278 Lubricant Additives: Chemistry and Applications
9.9 MEDIUM-TERM TRENDS
In general, there is a trend toward higher economy and ecologically and toxicologically safe
lubricants.
9.9.1 METALWORKING
Increased lubricant temperatures are a consequence of higher machine speeds, completely encap-
sulated machines, and reduced process steps. In the future, the thermal stability of metalworking
lubricants and their toxicological safety will be on the focus. Owing to integrated applications (e.g.,
one lubricant for process and machine lubrication), the additives need to cover wide temperature
ranges. The trend to replace multiple cutting steps with forming operations exists. Therefore, the
type of additives will also change.
Minimum amount lubrication requires new lubricant concepts in regard of performance and
marketing. Maintenance of lubricants will further be reduced. Again this trend calls for increased
stability of additives.
Sulfurized products for metalworking application will need improved thermal stability in com-
bination with good solubility in high paraffi nic or even synthetic base fl uids. Ecological and toxi-
cological safety will be the basic requirements. Improved lubricity and excellent compatibility with
process materials such as cleaners and paints will be essential for the formulation of modern lubri-
cants for deformation processes (e.g., cold forging and deep drawing).
9.9.2 INDUSTRIAL OILS
Synthetic fl uids such as PAOs, polyalkyleneglycols (PAGs), extra high VI mineral oils (XHVI),
or synthetic esters are being used in increasing volumes for the formulation of high-performance
industrial lubricants. Smaller lubricant sumps, reduced sizes of components, and increased perfor-
mance will place high demands on the lubricants. Especially in mobile equipment (e.g., excava-
tor and lawn mower), ecologically and toxicologically harmless lubricants will become a demand.
Reduced maintenance and longer lubricant change intervals require high lubricant stability.
Improved thermal stability, low copper corrosion, and excellent solubility in synthetic fl uids are
demands on sulfurized products for the new generation of industrial lubricants.
REFERENCES
- Sellei, H., Sulfurized extreme-pressure lubricants and cutting oils, Part 1, Petroleum Processing, 4,
1003 –1008, 1949. - Sellei, H., Sulfurized extreme-pressure lubricants and cutting oils, Part 2, Petroleum Processing, 4,
1116 –1120, 1949. - Base for metal-cutting compounds and process of preparing the same, George W. Pressell, Houghton &
Co. PA, US 1,367,428/GB 129132 (1921). - Byers, J.T., Patents show trend in extreme pressure lube technology, National Petroleum News, 28, 79,
1936. - van Voorhis, M.G., 200 lubricant additive patents issued in 1938 and 1939, National Petroleum News,
32, R-66, 1940. - Miller, F.L., W.C. Winning, and J.F. Kunc, Use of additives in automotive lubrication, Refi ner and Natl.
Gas Manuf. 20(2), 53, 1941. - Westlake, H.E., Jr., The sulfurization of unsaturated compounds, Chemical Reviews 39(2), 219, 1946.
- Musgrave, F.F., The development and lubrication of the automotive hypoid gear, Journal of the
Institution of Petroleum 32(265), 32, 1946. - Lubricating compound and process of making the same, Leonard A. Churchill, US 1,974,299 (1934).
- Method of sulphurizing pine oil and data thereof. M.C. Edwards, J. Heights, J.V. Congdon US 2,012,446
(1935).