Resin Particle Dispersion via Controlled Reduced-Pressure Distillation

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Solution Overview

Problem

Existing methods for producing resin particle dispersions face challenges in achieving high yield and narrow particle size distribution due to excessive foaming during reduced pressure distillation, which can mix resin into the distillate and destabilize the oil and water phases.

Innovation Solution

A controlled rate of pressure reduction during reduced pressure distillation, ranging from 0.01 kPa/min to 0.5 kPa/min, is applied when the organic solvent concentration is between 30% to 1% by mass, preventing excessive foaming and maintaining phase stability, thereby producing resin particles with a narrow size distribution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If reduced pressure distillation is performed to remove organic solvent from phase-inverted emulsion, then solvent removal efficiency is improved, but excessive foaming occurs which mixes resin into distillate and destabilizes phases

Engineering Contradiction:
Improvesolvent removal efficiencyVSAvoidexcessive foaming
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The patent applies parameter changes by controlling the pressure reduction rate within a specific range (0.01 to 0.5 kPa/min) during reduced pressure distillation. This parameter optimization prevents excessive foaming while maintaining efficient solvent removal, resolving the contradiction between productivity and harmful foaming effects.

Inventive Principle:
Principle #35Parameter changes

2Loss of time

If fast pressure reduction is applied during distillation, then distillation time is reduced, but resin particles aggregate and particle size distribution widens

Engineering Contradiction:
Improvedistillation timeVSAvoidparticle size distribution
Core Design Contradiction:
Loss of timeVSManufacturing precision

Solution Approach 1:

The patent optimizes the pressure reduction rate parameter to balance distillation time and particle size control. By setting the rate between 0.01 and 0.5 kPa/min, the process achieves reasonable processing time while preventing resin particle aggregation and maintaining narrow particle size distribution.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements feedback control by monitoring the pressure reduction rate and adjusting it to remain within the optimal range. This ensures that particle size distribution is maintained throughout the distillation process while achieving efficient solvent removal.

Inventive Principle:
Principle #23Feedback

3Productivity

If high pressure reduction rate is used, then distillation speed increases, but yield of resin particle dispersion decreases due to resin mixing into distillate

Engineering Contradiction:
Improvedistillation speedVSAvoidyield of resin particle dispersion
Core Design Contradiction:
ProductivityVSLoss of substance

Solution Approach 1:

The patent controls the pressure reduction rate parameter within the optimal range of 0.01 to 0.5 kPa/min to prevent resin from mixing into the distillate. This parameter optimization maintains high distillation speed while preserving resin particle dispersion yield.

Inventive Principle:
Principle #35Parameter changes

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

This method results in a resin particle dispersion with a high yield and narrow particle size distribution, suitable for producing toners with improved properties.

Implementation Method 1

preparing a phase-inverted emulsion by phase inversion emulsification of a resin using an organic solvent and an aqueous medium

Methodology Applied
Scientific EffectPhase inversion emulsification: Emulsion

Implementation Method 2

removing the organic solvent from the phase-inverted emulsion contained in a distillation tank by reduced pressure distillation

Methodology Applied
Scientific EffectReduced pressure distillation: Distillation

Implementation Method 3

removing the organic solvent from the phase-inverted emulsion contained in a distillation tank by reduced pressure distillation

Methodology Applied
Scientific EffectEvaporation: Evaporation

Data Source

PatentUS12398245B2Method for producing resin particle dispersion, method for producing toner for electrostatic image development, and toner for electrostatic image development
Publication Date: 2025.08.26 FUJIFILM BUSINESS INNOVATION CORP

AI summary

A method for producing a resin particle dispersion includes: preparing a phase-inverted emulsion by phase inversion emulsification of a resin using an organic solvent and an aqueous medium; and removing the organic solvent from the phase-inverted emulsion contained in a distillation tank by reduced pressure distillation. During the reduced pressure distillation, the rate of pressure reduction in an environment in which the pressure inside the distillation tank is equal to or higher than vapor pressure and equal to or lower than (the vapor pressure+5 kPa) when the concentration of the organic solvent in the phase-inverted emulsion is in the range of 30% by mass or less to 1% by mass or more is from 0.01 kPa/min to 0.5 kPa/min inclusive until the pressure inside the distillation tank reaches a preset reduced pressure for the reduced pressure distillation.