Thermosensitive recording material

Abstract

A thermosensitive recording material has a support, a thermosensitive recording layer formed thereon, containing an electron-donating coloring compound, an electron-accepting compound a binder resin, and a protective layer formed on the thermosensitive recording layer, which contains an ultraviolet-curing resin and a copolymer resin containing a silicone component as a copolymerizing component.

What is claimed is:  
     
       1. A thermosensitive recording material, comprising: 
       a support;  
       a thermosensitive recording layer formed thereon comprising an electron-donating coloring compound, an electro-accepting compound and a binder resin, and  
       a protective layer formed on said thermosensitive recording layer comprising an ultraviolet-curing resin and a copolymer resin comprising a silicone component as a copolymerizing component therefor, wherein the silicone component of the copolymer resin is a member selected from the group consisting of silicone-modified polyvinyl butyral, silicone-modified polyvinyl acetal, silicone-modified polyacrylate, silicone-modified polymethacrylate, silicone-modified polyvinyl acetoacetal, silicone-modified cellulose acetate propionate, silicone-modified cellulose acetate, silicone-modified cellulose acetate butyrate, silicone-modified ethylcellulose, silicone-modified polyurethane and silicone-modified polyester.  
     
     
       2. The thermosensitive recording material as claimed in  claim 1 , wherein said protective layer further comprises a cross-linking agent which reacts with said copolymer resin comprising said silicone component. 
     
     
       3. The thermosensitive recording material as claimed in  claim 2 , wherein said cross-linking agent comprises an isocyanate compound. 
     
     
       4. The thermosenmitive recording material as claimed in  claim 3 , wherein said isocyanate compound is xylylene diisocyanate. 
     
     
       5. The thermosensitive recording material as claimed in  claim 2 , wherein said cross-linking agent is a member selected from the group consisting of xylylene diisocyanate, tolylene diisocyanate, 4,4-diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, triphenylmethane triisocyanate, tolidine diisocyanate, xylene diisocyanate, hexamethylene diisocyanate and modified compounds thereof, dicyclohexylmethane diisocyanate and isophorone diisocyanate. 
     
     
       6. The thermosensitive recording material as claimed in  claim 1 , wherein said copolymer resin comprising said silicone component is a silicone graft copolymer or a silicone block copolymer. 
     
     
       7. The thermosensitive recording material as claimed in  claim 1 , wherein said copolymer resin comprising said silicone component is selected from the group consisting of a silicone-modified polyvinyl butyral and a silicone-modified polyvinyl acetal. 
     
     
       8. The thermosensitive recording material as claimed in  claim 1 , wherein said protective layer further comprises at least one component selected from the group consisting of a metallic soap and an amino-modified silicone oil. 
     
     
       9. The thermosensitive recording material as claimed in  claim 1 , wherein said thermosensitive recording layer or said protective layer further comprises at least one decolorization agent selected from the group consisting of compounds A to D: 
       a compound A with formula of:                    
       wherein n is an integer, R 1  is CH 3 ;                    
       a compound B with formula of:                    
       a compound C with formula of:                    
       a compound D of 1,3-dicyclohexyl-2-(2′,5′-dicyclophenyl)guanidine.  
     
     
       10. The thermosensitive recording material as claimed in  claim 1 , wherein said protective layer further comprises a filler. 
     
     
       11. The thermosensitive recording material as claimed in  claim 1 , wherein said ultraviolet-curing resin is contained in an amount of 10 to 50 wt. % of the total weight of the entire solid components of said protective layer. 
     
     
       12. The thermosensitive recording material as claimed in  claim 1 , wherein the weight ratio of said copolymer resin comprising said silicone component to said ultraviolet-curing resin is in the range of 1:9 to 7:3. 
     
     
       13. The thermosensitive recording material as claimed in  claim 1 , wherein said copolymer resin comprising a silicone component is silicone-modified polyvinyl butyral of silicone-modified polyvinyl acetal. 
     
     
       14. The thermosensitive recording material as claimed in  claim 1 , wherein the thickness of the protective layer is in the range of  0 . 3 - 10  μm. 
     
     
       15. The thermosensitive recording material as claimed in  claim 14 , wherein the filler is a finely divided inorganic filler of calcium carbonate, silica, zinc oxide, titanium oxide, aluminum hydroxide, zinc hydroxide, barium sulfate, kaolin, talc or surface treated calcium carbonate and silica or a finely divided organic filler or urea- formalin resin, styrene - methacrylic copolymer or polystyrene resin.   
     
     
       16. The thermosensitive recording material as claimed in  claim 2 , wherein the protective layer further comprises a filler having an average particle size of  3  μm or less and an oil absorption of at least  10  ml. 
     
     
       17. The thermosensitive recording material as claimed in  claim 16 , wherein the weight ratio of filler to resin component comprising the ultraviolet- curing resin and the copolymer resin to the cross - linking agent is  (   10 - 60   %):(   5 - 75   %):(   3 - 30   %).