Black Ink Composition for High-Density Polyester Inkjet Printing

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Solution Overview

Problem

Existing black inks for inkjet printing on polyester fabrics lack high optical density when used in small amounts, leading to a decrease in color intensity and a tendency to lighten excessively, which affects printing definition and speed.

Innovation Solution

A black ink formulation comprising a mixture of disperse blue 291 and/or 291:1, disperse red 82, and disperse red 54 dyes, optimized to maintain high optical density even with reduced ink deposition, achieved through specific dye concentrations and an aqueous vehicle composition that includes glycerol and propylene glycol, ensuring stable drop formation and high printing resolution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If conventional black ink formulations are used, then good color intensity is achieved with large amounts of ink, but the color intensity rapidly declines to grey when lower amounts of ink are used

Engineering Contradiction:
Improveoptical densityVSAvoidink amount
Core Design Contradiction:
Illumination intensityVSQuantity of substance

Solution Approach 1:

The patent changes the chemical composition parameters of the ink by using a specific mixture of disperse dyes (disperse blue 291 and/or 291:1, disperse red 82, and disperse red 54) in optimized concentrations. This parameter change allows the ink to achieve high optical density with smaller quantities, resolving the contradiction between ink amount and color intensity.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite dye system by combining multiple disperse dyes with complementary color properties. This composite approach enhances the overall optical density and color intensity of the black ink, allowing it to maintain intensity even when applied in smaller amounts, thus resolving the contradiction between ink quantity and color strength.

Inventive Principle:
Principle #40Composite materials

2Illumination intensity

If larger amounts of ink are deposited to maintain intensity, then good color intensity is achieved, but printing definition decreases and ejection frequency must be reduced

Engineering Contradiction:
Improvecolor intensityVSAvoidprinting speed
Core Design Contradiction:
Illumination intensityVSProductivity

Solution Approach 1:

By changing the chemical parameters of the ink formulation to include a optimized mixture of disperse dyes, the ink achieves higher efficiency in terms of color intensity per unit volume. This allows smaller drop volumes to maintain the required color intensity, thereby increasing ejection frequency and printing speed without sacrificing color quality.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent enables the use of smaller (partial) ink amounts to achieve the desired color intensity effect. The optimized dye mixture provides such high intensity that less ink is needed, which directly increases printing speed and definition while maintaining color quality, resolving the productivity contradiction.

Inventive Principle:
Principle #16Partial or excessive action

3Productivity

If smaller drop volumes are used to increase printing speed, then ejection frequency increases, but color intensity decreases

Engineering Contradiction:
Improveejection frequencyVSAvoidcolor intensity
Core Design Contradiction:
ProductivityVSIllumination intensity

Solution Approach 1:

The patent changes the optical parameters of the ink by formulating a concentrated mixture of disperse dyes with high molar absorptivity. This parameter change ensures that even smaller drop volumes contain sufficient dye concentration to achieve the required color intensity, thus allowing higher ejection frequencies without compromising print quality.

Inventive Principle:
Principle #35Parameter changes

4Ease of manufacture

If conventional dye mixtures are used, then manufacturing simplicity is maintained, but the ink lightens excessively when used in small amounts

Engineering Contradiction:
Improveformulation simplicityVSAvoidcolor stability
Core Design Contradiction:
Ease of manufactureVSStability of the object's composition

Solution Approach 1:

The patent employs a composite dye system combining disperse blue 291 and/or 291:1, disperse red 82, and disperse red 54. This composite formulation is designed to be relatively simple to manufacture while providing superior color stability. The complementary color properties of the dye mixture prevent excessive lightening when small amounts are used, resolving the contradiction between manufacturing ease and color stability.

Inventive Principle:
Principle #40Composite materials

Data Source

PatentEP3601453B1New black ink
Publication Date: 2021.05.26 JK GRP SPA

AI summary

The invention relates to a black ink comprising a black dye dispersion in an aqueous vehicle comprising disperse blue 291 and/or 291 : 1, disperse red 82 and disperse red 54 and the use of such black ink in a method for digital inkjet-printing of a fabric, preferably on polyester.