Silica powder and method for producing the same

#1. Field of the Invention

#The present invention relates to a silica powder which can be added to a recording material used for an ink jet printer. The present invention also relates to a method for producing the silica powder.

#2. Background of the Invention

#A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, where:

#FIG. 1 illustrates the steps for producing a silica powder having an amino group on its surface according the present invention, where the numerals 10-14 represent the following:

#10: silica powder

#As discussed above, at least a portion of the remaining epoxy groups of the epoxy compound are reacted and bound to the amine compound. In a preferred embodiment, all of the remaining epoxy groups of the epoxy compound are reacted and bound to the amine compound.

#In another preferred embodiment, the epoxy compound has a molecular weight ranging from 200 to 1000, preferably from 200 to 700. This range includes all specific values and subranges therebetween, including 250, 300, 500, and 750. Since an epoxy compound having a molecular weight greater than 1000 is highly viscous, dilution of the epoxy compound with a large amount of a solvent is needed, and hence it becomes also impossible to provide many epoxy groups on the surface of the silica powder.

#In a preferred embodiment, the epoxy compound contains no metal. If the epoxy compound contains any metal, then the percent surface occupation of the metal on the surface of the silica powder is high, and therefore it becomes impossible to provide many epoxy groups on the surface of the silica powder.