ELASTIC FILM CONTAINING RENEWABLE STARCH POLYMER Russian patent published in 2016 - IPC C08J5/18 C08L3/02 C08L23/00 C08L75/04 B01J20/22 A61F13/475 

FIELD: chemical industry.

SUBSTANCE: invention relates to a film which is used in a variety of disposable products such as diapers, sanitary napkins, garments for incontinent adults, dressings, etc. Elastic film comprising a thermoplastic composition wherein thermoplastic composition comprises at least one polymer, starch, comprising from about 1 wt.% to about 30 wt.% of polymer content in film, at least one elastomeric polymer comprising from about 30 wt.% to about 95 wt.% of polymer content in film and at least one plasticizer comprising from about 0.1 wt.% to about 30 wt.% of weight of film, wherein weight ratio of elastomeric polymer to amount of starch in polymer film is from about 1 to about 10, and elongation of elastic film in machine direction and transverse direction is about 250 % or more, wherein elastomeric polymer comprises an olefinic elastomer having a density of about 0.85 g/cm³ to about 0.89 g/cm³, selected from prepared using a metallocene catalyst ethylene α-olefin prepared using a metallocene catalyst propylene and αolefin or combinations thereof, or wherein elastomeric polymer comprises a thermoplastic polyurethane derived from a polyol and an organic diisocyanate and having a melting point of about 75 °C to about 250 °C. A film, which comprises a thermoplastic composition comprising a significant part of renewable natural polymer of starch, while maintaining elasticity and has good strength characteristics.

EFFECT: despite that due to differences in polarities of starch and most elastomeric polymers starch is normally chemically incompatible with most of elastomeric polymers according to present invention it has been found that phase separation may be minimised by selectively adjusting certain properties of said film such as nature of elastomeric polymer, starch polymer and other components of said film, relative amounts of components of said film and parameters of method of producing said film.

20 cl, 2 dwg, 3 tbl