Process for the preparation of intermediates of polyaddition and polycondensation resins
US3936522A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 20, 1973 |
| Grant date | Feb 3, 1976 |
| Priority date | — |
| Expiry date | Aug 20, 1993 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29B7/26
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A process for preparing fusible, crosslinkable resinous intermediates of polyaddition and polycondensation resins consisting essentially of continuously proportioning and feeding a resin precursor composition in solid and liquid form, in a mixing and kneading machine, intensively mixing the resin precursor composition in both the longitudinal and transversal directions and simultaneously heating said composition, thereby plasticizing and homogenizing the same below the temperature of cross-linking and hardening and at a temperature of 50.degree.-90.degree. C during a brief average dwell time in the mixing chamber of said machine which will prevent excessive stiffening of the mixture in the form of a pasty mass to thereby plug the machine, continuously expelling the plasticized intermediate resin mix at a temperature of 50.degree. to 90.degree. C in the form of a pasty mass through a hollow die with twin conical outlet heated to a temperature of not more than 50.degree. C. The intermediate resin mix which is expelled is cooled, solidified, preformed by a pair of rollers into a strand which is friable and is adapted to be broken by up grinding to form a powdered intermediate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.