Polyamide based laminated resin film roll and production process thereof

A polyamide based resin laminated film roll formed by winding up of the polyamide based resin laminated film in a width of 0.2 m or more to 3.0 m or less, and a length of 300 m or more to 30000 m or less,

• wherein when the polyamide based resin laminated film roll has a first sample cutout portion set up within 2 m from the winding end of film;
• and a final cutout portion set up within 2 m from the winding start of film, as well as has a sample cutout portion set up in approximately every 100 m from the first sample cutout portion, the polyamide based resin laminated film roll satisfies the following requirements (1) through (5):
• (1) when a maximum boiling water shrinkage percentage which is the maximum value of boiling water shrinkage percentages in all directions, of each sample cut out from each of the cutout portions is measured, an average boiling water shrinkage percentage which is average value of the maximum boiling water shrinkage percentages is 2% to 6%, and a degree of variability in the maximum boiling water shrinkage percentages of all samples is within a range of ±2% to ±10% relative to the average boiling water shrinkage percentage;
• (2) when a directional difference of boiling water shrinkage percentage which is an absolute value of the difference between a boiling water shrinkage percentage in the direction of +45° to the longitudinal direction and a boiling water shrinkage percentage in the direction of −45° to the longitudinal direction of each sample cut out from each of the cutout portion is determined, an average directional difference of boiling water shrinkage percentage which is the average of the directional differences of boiling water shrinkage percentage is 2.0% or less, and a degree of variability in the directional differences of boiling water shrinkage percentage of all samples is within a range of ±2% to ±30% relative to the average directional difference of boiling water shrinkage percentage;
• and
• (3) when each sample cut out from each cut out portion is measured for the three-dimensional surface roughness in the winding-up direction, the average surface roughness which is the average value of three-dimensional surface roughness of all the samples is within a range of 0.01 to 0.06 μm, and a degree of variability of three-dimensional surface roughness of all the samples is within a range of ±5% to ±20% to the average surface roughness;
• (4) when each sample cut out from each cut out portion is measured for the haze, the average haze which is the average value of hazes of all the samples is within a range of 1.0 to 4.0 and at the same time a degree of variability of haze of all the samples is within a range of ±2% to ±15% to the average haze;
• (5) a degree of variability in the thickness of a roll wound up over the entire length in the longitudinal direction is within ±2% to ±10% relative to the average thickness;
• wherein the polyamide based resin laminated film is produced with a method for obtaining a practically unoriented polyamide sheet comprising melting and coextruding each polymer that composes each layer by the use of separate extruders, casting from a nozzle on a rotating drum, and rapidly cooling and solidifying;
• and
• wherein the skin layer of the polyamide based mixed resin film wound up comprises inorganic particles 0.05 to 2.0% by weight.