| 摘要 |
<p>A process for the prepn. of toner compsns. comprises: (i) forming a dispersion of a resin (1) in an aq. ionic surfactant (2) soln. by addn. of (2) and, opt., a nonionic surfactant (3) to a latex of (1) prepd. by emulsion polymerisation; (ii) preparing dispersions in water of 3 different pigments (4), each of different colour using nonionic dispersant(s) (5) and, opt., an ionic surfactant (6) of the same polarity as (2); (iii) blending the latex from (i) with 2 or, opt., 3 dispersions from (ii), the total loading of (4) in the water suspension being opt. 2-30 wt.% of the solids content; (iv) adding an aq. soln. of a counter-ionic surfactant (7) to coagulate the dispersion while continuously subjecting the dispersion to high shear to give a homogeneous gel of the flocculated (1)+(4) blend; (v) heating the gel, pref. for 0.5-6 hrs., at 5-20 deg.C before the Tg of (1) with stirring at 200-500 rpm to provide statically bound toner sized aggregates of 2-12 microns ave. vol. dia., with narrow size dispersivity and geometric size distribution (GSD) 1.10-1.25, then opt. adding 0.01-5 wt.% of the solids of additional ionic surfactant (8) of the same polarity as (2) to stabilise the particles against further growth during (vi); (vi) heating the aggregate particles at 25-40 deg.C above the Tg of (1) to form coalesced rigid particles of toner compsn.; and opt. (vii) sepg. and drying the toner.</p> |
