Toner with Crystalline Polyester for Fixability and Storability

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Solution Overview

Problem

Existing toners face challenges in achieving both low-temperature fixability and image storability, with previous solutions either compromising on one aspect for the other, and existing toners are not effective in high-temperature environments during transportation.

Innovation Solution

A toner composition comprising a binder resin and crystalline polyester with a specific structure, which includes a polyester segment and a silicone structure, enhancing compatibility and recrystallization properties to improve both low-temperature fixability and image storability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If a crystalline polyester is added to the toner to improve low-temperature fixability, then the low-temperature fixability is improved, but the image storability deteriorates due to softening of the fixed image

Engineering Contradiction:

Improvelow-temperature fixabilityVSAvoidimage storability

Core Design Contradiction:

TemperatureVSReliability

Solution Approach 1:

The invention changes the chemical structure parameters of the binder resin by introducing a polyester component with specific structural features (formula 1) that has controlled polarity and molecular weight. This parameter change allows the binder resin to maintain appropriate adhesion at low temperatures while preventing excessive softening at high temperatures, thus resolving the contradiction between low-temperature fixability and image storability

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention creates a composite binder resin system combining the polyester component (formula 1) with other resin components in specific proportions. This composite structure allows the polyester to provide low-temperature flexibility while the other components maintain high-temperature stability, preventing image softening and improving both low-temperature fixability and image storability simultaneously

Inventive Principle:

Principle #40Composite materials

2Reliability

If compatibility between amorphous polyester and crystalline polyester is suppressed to improve image storability, then the image storability is improved, but the low-temperature fixability deteriorates

Engineering Contradiction:

Improveimage storabilityVSAvoidlow-temperature fixability

Core Design Contradiction:

ReliabilityVSTemperature

Solution Approach 1:

The invention optimizes the polarity parameter of the binder resin by carefully designing the polyester structure (formula 1) with balanced polar and non-polar segments. This parameter optimization ensures sufficient compatibility with crystalline polyester at low temperatures for good fixability, while maintaining appropriate phase separation at high temperatures for image storability

Inventive Principle:

Principle #35Parameter changes

3Temperature

If the toner is designed for good low-temperature fixability, then the low-temperature fixability is improved, but the image storability in high-temperature environments during transport deteriorates

Engineering Contradiction:

Improvelow-temperature fixabilityVSAvoidimage storability in high-temperature environment

Core Design Contradiction:

TemperatureVSObject-affected harmful factors

Solution Approach 1:

The invention changes the thermal transition parameters of the binder resin by selecting polyester with specific glass transition temperature and melting point characteristics. This ensures the toner remains stable and resistant to softening at high transport temperatures while maintaining flexibility for low-temperature fixing

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention converts the potential harm of crystalline polyester causing image softening at high temperatures into a benefit by controlling its compatibility relationship with the binder resin. The crystalline polyester provides structural support and heat resistance when properly balanced with the polyester component, improving image storability during transport

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The toner exhibits excellent low-temperature fixability and image storability, with a glass transition temperature range of 45° C. to 60° C., and endothermic quantities that promote recrystallization, ensuring heat resistance and reduced adhesion, thus maintaining image quality across varying temperatures and humidity levels.

Implementation Method 1

endothermic quantities that promote recrystallization, ensuring heat resistance

Methodology Applied

Scientific EffectRecrystallization: Crystallisation

Implementation Method 2

endothermic quantities that promote recrystallization

Methodology Applied

Scientific EffectEndothermic reaction: Endothermic Reaction

Data Source

PatentUS11698594B2Toner

Publication Date: 2023.07.11 CANON KK

AI summary

A toner including a toner particle comprising a binder resin and a crystalline polyester, wherein the binder resin contains a polyester having a structure represented by the following formula (1):in formula (1), Rs each independently represent hydrogen, a methyl group, or a phenyl group;A represents a polyester segment;B represents a polyester segment or any functional group selected from the group consisting of —R1OH, —R1COOH,and —R1NH2 wherein R1 represents a single bond or a C1-4 alkylene group; andthe average repeat number n is 10 to 80.