ACTIVE POLYSTYRENE FILM Russian patent published in 2023 - IPC C08J5/18 C08L25/06 C08K5/00 B32B27/06 B32B27/30 B65D85/72 

FIELD: active polymer materials.

SUBSTANCE: invention relates to an active polystyrene film that has antimicrobial or antioxidant activity, and to a method for producing said film. It also refers to wrappers, packages and slice separators (interlayer films) that contain said film. Polystyrene film intended for contact with food products includes at least one layer containing: 60-75% w/w_full of crystalline polystyrene (PS), 10-35% w/w_full of ethylene copolymer with polar monomers (EMP) with a comonomer content of 15-40% w/wof EMP, wherein the EMP is selected from the group consisting of ethylene vinyl acrylate copolymer (EVA), ethylene methyl acrylate copolymer (EMA), ethylene ethyl acrylate copolymer (EEA), ethylene butyl acrylate copolymer (EBA) and mixtures thereof, the active substance selected from the group consisting of an antioxidant agent and an antimicrobial agent, wherein the antioxidant agent is selected from the group consisting of tocopherol, green tea extract, olive leaf extract, rosemary extract, grape seed extract, coffee extract, dried Barbados cherry, citrus extract with a flavonoid concentration of more than 45%, tomato extract with a concentration of lycopene more than 5%, fruit extract, thymol and mixtures thereof, and the antimicrobial agent is an antibacterial agent selected from the group consisting of ethyl-N^α-dodecanoyl-L-arginate (LAE) and LAE salts, LAE hydrochloride and glycolipid surfactants of biological origin and mixtures thereof, and/or an antifungal agent selected from the group consisting of C₈–C₁₀ mono-, di-, triglycerides, glycolipid surfactants of biological origin, LAE and LAE salts, LAE hydrochloride and mixtures thereof, 0.5-2% w/w_full of migration agent (MA), which is selected from a group consisting of fatty acid amides, fatty acid esters and mixtures thereof, 0-15% w/w_full of emulsifying agent (EA) having an HLB value of more than 8 and present in an amount of 3-15% w/w_full where the active substance is an antimicrobial agent, wherein the EA is selected from the group of polyethylene glycol 400 dioleinate, sorbitan monolaurate, polyoxyethylene (20), polyoxyethylene sorbitan monopalmitate (20), polyoxyethylene sorbitan monostearate (20), polyoxyethylene sorbitan tristearate (20), polyoxyethylene sorbitan monooleate (20), sorbitan monooleate polyoxyethylene, ethylene polyoxide stearate (40), sorbitan monolaurate and mixtures thereof, wherein the ratio PS/(EMP + EA) is in the range between 1.2 and 7.5, the percentages being based on the relative total mass of the layer (w/w_full). A method for producing the film is also described.

EFFECT: providing a film in which it is possible to maintain the functionality of the active substance contained therein, even though said substance is usually thermolabile, and which is characterized by good processibility; a mixture of polymers allows one to obtain a homogeneous melt capable of flowing through an extruder without phase separation and transformable by molding methods used for thermoplastics, in addition, the composition of the active layer allows the active substance to be uniformly distributed in the polymer matrix of the layer and released into the environment (for example, the food with which it comes into contact) where it exhibits its activity (for example, antioxidant or antimicrobial).

16 cl, 9 dwg, 16 tbl, 7 ex