CA2174931A1

CA2174931A1 - Lubrication oil composition

Info

Publication number: CA2174931A1
Application number: CA002174931A
Authority: CA
Inventors: Hirotaka Tomizawa; Michihide Tokashiki
Original assignee: Individual
Current assignee: Tonen General Sekiyu KK
Priority date: 1993-11-30
Filing date: 1994-11-29
Publication date: 1995-06-08
Also published as: EP0731829A1; EP0731829A4; JPH07150177A; WO1995015368A1

Abstract

A lubricating oil composition comprising a basestock oil and, based on the oil composition, (A) 0.01 to 10 % by weight of oxymolybdenum monoglyceride or oxymolybdenum diethylate amide and (B) 0.5 to 7 % by weight of a metal dithiocarbamate represented by general formula (I), where M represents metal such as zinc, R1 to R4 represent C1-C30 oleophilic group at least one of which is a secondary oleophilic group. The composition may also contain (C) 0.01 to 5 % by weight of an organic amide compound. The lubricating oil composition is excellent in wear resistance, exhibiting a low coefficient of friction, capable of improving fuel economy and improved for copper corrosiveness, as well as capable of providing a low coefficient of friction already from the initial stage of operation.

Description

~ WO 95115368 ~ ~ ~ 4 ~ 3 1 PCTIUS94~13767 TTlR-~T~TTNr OIL
BAC OF TR~ INvl:!NTTflN
l. Field of the Invention The present invention concerns a novel lubricating oil '~ir~n ~md~ more particul~rly, it relateg to a lubricating oil 1-;r~n which i8 8uitable, for example, as engine oils (lubricAt-ing oil for internal ;rn engines), gear oils, automatic trans-mission fluids (ATF), power steering oils (PS oil), spindle oils, hydraulic fluids ~nd inA---~r;A1 lubricating oils, excellent in wear r~nlc~ n~.e~ ~Yhih~l inq a low friction ~ fEi~ nt~ capable of improv-ing fuel conomy And with improved cop,oer corrosion property, ~a well as a ~ rir~t;nq oil, t;nn having the ~ ,._ ;nnrA ~ aLa L~~
istics and capable of ~vh~h~1-;nq a low friction coefficient already from an initial ~tAge of operation (cnnAit;nn;n~ drivlng).

2. DesCrintion of the Related Art An increaE~e in the output of internal ~ i r~n engines such a8 r il.~ engineg ha8 cau~ed individual partg of engines, for ex~lmple valve tr~in ~ystems or cylinders, to bo exposed to high c~Lu . . Mor-over, the number of cont~cts per unit time of metal with each other hlls been increased, thus placing the internal combus-tion engine under fsevere operating cnnA;t;~ . Lubricating oils for internal ~ ;~n engines must function under severe cnnA;I ;nnn.
With a rc-A--~I ;nn of size and increase in the ~e~LI,~ l. e which results in en increase in the number of revolutions ~md an increase in the output, engine oils ~re re~uired to be versatile ~nd possess high levels of ~ . L~
.

As ~ L reguired for the engine oils, there can be ; nn~A~ reduction of friction, prevention of wear ~nd ~eizure, reduction of thermal and oxidative Ar~qr~A~ n~ d~:L~y_.~.y and dispersancy, ;nh;hi~;rm of corrosion and cooling and sealing WO 95115368 PCr/US94/13767 ~

3 ~

functions, nnd use of vArious kLnds of ~dditives h~3 been studied for ~nti~fying ~uch functions.
For instAnce, ~8 A lubrlcnting oil _ itinn excellent, particul~rly, in the reduction of ir:~1 friction loss for 4-cycle ~ngines, there hn~l been proposed a 1 rA- i nrJ oil : _ ' t i nn com-prising n minernl oil ~nd/or synthetic oil hnving ~ kinematic vi~cosity at 100C of 3 to 20 c8t nnd blended therewith, (n) 0.2 to 5#
by weight of ~ulfurized oxymolybdenum ~L~J~ LI _,I n 1:th~n~t-~ (here imLfter referred to simply as NoDTP) and/or sulfurized oxymolybdenum , 1th;1 ~ (hereinafter referred simply n8 MoDTC), (b) 0.l to 796 by weight of zinc ~-~thi ~ , (c) 0.l to 20# by weight of calcium alkylbenzene sulfonate ~nd (d) l to l5# by weight of alkenyl e--_r;nim~ nnd/or boron compound derivative of ~lkenyl ~ r~
(J~p~nese P~tent r 1 i rntinn No. 23595/l99l) . According to this 11.h~-~rnt~ oil _ ~inn/ the friction co~ffir~n~ in the mixed/boundary r-s~ion c~n be r-duced to ~bout l/3 of th~t for the conventional engine oil.
One of the important features of the lubric~ting oil i5 that it does not attack a metnl within the engine during use. It is cnni ~ that corrosion mny be c~used by free sulfur, sulfur com-pound~ or ~cidic cr~ r--~. Since a copper plate i8 most sensitive to thel:e L , the corrosion o~ n copper plate when exposed to ~r~t~Tg oil ig ev~luated A8 ~ meagure of the corrol3iveness of the r..t:rg oil. It i8 A common practice to add niLL-,y_.._~,.. metal de~ctiv~tors, such ns benzotri~zole, to the lubricating oil for the purpose of reducing the ccpper corrosiveness. However, the ~-ddition of these metal deactivators in a large ~imount resulto in hardening of ~eAling rubbers. Further, if MoDTP or MoDTC is added in a rel~tively grent ~mount ns 0.2 to 59~ by weight ns disclosed in the ~bove-cited patent r..h1irJIt~nn for reducing the friction, it results in a problem of c~ul~ing n strong corrosive effective to copper.
Further, a lubric~ting oil it~nn hnving nn org~no-molybdenum compound such ns MoDTP or MoDTC ndded thereto involves a problem that n friction rn-~ff;r~nt nt ~n initinl stage (during WO 95/15368 PCI~/US94J13767 ~Si74~3~

cQn~iitinn1n~ drivlng) i8 high. LubrLcating oLl addltLvea h~vo an effect of reducing the boundary friction by i~dsorption to metal surface to form boundary lubricating film but the organomolybdenum compounds descr$bed ~bove require a relatively long period of time until they are adsorbed on the metal surfAce to develop the friction reduoing effect.
Accordingly, when a ~ r~r-fim7 oil f~nn having the org~nomolybdenum compound added thereto Ls used as ~n engine oil, the effect of reducing the frict$on develops after running a distAnce of 2, 000 to 3, 000 Icm, although thLs depends cn the running condLtion of ' i loc~. However, after the a~ Llbed running, the time for the development of the effect of the friction often overlaps with the time for the r rl r of the engine oil. In such a c~se, an increase in the amount of ;~ddition of MoDTP or MoDTC does not lead to the development of the effect of r-ducing the friction ~t ~n earlier st~ge and rather incre~ses the copper corrosiveness.
cn~ rY OF m~TR INVENTION
The present invention has bRen mzlde under ~uch CiL.
with ~ view to provide a lubricz~ting oil i f i nn excellent Ln wear r~ f~nre~ olrhihifiT~ low friction cce~ffiri~nf~ capable of improving fuel economy, ~nd with improved copper oorrosiveness, 118 well aa a lubricating oil ~ If i nn hAving the foregoing ~ L ~ f; r~l and, in addition, capable of developing a low coefficient of friction from the initiAl l~tage of nre~rnf i nn The present inventors have made earnest studies for develop-ing ~ lubricating oil ~ ' f i nn having desired properties as ~nrrih~l above, a8 ~ re8ult, hl~ve noted that oxymolybdenum mono-glyceride or oxymolybdenum diethylate amide, not rnnf~ining sulfur atoms in the molecule, does not increase the copper corroaivenes3 as in the case of MoDTP or MoDTC And h~ve found that a 1 -hri rAf; nr~ oil ' f ~ nn of excellent wear re8igt~nce, ,.h i h i f i n.7 low cn~f f; r i onf of friction and with reduced copper corrosiveness can be obtained by combining the ~ compound with a met~l ~lifhi~ ~~ ' WO 95/15368 ~17 ~ ~ 31 PCT/US94/13767 "

hnvLng n secondary Glkyl group ~md blonding them each at a predeter-mined rGtLo to a lubricating oil ! '~ ' and, further, a lubricating oil _ t~nn hGving the foregoing .I.aL--~ LeListics ~nd, in Gddition, cGp~ble of reducing the frictlon coeffLcient Gt the initial stGge of driving c~n be obt~ined by iurther blending an organic amide compound at a yL. l 1_ . l I r~tio. The present invention has been bGffed on such f indings .
Th~t is, the present invention provides a ll.h.-~rJ-~in~ oil ; ~ i nn compri-ing A lubricGting oil ~ - ` Gnd, based on the oil composition, (A) 0.01 to 10% by weight of at least one of organomolybdenum com-pounds seleoted from oxymolybdenum monoglyceride and oxy-molybdenum diethylate amide, Gnd (B) 0.5 to 7% by weight of a metal rlithir~ ~ LG~L~ ` by the general formula (1):

\ 11 11 /
N -- C -- M -- S -- C -- N (1) where !5 L_~L~ - zinc, copper, nickel, iron, oGdmium, silver, lead, antimony, tin or bismuth; Rl, R2, R3 Gnd R4 repreaent ~ r ` ~y an nlGnrhi 1 ir group of 1 to 30 carbon atoms in which ~t le~st one of the four nl~nrh~l~r groups is a ~econd~ry nl Gnrh ~1 i r group . Another: ' relates to a lubric~ting oil _ r~inn comprising n lubricGting oil h~G~Gtnrl~ ~nd, bGsed on the oil _ 11 ~nn, 0.01 to 10~6 by weight of the ingredient (A) described above, 0.5 to 7~ by weight of the ingredient (E) described Gbove, nnd (C) 0.01 to 5~ by weight of nn organic Gmide compound.

~ WO 9S/15368 PCT~US94/13767 ~17~g31 _ 5 _ DF!T1~TT.l;~n ~ -~lUN OF Tl~ INVENTIOII
There il no particular restriction for the ~- u~ed in the lubricating oil _ ti~m according to the preaent invention ~nd those proposed 80 far a~3 the ~~ for the 11~hriri~tin~ oil, for example, mineral oils or synthetic oil~ can be used.
As the mineral oil, there c~n be ;~ -1, for ex~imple, 50 neutral oil, lOO neutral oil, lSO neutral oil, 300 neutral oil, 500 neutr~l oil ~nd bright stock obtained by :lolvent refining or hydro-genation, which m~y be used alone or as a mixture of two or more of them at ~n ~ppropriAte ratio.
As the rynthetic oLl, there can be 1 1, for example, poly a-olefin oligomer, polybutene, alkylbenzene, alkyldiphenyl, polyol eater, polyglycol ester, dibagic acid e~ter, phosphoric acid este r ~nd silicone oil, which may be u~ed alone or ~ a mixture of two or more of them at ~n Arrrr~pri At~ ratio . In addition, mlneral oi 1 ~md the 3ynthetic oil hc~a above may be u8ed in admixture.
As the b~se o$1 used in the lubric~ting oil i ~ i rn according to the present invention, tho~e having a kinematic viscosity nt a L _ e of 100C within a range from 3 to 20 mm2/s, prefer-ably 4 to lS mm2/s are preferred.
A!; the; n~re~ nt (A) in the . ; ~ n according to the present invention, oxymolybdenum monoglyceride cr oxymolybdenum diethyl~te ~mide (hereinafter referred to MoOxide type ccmpound~ ) i5 used. The oxymolybdenum monoglyceride is ~e~ Led by the general formula (2):
O
Il R - C - O -- CH2 - C}l - Cl H2 o o (2) Mo // \\
O O

WO 95115368 ~ PCTI~S94113767 whlle oxymolybdenum diethylnte nmide i8 .~ .. Led by the general formula (3):

Il / \ //
R - C - N No (3) / \\

In the general formul~e (2) and (3), R is hydrogen atom, alkyl group of l to 20 carbon Atoms, alkenyl group of 2 to 20 carbon atoms, cyclo~lkyl group of 6 to 26 carbon atoms, aryl group of 6 to 26 carbon ~toms, alkyl~ryl or arylalkyl group of 7 to 26 carbon atoms or I,.,....L~.. group rnntl~;n;ng ~ter bond, cther bond, ~lcohol group or c~rboxyl group. Preferred R is alkyl group of 6 to 18 cnrbon atom~, alkenyl group of 6 to 18 c~rbon iltoms, cyclo~lkyl group or 12 to 24 cnrbon atoms or Alkylnryl group of 12 to 24 carbon atoms. As preferred specific xi~mple~ of them, there can be innorl alkyl or ~lkenyl group~ of 6 to 18 carbon ~toms such ~8 n-hexyl group, 2-ethylhexyl group, n-octyl group, nonyl group, decyl group, lauryl slroup, tridecyl grcup, oleyl group ~md linoleyl group, nnd alkylaryl group h~ving An ~lkyl group of 3 to 18 carbon atoms such as nonyl-phonyl group.
The MoOxide type compound for the ingredient (A) may be used alone or two or more of them mny be combined for use. Further, it is necossary th~t the blending nmount is selected within a range from 0.01 to l09~ by weight, preferably, 0.05 to 8~ by weight based on the entire weight of the oil . _ it~nn. No 5~1ffir;ont friction reducing effect cnn be obtnined if the blending amount is less than 0.0l1 by weight wherea~ no ~ i ng; ~.. ' for the friction reducing effect cnn be observed if Lt exceeds l091 by weight.
As the ingredient (B) in the l ~r~t;n~ oil ~ t;nn nccording to the pre~ent invention, ~ metal ~l;thil ' '~ (herein-after referred to N-DTCn) .~ ..Led by the general formuln (l) is uued.

Rl S S R3 \ 11 11 /
N -- C -- M -- S -- C -- N (1) R2 \R4 In the above general formula (1), M is zinc, copper, nickel, iron, cadmium, ~iilver, lead, antimony, tin or bilimuth. Each of R1, R2, R3 and R4 i8 an ol~rrhllir group of 1 to 30 carbon atoms in which at least one of them ls a secondary nlerrh;lir qroup, preferably, at least two of them are seoondary Alerrh~l;r groupli and the residue include3 primary nl~rrhilir group~i. Further preferred nlr--~rh;lir group are thoLie in which _t l~_st t_ree of them are secondary A lkyl group~. Rl, R2, R3 _nd R4 may be ldentical or different with each other .
A~i the r~lerph;l;r group of 1 to 30 c~rbon atoms, there can be ' irno~l for Oxample, alkyl group of 1 to 30 carbon atoms, alkenyl group o 2 to 30 carbon atoms, cycloalkyl group of 6 to 30 carbon atoms, aryl group of 6 to 30 c~rbon atomEi, alkylaryl group of 7 to 30 c_rbon atoms, ArylAlkyl group of 7 to 30 cArbon atoms or l~ylL~ L~
group h~ving eLiter bond, ether bond, alcohol group or carboxyl group.
N-DTC Le~ ..L.zd by the general formula (1) in the oil '~irn _ccording to the pregent invention having four nlenph;l;r groups with the average number of oarbon _tomg between 1 and 5 are desirably reActed with an oil soluble amine compound for ~ leYin~
L.~ in order to incre_~e the ~iolubility to the lubricating oil ` and improve the wear rel;istance. M-DTC having four nlenrhilir group2s with an average number of carbon atoms of 1 (in which all the nlerrhilir groups are methyl) cannot provide a homo-geneouf~ hrirAl ;nq oil _ ~ir~ even if it ifl reacted with the oil soluble _mine compound ~iince the solubility of the resultant complex to the lubricAting oil b '~ poor. Since M-DTC exhibits it~
function by ~dsorption to metal ~urf_ce, no ~..ff;rienf effect c~n be expected if it di~isolves excessively but it will be quite useless unless it is soluble. The lower limit for the aver_ge number of carbon atoms of the nl~orhilir group ig preferably two or more in view ~7~3~

of both functions of the solubility and the wear rr~ni ,.1 Anr~ If the ~verage number of cnrbon atomD of the four nl~.nrh;lir groups i8 5 or more, solubLlity to the lubricatLng oil hA~.~n~nrl~ is ~ ;nf~-tnry with no lf~vinq ~ ' but it may be used after lf-Yinq if neces-~ary.
In N-DTC, it i8 preferred that all the four nl~nrh~lir groups ~re identical l.~ ..LL.,I. groups, more guit~bly, the four nlenrh;l~r grcups ~re ~lkyl groups of 3 to 6 carbon ~toms in view of e~sy produc-tion nnd wear r~ e Nore preferred r,l~-rhil;r group is alkyl group of 3 to 4 c~rbon ~toms. For the metal ~tom (M), zinc is preferred in view of e~sy availability And wear r~ nr~.
H-DTC clm be produced by a known method. For 1nstAnce, &inc diiYcpropyl ~I;l-h~- ' ' can be produced by reacting diiaopropyl-amine, c~rbon disulf ide ~nd sodium hydroxide to prep~re sodium diisopropyl ~ hif- - whioh is then reacted with zinc nitrate.
A~ the oil soluble ~mine compound uaed for 1 -Yi nq M-DTC, there cAn be ; I, for example, ashless oetergent dispersant such A8 polyi~lkenyl ~ rc;n;m;~- or ~lkylbenzylamine or ~lkylamine, alkyldi-mine and alkylpoly~mine.
For previously forming a complex of M-DTC _nd the oil soluble zlmine compound, it 18 preferred to employ a methcd of adding both of them to a lubricatlng oil ~ at a ratio of providing a high -Llon ~nd he~ting them. For instance, when a lubricating oil 'i-;nn rnnl ~in; nq 2 to 79~ by weight of M-DTC and 2 to 2591 by weight of oil aoluble amine compound, ~t ~ ratio of 1 to 10 parts by weight of the oil ~ioluble ~mine compound b~sed on 1 p~rt of weight of M-DTC i~ Atirred at a _ ~Lu~ of 100 to 230C, more preferably, 150 to 200C, prefer~bly for 1 to 60 minutes, more prefer~bly, 1 to 30 minutes, both of the compounds form A complex which is uniformly di~solved in the lubrionting oil hAn~ni-nrl~ As the heating temper~-ture 18 hlgher, they form ~ complex ln ~I shorter period of time and --W095/153C8 PCI'Il~S9U13767 ~17~
g _re dLssolved more uniformly. A I _ lubricating oil compo~L-tion cnnr~inin~ both of the compounds at a desired ratio can be obtA ined easily by diluting the resultant complex solution ~t high ..... ~_ I ~Al inr with the lubricnting oil I
In the ~ ' 'rAI ;ng oil i~inn according to the present Lnvention, ~5-DTC as the; ~ n~ (B) may bo u~ied alone or U5 a ' ' r ~e i nn of two or more of them. It is _ y to blend l~-DTC by 0.5 ~o 79 by weight, preferably, 1 to 59i by weight baaed on the oil itinn No sufficient wear resist_nt effect cAn be obtained if the blending Amount i8 less thAn 0.59 by weight, whereas the solu-bility tends to be lowered if it exceeds 79~i by weight.
sec~-DTc has _ function of _n extreme pressure ~gent, ~5 well a5 A function as an Anl inY;~ a corrosion inhibitor or the like.
In the l~.hl-irAI i~ oil il ~nn according to the pre~ent invention, the org~nic amide compound ~s the ingredient (C) can be us~ed ~8 required. The org~nic ~mide compound is a compound repre-ented by the general formula (4):

Il /
R7 - C - N (4) In the general formula (4), R5 and R6 each L~
hydrogen ~tom, alkyl group of 1 to 20 carbon atoms, alkenyl groups of 2 to 20 cArbon atoms, cycloalkyl group of 6 to 26 carbon ~toms, aryl group of 6 to 26 cArbon atoms, alkylaryl group or _rylalkyl group of 7 to 26 carbon atoms or alkylene oxide group of 2 to 30 carbon atoms which may be identic~l or different with etlch other. R7 ..,~ ..L~.
hydrogen atom, alkyl group of 1 to 20 carbon atoms, alkenyl group of 2 to 20 carbon Atoms, cycloalkyl group of 6 to 26 carbon ~toms, aryl group of 6 to 26 carbon atoms, alkylaryl or arylalkyl group of 7 to 26 c~rbon atoms or 1,,~ .1 . group ~nn~inin~ ester bond, ether bond, alcohol group or c~rboxyl group.

WO 9511S368 PCINS94/13767 ~¦1 The alkylene oxide group ; l ~ herein is ~ group repre-sented by general formula (5) or (6).
CH2CHO ~ H
(5) R' CHCH20 ~; H
(6) R' wherein R~ .. L8 hydrogen ~tom or methyl group and n is an inteyer of 1 to 10.
Preferred R5 and R6 in the general formula (4) are hydrogen Atom, alkyl group of 2 to 8 cArbon atoms, cyclo~lkyl group of 8 to 14 cArbon ~tom3, ~lkyl~ryl group of 8 to 14 carbon atoms, and alkylene oxide group in which n i8 1 to 5. Preferred R7 can include alkyl group of 6 to 18 cArbon atoms, alkenyl group of 6 to 18 cArbon atoms, cyclo~llkyl group of 12 to 24 carbon atoms and alkylaryl group of 12 to 24 carbon ~toms. As specific ex~mples of the organic amide compound, there can be i~ , for ex~mple, ole~mide or lnuramide, which mAy be used alone or as a inJIl inn of two or more of them.
In the lubricating oil ~ i nn according to the present invention, the org~nic ~imide compound 118 the i nqr~ i Pn~ (C) is blended by 0.01 to 59~ by weight, prefer~bly, 0.05 to 29~ by weight b~sed on the oil _ le~n Blending of the organic ~mide compound c~n reduce the friction ~ ff~Hf.n~ ~lre~dy from the initial stage of driving while ,, 'nq the copper corrosiveness. No sufficient effect for reducing the friction coefficient from the initial stage of driviny c~ln be ~ttained if the blending amount is less than 0.0196 by weight, whereas no ~ ,..ding ~ _ ~,. for the effect can be recognLzed if the ~imount exceeds 596 by welght.
In the lubricating oil _ i~rn according to the present invention, there c~n be properly added various kinds of additives used ~ WO 95/15368 PCIIUS94113767 ~17~9~1 _ ~ly in the lubricating oil8, for example, other extreme pressure _gents, ashless detergent fi~rfr~--nt~ Anl ~nY~tiAn~ metallic detergent, metal deactivdtor, viscosity index improver, pour point depressor, rust inhibitor, Ani-;' and corrosion inhibitor within such a range as not f~-' frifrA~in~ the purpose of the present inven-tion .
For other extreme .Ay.~ .: agent, there can be ~ inn~
fcr example, organomolybdenum compounds such as MoDTC or MoDq'P.
However, if the amount of the org_nomolybdenum compound used is increa_ed, the copper corro~ion becomes fnn~r;r~ a. Ag the a3hless detergent ~iiorfr~ , there cAn be ~ 1 i, for exAmple, 8--- f~n~m~fif., 8~f~-- fif., benzylAmine or egter type, as well as L~ AininfJ _shless detergent dispersant can be used. ~rhey are u~ed usually at a rAtic of 0.5 to 7% by weight.
Further, o8 the An1-~nvir~ there cAn be innfd, for ~x_mple, dmine-bA-ed ~ni-~nYi~nl such as alkylated dlphenylAmine, phenyl a ' ' hylamine, alkyl~Lf=d ~ r..~l.Lhylamine, and phenolic ~nt~nY~fi--lt euch 48 2,6-di-terti~ry-butylphenol, and 4,4~-methylene-bi~-(2,6-di-tertiAry-butylphenyl) And it ig usually u_ed At a ratio of 0 . 05 to 2 . 0% by weight .
As the metallic detergent, there can be ;nnf,fi, fcr ex~nple, C~ 1 fn-~ f~ lly _ 1 fnn~e~ Ba-sulfcnate, C~ ' ' , Mg-Phenate, BL r ' -, Ca-sOaliCylate, Ng-salicylate and Ba-salicylate which is generally u_ed _t a r~tio of 0.1 to 5.0% by weight. As the metal deactivator, there can be ~nnf~ for example, hfn7r~triA~nlf.
bcn_otri_zole derivative, bf~n7ni-h~ nlf~ bf-n7nfh;A-n]P deriv~tive, tri_zole, tri_zole derivative, f~ilh~f ` ~ ~lh~
derivative, indazole And indazole derivative, which may be used usually at ~ ratio of 0 . 005 to 0 . 3% by weight .
As the viscosity index improver, there can be I ~nnf~ for exAmple, polymethacrylate, polyisobutylene, ethylene-propylene co-polymer and ~Ly ~ if nf. I,y~ copolymer type improver, which m_y be u_ed usua ly at d rA-tio of 0. 5 to 35% by weight.

WO 95/15368 PCTII~S9U13767 217~31 Purther, ~8 the rust lnhibitor, there cAn be inn~rl~ for exAmple, ~lkenyl succinic acid or its parti~l egter and as the :~nl i-there cAn be ;t 1, for example, dimethyl polysilox~ne and poly-~cryl~te, which may be Added properly.
The lubricating oil 'tinn according to the preaent invention c~m be prepared by blending each of the various hinds of additives del~cribed above at ~ n~d amount with a h-and uniformly mixing them. The lubricating oil ~ It;nn according to the present invention c~n be used suitably, for example, to ~uto-mobile engine oil, gear oil5~ ATF oils, PS oils, spindle oils, hydrAulic fluids or industrial lubric~ting oils.
The present invention will now be described more in details by way of preferred ex~mples but the invention is not .~ rl ..A at all to such ex~mples.
1-9 and Com~llrative Exam~les 1-3 The pe~r~ of the lubricating oil itinn was --` by the method shown below.
1. C oef f icient of Friction The rneff~ri~nt of friction was measured by u3ing a reciprocal vibration friction te~ter ISRV). In the S~IV tester, a steel ball of l/2 inch diameter ~SUJ-2 specified in JIS G-4805) was used as the upper test piece, and a steel disc (SUJ-2 specified in JIS
G-4805 ) was used as the lower test piece . A sample oil was dropped on the lower test piece, a load was applied to the upper piece from the top, and the upper test piece w~s vibrated parallel to the lower test pi~ce with the upper test piece being passed against the lower test piece. The lateral load applied to the lower test piece was measured to c~lculate the rrJ~ff;r;~nt of friction (1~) ~ WO 95~1S368 PCI`/US9~1113767 ~7~31 The rroffir;ent of friction was me~sured twice, that i~, 5 minutes ~nd 20 mLnutes after the ~nit1Ai~rn of the vibr~tion of the upper teit piece. Testing crn~ irn~ are as follows:
Lozld: lOON

p , 8 Hz r 1;- ' 4 mm 2. CoPDcr Corrosiveness Corrosiveness was tested in a.. ,~,' wlth JIS X2513 "Copper strip Corro-ion Test Method ror Petroleum Products" at a test temper~-ture of 100C for a test period of 8 hourl~ by the test method, in which the state of ~ ol rrAi- i rr~ of the copper strip was observed in Accordance wLth "the StAnd~rd for Copper Corrosion~ and the corrosive-ness was cv~luated by LiubdLvision symbols 1A-4C. The corrosiveness is lower as the 'r~l value of the subdivisional mark ii smaller and the corroLiiveness is i nrr~^ 1 in the il l r~ '~ei- i r~ 1 order .
Specific ev~luation ex~imples are as follow~:
1~: p_le orAnge color which is ~Inl ~ally identical color with that of poll-hed copper pl~te upon finishing, lb: deep orAnge color, and 3~: reddish brown p~ttern on bronze color.
r 1~-- 1--4, OrmnJ~rAtive r 1~ 1--3 Lubricating oil _ li- i rn~. were prepared by blending 496 by weight o~ CA--~ nn~t~, 59~ by weight of ~ r1nlmi~ 0.59~ by weight of alkylAted diphenylAmine, 0.396 by weight of 2,6-di-t-butylphenol and 0.029~ by weight of 5-methyl-benzotri~zole to ~ mineral oil (150 neutral mineral oil having kinematLc viscotity at 100UC of 5.1 mm2/ti) batied on the entire weight of the oil , _ ' ~1 rn, ~nd blending each ~17~31 of the ;n7re~l~n~ shown in Table 1, ~nd the pe.C.,.~"."..,es were evaluated. The result~ of ~ of properties are ~hown ln Table 1.
Each of the in~r~ .nl ~ ~re ~8 shown below.
( 1 ) MoOxide compound o n -- C61113 -- C -- O -- C~2 -- CH -- CH2 O o Mo // \\
O O
(2) MoDTC (51lkur~--Lube0 _d by Asahi Denk~ Kogyo K.K. ) (2EII) 5 o s C 5 (2EEI) 11 11 / \ 11 11 N -- C -- S -- Mo Mo -- S -- C -- N
\ /
(2EH) S (2E~) 2EH: 2-ethylhcxyl group, here and hereinafter (3) MoDTP (Molyvnn L0 ' by R.T. Yzmderbilt) 2EH - O 5 0 5 0 5 0 - ( 2E}I ) \11 11 / \ 11 11/
P -- S -- Mo Mo -- S -- P
\ /
(2EH) - o 5 o - (2EH) ( 4 ) ~ec-ZnDTC
Rl S S R3 \ 11 11 /
N - C - M -- S - C - N

wherein two groups of Rl-R4 are isopropyl groups and the re~ldue~
are n-propyl group).

. wo - 15 _ ~17~31 s ) Ca-~ulf onat~
~`~53 ~)~ Ca loH21 - 2 ~6) S~ n;m~
o H2N ~ ) 4 CH2CH2 _ ~ fH -- PiB
~2 P~B: pol~i-obatyl~

-W095/15368 2~ 7~93~ PCT/US94/13767 ~

rl I I o I I ~1 --I
"' I o I I ~ I I o o O i ~i .-i 1 1 i O O _I
1~ 1 o o o I .i ~ I I I o o _l ~
O I I I I i l O l O O , O
I I I I ~ I I I o C~ -,~ i i o i o o _I C
~ i i i i i i I --I ~
I` I I I O I I I I _I O
É~ m o , I I _i I I I I O O
I I , I I j o ~ C~ o ~q i , i i i i O i O O ,, E
j o j j I j j j N o ,~ o j 0. j j j j j j No d p, 3 E .-1 N
_~ û ~, , ~, ~ ` ~ ol wo 95/15368 ~ 7 4 9 3 ~ PCTII~S94~13767 The present invention can provide a lubric~tlng oil composi-tion excellent ln we~r reslstance, exhibLting a low cn~ffiri~nt of friction, capablc of improving fuel economy and having improved copper corro~iv2nes~, all wcll ~ a ll~h~ ;n~ oil _ ~ir.n having the and, in addltlon, c~pable of attalning ~ low ~o~ffiri~nt of friction already from the initial ~itage of drivlng.

Claims

CLAIMS:

1. A lubricating oil composition comprising a lubricating oil basestock and, based on the oil composition, (A) 0.01 to 10% by weight of at least one of organomolybdenum com-pound selected from the group consisting of oxymolybdenum mono-glyceride and oxymolybdenum diethylate amide, and (B) 0.5 to 7% by weight of a metal dithiocarbamate represented by the general formula (1):

(1) where M represents zinc, copper, nickel, iron, cadmium, silver, lead, antimony, tin or bismuth, R1, R2, R3 and R4 represent independently an oleophilic group of 1 to 30 carbon atoms in which at least one of the four oleophilic groups is a secondary oleophilic group.

2. The composition of claim 1 further comprising form 0.01 to 5% by weight of an organic amide compound.

3. The composition of claim 1 wherein the oxomolybdenum monoglyceride has the formula (2) where R is hydrogen atom, alkyl group of 1 to 20 carbon atoms, alkenyl group of 2 to 20 carbon atoms, cycloalkyl group of 6 to 26 carbon atoms, aryl group of 6 to 26 carbon atoms, alkylaryl or arylalkyl group of 7 to 26 carbon atoms or a hydrocarbon group containing ester bond, other bond, alcohol group or carboxyl group.

4. The composition of claim 1 wherein the oxomolybdenum diethyate amide has the formula (3) wherein R is hydrogen atom, alkyl group of 1 to 20 carbon atoms, alkenyl group of 2 to 20 carbon atoms, cycloalkyl group of 6 to 26 carbon atoms, aryl group of 6 to 26 carbon atoms, alkylaryl or arylalkyl group of 7 to 26 carbon atoms or a hydrocarbon group con-taining ester bond, ether bond, alcohol group or carboxyl group.

5. The composition of claim 2 wherein the organic amide has the formula (4) wherein R5 and R6 each represents hydrogen atom, alkyl group of 1 to 20 carbon atoms, alkenyl groups of 2 to 20 carbon atoms, cycloalkyl group of 6 to 26 carbon atoms, aryl group of 6 to 26 carbon atoms, alkylaryl group or arylalkyl group of 7 to 26 carbon atoms or alkylene oxide group of 2 to 30 carbon atoms which may be identical or dif-ferent with each other and R7 represents hydrogen atom, alkyl group of 1 to 20 carbon atoms, alkenyl group of 2 to 20 carbon atoms, cyclo-alkyl group of 6 to 26 carbon atoms, aryl group of 6 to 26 carbon atoms, alkylaryl or arylalkyl group of 7 to 26 carbon atoms or hydro-carbon group containing ester bond, ether bond, alcohol group or carboxyl group.