INTERLAYER FILM WITH DARKENED STRIP Russian patent published in 2022 - IPC B32B17/00 

FIELD: manufacturing technology.

SUBSTANCE: group of inventions relates to an interlayer film with a transparent and an opaque region and to a method for production thereof. Interlayer film with a transparent and an opaque area, where the opaque area is provided with two outer layers, containing a first mixture of at least one plasticiser and at least one polyvinyl acetal, and one inner layer containing a second mixture of at least one plasticiser and at least one polyvinyl acetal. Transparent area is provided with one layer containing a third mixture of at least one plasticiser and at least one polyvinyl acetal. First and third mixtures have light transmission with wavelength from 380 nm to 780 nm of at least 85 % and the second mixture has light transmission with wavelength from 380 nm to 780 nm of less than 80 %. Opaque area is provided with a surface roughness with a ratio of Rz/Rv from 1.6 to 2.5, measured in accordance with EN ISO 4287 standard.

EFFECT: group of inventions is aimed at providing an interlayer film with a darkened strip by embossing without optical distortions on the inner boundaries of the area of the darkened strip.

11 cl, 3 ex, 3 dwg