MULTILAYER MATERIAL BASED ON FOAMED SECONDARY POLYETHYLENE TEREPHTHALATE AND METHOD OF ITS PRODUCTION Russian patent published in 2020 - IPC B32B7/02 B32B27/32 B32B27/36 B32B5/18 C08J11/04 C08J9/04 B65D65/40 

FIELD: packaging and storage.

SUBSTANCE: invention relates to a multilayer material intended for production of a packaging product for storage in ambient conditions and to a method for production thereof. Multilayer material is obtained based on foamed secondary polyethylene terephthalate and includes a printing layer, a layer of foamed secondary polyethylene terephthalate or a layer of foamed secondary polyethylene terephthalate, connected to a layer of non-foamed secondary polyethylene terephthalate, with density of 100 to 900 kg/m³, with characteristic viscosity of 0.5 to 1.0 dl/g, as well as a layer of polyethylene or copolymer of polyethylene, or copolymer of polyethylene terephthalate. Method of producing multilayer material consists in that wastes of polyethylene terephthalate are washed, cleaned, then crushed to fractions with size of 1 to 20 mm and separated by types of polymers and color, followed by melting polyethylene terephthalate and subsequent extrusion of molten polyethylene terephthalate. Polycondensation of polyethylene terephthalate in liquid phase is carried out under vacuum. Granular polyethylene terephthalate with characteristic viscosity of 0.5 to 1.0 dl/g is obtained. Further, granulated polyethylene terephthalate is extruded with simultaneous supply of nitrogen and/or carbon dioxide. Polyethylene terephthalate melt is then foamed, after which foamed secondary polyethylene terephthalate is cooled and calendered to thickness of 200 to 1,000 mcm. Layer of polyethylene or copolymer of polyethylene or copolymer of polyethylene terephthalate is applied on layer of foamed secondary polyethylene terephthalate or on layer of foamed secondary polyethylene terephthalate with extrusion layer of non-foamed secondary polyethylene terephthalate. Obtained material is thermostatted and a printed layer is applied on the outer surface.

EFFECT: technical result consists in creation of simple multi-layer material in production and suitable for use on the basis of foamed secondary polyethylene terephthalate obtained from polyethylene terephthalate wastes.

13 cl, 11 dwg