylcatechol borates can be offset by the addition of the lower alkylcai:echol borate or catechol borate which has a 26 positive effe<a on the overall dispersancy. The most 27 effective ratio to use for optimum results is a matter of 28 simple experiiaentation.

Examples of aromatic polyols which can be used to prepare 31 the borated aromatic polyols for use in this invention 32 include, but acre not limited to:

_ ....
~~ X97828 Catechal OH

OH
s Pyrogallol OH
' a OH

11 Alkyl (C~z) naphthalene 2,~-diol OH

17 4-tertiary butyl catechol OH

ZO

22 Alkyl (C6-Cs) catechol OH

2 S Cb-Ca x6 27 Alkyl (C~e-Cz,~) catechol OH

3 o C~e'Czc 32 Dialkyl (C~a-Cz4) catechol OH
3 3 C 1 ~''?~

3S f C~a''Czc The aromatic polyols useful in preparing the additives of this invention are well known in the art and many are commercially available. The alkyl catechols may be prepared, for example, as described in U.S. Patent 4,629,578.
The aromatic polyols are borated by methods well known in the art, see for example U.S. Patent. 4,975,,213 and 4,629,578. The preferred boron compound to employ in the boration reaction is boric acid. The borated compounds used in the working examples in this application were either prepared via published procedures in U.S. Patent 4,975,211 and 4,629,578, or were purchased from commercial sources.
It is believed that a boron compound with a labile hydrogen is necessary to borate the aromatic polyols of this invention. A. preferred boron source would have the formula:
OZ
ZO - B - OZ
where Z can be hydrogen or an alkyl group having 1 to 20 carbon atoms, preferably 1 to 8. Preferred is boric acid (B (OH) 3 ) .
The simplest borated aromatic polyol to use in the compositions of this invention is catechol borate.
Catechol borate is a general term which has been used in the literature to describe any catechol-boric acid complex or reaction product. The exact structure of the product, however, is dictated largely by stoichiometry (charge molar ratio of reactants). The extent of the reaction is most _ c ~.? _ Zpg7g28 1 conveniently followed by the amount of water of reaction Z collected in a Dean-Stark trap using soma appropriate 3 organic axeotroping solvent such as toluene, o-xylene, m-xylene, p-xylene, xlTlene mixture, and etc. A11 of catechol-boric acid structures are known from the literature and are s shown in Table A below, For example, when the molar ratio 7 of catechol to boric acid is 2:1, the major product was a expected to have structure I. At a molar ratio of :3:2, the 9 major product was expected to have structure IT. And to finally, at a stoichiometric ratio of ~.=1, the major product 11 was expected to have structure III initially, but on it continued heating, the expected product should have 13 structure IV. In a real world :~ituatian, all structures I-i4 IV, as well as the unreacted catechol, are probably present is in every product mixture, but in different amounts depending 16 on the stoichiometry employed and the equilibrium 17 phenomenon.
1~

_ -~~- 2~ 97828 ABL

O Structure I
6 ~ ~B.._ O
7 ~ OS HO

i~ B /O O \
i5 B Structure II
16 p~ ( ~ ~O

23 O\ Structure III
21 O' \B-OH

~O~ /O
31 O B- O -B O Structure IV
3 2 ~' O'~ ~O

__ 20 97828 1 The amount of the borated aromatic polyol to use in the 2 compositions of this invention is that amount which is 3 sufficient to improve the compatibility of the basic 4 nitrogen containing additives in the lube oil base stock towards fluorocarbon engine seals.

7 In general, the amount of borated aromatic polyol to add is 8 at least the :~toichiometric amount required to react or to 9 passivate the basic nitrogen atoms present, although depending on i~he circumstances, the amount of boron added 11 can be greater or less than the stoichiometric amount of 12 available basic nitrogen. When less than the stoichiometric 13 amount of boron was used, the full benefit of boron 14 containing additives may not be reached, and the results may not be optimum. Usually the weight percent of said borated 16 aromatic polyol is at least about 0.15 weight percent of the 17 lube oil composition, more usually 0.5 to 5 weight percent 18 although amounts to 10 weight percent or more can be used.

The borated aromatic polyols of this invention are useful in 21 complexing with basic nitrogen in the lubricating oil so as 22 to compatibilize the lubricating oil with the fluorocarbon 23 seals. By "compatibilize" is meant that the basic nitrogen 24 is passivated against attack on the fluorocarbon seals.
Compatibility is measured by a pass rating on a VW Bench 26 Test developed by Volkswagen and known in the industry as 27 PV3334 bench test, carried out in accordance with the DIN
28 53504 procedure, which will be described in detail below 29 using a standard reference elastomer AK6 from Parker-Pradifa GmbH of 2mm thickness (S2 specimen).

32 It is well known that organic amines containing basic 33 nitrogen attack fluorocarbon seals (See, for example, U.S.P.
34 4,873,009 described above; and Effects of Organic Amine Inhibitors on Elastomers in Elastomerics, September 1986, pages 24-27). Fluorocarbon elastamers or rubbers are also well known and are sold, for example, by t_he DuPont Company under the tradename "Viton°" fluoroelastomer (see "The Effect of Lubricating Oil Additives on the Properties of Fluorohydrocarbon Elastomers", by A. Nersasian of DuPont in Preprint No. 79-AM-3C-3 of American Society of Lubricating Engineers for a description of elastomers and the effect of various additives).
The oil soluble alkenyl or alkyl mono-- or bis-succinimides which are employed in this invention are generally known as lubricating oil detergents and are described in U.S. Patent Nos. 2,992,708; 3,018,291; 3,024,237; 3,100,673; 3,219,666;
3,172,892 and 3,272,746. The alkenyl succinimides are the reaction product of a polyolefin polymer-substituted succinic anhydride with an amine, preferably a polyalkylene polyamine. The polyolef:in polymer-substituted succinic anhydrides are obtained by reaction of a polyolefin polymer or a derivative thereof with malefic anhydride. The succinic anhydride thus obtained is reacted with the amine compound.
The preparation of the alkenyl succinimides has been described many times in the art. See, for example, U.S.
Patent Nos. 3,390,082; 3,219,666 and 3,172,892. Reduction of the alkenyl substituted succinic anhydride yields the corresponding alkyl derivative. R product comprising predominantly mono- or bis-succinimide can be prepared by controlling the molar ratios of the reactants. Thus, for example, if one mole of amine is reacted with one mole of the alkenyl or alkyl substituted succinic anhydride, a predominant 1y mono-succinimide product will be prepared.
If two moles of the succinic anhydride are reacted per mole of polyamine, a bis-succinimide will be prepared.

1 Particularly good results with the lubricating oil 2 compositions of this invention are obtained when the alkenyl 3 succinimide is a mono- or a bis-succinimide prepared from a 4 polyisobutene:-substituted succinic anhydride of a polyalkylene polyamine.

7 The polyisobu,tene (from which the polyisobutene-substituted 8 succinic anhydride is prepared) is obtained by polymerizing 9 isobutene and, can vary widely in its composition. The to average number of carbon atoms pan range from 30 or less to 11 250 or more, with a resulting number average molecular 12 weight of about 400 or less to 3,000 or more. Preferably, 13 the average number of carbon atoms per polyisobutene 14 molecule will range from about 50 to about 100 with the polyisobutene: having a number average molecular weight of 16 about 600 to about 1,500. More preferably, the average 17 number of carbon atoms per polyisobutene molecule ranges 18 from about 60~ to about 90, and the number average molecular 19 weight ranges. from about 800 to 1,300. The polyisobutene is reacted with malefic anhydride according to well-known 21 procedures to yield the polyisobutene-substituted succinic 22 anhydride. See, for example, U.S. Pat. Nos. 4,388,471 and 23 4,450,281.

In preparing the alkenyl succinimide, the substituted 26 succinic anhydride is reacted with a polyalkylene polyamine 27 to yield the corresponding succinimide. Each alkylene 28 radical of the polyalkylene polyamine usually has up to 29 about 8 carbon atoms. The number of alkylene radicals can range up to about 8. The alkylene radical is exemplified by 31 ethylene, propylene, butylene, trimethylene, tetramethylene, 32 pentamethylene, hexamethylene, octamethylene, etc. The 33 number of amino groups generally, but not necessarily, is 34 one greater than the number of alkylene radicals present in the amine, i.e., if a polyalkylene polyamine contains 3 1 alkylene radicals, it will usually contain 4 amino radicals.
2 The number o1: amino radicals can range up to about 9.
3 Preferably, t:he alkylene radical contains from about 2 to 4 about 4 carbon atoms and all amine groups are primary or secondary. 7:n this case, the number of amine groups exceeds 6 the number o!: alkylene groups by 1. Preferably the 7 polyalkylene polyamine contains from 3 to 5 amine groups.
8 Specific examples of the polyalkylene polyamines include 9 ethylenediamine, diethylenetriamine, triethylenetetramine, propylenediamine, tripropylenetetramine, ii tetraethylene~pentamine, trimethylenediamine, 12 pentaethylene~hexamine, di-(trimethylene)triamine, 13 tri(hexamethylene)tetramine, etc.

Other amines suitable for preparing the alkenyl succinimide i6 useful in this invention include the cyclic amines such as i7 piperazine, aiorpholine and dipiperazines.

19 Preferably the alkenyl succinimides used in the compositions of this invention have the following formula:

2 3 R~ CHi- C//
2~ ~N-(Alkylene-N)~H
2 5 CH2 C ~ A

27 wherein:

29 a. R~ represents an alkenyl group, preferably a substantially saturated hydrocarbon prepared by 31 polymerizing aliphatic monoolefins and preferably 32 R~ is prepared from isobutene and has an average 33 nuDnber of carbon atoms and a number average 3~ molecular weight as described above;
3s -1~- 2 8 g 7 8~ 2 8 1 b. the "Alkylene" radical represents a substantially 2 straight chain hydrocarbyl group containing up to 3 about 8 carbon atoms and preferably containing 4 from about 2 to 4 carbon atoms as described hereinabove;

7 c. "A" represents a hydrocarbyl group, an amine-sub;stituted hydrocarbyl group, or hydrogen; the hyd:rocarbyl group and the amine-substituted hyd:rocarbyl groups are generally the alkyl and 11 amino-substituted alkyl analogs of the alkylene 12 radicals described above; and preferably "A"
13 represents hydrogen; and d. n represents an integer of from about 1 to 10, and 16 preferably from about 3 to 5 inclusive.

19 The alkenyl succinimide is present in the lubricating oil compositions useful in this invention in an amount 21 sufficient to impart the desired dispersant properties to 22 the lubricating oil to prevent the deposit of contaminants 23 formed in the oil during operation of the engine. In 24 general, the weight percent succinimide is from 1 to 20 weight percent of the finished lubricating oil, usually from 26 2 to 15 weighi~ percent and preferably from 1 to 10 weight 27 percent of the total composition.

29 The addition of the borated aromatic polyols described above to the alkeny:l succ:inimide results in the formation of a 31 complex with i:he succinimide.

33 The exact structure of the complex of this invention is not 34 known for certain. Fioweverl, while not limiting this invention to any theory, it is believed to be compounds in - I? ' 1 which boron is either complexed by, or is the salt of, one 2 or more nitrogen atoms of the basic nitrogen contained in 3 the succinimide. Therefore, in most cases the alkenyl 4 succinimide will contain at most 5, but preferably 2 to 3 basic nitrogens per succinimide.
f 7 The complex may be formed by reacting the borated alkyl 8 catechol and the succinimide together neat at a temperature 9 above the melting point of the mixture of reactants and below the decomposition temperature, or in a diluent in ii which both reactants are soluble. For example, the 1? reactants may be combined in the proper ratio in the absence 13 of a solvent to form a homogeneous product which may be 14 added to the oil or the reactants may be combined in the proper ratio in a solvent such as toluene or chloroform, the 16 solvent stripped off, and the complex thus formed may be 17 added to the oil. Alternatively, the complex may be 18 prepared in a lubricating oil as a concentrate containing 19 from about 20 to 90~ by weight of the complex, which concentrate may be added in appropriate amounts to the Zi lubricating oil in which it is to be used or the complex may 2Z be prepared directly in the lubricating oil in which it is 23 to be used.

The diluent is preferably inert to the reactants and 26 products formed and is used in an amount sufficient to 27 ensure solubility of the reactants and to enable the mixture 28 to be efficiently stirred.

Temperatures for preparing the compltx may be in the range 31 of from 25°C to 200°C and preferably 25°C to 100~C
depending 3Z on whether the complex is prepared neat or in a diluent, 33 i.e., lower temperatures may be used when a solvent is used.

.. -18_ 2~ 97828 1 In general, i:he complexes of this invention may also be used 2 in combination with other additive systems in conventional 3 amounts for their known purpose.

For example, for application in modern crankcase lubricants, 6 the base composition described above will be formulated with 7 supplementary additives to provide the necessary stability, 8 detergency, dispersancy, anti-wear and anti-corrosion 9 properties.
11 Thus, as another embodiment of this invention, the 12 lubricating oils to which the complexes prepared by reacting 13 the borated alkyl catechols and succinimides may contain an l~ alkali or alkaline earth metal phenate, and Group II metal salt dihydrocarbyl dithiophosphate.

17 Also, since the succinimides act as excellent dispersants, 18 additional su.ccinimide may be added to the lubricating oil l9 compositions, above the amounts added in the form of the complex with the borated alkyl catechols. The amount of 21 succinimides can range up to about 20% by weight of the 22 total lubricating oil compositions.

2~ The alkali or alkaline earth metal hydrocarbyl sulfonates may be either petroleum sulfonate, synthetically alkylated 26 aromatic sulfonates, or aliphatic sulfonates such as those 27 derived from polyisobutylene. One of the more important 28 functions of the sulfonates is to act as a detergent and 29 dispersant. The sulfonates are well known in the art.
These hydrocarbyl group must have a sufficient number of 31 carbon atoms to render the sulfonate molecule oil soluble.
32 Preferably, the hydrocarbyl portion has at least 20 carbon 33 atoms and may be aromatic or aliphatic, but is usually 34 alkylaromatic. Most preferred for use are calcium, 1 magnesium or barium sulfonates which are aromatic in 2 character.

4 Certain sulfo~nates are typically prepared by sulfonating a petroleum fraction having aromatic groups, usually mono- or 6 dialkylbenzene groups, and then forming the metal salt of 7 the sulfonic acid material. Other feedstocks used for 8 preparing these sulfonates include synthetically alkylated 9 benzenes and aliphatic hydrocarbons prepared by polymerizing a mono- or diolefin, for example, a polyisobutenyl group 11 prepared by polymerizing isobutene. The metallic salts are 12 formed directly or by metathesis using well-known 13 procedures.
1~
The su.lfonates may be neutral or overbased having base 16 numbers up to about 44 or more. Carbon dioxide and calcium 17 hydroxide or oxide are the most commonly used material to 18 produce the basic or overbased sulfonates. Mixtures of 19 neutral and overbased sulfonates may be used. The sulfonates are ordinarily used so as to provide from 0.3% to 21 10% by weight of the total composition. Preferably, the 22 neutral sulfonates are present from 0.4% to 5% by weight of 23 the total composition and the overbased sulfonates are 24 present from 0.3% to 33% by weight of the total composition.
26 The phenates :for use in this invention are those 27 conventional products which are the alkali or alkaline earth 28 metal salts o;E alkylated phenols. One of the functions of 29 the phenates :is to act as a detergent and dispersant. Among other things, it prevents the deposit of contaminants formed 31 during high temperature operation of the engine. The 32 phenols may be mono- or polyalkylated.

34 The alkyl porl:ion of the alkyl phenate is present to lend oil solubility.to the phenate. The alkyl portion can be 1 obtained from naturally occurring or synthetic sources.
2 Naturally occurring sources include petroleum hydrocarbons 3 such as 6~hite oil and wax. Being derived from petroleum, 4 the hydrocarbon moiety is a mixture of different hydrocarbyl groups, the specific composition of which depends upon the 6 particular oil stock which was used as a starting material.
7 Suitable synthetic sources include various commercially 8 available alkenes and alkane derivatives which, when reacted 9 with the phenol, yield an alkylphenol. Suitable radicals obtained include butyl, hexyl, octyl, decyl, dodecyl, 11 hexadecyl, eicosyl, triacontyl, and the like. Other 12 suitable. synthetic sources of the alkyl radical include 13 olefin polymers such as polypropylene, polybutylene, 14 polyisobutylene and the like.
16 The alkyl group can be straight-chained or branch-chained, 17 saturated or unsaturated (if unsaturated, preferably 18 containing not more than 2 and generally not more than 1 19 site of olefinic unsaturation). The alkyl radicals will generally contain from 4 to 30 carbon atoms. Generally when 21 the phenol is monoalkyl-substituted, the alkyl radical 22 should contain at least 8 carbon atoms. The phenate may be 23 sulfurized if desired. It may be either neutral or 24 overbased and if overbased will have a base number of up to 200 to 300 or more. Mixtures of neutral and overbased 26 phenates may be used.

28 The phenates are ordinarily present in the oil to provide 29 from 0.2% to 27% by weight of the total composition.
3o Preferably, the neutral phenates are present from 0.2% to 9%
31 by weight of the total composition and the overbased 32 phenates are present from 0.2 to 13% by weight of the total 33 composition. Most preferably, the overbased phenates are 34 present from 0.2% to 5% by weight of the total composition.

-21_ 20 978 28 1 Preferred metals are calcium, magnesium, strontium or 2 barium.

4 The sulfurize:d alkaline earth metal alkyl phenates are preferred. These salts are obtained by a variety of 6 processes such as treating the neutralization product of an 7 alkaline earth metal base and an alkylphenol with sulfur.
8 Conveniently the sulfur, in elemental form, is added to the 9 neutralization product and reacted at elevated temperatures to produce the sulfuri2ed alkaline earth metal alkyl 11 phenate.

13 If more alkaline earth metal base were added during the 14 neutralization reaction than was necessary to neutralize the phenol, a basic sulfuri2ed alkaline earth metal alkyl 16 phenate is obtained. See, for example, the process of 17 Walker et al., U.S. Pat. No. 2,680,096. Additional basicity 18 can be obtained by adding carbon dioxide to the basic 19 sulfurized alkaline earth metal alkyl phenate. The excess alkaline earth metal base can be added subsequent to the 21 sulfurization step but is conveniently added at the same 22 time as the alkaline earth metal base is added to neutralize 23 the phenol.

Carbon dioxide and calcium hydroxide or oxide are the most 26 commonly used. materials to produce the basic or "overbased"
27 phenates. A process wherein basic sulfurized alkaline earth 28 metal alkylph.enates are produced by adding carbon dioxide is 29 shown in Hann.eman, U.S. Pat. No. 3,178,368.
31 The Group II metal salts of dihydrocarbyl dithiophosphoric 32 acids exhibit. wear, antioxidant and thermal stability 33 properties. Group II metal salts of phosphorodithioic acids 34 have been described previously. See, for example, U.S. Pat.
No. 3,390,080, columns 6 and 7, wherein these compounds and _ 20 97828 1 their preparation are described generally. Suitably, the 2 Group II metal salts of the dihydrocarbyl dithiophosphoric 3 acids useful in the lubricating oil composition of this 4 invention contain from about 4 to about 12 carbon atoms in each of the hydrocarbyl radicals and may be the same or 6 different and may be aromatic, alkyl or cycloalkyl.
7 Preferred hydrocarbyl groups are alkyl groups containing 8 from 4 to 8 c<zrbon atoms and are represented by butyl, 9 isobutyl, sec--butyl, hexyl, isohexyl, octyl, 2-ethylhexyl 1o and the like. The metals suitable for fonaing these salts 11 include barium, calcium, strontium, zinc and cadmium, of 12 which zinc is preferred.

14 Preferably, the Group II metal salt of a dihydrocarbyl dithiophosphoric acid has the following formula:

17 R20 ~ /S
18 /p 19 R30 S M~
21 wherein:

23 e. Rz and R3 each independently represent hydrocarbyl 24 radicals as described immediately above, and f. M~ represents a Group II metal cation as described 26 above.

28 The dithiopho~sphoric salt is present in the lubricating oil 29 compositions ~of this invention in an amount effective to 3o inhibit wear .and oxidation of the lubricating oil. The 31 amount ranges from about 0.1 to about 4 percent by weight of 32 the total composition, preferably the salt is present in an 33 amount ranging from about 0.2 to about 2.5 percent by weight 34 of the total lubricating oil composition. The final lubricating oil, composition will ordinarily contain 0.025 to 2pg7828 1 0.25% by weight phosphorus and preferably 0.05 to 0.15% by 2 weight.

4 The finished lubricating oil may be single or multigrade.
Multigrade lubricating oils are prepared by adding viscosity 6 index (VI) improvers. Typical viscosity index improvers are 7 polyalkyl methacrylates, ethylene-propylene copolymers, 8 styrene-diene copolymers and the like. So-called decorated 9 VI improvers having both viscosity index and dispersant properties are also suitable for use in the formulations of 11 this invention..

13 The lubricating oil used in the compositions of this 1~ invention may be a mineral oil or a synthetic oil of lubricating viscosity, preferably suitable for use in the 16 crankcase of an internal combustion engine. Crankcase 17 lubricating oils ordinarily have a viscosity of about 1300 18 cSt at 0°F. (-18°C.) to 22.7 cSt at 210°F.
(99°C.). The 19 lubricating oils may be derived fxom synthetic or natural sources. Mineral oil for use as the base oil in this 21 invention inc:Ludes paraffinic, naphthenic and other oils 22 that are ordinarily used in lubricating oil compositions.
23 Synthetic oils include both hydrocarbon synthetic oils and 24 synthetic esters. Useful synthetic hydrocarbon oils include liquid polymers of alpha olefins having the proper 26 viscosity. Especially useful are the hydrogenated liquid 27 oligomers of C6_~Z alpha olefins such as 1-decease trimer, 28 tetramer, and higher oligomers. Likewise, alkyl benzenes of 29 proper ~~iscosity, such as didodecyl benzene, can be used.
Useful synthetic esters include the esters of both 31 monocarboxylic acid and polycarboxylic acids as well as 32 monohydroxy a.lkanols and polyols. Typical examples are 33 didodecyl adi.pate, pentaerythritol tetracaproate, di-2-3~ ethylhexyl adlipate, dilaurylsebacate and the like. Complex w.._ -24-1 esters prepared from mixtures of mono and dicarboxylic acid 2 and mono and dihydroxy alkanols can ~.lso be used.

4 Blends of hyc3rocarbon oils with synthetic oils are also useful. For example, blends of 10 to 25 weight percent 6 hydrogenated 1-d~cene trimer with 75 to 90 weight percent 33 7 cSt at 100°F. (38°C.) mineral oil gives an excellent 8 lubricating oil base.

Other additives which may be present in the formulation 1l include rust inhibitors, foam inhibitors, corrosion 12 inhibitors, metal deactivators, pour point depressants, 13 antioxidants,, and a variety of other well-known additives.

The following examples are offered to specifically 16 illustrate the invention. These examples and illustrations 17 are not to be. construed in any way as limiting the scope of 18 the invention.

TESTING PROCEDURE

22 The candidate additives were tested for their compatibility 23 in a bench test (PV3334) by suspending a fluorocarbon coupon 21 (AK6) in an oil solution heated at 150°C for 96 hours (4 days) followcad by measuring a change in the physical 26 properties o:E the specimen, particularly the tensile 27 strength (TS), and the percent elongation to break (EL) in 28 accordance with DIN53504 procedure, and observing whether 29 any cracks had developed at 120% elongation (CR). A passing test criteria included the following: no evidence of crack 31 development; a tensile strength change of less than 20%
32 (gain or los:a); and an elongation change of less than 25%
33 (gain or los:~). Obviously, an ideal case would show no 31 cracks and 0'~ change in TS and EL. This test procedure will _. -25-1 be referred to above and later simply as the "VW Bench 2 Test."

4 The baseline :formulation used for testing a fluorocarbon coupon contained a dispersant (6% by weight), i.e., either a 6 mono- or bis-succinimide; an overbased calcium hydrocarbyl 7 sulfonate (30 mmol/kg); an overbased calcium phenate (20 a mmol/kg); mixed primary and secondary zinc dialkyl 9 dithiophospha~tes (22.5 mmol/kg); and ethylene-propylene copolymer viscosity index improver (13% by weight) in 150N
11 Exxon base oi:l. When borated additives were tested, these 12 were added in appropriate percentages as top treats on top 13 of the baseline formulation above.

FIRST SERIES c~F RUNS

17 A series of e:Kperiments were run to determine the effect of 18 substituents on borated catechols at one weight percent (1%) 19 treat level u:~ing in some experiments a mono-succinimide and in other experiments a bis-succinimide. The succinimides 21 were prepared as described above by the reaction of succinic 22 anhydride witla TEPA in the correct mole ratio to give either 23 the desired mono- or bis-product. The results are 24 summarized in Table 1 below.

2c 9782s J
N

N N N N N N N

'd O 0 O O C7 O O GlCl 0l d 0 Z Z Z Z ~ ~ Z ~

n LY N N N N

U ~ O 410 O O O O O O O O

?~ ~ ~ ~ Z Z Z Z Z Z Z Z

dP

N
a ~ o~ o m ~ ao W M N Y'1d' l~ N I~-1 e-1N r1 I 1 1 I O 1 1 I + 1 I 1 N C1 H N N r-IN N 10 e-1 H f'1l'1('1l11r1 N1 N r100 v-i~O r-1 I I I 1 f + 1 I 1 I f I

ro I

N C
O

,..I .,.mC

O U O O O O O
~

U v7 cn v1Z N v~ Z Z u~ Z u7 Z
f~

U ~ H H H O H H O O H O H O
'~1 41 N Ca GO C~Z W C7 Z Z 00 ~ a7 Z

ro U

,~ ~ I 1 1 1 N N N N <i e-ir1 r1 V

I C'1 f'1M !'1r-1~-1N N
~

W

' a ro as N

~

E
~

Or f O O o o O O O O O O O O
lyv N N N N 1p 1D I~ I~

~D ~O ~D ~O00 00 ~' V' N

C

O

'b C

O

N
CL

O
a v U b 1 O 1.a O

w O I

O ~ CO ~i 1l'1II1If1~1 1I1tf1If1 ro ro b ro ro ro ro ~

w '~ Cf 0 0 0 Gl Gl d N Cl 0 0 O

W ~ G G ~ +~ !~

0 0 0 o ro ro ro roro ro ro ro Z Z Z Z U v1 N N cn V~ U7 v1 d a so roZ

x o r1 c~

W e-1N f'1d' Il1 10 I~ 0001 r1 ri -1 20 978 2 s z z° 2 z° z°
N N
O v O O Cl O
z ~ z z ~ x C1 N If1 O l~
r1 er c~1 r1 et N

d' f~ r1 N l~ 00 r-1 d' N N tf1 N
1 ( 1 ( I 1 O O
cn z cn cn z cn m ~ m m ~ i a~
c N N N N N N
y,7 .. .. ..
1 ~ f'1 r1 t'1 P1 M r1 O

O O O O O O
W ~O ~D c~f c'1 M N
c"'f c1 '-1 ri v-1 M
O
E~
~.~1 W
x b ~r~1 r~~1 I
.17 O U a O '0I .C 1O
I 1 Wr1 ~ ~ U ~1 a d' % \ ~-~ U / \ ~ .-1 eh ~
O O ~ O O i0 O O
~t ro ~01~ N b b ~ U v +~ U ~ i~ U V ~ .-1 E3 ~ ~ 1° 1~
GOOU ~~V U u~7V7GOO~
r~ er u~wo 1~ ao o =.

m x m ro w .
_ _ _ mm omm x " oro.
w b= _ boo c ob a~ ar O C C

N

tp m m * ..1 ..~

1 C u1 m ..~Nx ~ U

~~ ro a w O

x O~ ~
O

.

~ C

T3 , U 0!

O
pt ..1 ro ~

~ ,C
>
U

1 C c1 '~
m a~
O y n ,C7 m cv v ~ O m 1 ~
H

O

Z~Zr U
O

W m . . GI
a ,-, d o .-.
m HZ~

H

H m A1 w 01 E ~

>. ~
O

~ Z O
a H Z m ~

s to m ro ~

U o~ a, m p, ~
c ~E

1 ~m a r V CI

.C ~ cn H
-.,1 E

1 al ..~ G
U a~ c ~ ro v~m a 'mC~B.~

27 c o >
U E

a .~
s~ o ~.7 a a E~ 01 r-1 01 U
~

ro c c .mo ~ m .~

o I 1 ~

m m a v ~
ro ~
x m , , b C C

y U
b ro ro p ro ~t 4 U

U U U
II

R

a a a v~

~n m v~aaw Cv f~ W
U W
U

ri .-1 N
t'1 V' 1f1 2p g78 28 1 Referring to Table :L, Examples 1-4 are base runs and show 2 that the presE:nce of mono- or bis-succinimides alone in the 3 formulation without borated aromatic polyols, lack 4 compatibility of the oil to the fluorocarbon elastomers, i.e., no pass of the VW Bench Test.

7 The addition of 1% catechol borate (Ex. 5-12) to the bis- or 8 mono-succinim:ide formulation results in a "Pass" of the VW
9 Bench Test except for. Example 7~which was a borderline pass, but which pas:aed on repeating (Ex 8). It should be noted 11 that the bis-compositions exhibited less change in tensile 12 strength and elongation (Ex's 6, 9 and 11) than the mono-13 compositions (Ex's 7" 8, 10 and 12) since the mono-14 compositions ~~ontain more basic nitrogen and are more difficult to ~passivate as discussed above.

17 The use of borated t-butyl catechol results in passivation 18 of the basic nitrogen (Ex 13) using bis-succinimides but 19 fails using t:he mono-succinimides (Ex 14). Examples 27 and 28 in Table 2 below show that increasing the concentration 21 of the borate3 t-butyl catechol to 2% results in a "PASS"
22 with the mono-succinimide.

24 Examples 15-19 show that using only 1 weight percent of several different alkylated borated catechols within the 26 scope of the invention is insufficient to passivate the 27 fluorocarbon elastomers. Examples in Table 2 below show 28 that increasing the: concentrations of such catechols results 29 in a PASS.

._ -30- 2~ 978 28 4 A second series of experiments were run to determine the effect of concentration of the borated catechols on the bis-6 and mono-succ:inimides needed to obtain a Pass on the VW
7 Bench Test. 'the various borated catechols were used in 8 concentration's from 0.5 to 4 weight percent. The results 9 are summarized in Table 2 below.

J

i z z z z ~ z ~ ~ z > ~ > >

M
p; N N N N N

a ~ ' ~ ~ z ~ z z > , z z z z z N
a ~ o~ o ~r In In W (h N M 'V'~ d' I~N 1~ N N

I 1 I 1 1 1 O I I I O I +

V1 O~ ~ N N ~ .-1 r1 N
E '1 " ' l1 -f f f 6 v l(1~-~1M N ~-1ll7lt1CA

t 1 I I I 1 1 + -1-1 1 1 1 1 U

ro ~ ~ z z z z z z z .d ~n cn cnO cn cn m O N H O O O O O
"' ' a7 f~ W ~ f~ ~ CO m ~. '.~'.F.'f.'~"r ro O

.. .... .. ..
C V r~ r~ c~ c~c~ eh cnch ,-~
N O

a O z o . ~ 0 0 0 0 0 0 0 0 0 0 0 0 0 ~r y ~ ~ r1 N N N N C1!'1N

ro t'1 t"1v0 t0~O ~D O~01 I

~ :fl O O O O tf1 1f1O O O O 1t11t)O
>

.r i 0 0 ,- ~-i.~ ~ ~ .-iN

O

a w ~ ~

0 0 o 0 0 0 0 0 O G

N N N N N N N N

r~ ri riri ri r1r~ r1 o ro I
w a W k k ro Q1 GO ~Ck 7 X x k t / \ d 4l Gl~ Gl 41d Gl p o O N N N N N N N N

b ro roro ro roro ro ~

O C C 'C ~ fs ~ t~f3 ~ f3~

0 0 0 o ro ro b roro ro roro ro z z z z a v~ cn ~n~n cn ~ncn m a.

so kz , W O r1 N <"1 r1 N M ' N N lf1vpI~ O N N N
~

N N N N N N

O 4l 0 C! O O O Cl0 0l O 0 O

z ~ z ~ ~ z z ~ z ~ z z z N N N N N

O d 0 G1 0 O O Cl 0 Gl O O 0 Cl z ~ z ~ z z z ~ z a~ z z z ~

e-ic'1N O O H f~ O O 00 N lf1ri d' d' d'M d' H M H t(1 M d' tf1~' I~ r1 t~ O d' M ~0 ~D d' r1 lf1v-1d' ~0 00N !n r1d' r1 Il1 N tf1 1 1 I 1 ( 1 ( ( 1 1 I I 1 z z z z z z z cn z cn cn cn cn m H O H O H O H O H O O O H O

?a ~',L>a~. ~ ~ ~ T4 m .~..~..~i ~ .~.

'fl N N N N N N N N N N N N N N

.. .. .. .. .. .... .. ..C. .. .. .. ..

.,i M M M M M M M M M M M M M M

N O
U

M O O O O O O O O O O O O O O
1 ~

pp CO ~C WD N N M M 10~D N e-1 N N

N H r1 M M I~ I~r1 e~ N N Il1r1 N N

W

ra 1f1C> O O O O O O O O O O O

O O ~~ H N N r1 r1 N N ~1'H N N

H

1f1~t1t~11f1t~1~ 1I7tf11f~tf1~ C~ 0~

r1 N N N N N ~ r-'1H r"1H H H

U

d O 41 d O ro d O d dl I 41 d '-1r~ r~lr~ r~l r~lr W r~ ~rl ri r~

~ U
N O

C! ~ ~ ~, ~ .~, ro~ ro v b ro I

h Ci~ k k !C ~C x m x x x x ~.~ x x a~

i v d iu c1 al a~a a~ a~or a~ o a~ al ~

..~ 0 0 ~

'!~ O N in N N N 'O N N N N 'd N N
O U

ro iC ro ro ro~ ro roro ro ~ ro ro U

V ~
~

ro a~ a~ ~ a~ a~ ~ ro d d a~ d ro o~ a~
a~

~ s~ ~ ~ ~ ~ s~
~ x o ro b ~ ro ro roo ro roro ro o~ ro ro ro m o cn cn N cn cnoa m cncn cn a~ cn cn ~ ro Il1 ~ O 1 ' 00tl7 l~ O ~ .- 1 N M
n d t~ O 0~

N N ~ H N N r1 r- 1 M M ~-1 M M
N

z m m ro _ _ n m O v z >

u. w ~o = al al >

w o 8a ov oo ~

r-1r1 C 'C !1 I I y O

m 'p d! 8r C

t0 ~D ;
N

m I 1 +~ ..r m x C u1 U
..1 N ro t 4 it H U

O 3aa z ar t ~ O

W

_ b 3t U
~

m 4l p~ m N N C C

C .. .. ro ro ~ o U E

C ~ = ii 1 ~n m m p M
o ro H

c-1 V

I o o x~~

~

N ~ ~ u1 U

C

W y m '"a _ ~

~

~ 2 aW

d ~

~' V' m H t >. a~ 0 t Z O ..1 N Z m a~

~

ov cv ~ ro ~

v >, m a.

c ~ ~I or G1 H m ..r -1 ~ ~
C
O

r r y .l Z

f/1 O N ..i E E "'~ lJ a 4i a v m w x k Cl l m c m ~
~

O ~

C O > E

Vl N m~~ w 0 O

IO IC H d m U

~ ~ ~ 8a .r ~ k3 a of al m U

cn cn a~ ~ x w m C C U 1 y roa mb tt 4 U

M

v1 07 v~aacw d' Ln !'1M

.-1 H M V' 1!f .,._ - 3 4 -1 Referring to Table 2, it can be seen that increasing the 2 concentration of the borated aromatic polyols of this 3 invention re:aults .in passivation of the fluorocarbon 4 elastomers e~ren with the higher alkylated catechols and in the presence of tha_ higher basic nitrogen containing mono-6 succinimides (Ex 3:1). The use of even higher alkyl catechol 7 [di (C~a-Cz')] results in a Pass at the 4.0 wt. % level with 8 the bis-succ:inimide (Ex 34) .

Considering l~he data in Tables 1 and 2, and ignoring the 11 effect of thca alkyl group or the concentration of the 12 additive, passing 'the VW Bench Test occurred with bis-13 succinimide disperaants at a minimum boron level of 180 ppm.
14 With mono-succinim.ides, the minimum boron level required to pass the same VW Bench Test was 470 ppm B.

17 THIRD SERIES OF RU~1S

19 A third series of experiments were run to determine the effect of boy.~ate structure using a one weight percent (1 21 wt%) treat ravel o:f the additive in a lubricating oil 22 formulation containing 6 weight percent of the bis-23 succinimide as the dispersant. The results are summarized 24 in Table 3 b~alow.

2pg7828 cn 1 I

u7 I 1 a o 0 0 0 0 0 o I o 1 z z z z z z z i z a~ a~

v ~ a ~' r a o 0 0 0 0 r ~ x z z z ,~ z N
~ o,o c~ r c,o ~ N
W

M N M N N M M O M O

I 1 I I 1 1 1 z I z I I

N 01 ~ N N CO p1(~ ~ ,.I

i~

U

a ~ w1 r1N N N N

U .. .... .. ..

M M M M M M

M

dl 't' a ro 7~ 0 0 0 'i wo ~

a o 0 0 0 0 ~ ~ o E"~ tC ~ t0 M I~(~ .-1e-1 N

~
>

p O O O O O O O

O O O
~

V iC ~- ~ N v-1N ri N

O

W

W

W ,O

G

a a ~ ~ a~ a~

~ O ~

V O O ~ f~ ?~ ?~
r Ca a7O O r1 r-I

m a1 C9 C9 > ~ .~ ~ ~

w w ?~ aZ-O ~ .~ ~ O d ~ O O ~
U

Gl O ~ L i G ~
r .i l 41 Gl 'O i~ 1. ,L"N ~ r1 r-1 a 1~ +~

T! C1 a!Cy b LL U U ?~ >, N rtJ b G ~ C La ~1 O r1 ~ .C
N 1r La 0 o a o sa 1~~ ~ +i +~
~ o o z z x cnm H H c~ c~ wao wao a~

a ~o roz x W

e-1N M M M M M ef ~ d' 2pg7g28 _.

m m ro ~ .

mm N of N ~ ro ro O O O O ~ Gl o, p, x z x ~ ~ >~

a 'coo v ar cwb z z z z z z O C C

N

m m O ~D 01 ri -.1 a M M N ~ '~

C u1 m 1 1 1 O + +

-aNx t U

u~ ro 'a s~

U

C

M 01 r1 ..
~

M M et' r'1CO et C! t W

I 1 0 + I I c E
'b N N N N N N

.. .. .. .. .. . a ro U

M M M M M M d't >
O U

m U
P

~ G
I a~
ro I ~ .G m V a 1 r m ~ o d .a M v O !~ O O O O O F 01 G

I 01 e~ N N d' d~ O u1 O

M e-1 M 10 lIl t0 Z
z all U E ro ai C 3 CI O m O O O O O O E z ~
4 C!

., , O ~ O
>, z a u, ~a o N ~ M .~ ~.-~~ ,.~

o d~
o d o .

s~ z o ~zmo m O O ~

t a m 1 ~ ~"~ >, w ~ ~
~
a - a . a ro ..r .
C ~
~
E

41 ~ O i~ I :C 1 01 ~

~ ~

O O 1r ~ y.~ .C +~ ~ C
r1 I I 0 0 a 0 o b a ~o o as sL ~ al z ~n o ~
.~ U

0 0 .u c ~ o ~ z o 0 0 -~ "~
o c a m o ro m w >,r c0 ~ W - O .
fw r O m -~ o'o ~ N ~
.
~

.-i .~ ~ ?~~ ~ ~ ( (O U ~ ~ a 0 >
E
~

~ ~/ '-' p U E
U

Si ir .a t ~ -1 a m O 4! GJ .i r m 41 GJ Ty U C' ~ 'C c c .0 +~ ~ -~ ~ m .~
1~ a~

U U 1 ~ a~ O ~ I -.~ .a b ro rt o t o .~

>, ~. mn ~ ~ x M .~ t w s~ +~
sr O ~ ~ ~ ~ >, ~ . m m m O O U

V' U' N ~1 U f1~ ,~ N O~ C~
CO CO CQ at 'O
0!

C C U
-a y x aroacaw tt 4 U

C~ U U
N a N .-a w w a ~n ro v~ m . ~naac~~c E w U
W U H

M d' ll1 10 n d' d' d' ~l1d' d' .-1 N
f~f d' v!1 v0 ~pg7g28 1 Referring to 'Table 3,, the effect of using a borated aromatic 2 polyol as defined in this invention is observed. For 3 example, borating the bis-succinimide (Ex 36) is not 4 successful, confirming the teachings of Anderson in Column 3, lines 3-5 of his rJ.S.P. 4,873,009 referred to above.
6 Further, the boration and use of other hydroxy containing 7 structures also fails as seen in Examples 37 through 45.
8 Examples 5, 46 and 47 show that the aromatic polyol can be a 9 single (Ex 5) or condensed ring (Ex 47) aromatic as long as to two hydroxy groups are present on adjacent aromatic ring 11 carbon atoms (Compare Examples 5 and 46, which were 12 successful, t.o Example 45 which was unsuccessful due to the 13 hydroxy grouF~s being on non-adjacent aromatic ring carbon 14 atoms). The presence of an additional hydroxy group on the ring (pyrogal.lol) i.s acceptable (See Example 46).

17 FOURTH SERIE:~ OF RUNS

19 A fourth series of experiments were run to determine the effect of various borating agents on the effectiveness of a 21 C~8-CZ' alkyl catecho:l for passivating the fluorocarbon 22 polymer seals. The results are shown in Table 4 below.

b b ..., O U U
~

_ A

m U ~ N ~ N
.~r r~', ''~ ~ w . .
~ ~

O 1 1 I I y~ y~ Gp ~

m 1 1 I I om oca ro ro .~ mm I 1 I I f~ a7 z z r~

ww 'p . s o v oo z z ~ z z ~ z z z V v '9 ~ O O O O O N

m m ~ ~ :~ ~ z z Z z z M ..1 .1 C tn m d' tT O O~ r1 O N tT t11 ~ N U

W N1 N t1 N I r-1 N N N ~ +t ~

; c a T7 C~ , ..
Glsw E

O WI tV I~ r1 O 00 00 1l1 C a p C

O V7 f'1f'1t'-)f'1 N ~ N C1 N b 3 m .t o v ~

of ~a ro ro ro m ~, .
' O N N ~
.G > m d' pa V I I I I .. .. I 1 I V

r~ n 0o a cn tn ~ m to o 0 o o E

z zo H y~ w cx o 0 0 0 o x a x c'c, m C~ t"~
O

m al O O O O ri N ~ r-i ~ p y ~.CO'O
E~x ~

o m ~.., ~ m~

~ C E
3 E"~
"

a O O ~o N r1 N W -1 ~-i ~
C

~ Z p ~
O N

~ x sc m roes ~.r yr ~e sr .t H O O .i al ~ y of >. m w E

C !7 01 N ~~t H

ro ~ C! ro >'r Ir w m a ~ C O a >'r ~ ~-1 ~ ~ r1 ~ c x o ~t o 0 E n ~ V G, O p O N p ~ '"' O O O .G .G a o Na hr ~ .c t .c m ; _ .c ro ro U V U ro U U U .r ro m G ro >~ +I w m a x a~ d ar ~ <r ~o a c~ ~ +~ a~ $ o ar > ~ '~ ' z co>

u, b ro~ bH ro N m m ~
v U N U U U~ at ~ ~~
p t G) t P. R m 0 m U i1 r~ r-~ r1 C a ~ 41 r1 ~a ,'~ r1 a 01 'O d d Cl >. ro G1 >. ~..~t>. ~ .~ o O .~ ,C ~ o ~t 'v ~ c c x+~ six s x~o xv x+~

0 0 0 ~ o ro ~t ~1 ro a o 0 z z z ~u mro cn ~v~ ~cn ~a ccu..~~>t to b ao row ~ .C Ir U

Gl U U U II
.-t b ~ N ~
p ro E W U ~
Z U t-t x oo tn vv ov o ,-r W r1 N M d' e-) N d' tit lL1 -l N f'~) -39- 20 9~ 8 28 1 Referring to Table 4, the use of boron salts, such as sodium 2 or lithium borate, gives unsatisfactory results (Examples 3 49-51) .

Sl:MISYNTHETIC AND SYNTHETIC BASE OILS

7 FIFTH SERIES OF RUN'S

9 In the experiments summarized in Tables 1 through 4 above, l0 only petroleum-derived, i.e., mineral base oils were used to 11 screen the various additives for Viton~ passivation. In a 12 fifth series of exF~eriments, extension was made to include 13 semi-synthetic and fully synthetic base oil formulations.

14 For example, in the: case of semi-synthetic base oil, the following formulation was tested: bis-succinimide 16 dispersant (5.8%), a mixture of low overbased and high 17 overbased calcium ~~ulfonates (3.7%), ZnDTP (1%), friction 18 modifier (0.25%), and polyol ester (6#) in 150N BP base oil 19 (22%), a synthetic polyalphaolefin (PAO) base oil (54%), and polyisoprene VI improver (7%), blended to a 5W40 21 specification. The PAO used was a mixture of decene-1 22 oligomers which was. formulated from 4 and 6 cSt products 23 obtained from Chevron Chemical Company. The borated 24 additives were added as "top treats" on top of the reference formulation i.n the percentages given in the examples which 26 are summarized in Table 5 below.

28 SYNTHETIC BASE OI~,S

The fully synthetic base oil was used in a formulation 31 containing a mixture of dispersants (7.3%), an overbased 32 calcium sulfonate (0.7%), highly overbased calcium phenate 33 (3.4%), mixed zinc: (2%), and polyol ester (8.3%) in a 34 commercial synthetic PAO base fluid (as above) (68%) and polyisoprene VI improver (10.3%), blended to a 5W40 1 specification. As before, the borated additives were added 2 as "top treat:" on top of the reference formulation in the 3 percentages given in the examples summarized in Table 5 4 below.

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SIXTH SERIES OF RUN'S

7 For reasons not fully understood, the most effective boron-8 containing compounds for passivation of the fluorocarbon 9 elastomer, are also the borated compounds which showed considerable antio~;idancy properties when examined in an 1l oxidation beach test.

13 For example, when a fully formulated base oil reference was 14 top treated with the given amount of additive, either in weight % or in ppm of boron for the boron-containing 16 compounds, the results summarized in Table 6 below were 17 obtained.

19 The referenda oil formulation contained 3.5% dispersant, 50 mmol/kg calcium as hydrocarbyl sulfonates, 17 mmol/kg zinc 21 dialkyl dithiophosphate, and 6.8% viscosity index improver 22 in Chevron 100N base oil. The oxidation test employed 23 herein measures the resistance of the test sample to 24 oxidation using pure oxygen with a Dornte-type oxygen absorption apparatus [R. W. Dornte, "Oxidation of White 26 Oils," Industrial and Enqineering~ Chemistry, 28 p. 26 27 (1936)]. The conditions are: an atmosphere of pure oxygen 28 exposed to the test oil, an oil temperature of 340° F.
29 (171°C.) and. an oxidation catalyst comprised of 0.69% Cu, 0.41% Fe, 8.0% Pb, 0.35% Mn, and 0.36% Sn (as naphthenates) 31 in the oil [J. Amer. Soc. Lubr. Eng., Vol. 37, p. 722, 32 (1981), Test: 1H]. The time required for 100 g of the test 33 sample to absorb :L.0 L. of oxygen is measured.

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1f1 W ~O ~O ~ ~0 t0 ~D ~D h h h h h h h ~D ~D h h 1 Referring to Table 6, the addition of alkyl-catechol to a 2 reference oil at 2%,, practically had no anti-oxidancy effect 3 (Example 62) as the data is typically reproducible to the 4 extent of + 0..5 hr. Addition of borated bis-succinimide (Examples 63-65), o:r borated glycerol monooleate (Examples 6 66-68), shows no antioxidancy, but actually prooxidant 7 effect, indicating 'that the reference oil was more stable in 8 the absence o:E added borated compounds than in their 9 presence. Addition of phenylborate (Examples 69-71) gave only a small ;prooxidant effect, but this value was not 11 statistically different from the reference (Example 61) and 12 for practical purposes was considered neutral. Borated 13 alkylcatechol (Examp:les 72-74) (R=Cue-C24) showed very 14 positive antioxidant properties, and borated dialkylcatechols (Examples 75-78) (R=C~8-C24) also showed 16 antioxidant properties, but these were lower than those 17 obtained in case of the monoalkylcatechols. Examples 79-81 18 show that when unb~~rated alkylcatechol was added with 19 borated glycerol monooleate, the addition of each individually led to either no effect or a small prooxidant 21 effect previously, now showed a positive antioxidant effect.

3 As was noted above, catechol borate and short chain alkyl 4 catechol borates (1-8 carbons in the alkyl chain) were found to have unexpectedly superior dispersancy properties 6 compared to long-chain alkyl catechol borates. The 7 dispersancy properties are measured by the "dispersancy spot 8 test" ("Test").

A general discussian of the Test can be found in A.
11 Shilling's "M:otor Oils and Engine Lubrications," Volume 1, 12 Scientific Pu.blicat:ions Limited, England, 1968, p. 2.53-13 2.84. One revision of the Test is set forth in Example 4 of 14 U.S. Patent 4,199,462, Column 7, lines 13 et seq. The Test set forth in ExampJ.e 4 of the '462 Patent has been modified 16 for the seventh series of runs to be discussed below.

18 The working conditions of the seventh series of runs for the 19 Test were as follows:
21 1 - Without water 23 5 g of artificial sludge containing approximately 2% of 24 carbonaceous matter are added to 20 g of a reference SAE 30 oil plus a small amount of a catechol borate of 26 this im~ention and mixed together, using a micro-27 crushing-mill (about 18,000 rpm): twice 30 seconds 28 with a :15 second pause between the two.

The following conditions must be observed in each test:

32 - keep to the micro-crushing time 34 - keep to the interval between the two periods of micro-crushing ._. 2097828 1 - use only 'S0 cc beakers 3 2 - With water Same as .above but add 1% water to the mixture. The oil 6 to be tested is then examined by making spots:

8 - cold dispersion:

Make a spot on the filter paper using a glass 11 stirrer (d:iam 8 mm) dipped into the sample with or 12 without water to about 2 cm taking the 3rd or the 13 4th drop.

- hot dispersion:

17 Place 2 ccs of the sample to be tested in a test 18 tube, place this in an acetophenone bath at 200°C
19 for 1 or 10 minutes. A spot is then made, taking the: first: drop to fall from the glass stirrer.

22 6 spots are made in the following conditions:

24 1 room temperature without water 2 10 minutes at 200° without water 26 3 10 minutes at 250° without water 27 4 room temperature + water 28 5 1 minute at 200°C + water 29 6 10 minutes at 200°C + water 1 ,~mDOrtant:

3 - The spot at. room temperature is made when the oil 4 has cooled completely (approximately 15 minutes after micro-crushing) . The micro-crushing raises 6 the temperature of the oil to around 50 to 60°C).

8 The hot spots are made as soon as the tube is 9 removed from the bath at 200°C.
11 - When applying the drop of oil to the filter paper 12 nevcar allow the glass stirrer to come into contact 13 with the latter.

The resu:Lts are obtained by measuring the spot after 48 16 hours of deposit on a flat surface protected from any 17 contamination.

19 The "spot" consists of an inner darker circle of diameter "d" surrounded by a translucent area soaked 21 with basic oil and forming a larger cixcle of diameter 22 "D."

24 For each spot, the ratio d:D is calculated and multiplied by 100. The "best" dispersion would be 26 where d:D equals 1 for each spot to give a combined 27 maximum of 600 dispersion units.

29 When oils of similar dispersive properties are compared, it is possible simply to compare the total of 31 the 6 spot ratios multiplied by 100.

33 The purpose c~f the seventh series of runs was to compare the 34 dispersive properties of (1) catechol borate (2) butyl catechol borate and (3) a long-chain (average CZZ) alkyl 1 catechol borate with the reference SAE30 oil containing the 2 sludge.

4 Catechol borate showed a gain of about 50 units over the reference value of 396. t-Butyl catechol borate showe3 a 6 gain of about 18 units while the long chain alkyl catechol 7 borate showed a loss of about 25 units. The attached Figure 8 is a plot of these data with the carbon number of the alkyl 9 group on the: x-axis and a loss or gain in dispersancy on the y-axis. The. Figure suggests that alkylcatechol borates with 11 alkyl groups. below 10 carbon i.e., 8 or 9, shol~ld not only 12 provide passing rs~sults in the VW Bench Test, but also offer 13 no loss in f:he ovs:rall dispersancy, a quite unexpected 14 result.
16 While catecriol borate has the advantages set forth above, it 17 and the lowE~r alkyl. catechol borates have low solubility in 18 base oils. For example, catechol borate was soluble only to 19 the extent of about 0.3 weight percent or less.
21 The following Tab:Le 7 demonstrates that alkyl catechol 22 borates coni~aining a long chain alkyl group can effectively 23 be employed to enhance the solubility of the less soluble 24 catechol borate i:n the base oil.
26 The following chart demonstrates the fact that alkyl-27 catechol bo:rates cantaining a long alkyl group can 28 effectively be employed to enhance the solubility of the 29 less soluble catechol borate in the formulate8 base oil.
For example, catechol borate was soluble only to the extent 31 of about <_0.3%, but this value was exceeded by adding an 32 alkylcatechol containing a long (avg C22) alkyl group.

3 SOLUBILITY OF CATECHOL BORATE VITON~ BASELINE OIL*
IN

CA'rECHOL BORATE, (CB) 5.6% B

6 AhICYL (C~g - C2~) BORATE,1.2% B (ACB) 8 Ratio CB/ACB 1/1 1/2 1/3 1/4 1/0 Wt % (CB + ACB) 11 in baseline 2 2 2 2 1 12 oil 14 Wt % CB in 1 0.67 0.5 0.4 1 baseline 16 oil 18 ppm B in 680 530 430 420 560 19 final oil blend 22 Appearance hazy very clear, clear, hazy 23 little slight bright, bright, some 24 solids haze, no no solids no solids solids 26 solids 29 * at room temper ature (20C) 31 The invent~.on not to be limited to the examples but only is 32 to the claims set forth below.

Claims

WHAT IS CLAIMED IS:

1. A lubricant composition comprising a major proportion of a lubricating oil; a minor proportion of at least one compound containing basic nitrogen and a minor but effective compatibilizing amount of a borated aromatic polyol as an additive to passivate fluorocarbon polymer seals, said aromatic polyol having the formula:

where R"' is selected from the group consisting of H;
OH; or an alkyl group having from 1 to 8 carbon atoms.

2. A composition according to claim 1 where the basic nitrogen compound is a succinimide.

3. A lube oil composition according to claim 2 wherein the succinimide comprises the reaction product of a C8-C500 polybutene succinimic acid or anhydride compound and an alkylene polyamine.

4. A composition according to claim 3 wherein the amount of the borated aromatic polyol is at least the stoichiometric amount to the basic nitrogen present in the composition.

5. A composition according to claim 4 wherein the borated aromatic polyol is borated catechol.

6. A composition according to claim 4 wherein the borated aromatic polyol is borated pyrogallol.

7. A composition according to claim 4 wherein the borated aromatic polyol is borated tertiary butyl catechol.

8. A lube oil composition according to claim 4 wherein the weight percent of said succinimide is from 1 to 20 weight percent of said composition.

9. A method to improve the compatibility of a lubricating oil containing basic nitrogen to fluorocarbon seals in engines which comprises adding to said lubricating oil a compatibilizing amount of a borated aromatic polyol having at least one aromatic ring and at least two hydroxyl groups and wherein at least two of said hydroxyl groups are on adjacent carbon atoms on said aromatic ring, the aromatic polyol having the formula:

where R' is H and R" is selected from H, OH or an alkyl group having from 1 to 8 carbon atoms.

10. The method according to claim 9 wherein the basic nitrogen compound is a succinimide.

11. A tube oil composition according to claim 1 which contains in addition a sufficient amount of a long-chain alkyl borated catechol wherein the alkyl group has at least 10 carbon atoms to aid in solubilizing said borated aromatic polyol.