FIELD: chemical industry; methods of production of the multilayered microporous films.
SUBSTANCE: the invention is pertaining to the multilayered microporous films and, in particular, to the microporous films including at least two microporous film layers and to the method of production of the multilayered microporous films. The film layers may be produced with the controlled size of the pores to meet the needs the customer or for optimization of the different properties of the multilayered films. The technical result of the invention consists in creation of the improved microporous films and specially in development of such microporous films, in which may be achieved the combination of the desirable properties, and also in the method of production of such films. The indicated problem is being solved due to the fact, that the multilayered microporous film includes the first and the second coextruded film layers, where each film layer gains the microporosity at its drawing. At that the first film layer is made out of from the first polymeric composition containing the ethylene polymeric compound and the first pore-forming filler and has the first maximum size of the pores; and the second film layer is made out o the second polymeric composition containing the polypropylene compound and the second pore-forming filler and has the second maximum size of the pores differing from the first maximum size of the pores. At that the second layer containing polypropylene has no the free surface in the multilayered film and so the multilayered microporous film is impermeable for the liquids at the atmospheric pressure. The problem also is being solved due to usage of the different versions of the multilayered microporous films and the method of production of such films.
EFFECT: the invention consists in creation of the improved microporous films, specially in development of such microporous films with combination of the desirable properties and in the method of production of such films.
35 cl, 1 tbl, 4 ex, 19 dwg
