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Kawasaki, Japan

Limura T.,Ibaraki University | Abe O.,Ibaraki University | Oguchi T.,Morimura Chemicals Ltd
International Conference on Digital Printing Technologies | Year: 2010

Core-shell (C-S) particles with a colored shell layer are prepared in an organic solvent system by a coacervation process. As the core-particles, a toner size polyethylene-norbomene copolymer particles are used. A dye molecules dissolved in acetone are precipitated onto the core particles from an acetone/water mixed solvent to form the colored C-S particles. The C-S particles are obtained without surfactant, need no washing process, and show sufficient color strength as well as good color reproduction. The colored shell layer also shows an excellent charge controlling capability, but the dye particles abraded from the colored shell layer function as a charge reducing agent. A resinous protecting layer deposited on the colored shell layer realizes colored particles with excellent durability and charge controlling capability. Source


Patent
Shin - Etsu Chemical Co. and MORIMURA CHEMICALS Ltd | Date: 2014-02-25

There is provided an electrostatic image developing toner less likely to cause image degradation even when used for a long period, by controlling CCA particles present on surfaces of toner particles and thereby keeping an amount of tribocharge generated between the toner and a magnetic carrier or the like constant. A charge control agent composition for external addition for controlling charge amount of toner particles includes: at least two types of carrier particles different in average particle size of primary particles; and a charge control agent (CCA), and an electrostatic image developing toner is constituted of a mixture of toner particles and the aforesaid charge control agent composition for external addition.


Tsunemi K.,Morimura Chemicals Ltd | Suka A.,Morimura Chemicals Ltd | Limura T.,Morimura Chemicals Ltd | Oguchi T.,Morimura Chemicals Ltd | Kobayashi N.,Chiba University
International Conference on Digital Printing Technologies | Year: 2010

Extemally-added charge control agents (EA-CCA) were prepared by means of a coacervation process. Spherical silica particles of 100 run average diameter were coated with two kinds of charge control agents (CCAs); one is a polymer type P-1 and the other is a low molecular weight type P-2. Both of them make a remarkable contribution to toner charge. In a concentration range from 1 to 1×103 ppm of CCA on toner, toner charge increased. From the relationship between the amount of EA-CCA in the toner and the tribocharge, P-2 was found more effective than P-1. It is estimated that 0.7 % of P-1 repeating units and 1.2 % of P-2 molecules contribute to toner charge, respectively. Calculation of the surface coverage of P-2 on spherical silica particles shows that the efficient concentration region of charge agreed with the surface coverage. The P-2 concentration was 50 ppm based on toner. This means that the CCA molecule has great effect on tribocharge in small concentration. Source


Tsunemi K.,Morimura Chemicals Ltd | Tsunemi K.,Chiba University | Suka A.,Morimura Chemicals Ltd | Iimura T.,Morimura Chemicals Ltd | And 3 more authors.
International Conference on Digital Printing Technologies | Year: 2011

Particles of externally-additive-charge-control-agent (EA-CCA) were prepared by means of coacervation process and their effects on toner charge were investigated. EA-CCA particles comprised with metal oxide core particles of 110nm diameter and CCA molecules adhered on the core surface. Four kinds of negative charge control agent (CCA), which were boron complex (N-F), zinc complex (N-2), iron complex (N-3) and styrene-acrylate copolymer with sulfonic acid (N-4), were applied to EA-CCA, respectively. Tribo-charge of the mixture of model toner and EA-CCA was measured in the CCA concentration range up to 1,000ppm against model toner by using blow off method. In both N-2 and N-4 added systems, tribo-charges were increased with increasing CCA concentration up to 1000ppm, in the range of these experiments. In other two CCA added systems, maximum region appeared in tribo-charge around 50ppm of CCA concentration. Relationships between tribo-charge and CCA concentration in all CCA show linear in smaller CCA concentration range, less than 20ppm. The former two kinds of CCA added system have slope value of one fifth smaller than latter two kinds of CCA system. It means that efficiency of CCA molecules was different among CCAs on tribo-charge. The difference considered to be dissociation energy and/or interaction between each CCA molecule on the core surface. ©2011 Society for Imaging Science and Technology. Source


Tsunemi K.,Morimura Chemicals Ltd | Tsunemi K.,Chiba University | Suka A.,Morimura Chemicals Ltd | Iimura T.,Morimura Chemicals Ltd | And 4 more authors.
Journal of Imaging Science and Technology | Year: 2012

Particles of externally added charge control agent (EA-CCA) were prepared by means of a coacervation process and their effects on toner charge were investigated. The EA-CCA particles comprised silica core particles of 110 nm diameter and CCA molecules adhered to the core surface. Four kinds of negative charge control agent (CCA), namely a boron complex (N-1), a zinc complex (N-2), an iron complex (N-3), and a styrene-acrylate copolymer with sulfonic acid (N-4), were prepared as EA-CCAs. The tribo-charge of the mixture of model toner and EA-CCA was measured using the blow-off method. The CCA concentration range was up to 1 μmol/g with respect to the model toner. In both the N-1 and N-3 experiments, the maximum tribo-charge values appeared around 0.01 μmol/g of CCA concentration. On the other hand, in both the N-2 and N-4 experiments, the tribo-charge was increased with increasing CCA concentration. The CCAs were classified into two types. One was the low concentration type, N-1 and N-3, and the other was the high concentration type, N-2 and N-4. The CCA efficiency on tribo-charge was different between the two types of CCA. Low concentration type CCAs were effective in the low concentration region. They had no effect in the high concentration region. High concentration type CCAs were effective in the high concentration region. They still had a small effect in the low concentration region. © 2012 Society for Imaging Science and Technology. Source

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