Film formed from a blend of biodegradable aliphatic-aromatic copolyesters
US8227658B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 14, 2007 |
| Grant date | Jul 24, 2012 |
| Priority date | — |
| Expiry date | Jan 3, 2030 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T442/678
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A film that is formed from a biodegradable polymer blend of different aliphatic-aromatic copolyesters is provided. More specifically, the blend contains a first copolyester formed from a terephthalic acid monomer. The use of a terephthalic acid monomer results in a polymer chain containing 1,4-(para-) terephthalate units linked in a generally linear configuration (e.g., ˜180°). The blend also contains a second aliphatic-aromatic copolyester formed from a phthalic acid and/or isophthalic acid monomer. The use of such a monomer results in a polymer chain containing 1,2-(ortho-) and/or 1,3-(meta-) linked units. The inclusion of 1,2-(ortho-) and/or 1,3-(meta-) linked units into the polymer backbone of the second copolyester introduces an angle or “kink” (e.g., ˜120° kink for a 1,3-linkage) into the otherwise linear polymer chain. The “kinks” in the second copolyester backbone reduce its melting point and degree of crystallinity, which have an influence on its physical properties (e.g., toughness, tensile strength, and crystallization rate). Thus, the physical properties of the second copolyester may differ substantially from those of the first copolyester. In this regard, the “kinked” …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.