process for protecting the cartridges of ink of ballpoint pens from crystalline masses to entry of tip of brass or other copper alloy and related formulas of ink

摘要

The inks contain ink-soluble antioxidants and/or corrosion inhibitors, which pass the accelerated heat ageing test and also either the accelerated 6-day corrosion test or 2 hr. Cu alloy wt. loss test as defined. Prefd. additives are aromatic phosphate amine salts, N,N'-disalicylol-1,1-propane diamine, Zn dibutyl dithiocarbamate, 2,2-methylene bis (4-methyl 6-tert.-phenol) or benzotriazole in amt. of 0.01-3 wt.%. Formation of crystalline or asphalt-like deposits inside plastics cartridges for the ink, at the interface between the ink and the brass tip during prolonged storage, leading to blockage of the flow of ink to the ball, is prevented.