Preparation of porous polyester beads
US5225448A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 19, 1992 |
| Grant date | Jul 6, 1993 |
| Priority date | — |
| Expiry date | Nov 19, 2012 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08J2367/02
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
High molecular weight polyethyleneterephthalate resin is currently being used in vast quantities in manufacturing tire cord and in manufacturing trays for frozen foods which can be heated in either microwave or convection ovens. In some applications polyester resins having ultra-high molecular weights are required. For example, some techniques for producing polyester yarn by solution spinning demand ultra-high molecular weight polyester. Unfortunately, it becomes progressively more difficult and expensive to produce polyester resins having higher and higher molecular weights utilizing standard commercial polymerization techniques. This invention discloses a technique for preparing porous polyester beads which can be solid state polymerized very rapidly to ultra-high molecular weights. This invention more specifically discloses a process for preparing ultra-high molecular weight polyester resin which comprises: (1) dissolving a polyester prepolymer in a suitable organic solvent to produce a polyester prepolymer solution; (2) allowing droplets of the polyester prepolymer solution to drip into a coagulation bath to produce porous polyester beads; (3) recovering the porous polyester be…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.