Process film for use in producing ceramic green sheet and method for production thereof

Abstract

There can be provided a casting film for producing a ceramic green sheet which film comprises a substrarte film, an undercoat layer and a cured layer, wherein the undercoat layer is composed of a condensation polymer from a metal alkoxide and/or a partially hydrolyzed product of a metal alkoxide, and the cured layer is formed by heat treating at 40 to 120° C., an addition reaction type silicone resin composition containing a photosensitizer in a coating amount of 0.01 to 0.3 g/m 2 expressed in terms of solid content, and thereafter ultraviolet irradiating the composition to cure the same. The casting film, which is employed for the production of a ceramic green sheet to be used in a ceramic capacitor, a laminated inductor element and the like, can easily be produced, has favorable adhesiveness to a substrate film, is excellent in ceramic slurry coating property and releasabilty from a ceramic green sheet, and possesses high flatness that has never been realized by any of the prior arts together with high antistatic property.

1 . A casting film, for producing a ceramic green sheet, comprising a substrate film, an undercoat layer and a cured layer, wherein said undercoat layer comprises a condensation polymer from a metal alkoxide, a partially hydrolyzed product of a metal alkoxide, or a combination thereof, and wherein said cured layer is formed by heat treating at 40 to 120° C., an addition reaction type silicone resin composition comprising a photosensitizer in a coating amount of 0.01 to 0.3 g/m 2  expressed in terms of solid content, and thereafter ultraviolet irradiating the same to cure the composition and form the cured layer.  
   
   
       2 . The casting film for producing a ceramic green sheet according to  claim 1 , wherein said metal alkoxide is tetraalkoxysilane.  
   
   
       3 . The casting film of  claim 1 , wherein the addition reaction type silicone resin composition comprises polydimethylsiloxane comprising at least one functional group.  
   
   
       4 . The casting film of  claim 3 , wherein the at least one functional group is a hexenyl group, a vinyl group, or a combination thereof.  
   
   
       5 . The casting film of  claim 1 , wherein the substrate film comprises polyethylene terephthalate.  
   
   
       6 . A process for the production of a casting film for producing a ceramic green sheet, comprising 
 forming, on a substrate film, an undercoat layer comprising a condensation polymer from a metal alkoxide, a partially hydrolyzed product of a metal alkoxide, or a combination thereof, and    forming a cured layer on the undercoat layer to form the casting film,    wherein the forming the cured layer comprises 
 placing an addition reaction type silicone resin composition comprising a photosensitizer in a coating amount of 0.01 to 0.3 g/m 2  expressed in terms of solid content on the undercoat layer;  
 heat treating the composition at 40 to 120° C.; and ultraviolet irradiating the same to cure the composition and form the cured layer.  
   
   
   
       7 . The casting film of  claim 2 , wherein the addition reaction type silicone resin composition comprises polydimethylsiloxane comprising at least one functional group.  
   
   
       8 . The casting film of  claim 2 , wherein the substrate film comprises polyethylene terephthalate.  
   
   
       9 . The casting film of  claim 3 , wherein the substrate film comprises polyethylene terephthalate.  
   
   
       10 . The casting film of  claim 4 , wherein the substrate film comprises polyethylene terephthalate.  
   
   
       11 . The casting film of  claim 1 , wherein the substrate film comprises polyethylene naphthalate.  
   
   
       12 . The casting film of  claim 1 , wherein the substrate film comprises polypropylene.  
   
   
       13 . The casting film of  claim 1 , wherein the substrate film comprises polymethylpentene.  
   
   
       14 . The casting film of  claim 1 , wherein the substrate film has a thickness of from 12 μm to 125 μm.  
   
   
       15 . The casting film of  claim 1 , wherein the coating amount is from 0.05 g/m 2  to 0.2 g/m 2 .  
   
   
       16 . The casting film of  claim 1 , wherein the heat treating is performed in the temperature range of from 50° C. to 100° C.  
   
   
       17 . The process of  claim 6 , wherein the coating amount is from 0.05 g/m 2  to 0.2 g/m 2 .  
   
   
       18 . The process of  claim 6 , wherein the heat treating is performed in the temperature range of from 50° C. to 100° C.  
   
   
       19 . The casting film of  claim 1 , wherein the photosensitizer is selected from the group consisting of benzoins, benzophenones, acetophenones, α-hydroxy ketones, α-diketones, α-diketone dialkyl acetals, anthraquinones, thioxanthones, and combinations thereof.  
   
   
       20 . The process of  claim 6 , wherein the photosensitizer is selected from the group consisting of benzoins, benzophenones, acetophenones, α-hydroxy ketones, α-diketones, α-diketone dialkyl acetals, anthraquinones, thioxanthones, and combinations thereof.