Black Disazo Dyes for Ink Jet Printing Stability

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Solution Overview

Problem

Current black dyes for ink jet printing lack high water solubility, neutral hue, excellent light stability, resistance to ozone degradation, and water fastness, often resulting in images with insufficient durability and surface issues like bronzing on nanoporous media.

Innovation Solution

Development of novel black disazo dyes with specific structural formulas and their salts, which are highly water-soluble, stable against light and ozone, and used in aqueous recording fluids for ink jet printing, along with methods for their preparation and application in dyeing and printing operations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional black dyes (C.I. Direct Black 168, C.I. Reactive Black 5, C.I. Acid Black 1) are used in ink jet recording fluids, then the recording speed and basic black color can be achieved, but the dyes exhibit insufficient water solubility, poor light stability, bad resistance to ozone degradation, and cause surface issues like bronzing on nanoporous media

Engineering Contradiction:

Improveimage durability and stabilityVSAvoidbronzing and degradation by light and ozone

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies parameter changes by systematically modifying the chemical structure of disazo dyes through varying substituents (R1-R10) at different positions of the naphthalene and benzene rings. This includes changing electron-donating and electron-withdrawing groups, their positions, and combinations to optimize the balance between solubility, light stability, and ozone resistance while maintaining black color properties

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention creates composite molecular structures by combining two different azo groups with specific substitution patterns on naphthalene and benzene rings. The disazo structure with carefully selected substituents (such as sulfonic acid groups for solubility, and specific aromatic rings for stability) forms a composite dye molecule that simultaneously achieves multiple desired properties

Inventive Principle:

Principle #40Composite materials

2Manufacturing precision

If conventional black dyes are used to achieve black color in recording fluids, then the basic printing function is fulfilled, but the dyes show insufficient water fastness and neutral hue on nanoporous recording sheets

Engineering Contradiction:

Improvehue accuracy and color neutralityVSAvoidwater fastness

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

The patent achieves neutral hue and improved water fastness by precisely controlling the substitution parameters on both aromatic rings. Specific combinations of electron-donating groups (like -OH, -NH2, -OCH3) and electron-withdrawing groups (like -NO2, -SO3H, -COOH) at defined positions (R1-R10) adjust the HOMO-LUMO gap and molecular polarity, resulting in dyes that exhibit neutral black hue and enhanced water fastness on nanoporous media

Inventive Principle:

Principle #35Parameter changes

3Ease of operation

If conventional black dyes are used in recording fluids, then the printing process can proceed, but the dyes cause clogging of nozzles due to deposition and show insufficient solubility in aqueous recording liquids

Engineering Contradiction:

Improvesolubility in aqueous recording liquidVSAvoidnozzle clogging from dye deposition

Core Design Contradiction:

Ease of operationVSObject-generated harmful factors

Solution Approach 1:

The patent improves solubility and prevents nozzle clogging by incorporating multiple sulfonic acid groups (-SO3H) at strategic positions (R2, R3, R6, R7, R8, R10) on the disazo structure. These highly polar groups enhance water solubility and prevent aggregation, while the overall molecular structure is designed to maintain stability in aqueous solutions, preventing deposition that would cause nozzle clogging

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 new black disazo dyes provide excellent water fastness, light stability, and resistance to ozone degradation, ensuring high-quality, durable images with improved solubility and reduced surface issues like bronzing, enhancing the performance of ink jet printing and textile dyeing processes.

Implementation Method 1

an amine of general formula (XII) is diazotised in an aqueous inorganic acid medium at a temperature between -5° C and 15° C

Methodology Applied

Scientific EffectDiazotization:

Implementation Method 2

coupled with the compound of formula (XIV) at an acidic to weakly acidic value of pH

Methodology Applied

Scientific EffectAzo coupling:

Implementation Method 3

Nanoporous recording sheets absorb the recording liquids very rapidly (in the microsecond range) by the action of the capillary forces of the nanoporous compounds

Methodology Applied

Scientific EffectCapillary action: Capillary Action

Data Source

PatentEP2441805B1Black disazo dyes, their preparation and their use

Publication Date: 2016.07.20 REX TONE IND

AI summary

Black disazo dyes of general formula (V) wherein A is a moiety of formula (VI) or of formula (VII) and B is a moiety of formula (VIII) or of formula (IX) and wherein M, R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, R11, R12, R13, R14, R15, R16, R17, R18, R19, R20, R21, R22, R23 and R24 are as defined in the specification, are excellent black dyes for dying and printing cellulose containing materials and textile materials and, in particular, for the preparation of recording liquids for ink jet printing and for writing utensils.