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US 9,069,270 B2Granted
Toner for electrostatic latent image development
AssigneeKYOCERA Document Solutions Inc.
InventorHidetoshi Miyamoto
Life of this patent
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Abstract
A toner containing a binder resin, a release agent, and pigment fine particles is produced by aggregating fine particles containing the components of the toner to obtain fine particle aggregates and then coalescing the fine particle aggregates. The pigment fine particles have an average primary particle diameter of 50 nm or less, a Cv value of less than 20%, and an average circularity of 0.900 or more.
Claims5
A toner for electrostatic latent image development,
- wherein the toner is prepared by aggregating at least fine particles comprising a binder resin, pigment fine particles, and fine particles comprising a release agent, to thereby obtain fine particle aggregates and then coalescing the fine particle aggregates,
- the binder resin is an amorphous a copolyester of 25 mole % of polyoxypropylene (2,2)-2,2-bis(4-hydroxyphenyl)propane 25 mole % of polyoxyethylene (2,0)-2,2-bis(4-hydroxyphenyl)propane, 46 mole % of fumaric acid and 4 mole % of trimellitic acid,
- a number average molecular mass of the amorphous copolyester is 2,500,
- a mass average molecular mass of the amorphous copolyester is 6,500,
- a softening point of the amorphous copolyester is 91° C.,
- glass transition point of the amorphous copolyester is 51° C.,
- an acid value of the amorphous copolyester is 15.5 mg KOH/g,
- the fine particles comprising the binder resin are fine particles prepared by microparticulation of the binder resin together with a polyoxyethylene alkylether sulfate, and
- the pigment fine particles have an average primary particle diameter of 50 nm or less, a Cv value of less than 20%, and an average circularity of from 0.94 to 0.97.
6 more elements
Dependencies are inferred from the claim text.