method for preparation of coloured, finely divided, hardened benzoguanamine resins with uniform particle size and excellent dispergeerbaarheid knew.

摘要

A process for producing a dyed finely divided hardened resin of uniform particle size excelling in dispersibility which comprises, in combination, the steps of reacting benzoguanamine with formaldehyde in a ratio of 1.0 mole of the former to 1.2 - 3.5 moles of the latter in an aqueous medium at a pH ranging between 5 and 10 to prepare an aqueous liquid of a soluble and fusible resin having a degree of modified water tolerance of 0-150%, preparing an aqueous emulsion of a dyed soluble and fusible resin by using said aqueous liquid, a dye and a protective colloid, adding to the thus prepared aqueous emulsion in a ratio of 1 - 15 parts by weight per 100 parts by weight of the soluble and fusible resin of ultramicroscopic silica of a specific surface area as measured by the Brunauer, Emmett and Teller Method in the range of about 50 m2/g to about 400 m2/g and a particle size in the range of about 0.005 to about 0.05 micron, adding a curing catalyst, holding the aqueous emulsion for at least one hour at a temperature in the range of 40 DEG -60 DEG C., heating the aqueous emulsion at a temperature in the range of 60 DEG -200 DEG C. at normal atmospheric or superatmospheric pressure to harden the resin thereby preparing a suspension of a dyed finely divided hardened resin, and thereafter separating the hardened resin from the suspension followed by drying and de-aggregating the dried hardened resin.