Multilayer polyolefinic film structures having improved heat seal characteristics
US5089321A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 10, 1991 |
| Grant date | Feb 18, 1992 |
| Priority date | — |
| Expiry date | Jan 10, 2011 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/3192
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
Multilayer thermoplastic film structures comprising at least one heat-sealable outer layer (A) and at least one core layer (B) are disclosed. Layer (A) has improved heat sealability after irradiation (e.g. electron beam). Layer (B) has improved shrinkage after irradiation. Layer (A) is a linear polyethylene having a melt index from about 2 to about 20 g/10 minutes, a density from about 0.88 to about 0.92 g/cc, a molecular weight distribution (I.sub.10 /I.sub.2) from about 5 to about 8, a fraction of the polyethylene having a degree of branching less than or equal to 2 methyls/1000 carbons of not more than 15% by weight and a fraction of the polyethylene having a degree of branching greater than or equal to 25 methyls/1000 carbons of not more than 25% by weight of the polymer. Layer (B) is a linear polyethylene having a melt index from about 0.05 to about 5 g/10 minutes, a density from about 0.88 to about 0.94 g/cc and a molecular weight distribution (I.sub.10 /I.sub.2) from about 8 to about 30.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.