Method for the production of highly transparent polyester film
US5475046A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 23, 1994 |
| Grant date | Dec 12, 1995 |
| Priority date | — |
| Expiry date | Nov 23, 2014 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08J2367/02
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A method for the production of polyester film is disclosed including the steps of: esterifying at least one species of carboxylic acid with at least one species of glycol; adding to the ester composition macro particles of silica of an average diameter of approximately 1.3 to approximately 2.0 .mu.m and fine particles of aluminum oxide of an average diameter of approximately 20 to approximately 200 nm; polycondensing the resulting mixture, to give a filled polyester resin; melting the filled polyester resin; molding the melt into a sheet; and biaxially stretching the sheet to produce a film product which is superior in haze and in static friction coefficient (U.sub.x)/kinetic friction coefficient (U.sub.k) ratio The polyester film of the present invention does not appear milky. In addition, after slitting the polyester film and tightly winding it around a roll it does not have a substantial number of protrusions.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.