TRANSPARENT FILMS Russian patent published in 2014 - IPC C08J5/18 C08L77/10 C08L77/00 B29C55/02 B29C71/02 

FIELD: chemistry.

SUBSTANCE: group of inventions relates to an optically transparent polymer product, such as a film or a three-dimensional extrudate, made from a polymer composition and a method for production and use thereof. The optically transparent polymer product, such as a film or a three-dimensional extrudate, is obtained from a polymer composition containing a semi-crystalline polyamide (A) wherein the semi-crystalline polyamide (A) has a melting temperature (Tm-A) of at least 270°C and is present in an amount of at least 60 wt % if the semi-crystalline polyamide (A) consists of a semi-aromatic semi-crystalline polyamide or a mixture of a semi-aromatic semi-crystalline polyamide and an aliphatic semi-crystalline polyamide, or at least 75 wt % if the semi-crystalline polyamide (A) consists of an aliphatic semi-crystalline polyamide, where the wt % is relative to the total weight of the polymer composition. The polymer composition has a melting point (Tm-C) of at least 270°C, and the film or part of the extrudate is characterised by haze of less than 12% and light transmittance of at least 88%, measured with the method according to ASTM D1003A. The method of producing a transparent polymer film includes steps of heating and melt-extruding a polymer composition through a slit die to form an extruded polymer layer, passing the extruded polymer layer over a chilling roll having a temperature below 40°C, thereby forming a polymer film, and collecting the polymer film. According to the after-treatment method, the transparent polymer film is subjected to drawing wherein the film is stretched, and/or heat setting and/or annealing, wherein transparent polymer film, having a glass transition point (Tg) and a melting point (Tm), is heated to or kept for a certain period at a temperature between the Tg and Tm. The method of producing the extrudate includes steps of: melt-extruding a polymer composition through a die, passing the extruded polymer composition through a quenching liquid having a temperature below 40°C, thereby forming a solid product, and collecting the solid product. According to another version of the group of inventions, a steam-sterilisable medical article comprising an extrudate is disclosed. According to yet another version, the transparent polymer product is used in packaging materials or in electrical engineering or electronics.

EFFECT: improved mechanical properties of the transparent polymer film and extrudate product, maintaining the required mechanical properties at high temperatures, stability of geometric dimensions with limited thermal expansion and/or high deformation temperatures, and improved barrier properties.

15 cl, 5 ex