Process for coextruding a tacky amorphous propylene copolymer composition with a low viscosity polyolefin and article prepared thereby
US7232535B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Sep 23, 1997 |
| Grant date | Jun 19, 2007 |
| Priority date | — |
| Expiry date | Sep 23, 2017 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31913
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
Disclosed is a process for producing non-blocking slats of normally tacky amorphous propylene copolymers. The process entails coextruding the normally tacky amorphous propylene copolymer with a low viscosity polyolefin such as a polyethylene wax forming a core of amorphous propylene copolymer covered with a sheath of polyethylene wax. The coextruded article is cooled, cut (while exposing less than 40 percent of the core) and then coated with a non-tacky powder; thereby, forming non-blocking slats. Disclosed is also a novel amorphous propylene copolymer composition containing no more than 90 weight percent propylene and up to 70 weight percent of an alpha olefin comonomer having a needle penetration greater than 70 to less than 100 dmm at 23° C. and a Brookfield Thermosel Viscosity below 1000 cP at 190° C.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.