Packaging shrink film
US4670529A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 10, 1984 |
| Grant date | Jun 2, 1987 |
| Priority date | — |
| Expiry date | Dec 10, 2004 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31913
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A packaging shrink film consisting essentially of a random copolymer of propylene and an .alpha.-olefin having 4 or more carbon atoms or a random copolymer of propylene, an .alpha.-olefin having 4 or more carbon atoms and ethylene, said random copolymer satisfying the following conditions: PA1 (1) the content of an .alpha.-olefin having 4 or more carbon atoms in the copolymer is 8 to 30 mole %, PA1 (2) the content of ethylene in the copolymer is 3 mole % or less, PA1 (3) the content of a cold xylene-soluble portion in the copolymer is 15 to 60% by weight, and PA1 (4) the content of a boiling n-heptane-insoluble portion in the copolymer is 7% by weight or more, said film having been stretched. The packaging shrink film is soft and excels in low-temperature shrink characteristics as well as in transparency and gloss.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.