PREPARATIVE PROCESS FOR SILICONE CONTAINING N-CAP TONERS
Original Publication Date: 1995-Aug-31
Included in the Prior Art Database: 2004-Apr-07
Xerox Disclosure Journal
AbstractDisclosed is a process for the preparation of encapsulated silicone containing toner particles wherein a functionalized polysiloxane is initially prepared by catalytic coupling followed by copolymerization with acrylate monomers and subsequent encapsulation.
XEROX DISCLOSURE JOURNAL
PREPARATIVE PROCESS FOR Proposed Classification SILICONE CONTAINING N-CAP U.S. C1.430/109 TONERS Int. C1. G03g 09/08 Guerino Sacripante
Beng S. Ong
Disclosed is a process for the preparation of encapsulated silicone containing toner particles wherein a functionalized polysiloxane is initially prepared by catalytic coupling followed by copolymerization with acrylate monomers and subsequent encapsulation.
The toner exhibits high fix characteristics (80%-95%) at half the transfix pressure of the Delphax printer without displaying undesirable image ghosting or agglomeration. In addition, the toner also possesses good powder flow characteristics as evidenced from its low cohesiveness (11% as compared to 13% for a Coates' toner). The cohesiveness of this toner can be further reduced to about 2 to 5% by additional silane surface treatment.
The preparation of the silicone toner utilizes a bis(methacry1oxy)- functionalized polysiloxane to generate the long-range crosslinked silicone- containing poly(laury1 methacrylate) core binder resin. This core binder is essential for the provision of high fix characteristics without image ghosting and agglomeration. The synthesis of the methacryloxy-functionalized
polysiloxane involves bis-hydrosilylation of about two equivalents of allylmethacrylate with a silylhydride-terminated polysiloxane.
To 46.0 grams of hydride-terminated polydimethylsiloxane (MW = 28,000, Petrarch Systems) was added 1.4 grams of allylmethacrylate and a catalytic amount of platinum hydrogen chloride, and the mixture was stirred at room temperature overnight. The molecular weight of the resulting viscous liquid, methacryloxypropyl-terminated polydimethysiloxane was analyzed by GPC, which yielded an Mn of 37,000 and Mw of 74,000. Furthermore, the NMR spectral properties of this polysiloxane product are similar to those of commercial material. 13.0 grams of this polysiloxane was added to a mixture of 120.0 grams of lauryl methacrylate, 47.0 grams of Isonate...