Date of Award

4-2010

Thesis Type

Masters

Document Type

Dissertation

Divisions

Faculty of Science

Department

Department of Chemistry

Institution

Universiti Malaya

Abstract

This project studied the full process of producing Chemically Produced Toner (CPT) used in laser printer. Latex particles of 0.40 to 0.60 μm were prepared by semicontinuous emulsion polymerization process. A series of latexes was made from the copolymerization of styrene, butyl acrylate and acrylic acid monomers in the presence of surfactants Dowfax 2A1 (anionic) and Ipegal 897 (non-ionic) surfactants with potassium persulphate as the initiator. The addition of different percentage of chain transfer agent (CTA), 1-dodecanethiol was used to control the molecular weight distribution. As the percentage of CTA was increased, the molecular weight and glass transition temperature decreased while the melt flow index increased. The latexes were then used in the emulsion-aggregation (EA) process to produce raw toner by incorporating pigment, wax, charge control agent and other additives. The EA process experiments were carried out using the latexes of different percentage of CTA from 1.0% to 2.2% and also on latexes of 1.0% and 1.4% CTA blended in different ratio. A few parameters of the EA process were varied to study their variation in the molecular weight distribution, the particle size distribution (PSD), sharpness index, melt flow index, relative dielectric constant, dissipation factor, tribocharge, glass transition temperature (Tg), wax melting temperature (Tp), wax content and the fusing properties of the raw toner. Additive blending is the final stage of chemically produced toner (CPT) process, by incorporating mainly the silica such as RY200L2 and SS50F to improve the flowability properties of the toner before proceeding to the test print and performance test. The results obtained were used to compare with the Original Equipment Manufacturer (OEM) and other market toners from other manufacturers. Overall, the other after market and OEM toner showed the PSD of the average particle diameter by mass (D50) in the range of 5.5 to 8.0 μm, sharpness index in the range less than 15.0, Tg in the range 52-57°C, the wax content is less than 8%, tribocharge in the range of -30.0 to -16.0 μC/g, melt flow index in the range of 10- 30 g/10min, Mw in the range of 2.00 to 9.00 × 104 g/mol, Mn in the range of 1.00 to 3.00 × 104 g/mol, Mp in range of 2.00 to 5.00 × 104 g/mol, polydispersity in the range of 1.5 to 3.0, the flowabilty in the range of 4 to 6 mm disc size and the apparent density in the range of 0.30 to 0.50 g/m. Results from all the experiments that were carried out, the two batches of the finished toners at the final stage managed to obtain PSD of D50 in the range of 5.56 to 6.04 μm with sharpness index of 10.18 to 12.30, the tribocharge in the range of -20.0 to -17.0 μC/g, melt flow index in the range of 20.0 to 25.0 g/10min, flowability at 5 mm, apparent density at 0.33 g/m, Tg at 55.0°C, wax content 5.8 to 6.5%, Mw in the range of 4.50 to 5.50 × 104 g/mol, Mn in the range of 1.80 × 104 g/mol,, Mp in the range of 2.80 × 104 g/mol, and the polydispersity in the range of 2.5 to 3.0. These toners were able to product good printing effect after 1 cycle of printing test done

Initial

khm

Additional Information

Dissertation (M.A.) – Faculty of Science, Universiti Malaya, 2010.

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