Core-Shell Toner with Organopolysiloxane Shell for Cold Offset
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Solution Overview
Problem
Existing toners with organopolysiloxane structures face challenges in achieving both environmental stability, durability, and low-temperature fixability due to issues like cold offset, susceptibility to humidity, and softening of the toner surface, which affect their performance in severe environments.
Innovation Solution
A toner with a core-shell structure containing a core resin, colorant, and wax, and a shell layer with a specific organopolysiloxane structure optimized by controlling the amount of Si derived from the organopolysiloxane and crosslink density, using a polymer composition with monomers having multiple polymerizable unsaturated groups to enhance durability and environmental stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If organopolysiloxane is incorporated into the core resin to improve environmental stability, then charging performance stability in humid environments is improved, but wax exudation is inhibited causing cold offset
Solution Approach 1:
The patent extracts the organopolysiloxane from the core resin and relocates it exclusively to the shell resin. This separation allows the core resin to maintain its wax exudation properties for low-temperature fixability while the shell resin provides environmental stability through the organopolysiloxane content, resolving the contradiction between charging stability and cold offset prevention.
Solution Approach 2:
The patent applies local quality by concentrating the organopolysiloxane specifically in the shell resin layer rather than distributing it throughout the core resin. This localized placement ensures that the shell resin provides humidity resistance and charging stability while the core resin remains free to exhibit wax exudation behavior for low-temperature fixation, thus eliminating cold offset.
2Reliability
If a thick shell layer is used to improve environmental stability, then durability is improved, but heat transfer to the core resin is reduced causing poor low-temperature fixability
Solution Approach 1:
The patent optimizes the shell resin composition by incorporating organopolysiloxane, which modifies the thermal and mechanical parameters of the shell layer. This allows the shell to maintain sufficient thickness for durability and environmental stability while improving heat transfer efficiency to the core resin, enabling low-temperature fixability without sacrificing environmental stability.
3Reliability
If organopolysiloxane is present in large amounts in the shell resin to improve environmental stability, then charging performance stability is improved, but the toner surface softens reducing durability
Solution Approach 1:
The patent carefully controls the organopolysiloxane content parameter in the shell resin within an optimal range. This parameter optimization ensures that sufficient organopolysiloxane is present to provide charging performance stability and environmental stability, while preventing excessive softening of the toner surface that would compromise durability.
Data Source
AI summary
Provided is a toner including toner particle, the toner particle having a core-shell structure having: a core containing a core resin, a colorant, and a wax; and a shell layer containing a resin “A” on a surface of the core, in which: the resin “A” contains a segment having an organopolysiloxane structure; the toner particle has an amount of Si derived from the organopolysiloxane structure of 6.0 or more and 10.0 or less, the amount of Si being measured by X-ray photoelectron spectroscopy; the resin “A” is a polymer of a monomer composition containing a monomer “a” having two or more polymerizable unsaturated groups in one molecule thereof; and the monomer “a” satisfies the following formula (1).(Xa−1.0)×Ya≧3.0×10−5 (1)