Planographic printing plate precursor, substrate for the same and surface hydrophilic material

Abstract

A planographic printing plate precursor comprises a substrate having disposed thereon a hydrophilic layer which includes hydrophilic graft chains and a crosslinked structure formed through hydrolytic polycondensation of an alkoxide of an element selected from Si, Ti, Zr and Al. An aluminum substrate for a planographic printing plate includes a hydrophilic surface which is formed by a hydrophilic polymer including a functional group that chemically bonds to the aluminum substrate directly or is chemically bindable to the aluminum substrate via structural component having a crosslinking structure. A surface-hydrophilic member comprises a substrate having disposed thereon a hydrophilic layer, wherein the hydrophilic layer includes hydrophilic graft chains and a crosslinked structure formed through hydrolytic polycondensation of an alkoxide of an element selected from Si, Ti, Zr and Al.

What is claimed is:  
     
         1 . A planographic printing plate precursor comprising a substrate having disposed thereon a hydrophilic layer which includes hydrophilic graft chains and a crosslinked structure formed through hydrolytic polycondensation of an alkoxide of an element selected from Si, Ti, Zr and Al.  
     
     
         2 . The planographic printing plate precursor according to  claim 1 , wherein the hydrophilic layer includes a polymer compound represented by the following general formula (I)  
       
         
           
           
               
               
           
         
       
       wherein each of R 1 , R 2 , R 3  and R 4  independently represents a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms; m is an integer of 0 to 2; n is an integer of 1 to 8; 
 L represents a single bond or an organic linking group; Y represents —NHCOR 5 , —CONH 2 , —CON(R 5 ) 2 , —COR 5 , —OH, —CO 2 M or —SO 3 M; R 5  represents an alkyl group having 1 to 8 carbon atoms;  
 and M represents one of a hydrogen atom, an alkali metal, an alkaline earth metal and an onium.  
 
     
     
         3 . The planographic printing plate precursor according to  claim 2 , wherein the hydrophilic layer is formed by 
 preparing a coating liquid composition including the hydrophilic polymer compound represented by general formula (I) and a crosslinking component represented by the following general formula (II),    applying the coating liquid composition onto a surface of the substrate, the substrate comprising aluminum, and    drying the coating liquid composition:    general formula (II)    (R 6 ) m —X—(OR 7 ) 4-m      wherein each of R 6  and R 7  independently represents an alkyl group or an aryl group; X represents Si, Al, Ti or Zr; and m is an integer of 0 to 2.    
     
     
         4 . The planographic printing plate precursor according to  claim 1 , wherein the planographic printing plate precursor further comprises an image forming layer on the hydrophilic layer, and the image forming layer contains a polymer compound including a functional group that changes from one of hydrophilic to hydrophobic and hydrophobic to hydrophilic in the presence of an acid, by application of heat, or by irradiation with radiation.  
     
     
         5 . The planographic printing plate precursor according to  claim 4 , wherein the polymer compound including a functional group that changes from hydrophobic to hydrophilic is at least one selected from the group consisting of second arysulfonate polymers, tertiary carboxylate polymers, and alkoxyalkyl carboxylate polymers; and the polymer compound including a functional group that changes from hydrophilic to hydrophobic is at least one selected from the group consisting of polymers having an ammonium group and polymers having a decarboxylation polarity-changing group represented by the following general formula:  
       
         
           
           
               
               
           
         
       
       wherein X represents —O—, —S—, —Se—, —NR 3 —, —CO—, —SO—, —SO 2 —, —PO—, —SiR 3 R 4 —, or —CS; each of R 1 , R 2 , R 3  and R 4  independently represents a monovalent group; and M represents a cation.  
     
     
         6 . The planographic printing plate precursor according to  claim 1 , wherein the hydrophilic layer further includes a compound that forms a hydrophobic surface region by application of heat or irradiation with radiation.  
     
     
         7 . The planographic printing plate precursor according to  claim 2 , wherein the hydrophilic layer is formed by 
 preparing a coating liquid composition including the hydrophilic polymer compound represented by general formula (I), a crosslinking component represented by the following general formula (II), and a compound that forms the hydrophilic surface region by application of heat or by irradiation with radiation,    applying the coating liquid composition onto a surface of the substrate, the substrate comprising aluminum, and    drying the coating liquid composition:    general formula (II)    (R 6 ) m —X—(OR 7 ) 4-m      wherein each of R 6  and R 7  independently represents an alkyl group or an aryl group; X represents Si, Al, Ti or Zr; and m is an integer of 0 to 2.    
     
     
         8 . The planographic printing plate precursor according to  claim 6 , wherein the compound that forms the hydrophobic surface region is at least one of a compound that changes from hydrophilic to hydrophobic by application of heat or irradiation with radiation, and thermo-fuseable hydrophobic particles, and when the compound that changes from hydrophilic to hydrophobic is used and formed into a film, a contact angle between a surface of the film and a water drop in air is at most 20° before the film is heated, and increases to at least 65° after the film has been heated.  
     
     
         9 . The planographic printing plate precursor according to  claim 6 , wherein the coating liquid composition includes one of an acid catalyst and a basic catalyst.  
     
     
         10 . The planographic printing plate precursor according  claim 1 , wherein the planographic printing plate precursor further comprises an image forming layer on the hydrophilic layer, and the image forming layer includes a hydrophobic precursor and a hydrophilic resin.  
     
     
         11 . The planographic printing plate precursor according to  claim 10 , wherein the hydrophobic precursor comprises particles that form a hydrophobic region in the image forming layer by application of heat, and the particles are at least one selected from the group consisting of thermoplastic polymer particles, thermosetting polymer particles, thermo-reactive functional group-having polymer particles, and microcapsules encapsulating a hydrophobic compound, with the particles being dispersed in a matrix of the image forming layer.  
     
     
         12 . The planographic printing plate precursor according to  claim 11 , wherein the polymer particles fuse together or react with each other by application of heat to form the hydrophobic region.  
     
     
         13 . The planographic printing plate precursor according to  claim 11 , wherein the micro capsules include walls that are broken or become permeable by application of heat, so that the hydrophobic compound encapsulated therein is let out, whereby a predetermined region of the image forming layer changes polarity to become hydrophobic and form the hydrophobic region.  
     
     
         14 . A substrate for a planographic printing plate, the substrate comprising aluminum and including a hydrophilic surface formed by a hydrophilic polymer including a functional group that chemically bonds to the aluminum substrate directly or is chemically bindable to the aluminum substrate via structural component having a crosslinking structure.  
     
     
         15 . The substrate according to  claim 14 , wherein the hydrophilic polymer includes the functional group as a terminal group.  
     
     
         16 . The substrate according to  claim 14 , wherein the hydrophilic surface comprises a crosslinked structure formed through hydrolytic polycondensation of an alkoxide of an element selected from Si, Ti, Zr and Al.  
     
     
         17 . The substrate according to  claim 14 , wherein the hydrophilic surface comprises at least one of polymer compounds represented by the general formulae (III) and (IV), the polymer compound represented by the general formula (III) being a polymer compound comprising the following units (i′) to (iii′), and a silane coupling group represented by unit (iii′) is a terminal end bounded to at least one of the units (i′) and (ii′);  
       
         
           
           
               
               
           
         
       
       in the general formula (III), each of R 1 , R 2 , R 3 , R 4 , R 5  and R 6  independently represents a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms; m is an integer of 0 to 2; 
 n is an integer of 1 to 8; x and y are numbers showing a ratio of compositions when x+y=100, and a ratio of x to y=100.0 to 1:99; each of L 1 , L 2  and L 3  represent a single bond or an organic linking group; each of Y 1  and Y 2  represents —N(R 7 ) (R 8 ), —OH, —NHCOR 7 —, —CO 2 M—, or —SO 3 M; each of R 7  and R 8  independently represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms; and M represents one of a hydrogen atom, an alkali metal, an alkaline earth metal and an onium,  
 the polymer compounds represented by the general formula (IV) comprises units (i″) and (ii″),  
                     
 in the general formula (IV), each of R 1 , R 2 , R 3 , R 4 , R 5  and R 6  independently represents a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms; m is an integer of 0 to 2;  
 x and y are numbers showing a ratio of compositions when x+y=100, and a ratio of x to y=99:1 to 50:50; each of L 1  and L 2  represents a single bond or an organic linking group;  
 Y represents t least one of —N(R 7 )(R 8 ), —OH, —NHCOR 7 —, —CO 2 M—, or —SO 3 M; each of R 7  and R 8  independently represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms; and M represents one of a hydrogen atom, an alkali metal, an alkaline earth metal and an onium.  
 
     
     
         18 . A surface-hydrophilic member comprising a substrate having disposed thereon a hydrophilic layer, wherein the hydrophilic layer includes hydrophilic graft chains and a crosslinked structure formed through hydrolytic polycondensation of an alkoxide of an element selected from Si, Ti, Zr and Al.  
     
     
         19 . The surface-hydrophilic member according to  claim 18 , wherein the hydrophilic layer is obtained by preparing a coating liquid composition comprising the following general formula (I) and applying the liquid composition on the substrate:  
       
         
           
           
               
               
           
         
       
       wherein each of R 1 , R 2 , R 3  and R 4  independently represents a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms; m is an integer of 0 to 2; n is an integer of 1 to 8; 
 L represents a single bond or an organic linking group; Y represents —NHCOR 5 , —CONH 2 , —CON(R 5 ) 2 , —COR 5 , —OH, —CO 2 M or —SO 3 M; R 5  represents an alkyl group having 1 to 8 carbon atoms;  
 and M represents one of a hydrogen atom, an alkali metal, an alkaline earth metal and an onium.  
 
     
     
         20 . The surface-hydrophilic member according to  claim 19 , wherein the coating liquid composition further comprises a hydrolyzable compound represented by the following general formula (II): 
 general formula (II)    (R 6 ) m —X—(OR 7 ) 4-m      wherein each of R 6  and R 7  independently represents an alkyl group or an aryl group; X represents Si, Al, Ti or Zr; and m is an integer of 0 to 2.