Standard Barrier Film

Abstract

The invention provides a water vapor transmission rate of 10 ‑6 ~10 ‑ 3 g / m 2 / day's standard gas barrier film. The standard gas barrier film (10) is used for calibration of the water vapor transmission rate measuring device. The standard gas barrier film (10) has: a base material (12) with an opening (12a); and a barrier layer (14) provided on the base material (12) so as to cover the opening (12a). The barrier layer (14) contains nanoparticles of Li-type montmorillonite and polyimide. The ratio of the maximum diameter of the opening (12a) to the thickness of the barrier layer (14) is 50-2000. The standard gas barrier film (10) has a water vapor transmission rate of 10 at 40°C and a relative humidity of 90%. ‑6 ~10 ‑3 g / m 2 / day. The substrate (12) is a metal plate having an arithmetic average roughness Ra of 2 nm or less on the surface opposite to the surface on which the barrier layer (14) is provided.

Description

technical field [0001] The invention relates to a standard gas barrier film used for calibration and evaluation of a gas permeability measuring device. Background technique [0002] Gas barrier films are used for packaging and encapsulation of food, electronic parts, etc. based on their water vapor and oxygen permeability. Therefore, it is important to accurately measure the water vapor and oxygen permeability of the gas barrier film. The determination of the water vapor transmission rate of the gas barrier film can be classified into equal pressure method and differential pressure method. The equal pressure method includes: cup method, electrode method, calcium method, membrane Kang (MOCON) method, gas chromatography, API- The MS method and the like, and the differential pressure method include a pressure method, a volumetric method, and gas permeability measurement described in Patent Document 1, and the like. Most gas permeability measuring devices require a standard ga...

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Problems solved by technology

[0005] However, in the former method, when the hole diameter is reduced, the processing accuracy of the drilling process and the measurement accuracy of the shape measurement of the hole deteriorate, so the variation in the water vapor transmission rate of the standard gas barrier film becomes large.

In addition, the ratio of the film thickness to the pore diameter of the plastic film becomes large, so there is a problem that the concentration distribution of water vapor is generated in the surface of the plastic film, and the opening area of ​​the opening of the hole is not proportional to the water vapor permeation amount.

In addition, this is because the inorganic gas barrier layer is destroyed due to the swelling of the organic film, so the reproducibility of the measurement cannot be obtained.

[0007] In addition, when a plastic film coated with a multilayer inorganic gas barrier layer is used as a standard gas barrier film, there are also problems in that the trajectory of water vapor passing through the multilayer film is complicated, and it is difficult to determine the saturation point of the water vapor transmission rate. point in time

In addition, in the case of high barrier measurement, it is desirable to degas the standard gas barrier film by heating to reduce the outgas from the standard gas barrier film itself, but the standard gas barrier film produced in this way cannot withstand temperatures above 100°C. bake

In addition, when an adhesive is used to bond the inorganic gas barrier layer to a plastic film, the water vapor transmission rate in the adhesive becomes a problem.

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