摘要:
A process for the preparation of encapsulated toner which comprises (1) mixing a blend of a core monomer or monomers, free radical chemical initiator, pigment, and an oil soluble shell monomer to form an organic phase; (2) dispersing the resulting organic phase in the absence of surfactant or stabilizer in an aqueous solution comprised of a water-soluble shell monomer whereby interfacial shell polymerization is initiated; (3) stirring the resulting suspension to allow completion of interfacial shell polymerization; (4) initiating free radical core polymerization by increasing the temperature of the suspension from ambient to about 75.degree. to about 90.degree. C.; (5) completing core polymerization by maintaining the aforementioned temperature in step (4) for an effective period of time; (6) cooling; (7) filtering; and (8) drying.
摘要:
A process for the continuous preparation of an encapsulated toner comprised of a core comprised of polymer and pigment encapsulated within a polymer shell, which process comprises continuously separately feeding an oil phase containing core monomers, oil soluble shell monomers and pigment and an aqueous phase containing surfactant into a continuous flowthrough mixing tank; homogenizing the aforementioned two phases to enable small oil droplets with an average diameter of from between about 3 to about 25 microns; overflowing the resulting droplets to at least one continuously stirred tank reactor while simultaneously feeding water soluble shell monomer to said stirred reactor to effect interfacial polymerization thereby causing shell formation; and thereafter allowing the encapsulated droplets to flow into a reactor or reactors and heating the reactor or reactors to effect free radical polymerization of the core monomers, followed by cooling, and isolating the said encapsulated toner.
摘要:
A process for the preparation of encapsulated toner compositions which comprises dispersing a mixture of addition monomers, an optional preformed polymer resin, a free radical initiator, a colorant comprised of a pigment, dye or mixtures thereof, and shell forming monomer in an aqueous medium containing a cellulose polymer and a first ionic surfactant thereby forming a stable microdroplet suspension; and subsequently adding an aqueous solution of a second stabilizing surfactant followed by the formation of a soluble monomer forming shell wall by interfacial polymerization, and thereafter initiating and completing the core resin-forming free radical polymerization by heating thereby resulting in toner compositions with an average volume particle size of from about 3 to about 7 microns.
摘要:
Pressure sensitive adhesive compositions for use in transdermal drug delivery systems comprising an adhesive composition which is tolerant to plasticization by cutaneous penetration enhancers contained in the transdermal drug formulation are disclosed. Specifically, the pressure sensitive adhesive composition of the present invention comprises an acrylic copolymer prepared from (i) at least 40% by weight of th total monomer composition of alkyl acrylate monomers with a Tg of -90 to 0.degree. C., (ii) 0-15% by weight of the total monomer composition of monomers with a Tg of 0 to 250.degree. C., and (iii) 10-60% by weight of the total monomer composition of substituted acrylamides or methacrylamides having the structural formula: ##STR1## wherein R.sub.1 is H or CH.sub.3,R.sub.2 is H or CH.sub.3, andR.sub.3 is (a) CH.sub.3,(b) C(CH.sub.3).sub.2 --(CH.sub.2).sub.n --CH.sub.3 where n is 0 through 17, or(c) substituents of the formula: ##STR2## where m is 0 through 10, and optionally(iv) at least 0.2% by weight of acrylic monomers containing at least one group having a reactive hydrogen, and (v) 0.01-2% by weight of a chelated metal alkoxide crosslinker to (i), (ii) and (iii).
摘要:
An encapsulated toner composition and process thereof, which toner is comprised of a core comprised of a polymer resin or resins, color pigment, dye, or mixtures thereof, and thereover an inner shell resin comprised, for example, of a polyurea, and thereover an outer shell coating comprised of an alkyl cellulose. The colored encapsulated toners are useful in reprographic processes wherein, for example, low gloss is desired.