Ink-jet absorber solvent selection to prevent 2-pyrrolidone aggregation

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Solution Overview

Problem

Water-based inks containing 2-pyrrolidone tend to aggregate and accumulate in absorbers of liquid discharge recording apparatuses, leading to contamination of ink-jet heads and recording paper.

Innovation Solution

A liquid discharge recording apparatus and method that incorporates a first liquid with 2-pyrrolidone and a second liquid with specific solvents like diethylene glycol and triethylene glycol n-butyl ether, which have a freezing point less than 20°C and specific gravity less than 1.12, to prevent accumulation by using absorbers such as flushing, waste liquid, and platen absorbers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If water-based ink containing 2-pyrrolidone is used to improve wettability and chromogenic property, then the ink discharge quality is improved, but the ink easily aggregates and accumulates in the absorber causing contamination

Engineering Contradiction:
Improveink discharge qualityVSAvoidaggregation and accumulation in absorber
Core Design Contradiction:
Manufacturing precisionVSObject-generated harmful factors

Solution Approach 1:

The patent changes the chemical composition parameters of the second liquid by selecting specific solvents with defined properties (freezing point below 20°C, specific gravity below 1.12) and controlling the blending ratio of 2-pyrrolidone to these solvents at 1:5 or higher. This parameter optimization prevents aggregation while maintaining ink discharge quality

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite liquid system by combining 2-pyrrolidone-containing ink with a second liquid comprising specific solvents (diethylene glycol, triethylene glycol n-butyl ether, N-methyl-2-pyrrolidone, etc.). This composite formulation leverages the complementary properties of both liquids to achieve both good discharge quality and anti-aggregation performance

Inventive Principle:
Principle #40Composite materials

2Loss of substance

If absorber is used to absorb the ink, then the ink is recovered, but the ink accumulates in the absorber and contaminates the ink-jet head and recording paper

Engineering Contradiction:
Improveink recoveryVSAvoidcontamination of ink-jet head and recording paper
Core Design Contradiction:
Loss of substanceVSObject-affected harmful factors

Solution Approach 1:

The patent introduces a second liquid as an intermediary substance between the ink and the absorber. This intermediary liquid modifies the absorption process by preventing ink aggregation during contact with the absorber, enabling effective ink recovery while avoiding contamination of the ink-jet head and recording paper

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent optimizes the physical and chemical parameters of the second liquid (freezing point below 20°C, specific gravity below 1.12, blending ratio of 2-pyrrolidone to solvent at 1:5 or higher) to control the absorption characteristics and prevent harmful accumulation effects

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

Effectively suppresses the accumulation of 2-pyrrolidone and colorants in absorbers, preventing nozzle clogging and contamination of ink-jet heads and recording paper, while allowing for efficient absorption and recovery of the first liquid.

Implementation Method 1

an absorber which contains the second liquid and which is configured to absorb the first liquid exited from the liquid discharge head

Methodology Applied
Scientific EffectAbsorption: Absorption (physical)

Implementation Method 2

an absorber which contains the second liquid and which is configured to absorb the first liquid exited from the liquid discharge head

Methodology Applied
Scientific EffectCapillary action: Capillary Action

Data Source

PatentEP2853391B1Liquid discharge recording apparatus and method for recovering liquid
Publication Date: 2018.05.02 BROTHER KOGYO KK
  • EP2853391B1 patent drawingFigure 1
  • EP2853391B1 patent drawingFigure 2
  • EP2853391B1 patent drawingFigure 3A~3B

AI summary

A liquid discharge recording apparatus includes: a first liquid containing 2-pyrrolidone; a liquid discharge head configured to discharge the first liquid; a second liquid containing a solvent of which freezing point is less than 20 degrees Celsius and of which specific gravity is less than 1.12 g/cm3; and an absorber which contains the second liquid and which is configured to absorb the first liquid exited from the liquid discharge head.