Water-Based Ink Dye Formulation for Optical Density and Light Resistance
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Solution Overview
Problem
Water-based black dye inks for ink-jet recording often lack sufficient optical density and light resistance, with blue dyes used to enhance density but experiencing degradation issues over time, leading to color changes such as yellowing or reddening.
Innovation Solution
A water-based ink formulation incorporating a blue dye with a hue angle of 220° to 280°, a yellow dye with a hue angle of 70° to 120°, and a copper phthalocyanine dye, with a mass ratio of copper phthalocyanine to blue dye of 0.5 or higher, ensuring a total dye content of 6% or more by mass, which maintains optical density and light resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If blue dye is used to increase optical density, then OD value is improved, but light resistance deteriorates
Solution Approach 1:
The patent combines blue dye and copper phthalocyanine dye in a composite ink formulation. The blue dye provides high optical density while the copper phthalocyanine dye provides light resistance, creating a composite material that achieves both high OD value (≥1.8) and excellent light resistance, preventing the black recorded image from turning yellow over time.
2Reliability
If mixture of three primary colors is used, then light resistance is improved, but optical density deteriorates
Solution Approach 1:
The patent changes the dye composition parameters by introducing copper phthalocyanine dye and optimizing the dye content ratio. Specifically, the ink contains 0.5-5.0 mass% blue dye and 0.1-2.0 mass% copper phthalocyanine dye, with total dye content of 0.6-10.0 mass%. This parameter optimization achieves both high light resistance and high OD value (≥1.8), resolving the contradiction between light resistance and optical density.
Data Source
AI summary
A water-based ink for ink-jet recording includes dyes and water. The dyes include a blue dye having a hue angle of 220° to 280°; a yellow dye having a hue angle of 70° to 120°; and a copper phthalocyanine dye. A mass ratio (C/B) of a content (C) of the copper phthalocyanine dye to a content (B) of the blue dye in an entire amount of the water-based ink is equal to or more than 0.5, and a total content of the dyes in the entire amount of the water-based ink is equal to or more than 6% by mass.