Multilayered biaxially-oriented styrene based resin sheet and method for production thereof
US6153308A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 17, 1999 |
| Grant date | Nov 28, 2000 |
| Priority date | — |
| Expiry date | Feb 17, 2019 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31909
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A multilayered biaxially-oriented styrene based resin sheet comprises; a styrene based resin layer (A) as at least two outer layers formed by the polymerization of methacrylic acid in a weight proportion of 1-3.5% and styrene, and a styrene based resin layer (B) formed from polystyrene which is sandwiched between the outer layers and for which the loss tangent (tan .delta.) maximum peak value temperature for dynamic viscoelasticity measurement is 6.5-25.degree. C. lower than that for the resin of the resin layer (A). The sheet has excellent properties of transparency and external appearance, can be reused by recovering and moreover does not suffer from raindrop occurrence by secondary forming.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.