Water-barrier laminate
A water-barrier laminate having a water-trapping layer ( 1 ) in which a hygroscopic agent is dispersed, wherein a hygroscopic agent has such a hygroscopic property that the ratio (Ax/Ay) of a hygroscopic amount Ax at a relative humidity of 80% and a hygroscopic amount Ay at a relative humidity of 30% is not less than 3, and the water-trapping layer is positioned between the two inorganic barrier layers ( 3 a ) and ( 3 b ). The water-barrier laminate exhibits barrier property against the water over extended periods of time.
1. A water-barrier laminate having a water-trapping layer in which a hygroscopic agent is dispersed, wherein a hygroscopic agent has such a hygroscopic property that the ratio (Ax/Ay) of a hygroscopic amount Ax at a relative humidity of 80% and a hygroscopic amount Ay at a relative humidity of 30% is not less than 3, the water-trapping layer is positioned between two inorganic barrier layers,
the water-trapping layer has a dispersion structure in which the hygroscopic agent is dispersed in a matrix of a cationic polymer,
the matrix of the cationic polymer has a water absorption of 20% or more in an atmosphere of a humidity of 80% RH and 30° C., and has a crosslinked structure provided by a crosslinking agent,
the crosslinking agent is a silane compound represented by a formula (1):
X—SiR 1 n (OR 2 ) 3-n (1)
wherein X is an organic group having an epoxy group at the terminal, R 1 and R 2 are, respectively, methyl groups, ethyl groups or isopropyl groups, and n is 0, 1 or 2, and
the hygroscopic agent is a crosslinked product of a monovalent metal salt of a poly(meth)acrylic acid and has an average primary grain size D 50 not larger than 100 nm.
2. The water-barrier laminate according to claim 1 , wherein an organic layer is provided between the inorganic barrier layer on a side of absorbing water and the water-trapping layer.
3. The water-barrier laminate according to claim 2 , wherein the two inorganic barrier layers comprise a first inorganic barrier layer formed on a plastic base material and a second inorganic barrier layer formed, via an organic layer, on the water-trapping layer positioned on the first inorganic barrier layer.