Stretched polyester film from a polymer blend
US4070417A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 18, 1975 |
| Grant date | Jan 24, 1978 |
| Priority date | — |
| Expiry date | Dec 18, 1995 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB32B2367/00
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A transparent polyester film having excellent printability, flexing resistance and pinhole resistance and further excellent interlaminar strength, which is made from a polymer mixture or blend comprising (i) a polyester consisting essentially of a residue of dibasic acids wherein at least 80 % by mol is terephthalic acid and a residue of at least one glycol and (ii) a block copolyester consisting of a crystalline polyester (hard) segment having a high melting point and a soft polymer segment having a low melting point and a number average molecular weight of 400 to 8,000, said soft polymer segment having a low melting point being contained in an amount of 0.5 to 10 % by weight on the basis of the whole weight of the polymer mixture or blend, and said crystalline polyester segment having a melting point of at least 170.degree. C when a polymer is produced by the monomers composing the segment alone and said soft polymer segment having a melting or softening point of 100.degree. C or lower.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.