Solution casting method
AssigneeFUJIFILM Corporation
InventorKouji Tonohara
Life of this patent
Estimating the term…
Abstract
A casting dope (27) prepared from CAP, additive and solvent is cast onto a belt (46) and peeled as a wet film (74) that is drawn in the longitudinal direction in a transporting area (80). In a tenter device (47), while the wet film (74) is stretched in the widthwise direction, a relaxation of the wet film (74) in the longitudinal direction is made. If an extent percentage of the stretch is less than 70%, the relation is started. The wet film (74) is fed out as a polymer film (82) from the tenter device (47). On the polymer film (82), the in-plane retardation increases and the thickness retardation decreases. Thus the optical properties become preferable.
Claims8
A solution casting method comprising steps of:
- casting from a casting die onto a support a casting dope containing polymer and solvent, so as to form a casting film;
- peeling said casting film as a film from said support;
- drying said film;
- stretching said film in a widthwise direction thereof during the drying;
- performing during the stretch a relaxation of said film in a longitudinal direction thereof;
- and
Dependencies are inferred from the claim text.