Process for producing encapsulated toner
First Claim
1. A process for producing an encapsulated toner, comprising:
- preparing a solution of a shell material resin set to an acidic pH region or a basic pH region wherein the shell material resin comprises a vinyl copolymer having a number-average molecular weight of 5,000 to 40,000, said shell material resin being dissolved in an aqueous medium containing an organic solvent having a solubility parameter of at least 11.0,dispersing solid core particles in the solution to form a dispersion,changing the pH of the dispersion to a pH region where the shell material resin is precipitated from the dispersion, andcoating the core particles with the precipitated shell material resin.
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Abstract
An encapsulated toner for electrophotography is produced through a process, comprising: preparing a solution of a shell material resin set to an acidic (or basic) pH region; dispersing solid core particles in the solution to form a dispersion; changing the pH of the dispersion to a pH region, which is preferably a basic (or acidic) pH region, where the shell material resin is precipitated from the dispersion; and coating the solid core particles with the precipitated shell material resin. The shell material is preferably a proton-attracting basic (or dissociative acidic) vinyl-type copolymer and is dissolved in a pH-adjusted aqueous medium comprising water and a polar solvent, such as a lower alcohol. Thus, an encapsulated toner with excellent triboelectric chargeability and environmental characteristic is prepared without coalescence of capsules or formation of free shells.
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Citations
58 Claims
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1. A process for producing an encapsulated toner, comprising:
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preparing a solution of a shell material resin set to an acidic pH region or a basic pH region wherein the shell material resin comprises a vinyl copolymer having a number-average molecular weight of 5,000 to 40,000, said shell material resin being dissolved in an aqueous medium containing an organic solvent having a solubility parameter of at least 11.0, dispersing solid core particles in the solution to form a dispersion, changing the pH of the dispersion to a pH region where the shell material resin is precipitated from the dispersion, and coating the core particles with the precipitated shell material resin. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58)
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Specification