Light color, color stable rosin esters and methods for preparing same
US5830992A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 12, 1996 |
| Grant date | Nov 3, 1998 |
| Priority date | — |
| Expiry date | Dec 12, 2016 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09F1/04
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
Rosin esters that are both light colored and color stable are produced by reacting polyhydric alcohol with an equivalent excess of rosin, in the presence of calcium bis(monoethyl(3,5-di-tert-butyl-4-hydroxybenzyl)phosphonate. When phosphinic acid is added to the reaction mixture, light colored and color stable rosin esters are produced regardless of whether the rosin or polyol are in equivalent excess, although preferably the rosin is in equivalent excess. It is preferred to include a phenol sulfide compound, such as Vultac.RTM. 2, with the calcium bis(monoethyl(3,5-di-tert-butyl-4-hydroxybenzyl)phosphonate, and to add the phosphinic acid incrementally after the acid number of the rosin and polyhydric alcohol reaction mixture has dropped to about 100. Excess rosin is preferably stripped from the product mixture at about 275.degree. C.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.