Stable Color-Changing Ink via Surface-Treated Microcapsules

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Solution Overview

Problem

Existing color-changing inks, particularly those using microcapsule pigments, face stability issues due to large particle diameters, leading to phenomena like pen blockage and ink layering during high-speed centrifugation, limiting their application in writing tools.

Innovation Solution

A stable color-changing ink formula is developed, which includes water, a pH regulator, corrosion inhibitor, dispersant, emulsion-type lubricant, water-soluble resin, thickener, and microcapsule color-changing pigment, optimized to maintain even dispersion and suspension, enhancing stability and writing performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If microcapsule pigment with large particle diameter (1 to 20 μm) is used for color-changing ink, then the color-changing function is achieved, but the ink system stability deteriorates due to sedimentation and layering

Engineering Contradiction:
Improvecolor-changing functionVSAvoidink system stability
Core Design Contradiction:
Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

A surface-treated microcapsule pigment is used as an intermediary between the microcapsule pigment and the ink system. The surface treatment modifies the pigment surface to improve compatibility with the ink medium, preventing sedimentation and layering while maintaining the color-changing function. This intermediary layer resolves the contradiction by enabling large-particle microcapsules to remain stably suspended in the ink.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention changes the surface parameters of the microcapsule pigment through surface treatment, altering its physical and chemical properties. This parameter change enables the pigment to maintain stability in the ink system without requiring reduction of particle size, thus resolving the contradiction between maintaining color-changing function and achieving ink stability.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If microcapsule pigment with large particle diameter is used, then color-changing effect is achieved, but writing effect stability deteriorates due to hollow phenomenon and ink accumulation

Engineering Contradiction:
Improvecolor-changing effectVSAvoidwriting effect stability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The surface-treated microcapsule pigment acts as an intermediary that prevents direct aggregation and hollow phenomenon during writing. The surface treatment ensures uniform distribution and controlled release, maintaining writing effect stability while preserving the color-changing effect.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The surface treatment is applied in advance to the microcapsule pigment before ink formulation. This preliminary action prepares the pigment surface to prevent writing defects such as hollow phenomenon and ink accumulation, ensuring stable writing performance from the outset.

Inventive Principle:
Principle #10Preliminary action

3Ease of manufacture

If conventional ink formulation is used with microcapsule pigment, then manufacturing is simplified, but centrifugation stability fails due to ink layering and pen blockage

Engineering Contradiction:
Improveformulation simplicityVSAvoidcentrifugation stability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The surface-treated microcapsule pigment serves as an intermediary that maintains centrifugation stability without complicating the formulation process. The treatment is applied during pigment manufacturing, allowing the ink formulator to use the treated pigment directly in conventional formulations while achieving improved centrifugation resistance.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 formula achieves high stability in ink systems and writing effects, allowing for wide application in various writing tools without layering or blockage, meeting industry standards even after prolonged centrifugation.

Implementation Method 1

0.1 to 3 parts of a dispersant... the microcapsule pigment is evenly dispersed in the system

Methodology Applied
Scientific EffectDispersion: Dispersion (of waves)

Implementation Method 2

0.1 to 3 parts of a thickener... cooperate with the thickener for mutual promotion, so as to reach an even and stable suspension state

Methodology Applied
Scientific EffectViscosity:

Implementation Method 3

0.1 to 3 parts of an emulsion type lubricant... increase the fluidity and lubricity of the ink

Methodology Applied
Scientific EffectLubrication: Lubrication

Implementation Method 4

0.1 to 2 parts of a pH regulator... adjust the pH value of the ink

Methodology Applied
Scientific EffectpH regulation:

Implementation Method 5

0.1 to 1 part of a corrosion inhibitor... protect the metal tip for filling the ink into the writing tool from being corroded

Methodology Applied
Scientific EffectCorrosion inhibition:

Data Source

PatentEP2977416B1Stable color-changing ink background
Publication Date: 2016.07.27 WANG YONG

AI summary

The present invention discloses a stable color-changing ink, which includes the following components in parts by weight: 10 to 60 parts of water, 0.1 to 2 parts of a pH regulator, 0.1 to 1 part of a corrosion inhibitor, 0.1 to 3 parts of a dispersant, 0.1 to 3 parts of an emulsion type lubricant, 0.5 to 10 parts of a water soluble resin, 10 to 50 parts of a microcapsule color-changing pigment, and 0.1 to 3 parts of a thickener. The present invention achieves the stability of an ink system and the stability of the writing effect, and moreover, by means of minute adjustment and extension of the formula, can be used in different application fields, involving color-changing gel inks, color-changing watercolor inks, color-changing water-based inks, color-changing medium oil inks, color-changing fountain pen inks, color-changing writing brush inks, color-changing writing brush inks, color-changing inkjet inks, anti-counterfeiting inks, high-temperature disappearing inks, and other application systems.