Styrene tetrablock copolymers and polymer blend compositions based upon such copolymers
US8173740B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 24, 2007 |
| Grant date | May 8, 2012 |
| Priority date | — |
| Expiry date | Aug 23, 2028 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08L2666/02
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A composition of matter that may be used to make transparent, substantially gel-free polymeric films includes at least a styrenic block copolymer and a thermoplastic resin other than the styrenic block copolymer. The styrenic block copolymer (e.g. S-I-B-S) has four distinct and sequential blocks: a first styrenic block (S), a first diene block (e.g. isoprene or I), a second diene block that differs from the first diene block (e.g. butadiene or B) and a second styrenic block (S). The styrenic block copolymer desirably lacks any random diene block (e.g. a random isoprene/butadiene block). The styrenic block copolymer also desirably lacks any significant percentage of a triblock copolymer (S-I-B). The composition of matter may also include an extender material such as white mineral oil. The compositions may be used to make mono-layer or multi-layer cast or blown films.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.