Foamed particles of polypropylene homopolymer and molded article of the foamed particles
US5747549A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 5, 1996 |
| Grant date | May 5, 1998 |
| Priority date | — |
| Expiry date | Dec 5, 2016 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08J2323/12
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
The molded articles of foamed particles, which are produced by using foamed particles composed of a polypropylene-based polymer, have had excellent cushioning characteristics and impact resilience, but have been not always satisfactory in stiffness such as compressive strength. The invention is directed to foamed particles comprising a polypropylene homopolymer as a base resin and having a tensile modulus of 15,000-25,000 kg/cm.sup.2 and a crystal structure that an inherent peak and a high-temperature peak appear as endothermic peaks on a DSC curve obtained by differential scanning calorimetry of the foamed particles. A quantity of heat at the high-temperature peak is 30-60 J/g. A molded article of foamed particles according to the invention is obtained by using the foamed particles as described above and molding them, and has a density of 0.01-0.3 g/cm.sup.3 and a tensile modulus of 15,000-25,000 kg/cm.sup.2. It has a crystal structure that an inherent peak and a high-temperature peak appear on a DSC curve obtained by its differential scanning calorimetry like the case of the foamed particles. As with the foamed particles, a quantity of heat at the high-temperature peak is 30-60 J…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.