Primer for electroless plating

Abstract

It is an object of the present invention to provide a novel primer for use in pretreatment steps in electroless plating which is environmentally friendly, by which process is easy with fewer steps, and which can realize cost reduction. A primer for forming a metal plating film on a base material by electroless plating, the primer including: a hyperbranched polymer having an ammonium group at a molecular terminal and a weight-average molecular weight of 500 to 5,000,000; a metal fine particle; and an alkoxysilane.

1 . A primer for forming a metal plating film on a base material by electroless plating, the primer comprising:
 (a) a hyperbranched polymer having an ammonium group at a molecular terminal and a weight-average molecular weight of 500 to 5,000,000;   (b) a metal fine particle; and   (c) an alkoxysilane having an amino group optionally substituted with an aliphatic group or an epoxy group, or an oligomer of the alkoxysilane.   
     
     
         2 . The primer according to  claim 1 , wherein
 the ammonium group of the hyperbranched polymer (a) is attached to the metal fine particle (b) to form a complex.   
     
     
         3 . The primer according to  claim 1 , wherein
 the hyperbranched polymer (a) is a hyperbranched polymer of Formula [1]:   
       
         
           
           
               
               
           
         
       
       (where R 1  are each independently a hydrogen atom or a methyl group; R 2  to R 4  are each independently a hydrogen atom, a linear, branched, or cyclic alkyl group having a carbon atom number of 1 to 20, a C 7-20  arylalkyl group, or —(CH 2 CH 2 O) m R 5  (where R 5  is a hydrogen atom or a methyl group; and m is an integer of 2 to 100) (where the alkyl group and the arylalkyl group are optionally substituted with an alkoxy group, a hydroxy group, an ammonium group, a carboxy group, or a cyano group), or two groups of R 2  to R 4  together represent a linear, branched, or cyclic alkylene group, or R 2  to R 4  together with a nitrogen atom to which R 2  to R 4  are bonded optionally form a ring; X −  is an anion; n is the number of repeating unit structures and an integer of 5 to 100,000; and A 1  is a structure of Formula [2]: 
       
         
           
           
               
               
           
         
       
       (where A 2  is a linear, branched, or cyclic alkylene group having a carbon atom number of 1 to 30 optionally containing an ether bond or an ester bond; and Y 1  to Y 4  are each independently a hydrogen atom, a C 1-20  alkyl group, a C 1-20  alkoxy group, a nitro group, a hydroxy group, an amino group, a carboxy group, or a cyano group)). 
     
     
         4 . The primer according to  claim 3 , wherein
 the hyperbranched polymer (a) is a hyperbranched polymer of Formula [3]:   
       
         
           
           
               
               
           
         
       
       (where R 1 , R 2 , and n have the same meanings as described above). 
     
     
         5 . The primer according to  claim 1 , wherein
 the metal fine particle (b) is a fine particle of at least one selected from the group consisting of iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), palladium (Pd), silver (Ag), tin (Sn), platinum (Pt), and gold (Au).   
     
     
         6 . The primer according to  claim 5 , wherein
 the metal fine particle (b) is a palladium fine particle.   
     
     
         7 . The primer according to  claim 5 , wherein
 the metal fine particle (b) is a fine particle having an average particle diameter of 1 to 100 nm.   
     
     
         8 . The primer according to  claim 1 , wherein
 the alkoxysilane (c) is a compound of Formula [4]:
   Z-L-Si(R 6 )) a (OR 7 ) 3-a   [4]
 
   
       (where R 6  is a C 1-6  alkyl group or a phenyl group; R 7  are each independently a methyl group or an ethyl group; L is a C 1-6  alkylene group optionally containing an ether bond; Z is an amino group optionally substituted with an aliphatic group, or an epoxy group; and a is 0 or 1). 
     
     
         9 . A priming layer for electroless plating, obtained by forming a layer of the primer as claimed in  claim 1 . 
     
     
         10 . A metal plating film, formed on the priming layer by performing electroless plating on the priming layer for electroless plating as claimed in  claim 9 . 
     
     
         11 . A metal-coated base material comprising:
 a base material;   the priming layer for electroless plating as claimed in  claim 9  formed on the base material; and   the metal plating film formed on the priming layer by performing electroless plating on the priming layer for electroless plating.   
     
     
         12 . A method for producing a metal-coated base material, the method comprising:
 a process A: coating a base material with the primer as claimed in  claim 1  to form a priming layer; and   a process B: immersing the base material having the priming layer in an electroless plating bath to form a metal plating film.