Biodegradable Polyester Toner via Emulsion Aggregation

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Solution Overview

Problem

There is a need for improved and environmentally friendly emulsion aggregation toner compositions and processes, particularly due to the potential restrictions on the use of bisphenol A-based polyesters, which are carcinogenic and endocrine disruptors, necessitating the development of biodegradable alternatives.

Innovation Solution

The use of semicrystalline biodegradable thermoplastic polyester resins, such as polyhydroxyalkanoate (PHA) resins, in the emulsion aggregation process, which includes forming an emulsion latex of resin particles and combining them with colorants and waxes to achieve aggregated, fused toner particles without the need for organic solvents, thus avoiding the use of bisphenol A and reducing environmental impact.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If bisphenol A-based polyester resins are used in emulsion aggregation toner processes, then manufacturing performance and toner properties are achieved, but environmental safety and health hazards worsen due to carcinogenic and endocrine disruptor concerns

Engineering Contradiction:

Improvetoner performanceVSAvoidenvironmental and health hazards

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent removes bisphenol A and other harmful substances from the polyester resin composition. The resin is formulated without bisphenol A, bisphenol F, and other restricted substances while maintaining the necessary functional properties for toner performance through alternative chemical structures and compositions.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent modifies the chemical composition parameters of the polyester resin by adjusting the molar ratios of diols and dicarboxylic acids, controlling molecular weight distribution, and optimizing functional group content to achieve desired toner properties without using harmful substances. The resin composition is tailored with specific constraints on various chemical components to ensure both performance and safety.

Inventive Principle:

Principle #35Parameter changes

2Stability of the object's composition

If conventional polyester resin emulsification processes are used, then resin dispersion is achieved, but production costs increase due to the costly emulsification step

Engineering Contradiction:

Improveresin dispersionVSAvoidproduction cost

Core Design Contradiction:

Stability of the object's compositionVSEase of manufacture

Solution Approach 1:

The patent eliminates the costly emulsification step from the manufacturing process. Instead of using traditional emulsification methods that require additional equipment, time, and materials, the resin is directly dispersed in the aqueous medium containing colorant and wax through simplified mixing and heating processes, significantly reducing production costs while achieving stable dispersion.

Inventive Principle:

Principle #2Taking out (Extraction)

3Object-affected harmful factors

If biodegradable polyester resins are used to replace conventional resins, then environmental friendliness improves, but manufacturing precision and toner particle control may worsen

Engineering Contradiction:

Improveenvironmental impactVSAvoidparticle size control

Core Design Contradiction:

Object-affected harmful factorsVSManufacturing precision

Solution Approach 1:

The patent optimizes multiple parameters of the biodegradable polyester resin including molecular weight, functional group content, molar ratios of monomers, and composition distribution to achieve precise control over toner particle size, shape, and properties. The resin is formulated with specific constraints on chemical composition and physical properties to ensure consistent and precise manufacturing of toner particles with desired characteristics.

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 approach results in biodegradable toner compositions that are environmentally friendly, eliminate the costly polyester resin emulsification step, and provide efficient toner production with controlled particle size and shape, enhancing the sustainability and performance of toner particles.

Implementation Method 1

adding a coagulant to said mixture; heating the mixture, permitting aggregation and coalescence of said semicrystalline biodegradable polyester resin, colorant, and wax, to form toner particles

Methodology Applied

Scientific EffectCoagulation: Coagulation

Implementation Method 2

heating the mixture, permitting aggregation and coalescence of said semicrystalline biodegradable polyester resin

Methodology Applied

Scientific EffectMelting: Melting

Implementation Method 3

permitting aggregation and coalescence of said semicrystalline biodegradable polyester resin, colorant, and wax, to form toner particles

Methodology Applied

Scientific EffectCoalescence:

Data Source

PatentUS8137884B2Toner compositions and processes

Publication Date: 2012.03.20 XEROX CORP

AI summary

A toner composition includes toner particles including a polymeric resin, a colorant, a wax, and a optional coagulant.