Process for the preparation of phenol formaldehyde resole resins
US4656239A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 27, 1986 |
| Grant date | Apr 7, 1987 |
| Priority date | — |
| Expiry date | Mar 27, 2006 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08G8/08
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
The process described herein involves the gradual addition of aqueous formaldehyde, containing 35-60 percent by weight of formaldehyde, to a phenol maintained at a temperature of 60.degree.-100.degree. C., preferably 70.degree.-90.degree. C., and at a reduced pressure of 11-26 inches of mercury in the presence of an alkaline catalyst. The rate of formaldehyde addition is such that the exothermic reaction aids in maintaining the stated temperature range and thereby simultaneously distills approximately all the water added with the formaldehyde and that formed by the condensation so that the volume of the reaction mass is maintained approximately constant. This constant volume allows efficient use of the equipment.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.