Note: Descriptions are shown in the official language in which they were submitted.
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l This invention relates to a lubricating oil addi~
2 tive and lubricating oils incorporating a minor proportion
3 of said additive to depress the pour poin~ o said oil.
4 The additi~e is a copolymer of straight-chain 1-
olefins of ~rom 50 mole % to 100 mole % having 20 ~o 24 car~
6 bons and from 0 to 50 mole % having 8 to 14 carbons and an
7 ethylenlcally unsaturated dicarboxylic anhydride, prefer~
8 ably maleic anhydride, said l~ol~fins and said anhydride
9 being present in a~out equimolar ~mounts.
A wid~ variety of compositions comprising poly-
11 meric materials derived ~rom the addition reaction o~ ~ ~
12 olefins and dicarboxylic alkenes have been described in the
3 literature as dispersants for fuels and lubricants and as
14 viscosity index improvers for lubricants. For example:
15 U.S. Pate~t 2,615~845 teaches that the copolymer o~ maleic
6 anhydride and a straight~chain ~ ~olefin having up to 20
17 carbon atoms which is su~sequently esterified with long,
18 straigh~Qchain, sa~urat~d alcohols in oxder to make lt suit-
19 ably oil-soluble, can be usefull~ added to a mine~al lubri~
20 cating oil for pour point depression; and9
21 UOSo Patent 2~542,542 discloses the general pre-
22 paration of copolymers of ethylene~l~2 dicarbosylic acids
23 and their derlvatives and ~ ~oleins contai.ning f~om 8 to
24 24 straight chain carbon atoms and teaches ~hat only copoly~
mers derived from ~ octadecene were useful as lubricating
.
26 oil pour point depressants.
27 U.S. Patent 2,65$~479 polnts out that a factor o
28 particularly g~eat effect on ~he pour depressant activity of
29 acrylic ester polymers is the length of the alkyl side
chains (apparently a unction of the oil solubilizing effect
31 of the alkyl side chain). This a~tor~ however, is further
32 limited by the conslderation that the "polymers of single
. ~,~
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1 esters are rarely pour point depressants"O
2 It is the purpose of this disclosure to teach the
3 utility of polymeric additives derived from the reaction o~
4 an ethylenically unsaturated dicarboxylic anhydride and at
least 50 mole % of C20~c24 l~olefi~s to depress the pour
6 point o mineral oil lubricants.
'~ 7 Oil~soluble addition copolymers particuLarly use~
3 ful as po~r point depressants when compounded in lubrlcating
: 9 oils in a minor amount~ e.gO OoOl to 1.0 wt. %, usually 0.1
10 to 0O3 wt. % based on the total composition, have been pre-
11 pared and com~rise l~olefins of from 50 mole % to 100 mole
12 % having 20 to 24 carbon atoms and ~rom 0 to 50 mole % hav~
:. 13 ing 8 to 14 carbons and a dicarboxylic anhydride, said 1-
14 olefin and said anhydride being present in about equimolar
amounts.
16 Such sys~ems ~xhibit highly useful pour point de~
17 pressant characteristics when admixed with lubricants.
18 Thes~ copolym~rs can be ully esterified with al~
19 cohols of up to and including 8 carbon atoms to improve the
pour point depressant ac~ yO
21 It has fur~her been found that oil~soluble copoly~
22 me~s of a mi~ture of at least 50 mol percent of l-olefins
23 having from 20 to X4 carbon atoms and the balance l-hexene
; 24 olefins and maleic anhydride, said l~oleins and maleic an-
hydride being present in a~out equlmolar amounts9 upon es~i
26 fication with an alcohol o up to and including 8 carbons
27 exhi~its pour polnt depressant activity.
28 The copolymers of the invention result from the
29 addition reaction o~ abou~ equimolar amounts of l~olefins
and an ethylenically unsaturated dicarboxyl.ic anhydride such
31 as maleic and itaconicO Maleic anhydride or a derivative is
32 preferredO
~ 3
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1Such deriva~ives include those of the generic
2 formula~
4 Rl R2
S C ~C
6 l l
7 Q - C / C - 0
8 \ X
9 wherein Rl and R2 are hydrogen9 or a halogen and X is oxy~
gen, NX~ or NR3, wherein R3 is an alkyl group~ preferably
11 a Cl to C40 alkylO Suitable example~ of such derivatives
12 include itaconic anhydride, Nethyl male-imide, N hexyl male-
13 imide, N-dodecyl maleimide, N~tetradecyl maleimide, N~eico-
14 syl malei~ide9 Ntetxacosyl maleimide, chloromaleic anhy-
dride and dichloro maleic anhydride~ The copolymers have
16 number average molecular weights in the range of about
17 1,000 to 30,000 and are more frequently in the range of
18 about 2,000 to 6,0000
19 A suitablP source for the C20~C24 1olefins is a
commercial fraction consisting of about 90~95~/0 monoolefins
21 and with the typical composition
22 ~ Ye~ AEE~
23 ~ ~olefin 70
24 vinyLidene 20
Alternatively, the individual l~olefins~l-eicosene;
26 Z~methyl~l~eicosene; 3 methyl~l eicosene; l~heneicosene, 1-
27 docosene; l~tricosene, l~tetracosene; and mix~ures thereo
23 as ~sired can be employed.
29 A suitable source for the C~C14 1ole~ins may be
the individual l;olefins; l-oc~ene; 20me~hyl-l-heptene; 2,~,
31 4~trimethyl~1pentene; l~nonene; l~decene; l~dodecene; 1~
32 tridecene; l~tetradecene; l~undecene and mi~tures thereof
33 can be employedO
34The l-olefin content of the copolymer of the
~ ~ 7'~ 5 ~ S
1 invention has a range of S0 to 100 mole % C20~c24 l~olefin
2 and 0 to S0 mole ~/3 C~c~ olefinO
3 The reaction between the maleic anhydride and 1-
4 olefins mixture can conveniently be carried out by mixing
the olefins and maleic anhydride in about equal amounts,
6 and heating the mixture to a temperature of at least 50C.,
7 preferably at leas~ 80~Co A free radical polymeriza~ion
8 promoter such as azo isobutylnitrile, benzoyl peroxide, t-
9 butyl hydroperoxide or di~t~butyl peroxide is uscd.
The oil~soluble reactiQn products of this inven-
11 tion can be incorporated in lubricating oil compositions,
12 e.gO automotive crankcase lubricating oils, in concentra-
13 tions within the range of about OoOl to 200 wt. %, prefer-
14 ably 0~1 to 0.5 w~. %, of the total composi~ion. The
lubricants t~which the poiymeric products o~ this invention
16 can be added include not only hydrocarbon oils derived from
17 petroleum, tar sand or shale but also include synthetic 9ils
18 of the hydrocarbon or polyester variety and mixtures thçreof.
19 The additive may be conveniently dispensed as a
concentrate comprising 20~60 par~s by weight, preerred
21 about 50 parts by weight o the additive dissolved in from
22 40 to 80 parts by weight of a mineral lubricating oil with
23 or without other additives being present.
24 The copolymers of the invention can be esterified
with saturated alipha~ic alcohols of up to 8 carbon atoms to
26 impro~e the pour point depressant acti~ity o~ the copolymer.
27 l~ese alcohols can be eitheP straight or branched chain and
28 include methanol, ethanol, propanol, butanol, pentanol,
29 hexanol, heptanol, octanol, 2~ethyl hexanol, etc.
. .
For purposes of this disclosure a l~olefin is a
31 hydrocarbon which had a double bond between the Cl and C2
32 carbons and may or may not have another substituent on the
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1 C2 carbon, e.g. l~hexene and 2~methyl l-pentene.
2 This invention will be further understood by ref-
3 erence to the following examples, which include preferred
4 embodiments of ihe invention.
EXAMPLE 1
6 A copolymer of (C20~G24) lDolef-Lns and maleic an-
7 hydride was prepare~ by mixing 108 g. of maleic anhydride,
8 320 g. of C20~C2~ l~olefins3 400 mlO of ethylene dichloride,
9 and 2.4 g of Lucidol 70 (70% benzoyl peroxide and 30 wt. %
water) in a liter r~sin pot which was fitted with an agi~
11 tator, condens~r, thermometer3 nitrogen sparging tube and
12 heating mant~e. The mixture was heated to 38C.3 sparged
13 slightly with nitrogen and then heated to 72Co where it was
14 maintained for 3 hours with agitationO Therea~ter 0.9 g. of
Lucidol 70 was added and polymerization continued for an ad-
16 ditional 18 hours by maintenance at 72~80C~
17 The polymer may be fr ed of raw materials by pre~
18 cipitation in cold isopropanol or by dialysis against a rub~
19 ber membrane for thr~e hours with toluene.
EXAMPLE 2
21 A copolymer of ~C20l~2~) ~ C6 l~olefins and maleic
22 acid anhydride was p~epared by the procedure of Example 1
23 except that 182 g~ maleic anhydride9 324 gO of C20-c24 1-
24 olefins and 68 g. of hexene~l was used. The copolymer prod-
uct was insoluble in ~il at room temperature.
26 EXAMPLE 3
27 A copolymer of (C20~C2~) ~ C8 l olefins and maleic
28 anhydride was prepared by the procedure of Example 2 except
2~ that 92 g. of octene-l was used Ln place o~ hexeneol.
EXAMPLE 4
. .
31 A copolymer of (C20-C24) ~ C10 l-olefins and mal~ic
32 anhydride was prep~red by the procedure o~ Example 2 except
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1 that 115 g. of decene l was used in place of hexene-l.
2 EXAMPLE 5
3 The product of Example 1, i.e. thP copolymer of
4 C20 C24 l~olefins and maleic anhydride was fully esterified
with 2~ethyl hexanol using p~toluene sulfonic acid as the
6 catalyst and azeotxoping of~ the water of esteri~ication
`7 with toluene.
8 EXAMPI~ 6
; . 9 The product o~ Example 2, i.e. the copolymer of
(C20-C24) ~ C6 l olefins and maleic anhydride, was fully
11 esterified with 2~ethyl hexanol using the procedure of
12 Example 5.
13 The copolymers prepared în Examples 1-6 had the
14 following properties~
Product Example Yield % Mol.Wt.*Mn %C %H
16 1 6~ ~00 71.511.6
- 17 2 67 5~00 71o 710~ 9
l8 3 ~7-~ ~7~0 71.~10.6
19 ~ 3000 72.7 7.5
,~ 20 5
21 6 68 7000 74.511.6
22 *number average molecular weight determined by vapor
23 phase osmometry on Mechrolab Vapor Phase Osmometer
24 Model 310A.
The various copolymers described above were admix
i 26 ed at room temperature by stirring with a lubricating oil
27 and subjected to an ASTM test which demonstrates the copoly-
28 mers o~ the invention be highly e~fective pour point depres-
29 sants as is apparent from ~he following table.
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TABL;E
2 Pour De ressan~ Activit
3 Product of ~i~u~
4 Ex~mple~dditivetD-e D~e-~cd 0-1
1 0.2 -15
6 2 insolubla 0
7 3 0.2 o20
8 4 0.2 ~20
9 5 0,2 ~25
6 0.2 ~25
11 *ASTM Test D~97. The treated oil is a mineral lubricat-
:. 12 ing oil having a pour point of 0F. and a viscosity
13@210F. o about 44. 0SUSO
