Toner Set Solubility Parameter Difference for Scratch Peelability

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional methods for producing scratch images with a scratch concealing layer are unsuitable for low-volume, high-mix production and require additional protective layers, increasing device complexity and cost.

Innovation Solution

A toner set comprising an image forming toner and a scratch toner with a solubility parameter difference of 1.1 or greater, ensuring excellent peelability of the scratch layer, which is formed using electrophotography without the need for a protective layer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional printing methods (offset printing, gravure printing, screen printing) are used to form the scratch concealing layer, then the layer can be produced, but the production is unsuitable for low-volume, high-mix production

Engineering Contradiction:
Improvesuitability for low-volume, high-mix productionVSAvoidmanufacturing flexibility
Core Design Contradiction:
ProductivityVSEase of manufacture

Solution Approach 1:

The patent replaces conventional mechanical printing methods (offset printing, gravure printing, screen printing) with an electrophotographic system. This substitution enables on-demand production of scratch images with high flexibility for low-volume, high-mix production scenarios, as the electrophotographic apparatus can quickly switch between different scratch patterns without requiring physical plate changes or screen replacements.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If a protective layer is added to the scratch sheet as proposed in JP-2013-068787-A and JP-2013-088700-A, then the scratch image is protected, but the device configuration becomes more complex and cost increases

Engineering Contradiction:
Improveprotection of scratch imageVSAvoidnumber of layers and processes
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts and eliminates the protective layer from the scratch sheet structure. By forming the scratch concealing layer directly with electrophotography using toner with specific solubility parameters, the invention achieves sufficient durability and protection without requiring an additional protective layer, thereby simplifying the device configuration and reducing production costs.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The scratch concealing layer formed by electrophotography serves multiple functions simultaneously: it provides the scratch-off functionality, ensures durability during handling, and eliminates the need for a separate protective layer. The toner composition with controlled solubility parameters enables this multi-functionality, making the layer both the functional scratch layer and the protective element.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Ease of operation

If the scratch concealing layer is formed with ink having peelability, then the layer can be peeled when scratched, but the concealability and peelability balance is difficult to achieve with conventional methods

Engineering Contradiction:
Improvepeelability when scratchedVSAvoidconcealability and peelability balance
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The patent controls the solubility parameters (SP) of the toner components to achieve the optimal balance between concealability and peelability. By selecting binder resins and pigments with specific solubility characteristics and controlling their ratios, the invention creates a scratch concealing layer that maintains excellent concealability when intact and provides smooth, controlled peelability when scratched, overcoming the limitations of conventional ink-based approaches.

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

Enables cost-effective, on-demand production of scratch images with improved peelability and reduced process complexity, suitable for a wide variety of products in small quantities.

Implementation Method 1

An absolute difference (|SPi-SPs|) between a solubility parameter (SPi) of the image forming toner and a solubility parameter (SPs) of the scratch toner is 1.1 or greater

Methodology Applied
Scientific EffectSolubility parameter difference: Solvation

Data Source

PatentEP3825766A1Toner set, image forming method, and scratch image formed product
Publication Date: 2021.05.26 RICOH CO LTD
  • EP3825766A1 patent drawingFigure 1
  • EP3825766A1 patent drawingFigure 2
  • EP3825766A1 patent drawingFigure 3

AI summary

A toner set comprising an image forming toner and a scratch toner is provided. An absolute difference (|SPi-SPs|) between a solubility parameter (SPi) (cal/cm3)0.5 of the image forming toner and a solubility parameter (SPs) (cal/cm3)0.5 of the scratch toner is 1.1 (cal/cm3)0.5 or greater.