Solid anti-friction devices – materials therefor – lubricant or se – Lubricants or separants for moving solid surfaces and... – Solid hydrocarbon polymer
Reexamination Certificate
2002-07-16
2004-12-28
McAvoy, Ellen M. (Department: 1764)
Solid anti-friction devices, materials therefor, lubricant or se
Lubricants or separants for moving solid surfaces and...
Solid hydrocarbon polymer
C585S012000, C526S072000
Reexamination Certificate
active
06835698
ABSTRACT:
TECHNICAL FIELD
The present invention relates to an ethylenic copolymer, a process for producing the same and a lubricating oil composition comprising the same. More particularly, it is concerned with an ethylenic copolymer which is useful as a lubricating oil base oil having a high viscosity index and a low pour point also as a viscosity index improver, a process for producing the ethylenic copolymer and a lubricating oil composition comprising the same.
BACKGROUND ART
Oils (lubricating oils) are used for preventing friction of each of part items in engines for automobiles and the like and in industrial gears. The lubricating oils are required to be usable at a wide range of temperature, in particular at a low temperature in cold districts. Such being the case, lubricating oils are required to have such performances as a high viscosity index and a low pour point. In order to meet the requirement, there are developed base oils as components of lubricating oils and viscosity index improvers.
In general, however, viscosity index and pour point are each a conflicting property, and therefore it has been difficult to reconcile a high viscosity index and a low pour point. As a countermeasure, there is proposed a synthetic oil such as poly &agr;-olefin and ethylene-&agr;-olefin copolymer. Nevertheless, their performances are still insufficient.
For instance, there is disclosed a liquid ethylene base random copolymer having specific properties in Japanese Patent Publication No.821/1994 (Heisei 6), which however has not been satisfactory regarding viscosity index or pour point.
DISCLOSURE OF THE INVENTION
In such circumstances, an object of the present invention is to solve the above-mentioned problems and thus provide an ethylenic copolymer which is useful as a base stock for lubricating oil having a high viscosity index and a low pour point also as a viscosity index improver, a process for producing the ethylenic copolymer and a lubricating oil composition comprising the same.
As a result of intensive investigation accumulated by the present inventors in order to achieve the aforesaid object, it has been found that it is made possible to solve the foregoing problems by using an ethylenic copolymer in which diad chain distribution of ethylene and &agr;-olefin as determined by the nuclear magnetic resonance spectrum method (
13
C-NMR method) satisfies a specific relationship, which has an ethylene content within a specific range, and in which the &agr;-olefin has the number of carbon atoms within a specific range. The present invention has been accomplished by the aforesaid findings and information.
That is to say, the present invention provides an ethylenic copolymer, a process for producing the same and a lubricating oil composition comprising the same, each being described hereunder.
{1} An ethylenic copolymer comprising ethylene and an &agr;-olefin in which diad chain distribution [EA] of ethylene [E] and &agr;-olefin [A] as determined by the nuclear magnetic resonance spectrum method (
13
C-NMR method) and ethylene content &agr; (mol %) as determined by nuclear magnetic resonance spectrum satisfy the following relational expressions (1) and (2):
0.7−2.8(0.5−&agr;/100)
2
−|0.25(0.5−&agr;/100)|≦[
EA
]≦2&agr;/100 (1)
(| | represents the absolute value)
10≦&agr;≦90 (2)
and in which the &agr;-olefin has 3 to 20 carbon atoms.
{2} The ethylenic copolymer as set forth in item {1}, wherein the ethylene content a satisfies the following relational expression (3):
10≦&agr;≦43 (3)
{3} The ethylenic copolymer as set forth in item {1}, which has a kinematic viscosity at 100° C. of 3 to 2000 (mm
2
/sec).
{4} The ethylenic copolymer as set forth in item {1}, which has a number average molecular weight (Mn) being 10000<Mn≦200000 and the ratio of weight average molecular weight (Mw) to number average molecular weight (Mn) [Mw/Mn] being 1<Mw/Mn≦5.
{5} A process for producing the ethylenic copolymer as set forth in any of the items {1} to {4} by copolymerizing ethylene and the &agr;-olefin in the presence of a catalyst for producing an ethylenic copolymer which comprises (A) at least one transition metal compound represented by the following general formula (I) or (II) and (B) at least one species selected from (a) organoaluminum oxy-compounds and (b) ionic compounds convertible into cations by reacting with the above-mentioned transition metal compound:
wherein R
1
to R
12
and X
1
to X
4
are each independently of one another a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a halogen-containing hydrocarbon group having 1 to 20 carbon atoms, a silicon-containing group, an oxygen-containing group, a sulfur-containing group, a nitrogen-containing group or a phosphorus-containing group; adjacent groups may be bonded to each other to form a ring; R
9
and R
10
may be the same as or different from each other; Y
1
to Y
4
are each independently of each other a bivalent group bonding two ligands, and denote a hydrocarbon group having 1 to 20 carbon atoms, a halogen-containing hydrocarbon group having 1 to 20 carbon atoms, a silicon-containing group, a germanium-containing group, a tin-containing group, —O—, —CO—, —S—, —SO
2
—, NR
13
—, PR
13
—, —P(O)R
13
—, —BR
13
—, or —AlR
13
—, wherein R
13
is hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a halogen-containing hydrocarbon group having 1 to 20 carbon atoms; and M
1
and M
2
are each a transition metal belonging to any of the group IVA, VA and VIA of the Periodic Table.
{6} A lubricating oil composition which comprises the ethylenic copolymer as set forth in any of the preceding items {1} to {4}.
{7} A lubricating oil composition wherein the ethylenic copolymer as set forth in any of the preceding items {1} to {4} is contained for use as a base oil.
{8} A lubricating oil composition wherein the ethylenic copolymer as set forth in any of the preceding items {1} to {4} is contained for use as a viscosity index improver.
REFERENCES:
patent: 5446221 (1995-08-01), Struglinski
patent: 6063880 (2000-05-01), Winter et al.
patent: 6261474 (2001-07-01), Egawa et al.
patent: 6339135 (2002-01-01), Kashiwamura et al.
patent: 6414090 (2002-07-01), Minami et al.
patent: 6583239 (2003-06-01), Minami et al.
patent: 6589920 (2003-07-01), Okada et al.
patent: 129414 (1984-12-01), None
patent: 422859 (1991-04-01), None
patent: 721954 (1996-07-01), None
patent: 818458 (1998-01-01), None
patent: 2000-72825 (2000-03-01), None
patent: 2000-351813 (2000-12-01), None
Egawa Tatsuya
Minami Yutaka
Idemitsu Petrochemical Co. Ltd.
Oblon & Spivak, McClelland, Maier & Neustadt P.C.
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