Process for multi-layer continuos roll-to-roll coating

Abstract

The invention relates to a process for the continuous production of a flexible substrate, preferably a plastics film containing a multi-layer coating in a roll-to-roll coating process, in which at least one vacuum coating process and at least one wet coating process are combined together, and to a device for use in such a process.

1 . A process for continuous production of a flexible substrate, optionally a plastic film comprising a multi-layer coating in a roll-to-roll coating process, wherein the multi-layer coating comprises at least one inorganic and at least one organic layer, said process comprising:
 (a) applying at least one inorganic layer of the multi-layer coating in at least one vacuum coating chamber at a pressure of less than 10 −2  bar with a vacuum coating process, and   (b) applying at least one organic layer of the multi-layer coating at atmospheric pressure in a wet coating process,   wherein at least one gas gate is located between a vacuum coating chamber and an area for the wet coating process, and further wherein   transport of the coated flexible substrate outside the at least one vacuum coating chamber takes place in such a way that a side of the flexible substrate having the coating has no direct contact with transport rolls and/or guide rolls.   
     
     
         2 . The process according to  claim 1 , wherein the pressure in the vacuum coating chamber is from 10 −3  to 10 −7  bar. 
     
     
         3 . The process according to  claim 1 , wherein the inorganic layer comprises at least one oxide, nitride, carbide, boride, fluoride or a mixture thereof. 
     
     
         4 . The process according to  claim 1 , wherein the vacuum coating process is a chemical and/or physical vapour deposition, a reactive sputtering process and/or a reactive evaporation process. 
     
     
         5 . The process according to  claim 1 , wherein the wet coating process is a spray process, casting process, knife-coating process, printing process, roller coating and/or other wet coating process. 
     
     
         6 . The process according to  claim 1 , wherein the organic layer is optionally dried, optionally thermally dried, and the optionally dried organic layer is cured, optionally radiation-cured, after application. 
     
     
         7 . The process according to  claim 1 , wherein a coating composition for the organic layer comprises an ethylenically unsaturated compound. 
     
     
         8 . The process according to  claim 1 , wherein inorganic and organic layers alternate in the multi-layer coating and (a) and (b) are followed once more by at least (a), optionally at least once more by (a) and (b). 
     
     
         9 . The process according to  claim 1 , wherein the multi-layer coating is a barrier coating. 
     
     
         10 . A roll-to-roll coating device for continuous production of a flexible substrate, optionally a plastic film comprising a multi-layer coating, wherein the device comprises
 at least one unwinding device,   at least one vacuum coating chamber with a pressure of less than 10 −2  bar with at least one vacuum coating module,   at least one wet coating area at atmospheric pressure with at least one wet coating unit,   at least one gas gate between a vacuum chamber and a wet coating area,   at least one air turn roller for contactless transport of a coated flexible substrate outside the vacuum chamber, and   at least one winding device.   
     
     
         11 . The roll-to-roll coating device according to  claim 10 , wherein said roll-to-roll coating device comprises a drying device, optionally a thermal drying device, within and/or downstream of the wet coating area. 
     
     
         12 . The roll-to-roll coating device according to  claim 10 , wherein said roll-to-roll coating device comprises a device for curing an organic coating, optionally a UV irradiation device, within and/or downstream of the wet coating area. 
     
     
         13 . The roll-to-roll coating device according to  claim 10 , wherein a vacuum chamber and a wet coating area follow one another alternately in each case. 
     
     
         14 . The roll-to-roll coating device according to  claim 10 , wherein a gas gate is located between a vacuum chamber and a wet coating area in each case. 
     
     
         15 . The roll-to-roll coating device according to  claim 10 , wherein said roll-to-roll coating device comprises
 at least two vacuum coating chambers with a pressure of less than 10 −2  bar with at least one vacuum coating module each,   at least one wet coating area at atmospheric pressure with at least one wet coating unit between said two vacuum coating chambers,   at least one, optionally in each case one, gas gate between a vacuum chamber and the wet coating area.