Color temperature indicator for lubricating grease
US5360561A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 24, 1993 |
| Grant date | Nov 1, 1994 |
| Priority date | — |
| Expiry date | May 24, 2013 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC10N2040/50
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
Lubricating compositions containing a color temperature indicator are disclosed. The compositions irreversibly change their color when exposed to temperatures exceeding a predetermined limit temperature. The compositions include, as an essential component, from 0.2% to 4% weight of metal dithiocarbamates or dialkyldithiocarbamates, preferably of antimony and/or lead in combination with a dye, preferably a blue dye, in an amount of from 50 ppm to 2000 ppm. Other components, such as epoxy resins, may be also present, to increase and/or extend the range of temperatures in which the changes of color are observed. The compositions are useful as indicators of overheating of lubricated elements under severe operating conditions.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.