Biaxially oriented aromatic polyester film
US4761327A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 14, 1987 |
| Grant date | Aug 2, 1988 |
| Priority date | — |
| Expiry date | Jan 14, 2007 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31786
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A biaxially oriented film formed from a intimate mixture comprising (I) an aromatic polyester, (II) 0.005 to 1.0% by weight, based on the aromatic polyester, of fine particles of a silicone resin having (a) a composition represented by the following formula (A) EQU R.sub.x SiO.sub.2-x/2 (A) wherein R represents a hydrocarbon group having 1 to 7 carbon atoms, and x is a number of from 1 to 1.2, (b) a volume shape factor (f), represented by the following formula (B), of more than 0.4 but not exceeding .pi./6 EQU f=V/D.sup.3 (B) wherein V is the average volume (.mu.m.sup.3) of the particles and D is the average maximum particle diameter (.mu.m) of the particle, and (c) an average particle diameter of 0.3 to 4 .mu.m. The film optionally contains (III) 0.005 to 1% by weight, based on the aromatic polyester, of inert fine particles having an average particle diameter of 0.01 to 1 .mu.m but being smaller than the average particle diameter of the silicone resin particles. The film is useful for a base film on a magnetic recording medium.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.