Solid anti-friction devices – materials therefor – lubricant or se – Lubricants or separants for moving solid surfaces and... – Heavy metal or aluminum in an organic phosphorus compound...
Reexamination Certificate
2001-10-19
2003-05-13
McAvoy, Ellen M. (Department: 1764)
Solid anti-friction devices, materials therefor, lubricant or se
Lubricants or separants for moving solid surfaces and...
Heavy metal or aluminum in an organic phosphorus compound...
C508S390000, C508S409000, C508S481000, C508S496000, C072S042000
Reexamination Certificate
active
06562766
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a metal working oil composition. Precisely, it relates to a metal working oil composition especially favorable for cutting metals.
2. Description of the Related Art
Metal working oil for cutting or grinding metals generally contains a chlorine compound as an additive. Recently, however, some problems have been pointed out with chlorine compound-containing, non-aqueous cutting oil. Specifically, when the oil is incinerated after use, it gives off dioxin and chlorine gas. The former pollutes the environment, and the latter corrodes and damages incinerators. In addition, some chlorine compounds such as chloroparaffins can be toxic and carcinogenic. In such an environment, metal working oil compositions not containing a chlorine compound are desired. Up to the present, however, no one has been able to obtain non-chlorine metal working oil compositions of which their working capabilities in low-speed cutting or heavy cutting operations are comparable to or better than those of chlorine compound-containing, metal working oil compositions.
For example, Japanese Patent Laid-Open Nos. 313182/1994 and 330076/1994 disclose cutting oil compositions that contain an alkali metal and/or alkaline earth metal sulfonate. The cutting oil compositions actually disclosed in these patent publications can be applied to lathing and boring operations, but they still involve some problems. Concretely, in low-speed cutting or heavy cutting operations for broaching or gun-drilling for which the cutting speed shall be 40 m/min or lower, their related working conditions with them must be extremely degraded. For example, a large amount of the oil composition must be used, or the pitch of cut in an operation must be reduced. If it is not, the cutting force will be high, and the cutting tools used will be broken. To that effect, it cannot be said that the working capabilities of the cutting oil compositions disclosed in these patent publications are comparable to or better than those of chlorine compound-containing, metal working oil compositions.
SUMMARY OF THE INVENTION
From the viewpoint noted above, we, the inventors, have made the present invention. The object of the invention is to provide a metal working oil composition which does not contain a chlorine compound and of which their working capabilities in low-speed cutting or heavy cutting operations, for example, in broaching or gun-drilling operations, are comparable to or better than those of chlorine compound-containing, metal working oil compositions.
We, the present inventors, have assiduously studied and, as a result, have found that, when a lubricating oil composition that contains a &pgr; electron-containing synthetic oil as the essential ingredient of the base oil is used in cutting metals, it shows improved working capabilities in cutting operations and the necessary cutting force can be reduced. On the basis of this finding, we have completed the present invention.
Specifically, the subject matter of the invention includes the following:
(1) A metal working oil composition comprising 100 parts by weight of a lubricant base oil that is comprised of from 0 to 30% by weight of (a) a mineral base oil, and from 70% to 100% by weight of (b) a &pgr; electron-containing synthetic base oil, from 0.1 to 25 parts by weight of (c) a sulfur-containing extreme-pressure agent, and from 0.1 to 7 parts by weight of (d) an alkali metal and/or alkaline earth metal sulfonate.
(2) The metal working oil composition as in the above (1), which further contains from 0.1 to 7 parts by weight of (e) a zinc dithiophosphate.
(3) The metal working oil composition as in the above (1) or (2), wherein the component (b) is a compound having carbon-carbon and/or carbon-oxygen multiple bonds.
(4) The metal working oil composition as in any of the above (1) to (3), wherein the &pgr; electron content of the component (b) falls between 0.001% and 50%.
(5) The metal working oil composition as in any of the above (1) to (4), wherein the component (b) is at least one compound selected from esters, olefins, aromatic compounds and acetylenes.
DETAILED DESCRIPTION OF THE INVENTION
The invention is described in detail hereinunder.
In the metal working oil composition of the invention, the lubricant base oil is comprised of from 0 to 30% by weight of (a) a mineral base oil and from 70% to 100% by weight of (b) a &pgr; electron-containing synthetic base oil.
The mineral base oil of the component (a) may be any ordinary one generally used in metal working oil, and is not specifically defined. Preferably, however, it has a kinematic viscosity at 40° C. of from 1 to 100 mm
2
/sec, more preferably from 3 to 50 mm
2
/sec. Base oil having too high kinematic viscosity is not preferred as being uneconomical, since the amount of it that may adhere to the objects being worked and may be therefore carried off by the worked objects will increase. Contrary to this, base oil having too low kinematic viscosity is also not preferred, since such gives off mist when used in cutting operations, and will therefore worsen the working environment. The pour point of the base oil is not specifically defined, but is preferably not higher than −10° C. Mineral base oils of that type include, for example, distillate oils as obtained through normal pressure distillation of paraffin base crude oils, intermediate base crude oils or naphthene base crude oils as obtained through reduced pressure distillation of the oily residues from such normal pressure distillation, as well as purified oils as obtained through purification of those distillate oils, such as solvent-purified oils, hydrogenation-purified oils, dewaxed oils, clay-processed oils, etc.
As the &pgr; electron-containing synthetic base oil of the component (b), usable are compounds having at least one &pgr; bond in the molecule. Of the compounds, preferred are those having carbon-carbon and/or carbon-oxygen multiple bonds. More preferred are those of which the &pgr; electron content represented by the following formula falls between 0.001% and 50%, even more preferably between 1% and 20%.
&pgr; electron content (%)=[number of double bonds+number of triple bonds×2]×100/[number of single bonds+number of double bonds×2+number of triple bonds×3]
Compounds of which the &pgr; electron content is too small are not preferred, since the metal working oil composition comprising such compounds cannot satisfactorily adhere to the newly appearing cross sections of the metal object being cut (that is, the new surfaces of the pieces of the metal object having been cut), and therefore cannot fulfill the effect of the invention. In other words, the working capabilities of the composition in low-speed cutting or heavy cutting operations cannot become comparable to or better than those of chlorine-containing, metal working oil compositions. Contrary to this, compounds of which the &pgr; electron content is too large are also not preferred, since the base oil comprising such compound loses its chemical stability, and will therefore be unsuitable for metal working oil compositions.
In the above formula, single bonds, double bonds and triple bonds are not limited to carbon-carbon bonds and carbon-oxygen bonds, but shall encompass all bonds in the compound, including carbon-hydrogen bonds and others.
The kinematic viscosity and the pour point of the component (b) are not specifically defined, but preferably fall within the ranges defined for the component (a) as above.
Concretely, the component (b) includes esters such as acetates, propionates, butyrates, valerates, caproates, caprates, caprylates, laurates, oleates, myristates, palmitates, behenates, natural oils and fats, oxalates, malonates, succinates, adipates, maleates, fumarates, acetylene-dicarboxylates, benzoates, toluates, phthalates, trimellitates, pyromellitates, etc.; olefins such as 1-octene, 1-decene, 2-decene, 3-decene, 4-decene, 1-dodecene, 1-tetradecene, 1-he
Koyama Saburo
Matsuoka Hiroshige
Okuda Ryouichi
Idemitsu Kosan Co. Ltd.
McAvoy Ellen M.
Oblon & Spivak, McClelland, Maier & Neustadt P.C.
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