Abstract: A process for purifying a composition comprising: i) an encapsulated pigment comprising a pigment and an encapsulant material comprising a cross-linked dispersant; ii) a liquid medium; and iii) free dispersant; said process comprising removal of at least some free dispersant from the composition using a membrane having a molecular weight cut-off of 3 to 30 times the weight average molecular weight of the dispersant prior to cross-linking, with the proviso that all of conditions a), b) and c) are met: a) the pigment is not silicon dioxide; b) the cross-linked dispersant is not cross-linked polyethyleneimine; and c) the cross-linked dispersant is not a dispersant which has been cross-linked with bis-ethene,1,1?-[methylene bis(sulfonyl)].

Abstract: A process for preparing an encapsulated particulate solid using an epoxy functional cross-linking agent and a carboxylic acid functional dispersant characterized in that the crosslinking is performed in the presence of a borate compound. The resultant solids are useful in, for example, ink jet printing inks where high optical density prints may be obtained.

Abstract: A process for manufacturing an ink, or pigment formulation (e.g. a concentrate) for use in inks, comprising filtration of a composition comprising a particulate pigment and a liquid medium through an inorganic filter having pores of a uniform size below 10 microns. The process accurately removes oversized particles that could cause problems in inkjet printers without wasting non-problematic under-sized pigment. High flow rates are achieved even with low trans-filter pressure differences. In one embodiment, high flow rates are maintained by selection of pH and/or ionic strength. The filters are more robust than conventional polymeric filters and withstand cleaning with aggressive cleaning agents.

Abstract: A process for purifying a pigment comprising washing the pigment with water having less than 100 ppm by weight of total dissolved solids and a microbiological contamination of less than 100 colony forming units per ml. Pigments so purified are especially suitable for use in preparing ink jet printing inks.

Abstract: A process for preparing an encapsulated particulate solid using an epoxy functional cross-linking agent and a carboxylic acid functional dispersant characterised in that the crosslinking is performed in the presence of a borate compound. The resultant solids are useful in, for example, ink jet printing inks where high optical density prints may be obtained.

Abstract: A process for purifying a composition comprising: i) an encapsulated pigment comprising a pigment and an encapsulant material comprising a cross-linked dispersant; ii) a liquid medium; and iii) free dispersant; said process comprising removal of at least some free dispersant from the composition using a membrane having a molecular weight cut-off of 3 to 30 times the weight average molecular weight of the dispersant prior to cross-linking, with the proviso that all of conditions a), b) and c) are met: a) the pigment is not silicon dioxide; b) the cross-linked dispersant is not cross-linked polyethyleneimine; and c) the cross-linked dispersant is not a dispersant which has been cross-linked with bis-ethene,1,1?-[methylene bis(sulfonyl)].

Abstract: A process for manufacturing an ink, or pigment formulation (e.g. a concentrate) for use in inks, comprising filtration of a composition comprising a particulate pigment and a liquid medium through an inorganic filter having pores of a uniform size below 10 microns. The process accurately removes oversized particles that could cause problems in inkjet printers without wasting non-problematic under-sized pigment. High flow rates are achieved even with low trans-filter pressure differences. In one embodiment, high flow rates are maintained by selection of pH and/or ionic strength. The filters are more robust than conventional polymeric filters and withstand cleaning with aggressive cleaning agents.