Abstract The compositions (toners) are useful in electrostatic printing and xerography and are a mixture of base and modifier particles with the base particles having a dielectric constant K and the modifier particles being of a normally solid, inert, nonhygroscopic, inorganic compound which compound has a dielectric constant K'' of at least 10 and sufficient to give a K''/K ratio of at least 2 and an electropositive metal containing moiety chemically associated with an electronegative moiety. The metal of the electropositive moiety has a work function of up to about 2.5 electron volts. The toner has a charge/mass ratio at least about 50 percent greater than that of the base particles in their unmodified state.
An improved toner as claimed in claim 1, wherein said mixture comprises composite particles wherein the modifying particles are located substantially only on the surface or are located both on the surface and interiorly of the composite particles.
Claim 2
Dependent Claim
22 words
An improved toner as claimed in claim 1, wherein said mixture comprises base particles with modifier particles essentially on the surface thereof.
Claim 3
Dependent Claim
34 words
An improved toner as claimed in claim 1 wherein said mixed particles are disbursed in and carried by a liquid phase which is volatile and inert, and non-solvating in respect to said mixed particles.
Claim 4
Dependent Claim
28 words
An improved toner as claimed in claim 1, wherein said modifier particles have an average particle size below about 1 micron and are finer than said base particles.
Claim 5
Dependent Claim
25 words
An improved toner as claimed in claim 1, wherein said charge/mass ratio of the toner is at least double that of said unmodified base particles.
Claim 6
Dependent Claim
14 words
An improved toner as claimed in claim 6, wherein said base particles are fusible.
Claim 7
Dependent Claim
21 words
An improved toner as claimed in claim 6, wherein said base particles are pigmented so as to be dark in color.