Toner Additive Attachment via Acid-Base Interaction Parameter

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Solution Overview

Problem

Current methods for achieving strong adhesion of surface additives to toner particles in xerographic developer materials are inefficient, leading to issues like ghosting, toner buildup, and increased costs due to loose additives, and are compromised by the use of larger spacer particles or increased energy consumption.

Innovation Solution

A method involving the calculation of an Interaction Surface Parameter (ISP) using Lewis acid and base values to select suitable toner and surface additives, ensuring a predictive acid-base interaction for improved adhesion, defined by the equation [(Ka)toner×(Kb)additive]+[(Kb)toner×(Ka)additive]−[(Ka)toner×(Ka)additive]−[(Kb)toner×(Kb)additive], with ISP greater than 0, to enhance the attachment of additives to toner particles.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If small additive size is used, then additive attachment is improved, but impaction reduction and cost efficiency deteriorate

Engineering Contradiction:
Improveadditive attachmentVSAvoidimpaction
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent changes the chemical parameter of the toner surface by incorporating basic groups (such as amine-functionalized polymers) to create a positive surface charge. This parameter change enables strong electrostatic attraction to negatively charged additives, allowing larger additive sizes (reducing impaction) while maintaining secure attachment through enhanced surface chemistry rather than relying solely on small additive size.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If strong additive embedding is used, then additive attachment is improved, but developer flow and charging performance deteriorate

Engineering Contradiction:
Improveadditive attachmentVSAvoiddeveloper flow
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent modifies the surface charge parameter of the toner to be more positive (through basic groups), creating strong electrostatic attraction that secures additives without requiring deep embedding. This maintains developer flow properties because the additives remain on the surface through electrostatic forces rather than being mechanically embedded, preserving the smoothness and flow characteristics of the developer.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If increased blend power is used, then additive attachment is improved, but energy consumption increases

Engineering Contradiction:
Improveadditive attachmentVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by stationary object

Solution Approach 1:

The patent changes the chemical composition parameter of the toner surface by adding basic groups that create positive charge. This chemical modification enables strong additive attachment through electrostatic attraction during normal blending operations, eliminating the need for increased blend power and thereby reducing energy consumption while achieving reliable additive attachment.

Inventive Principle:
Principle #35Parameter changes

4Reliability

If increased blend time is used, then additive attachment is improved, but cycle time and energy consumption increase

Engineering Contradiction:
Improveadditive attachmentVSAvoidcycle time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent modifies the surface charge parameter of the toner to be more positive through incorporation of basic groups. This parameter change creates strong electrostatic attraction that enables rapid additive attachment during blending, reducing the required blend time and thereby decreasing cycle time and energy consumption while maintaining effective additive attachment.

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 ensures strong and stable attachment of surface additives to toner particles, preventing ghosting and toner buildup, while reducing energy consumption and costs by optimizing the size and interaction of additives, thereby improving print quality and extending component life.

Implementation Method 1

an acid-base interaction has an Interaction Surface Parameter (ISP) of greater than 0

Methodology Applied
Scientific EffectAcid-base interaction: Chemical Bonding

Implementation Method 2

determining the Lewis acid and Lewis base constants for the candidate toner and the candidate external surface additive

Methodology Applied
Scientific EffectLewis acid-base theory: Lewis

Data Source

PatentUS7858281B2Acid-base property considerations for improved additive attachment on toner
Publication Date: 2010.12.28 XEROX CORP

AI summary

A developer comprised of a toner and at least one external surface additive, wherein an acid-base interaction has an Interaction Surface Parameter (ISP) of greater than 0, and wherein ISP is defined by the following equation: [(Ka)toner×(Kb)additive]+[(Kb)toner×(Ka)additive]−[(Ka)toner×(Ka)additive]−[(Kb)toner×(Kb)additive], wherein Ka is the Lewis acid value and Kb is the Lewis base value.