Kuraray Co., Ltd.

Shigeyuki Harita

Satoshi Hirofuji

Takanori Isozaki

Susumu Fukutome

Naoki Fujiwara

A polyvinyl alcohol polymer film includes a polyvinyl alcohol polymer and a plasticizer selected from the group consisting of ethylene glycol, glycerin, propylene glycol, diethylene glycol, diglycerin, triethylene glycol, tetraethylene glycol, and trimethylolpropane. The amount of the polyvinyl alcohol polymer eluted when a 10 cm square of the polyvinyl alcohol polymer film is left in 1 liter of water of 50&#xb0; C. for 4 hours is from 1 to 100 ppm. The film has only a small number of defects and is useful as raw material for producing a polarization film.

Polyvinyl alcohol polymer film and polarization film

Difference in retardation between two points separated by 1 cm along the TD direction of a polyvinyl alcohol polymer film is 5 nm or less. The length of a surface for drying a polyvinyl alcohol polymer film is 3 m to 200 m, and the water content of the polyvinyl alcohol polymer film when peeled after passing through the drying surface is 50% by weight or less, in film formation.

Polyvinyl alcohol polymer film, method of producing the same and polarization film

A multi-layer construction film is prepared by co-extrusion coating a molten multilayered polymer which satisfies the relationship: 0.08.ltoreq..eta.E/.eta.A.ltoreq.8, which comprises at least one layer (A) of ethylene-vinyl alcohol copolymer and having an ethylene content of 20-60 mol %, and a melt index of .eta.Eg/10 min., and at least one adhesive resin layer (B) of ethylene polymer having a melt index of .eta.Ag/10 min. and a density of not more than 0.9 g/cm.sup.3, onto a plastic film (C) in a manner that layer (B) is laminated adjacent to plastic film (C).

Method for the production of a multi-layer construction film

A multi-layer construction film comprising at least one layer (A) of ethylene-vinyl alcohol copolymer and having an ethylene content of 20-60 mol %, and a melt index of .eta. Eg/10 min., at least one adhesive resin layer (B) of ethylene polymer and having a melt index of .eta. Ag/10 min. and density of not more than 0.90 g/cm.sup.3, and a plastic film (C) wherein the layer (B) is laminated adjacent to the plastic film (C), which satisfies the following formulas.

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Kurashiki, Japan

Shigeyuki Harita