Inkjet Yellow Ink Pigment Selection for Light Fastness and Chromaticity Balance

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Solution Overview

Problem

Inkjet recording technologies face challenges in achieving balanced light fastness and chromaticity among different ink compositions, leading to uneven image degradation and poor storage stability due to factors like light, ozone, and humidity.

Innovation Solution

A yellow ink composition using specific pigments like C. I. Pigment Yellow 213, 185, and 155, combined with cyan and magenta ink compositions containing phthalocyanine and quinacridone pigments, and black ink with carbon black, to create an inkset that enhances light fastness, chromaticity, and storage stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If conventional ink compositions are used to achieve good coloring properties, then chromaticity is improved, but light fastness and storage stability deteriorate due to oxidation and environmental factors

Engineering Contradiction:

ImprovechromaticityVSAvoidlight fastness

Core Design Contradiction:

Illumination intensityVSReliability

Solution Approach 1:

The patent uses composite pigments combining organic and inorganic materials to achieve both good chromaticity and light fastness. Specifically, it employs pigment combinations such as pigment red 57:6 and pigment blue 60 in specific ratios to create ink compositions that maintain color vibrancy while resisting degradation from light and environmental factors.

Inventive Principle:

Principle #40Composite materials

2Reliability

If specific pigment combinations are used to improve light fastness, then storage stability is improved, but chromaticity balance among different ink compositions deteriorates

Engineering Contradiction:

Improvestorage stabilityVSAvoidchromaticity balance

Core Design Contradiction:

ReliabilityVSIllumination intensity

Solution Approach 1:

The patent optimizes the concentration ratios of different pigments within specific ranges to achieve both storage stability and chromaticity balance. For example, it specifies pigment red 57:6 at 0.5-5.0 wt% and pigment blue 60 at 0.5-5.0 wt% in the magenta ink composition, and adjusts yellow ink compositions to ensure uniform fading characteristics across all colors when stored under identical conditions.

Inventive Principle:

Principle #35Parameter changes

3Reliability

If ink compositions are optimized for excellent light fastness, then image degradation resistance is improved, but manufacturing complexity increases due to multiple pigment combinations and ratios

Engineering Contradiction:

Improveimage degradation resistanceVSAvoidmanufacturing complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies different pigment combinations and concentrations to specific ink compositions (yellow, magenta, cyan, black) based on their individual requirements. Each ink composition is tailored with specific pigments in optimized ratios to achieve uniform degradation characteristics across all colors, rather than using a universal formulation for all inks.

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS7670418B2Yellow ink composition, inkset for inkjet, inkjet recording method, and recorded matter

Publication Date: 2010.03.02 SEIKO EPSON CORP

AI summary

A yellow ink composition for inkjet recording, containing one or more pigments selected from a group consisting of C. I. Pigment Yellow 213, 185, and 155 as a colorant.