Molding of polypropylene with enhanced reheat characteristics
US7303795B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 13, 2003 |
| Grant date | Dec 4, 2007 |
| Priority date | — |
| Expiry date | Feb 8, 2025 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/1352
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
Bottles, containers and other articles are formed from polypropylene compositions that include a reheating agent, such as antimony, carbon black, graphite, titanium, copper, manganese, iron, tungsten, graphite, infra-red absorbing dyes or other infra-red absorbing material. The reheating time for the polypropylene composition is shortened for injection stretch blow molding or thermoforming, and the polypropylene granule composition with reheating agent has an L* value of at least 80% of the L* value for a polypropylene granule control without added reheating agents as measured by the Gardner color test. The reheating agent may be incorporated into the polypropylene composition by in situ chemical reduction of a metal compound, such as antimony triglycolate, with a reducing agent, such as hypophosphorous acid. In addition, the polypropylene composition with reheating agent may be derived from a polypropylene masterbatch with high concentrations of reheating agent.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.