Inkjet Recording Medium Calcium Carbonate Silica Composite

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Solution Overview

Problem

Inkjet recording media using calcium carbonate as a pigment face challenges with poor ink-drying properties, water resistance, and color development, while also having a texture different from offset printing and poor writing suitability due to the instability of the coating color and low ink absorption of calcium carbonate.

Innovation Solution

An inkjet recording medium with an ink-receiving layer containing 50% or more calcium carbonate, a binder, and an inkjet ink-fixing agent, optimized with specific weight ratios and properties to enhance ink-drying, water resistance, and image quality, while maintaining a texture suitable for offset printing and writing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If calcium carbonate is used as a pigment in the ink-receiving layer, then cost is reduced and texture similar to offset printing is achieved, but ink-drying property and water resistance deteriorate

Engineering Contradiction:
ImprovecostVSAvoidink-drying property
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent uses a composite pigment system combining calcium carbonate (50-90 wt%) with silica (10-50 wt%). This composite approach allows the ink-receiving layer to benefit from calcium carbonate's cost-effectiveness and offset-printing-like texture while silica provides the necessary ink absorption and drying properties. The synergistic combination resolves the contradiction between cost reduction and ink-drying performance.

Inventive Principle:
Principle #40Composite materials

2Ease of manufacture

If calcium carbonate is used as a pigment in the ink-receiving layer, then cost is reduced and texture similar to offset printing is achieved, but water resistance deteriorates

Engineering Contradiction:
ImprovecostVSAvoidwater resistance
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The composite pigment system of calcium carbonate and silica provides both cost benefits and water resistance. The silica component contributes to water resistance while calcium carbonate maintains the offset-printing-like texture and reduces cost. Additionally, the binder resin and its specific content ratio (1-10 parts by weight per 100 parts pigment) further enhance water resistance properties.

Inventive Principle:
Principle #40Composite materials

3Shape

If calcium carbonate is used as a pigment in the ink-receiving layer, then offset printing texture is achieved, but color development deteriorates due to low ink absorption

Engineering Contradiction:
ImprovetextureVSAvoidcolor development
Core Design Contradiction:
ShapeVSManufacturing precision

Solution Approach 1:

The patent employs a composite pigment system where silica (10-50 wt%) compensates for calcium carbonate's low ink absorption capability. Silica provides excellent ink absorption properties that enhance color development, while calcium carbonate (50-90 wt%) maintains the desired offset-printing-like texture. This composite approach resolves the contradiction between texture and color development.

Inventive Principle:
Principle #40Composite materials

4Manufacturing precision

If a coated paper type inkjet recording medium with bulky pigment is used to improve color development, then ink absorption and color development are enhanced, but writing suitability deteriorates

Engineering Contradiction:
Improvecolor developmentVSAvoidwriting suitability
Core Design Contradiction:
Manufacturing precisionVSEase of operation

Solution Approach 1:

The patent changes the particle size parameter of the pigment to resolve the contradiction. By using fine calcium carbonate particles (D50: 0.5-5.0 μm) instead of bulky pigments, the surface becomes smoother and more suitable for writing, while still achieving good color development through the composite pigment system and optimized binder content. This parameter change transforms the surface characteristics from rough to smooth, improving writing suitability.

Inventive Principle:
Principle #35Parameter changes

5Manufacturing precision

If a coated paper type inkjet recording medium is used to improve color development, then ink absorption is enhanced, but the ink-receiving layer easily falls off from the substrate

Engineering Contradiction:
Improveink absorptionVSAvoidadhesion strength
Core Design Contradiction:
Manufacturing precisionVSStrength

Solution Approach 1:

The patent optimizes the binder content parameter (1-10 parts by weight per 100 parts pigment) to achieve the right balance between ink absorption and adhesion. The binder resin provides binding force that prevents the ink-receiving layer from falling off, while still allowing sufficient ink absorption. This parameter optimization resolves the contradiction between ink absorption enhancement and adhesion strength.

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 excellent ink-drying properties, high color development, and writing suitability, with improved stability and surface strength of the ink-receiving layer, reducing cockling and bleeding, and maintaining the texture of offset printing.

Implementation Method 1

an ink-receiving layer containing a pigment, a binder and an inkjet ink-fixing agent comprising a cationic compound

Methodology Applied
Scientific EffectCapillary action: Capillary Action

Implementation Method 2

an inkjet ink-fixing agent comprising a cationic compound... which is fixed by forming an ion complex by ionic bonds with an anionic coloring agent in the inkjet ink

Methodology Applied
Scientific EffectIon complex formation: Ion Repulsion/Attraction

Data Source

PatentUS9242497B2Inkjet recording medium
Publication Date: 2016.01.26 NIPPON PAPER IND CO LTD

AI summary

An inkjet recording medium, comprising an ink-receiving layer containing a pigment, a binder and an inkjet ink-fixing agent comprising a cationic compound disposed on at least one surface of a base paper, wherein 50% or more by weight of calcium carbonate is contained in terms of a solid content based on a total amount of the pigment contained in the ink-receiving layer; 75 to 90 parts by weight of the pigment, 1 to 10 parts by weight of the binder and 5 to 20 parts by weight of the inkjet ink-fixing agent are contained based on 100 parts by weight of the ink-receiving layer; the drop water absorbency of the ink-receiving layer (according to the drop water absorbency defined in Japan Technical Association of the Pulp and Paper Industry, J. TAPPI, No. 32-2:2000 except that a drop water amount is 0.001 ml) is 200 seconds or less; and a Stockigt sizing degree according to JIS-P-8122 for the inkjet recording medium is 5 seconds or less.