Toners for use in electrophotography and production thereof

A method of producing a deformed toner particle for use in electrophotography which comprises the following steps carried out in sequence:

• (a) dispersing particles of a colorant and a charge controlling agent minutely and uniformly both as finely divided particles of not more than 1 .mu.m in particle size in a radical polymerizable liquid monomer;
• (b) adding an azobisnitrile polymerization initiator to the resultant monomer composition, suspending the composition in water containing polyvinyl alcohol as a suspending agent, suspension polymerizing the monomer to provide spherical polymer particles composed of a matrix of the polymer and the colorant and charge controlling agent dispersed therein and having a diameter of 1-30 .mu.m, and treating the suspension containing the polymer particles at temperatures in the range of .+-.10.degree. C. of the glass transition temperature of the matrix forming the polymer particles with a continuous wet type agitation mill, thereby to deform the spherical particles into dislike particles having a diameter of 3-30 .mu.m, a thickness of 1-15 .mu.m and a flatness of not more than 0.5, the flatness of the dislike particles being defined as a ratio of average thickness to average diameter of the particles, or oval particles having a major axis of 3-30 .mu.m in length, a minor axis of 1-25 .mu.m in length and a flatness of not more than 0.5, the flatness of the oval particles being defined as a ratio of twice the average thickness to the sum of length of average major axis and length of average minor axis, or a mixture of these;
• (c) saponifying the polyvinyl alcohol;
• and
• (d) recovering, drying and washing the polymer particles, and optionally classifying to a desired particle size.