| 摘要 |
A method of producing a laminate film includes coating a support with coating solutions with at least two monolayer extrusion dies to provide layers. A difference in solubility parameter between the coating solution and a solute in the adjoining layer ≧0.1 for respective coating solutions. Viscosity of the downstream side die coating solution is lower than that of an upstream side die. Each coating solution has a Capillary number Ca<1.7. A difference in surface tension |&sgr;2−&sgr;1| between the adjoining layers satisfies |&sgr;2−&sgr;1|>0.5 [mN/m], where &sgr;1, &sgr;2 are surface tensions of coating solution from upstream and downstream side dies, respectively. A ratio of a coating thickness h1 [μm] of the coating solution for an upper layer and a distance L [μm] of the upper layer from the support surface satisfies h1/L<0.14. Distance between discharge nozzles is ≧1 mm and ≦̸700 mm. |
