Ink-Receiving Layer Pore Radius Optimization for Scratch Resistance

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Solution Overview

Problem

Existing recording media for outdoor use have insufficient scratch resistance and water resistance due to the absorption of hydrophobic binders by inorganic particles, which reduces their binding capability and ink absorbency.

Innovation Solution

A recording medium with an ink-receiving layer containing a hydrophobic and less hydrolyzable binder, such as acrylic resins, polycarbonate-modified urethane resins, or polyether-modified urethane resins, where the ratio of water-soluble resin to binder is 20% by mass or less, and the pore radius distribution of inorganic particles is optimized to 7 nm or more, reducing binder absorption and enhancing scratch resistance and ink absorbency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a hydrophobic binder is used to improve water resistance, then water resistance is improved, but the binder is absorbed by inorganic particles reducing binding capability and ink absorbency

Engineering Contradiction:
Improvewater resistanceVSAvoidbinding capability
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent changes the pore radius parameter of inorganic particles to 7 nm or more, which significantly reduces the absorption of hydrophobic binder by the particles. This parameter change allows the binder to maintain its binding capability while providing water resistance, as the larger pore radius prevents the binder from being trapped within the particle pores.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses a composite ink-receiving layer containing both inorganic particles with optimized pore radius and hydrophobic binder. This composite structure achieves synergistic effects where the inorganic particles provide water resistance while the binder maintains binding capability, resolving the contradiction between water resistance and binding strength.

Inventive Principle:
Principle #40Composite materials

2Reliability

If inorganic particles with small pore radius are used, then water resistance is improved, but binder absorption increases reducing ink absorbency

Engineering Contradiction:
Improvewater resistanceVSAvoidink absorbency
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent optimizes the pore radius parameter of inorganic particles to 7 nm or more. This specific parameter change creates an optimal balance where the particles are still sufficiently hydrophobic to provide water resistance but have large enough pores to prevent excessive binder absorption, thereby maintaining ink absorbency.

Inventive Principle:
Principle #35Parameter changes

3Strength

If binder content is increased to improve scratch resistance, then scratch resistance is improved, but ink absorbency decreases due to excessive binder absorption by particles

Engineering Contradiction:
Improvescratch resistanceVSAvoidink absorbency
Core Design Contradiction:
StrengthVSQuantity of substance

Solution Approach 1:

By changing the pore radius parameter of inorganic particles to 7 nm or more, the patent reduces the amount of binder absorbed by particles. This allows for lower binder content in the ink-receiving layer while still achieving sufficient scratch resistance, thereby maintaining ink absorbency.

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

The solution achieves high levels of ink absorbency, scratch resistance, and water resistance by minimizing binder absorption into inorganic particle pores, ensuring the binder effectively binds particles and maintains surface integrity under external forces and moisture exposure.

Implementation Method 1

the absorption of hydrophobic binders by inorganic particles, which reduces their binding capability

Methodology Applied
Scientific EffectAbsorption: Absorption (physical)

Implementation Method 2

a hydrophobic and less hydrolyzable binder, such as acrylic resins, polycarbonate-modified urethane resins, or polyether-modified urethane resins, where the ratio of water-soluble resin to binder is 20% by mass or less, and the pore radius distribution of inorganic particles is optimized to 7 nm or more, reducing binder absorption and enhancing scratch resistance and ink absorbency

Methodology Applied
Scientific EffectAdhesion: Adhesive

Data Source

PatentEP3069895B1Recording medium with increased scratch and water resistance
Publication Date: 2017.11.01 CANON KK

AI summary

A recording medium includes a substrate and an ink-receiving layer, wherein the ink-receiving layer contains an inorganic particle and a binder, and does not contain any water-soluble resin or contains a water-soluble resin such that a ratio of the content of the water-soluble resin to the content of the binder in the ink-receiving layer is 20% by mass or less, the binder contains at least one component selected from the group consisting of acrylic resins, polycarbonate-modified urethane resins, and polyether-modified urethane resins, and, for the recording medium, a ratio of a total pore volume in a pore radius range of 7 nm or more and 20 nm or less to a total pore volume in a pore radius range of 0 nm or more and 20 nm or less is 25% by volume or less.