Nucleation and orientation of linear polymers
US4000229A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 10, 1975 |
| Grant date | Dec 28, 1976 |
| Priority date | — |
| Expiry date | Apr 10, 1995 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29K2105/12
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
Additions of small amounts of fine particle size specialized monoclinic inorganic crystals to otherwise relatively pure polyalkylene terephthalate molding compounds increases the rate and extent of crystallization and the specific gravity of the polyalkylene terephthalate molded part. Both low and high molecular weight polyalkylene terephthalates are improved with regard to physical properties and dimensional stability through addition of these small quantities of these specialized monoclinic materials. Under controlled conditions of injection and forming, anisotropic properties may be obtained as a consequence of the effect and extent of the crystallization of the polyalkylene terephthalates which has been promoted by these strongly active nucleating agents. In addition to the improvement of the physical properties of the molded article, the use of these specialized nucleating agents in suitable particle size yields a significant shortening of the retention time of the injection molded material in the mold, this being an item of economic significance. An important aspect of the invention is the added capability of polyalkylene terephthalate crystal orientation by controlled applic…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.