Method of preparing modified polyester bottle resins
US6335422B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | May 8, 2001 |
| Grant date | Jan 1, 2002 |
| Priority date | — |
| Expiry date | May 8, 2021 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/1397
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
The present invention is a method of preparing a high molecular weight copolyester bottle resin that has excellent melt processing characteristics. The method includes the steps of reacting a diacid or diester component and a diol component to form modified polyethylene terephthalate, wherein diol component is present in excess of stoichiometric proportions. Together, the diacid or diester component and the diol component must include at least 7 percent comonomer. The remainder of the diacid component is terephthalic acid or dimethyl terephthalate and the remainder of the diol component is ethylene glycol. The modified polyethylene terephthalate is copolymerized in the melt phase to an intrinsic viscosity of between about 0.25 dl/g and 0.40 dl/g to thereby form a copolyester prepolymer. Thereafter the copolyester prepolymer is polymerized in the solid phase to form a high molecular weight bottle resin that has an intrinsic viscosity of at least about 0.70 dl/g, and a solid phase density of less than 1.413 g/cc.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.