Method for forming a laminated film on a substrate

A method for forming a laminated film on a substrate, the method comprising:

• i) providing a film forming apparatus comprising:
• a substrate conveying compartment,
• a plasma pretreatment compartment, and
• a vapor deposition compartment,
• wherein a pulse voltage of 200 volts to 1000 volts is applied to a power source of the film forming apparatus;
• ii) conveying the substrate from the substrate conveying compartment into the plasma pretreatment compartment at a conveying speed of from 480 m/min to 1000 m/min;
• iii) performing plasma pretreatment on the substrate in the plasma pretreatment compartment to produce a plasma pretreated substrate,
• wherein the plasma pretreatment compartment has a maintained pretreatment pressure of 0.1 Pa to 100 Pa,
• wherein the plasma pretreatment comprises:
• a) supplying a plasma source gas from a plasma-supply nozzle as plasma into a gap between a magnet and a pretreatment roller such that the plasma is entrapped in the gap,
• wherein the plasma source gas comprises argon and at least one additional gas selected from the group consisting of oxygen, nitrogen, carbon dioxide gas, and ethylene,
• wherein the plasma source gas has a mixing ratio of the at least one additional gas:the argon of 1.5:1 to 3:1, and
• wherein the magnet has a flux density of 100 gauss to 10,000 gauss, and
• b) holding the plasma and applying a voltage between the pretreatment roller and the plasma-supply nozzle
• wherein the plasma has a plasma density of 100 W·sec/m2 to 1824 W·sec/m2, and
• wherein the voltage is applied as an alternating current voltage with a frequency of 10 Hz to 50 MHz;
• iv) conveying the plasma pretreated substrate from the plasma pretreatment compartment into the vapor deposition compartment by a film-forming roller at a conveying speed of from 480 m/min to 1000 m/min;
• v) forming a vapor deposition film by vapor deposition on a surface of the plasma pretreated substrate that was pretreated in step iii),
• wherein the vapor deposition film has a thickness of 10 to 50 nm;
• wherein steps i) to v) proceed continuously,
• vi) forming a barrier coat layer on a surface of the vapor deposition film that was formed in step v) to obtain a laminated film,
• wherein the barrier coat layer is formed by applying a composition for barrier coating film and polymerizing the composition by a sol-gel method,
• wherein the composition is obtained by:
• 1) obtaining a gas barrier composition comprising silicon alkoxide, isopropyl alcohol, and ion exchanged water;
• and then
• 2) adding to the gas barrier composition a prepared liquid mixture comprising a polyvinyl alcohol aqueous solution, isopropyl alcohol and ion exchanged water;
• and
• vii) retorting the laminated film that was obtained in step vi) with hot water for 40 minutes at 121° C.,
• wherein, after retorting,
• under measurement conditions of 40° C. and 90% RH, a water vapor transmission rate of the laminated film is 0.8 g/m2/24 h or less, and
• a water-applied laminate strength of the laminated film, measured in accordance with JIS Z6854-2, is 2.1 N/15 mm or more, and
• wherein the substrate conveying compartment has a maintained pressure that is 10 to 10,000 times greater than the maintained pretreatment pressure.