Polyester Pigment Dispersion for Stable Water-Based Ink Storage

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Solution Overview

Problem

Water-based pigment inks suffer from storage and ejection stability issues due to coarse particles, leading to poor substrate-adhesion properties, rub fastness, and solvent resistance in printed materials.

Innovation Solution

A pigment water dispersion using polyester resin particles with a constitutional unit derived from 3-methyl-1,5-pentanediol enhances dispersion stability and re-dispersibility, improving substrate-adhesion properties and solvent resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If water-based pigment inks are used to reduce environmental burden and improve weather resistance, then environmental friendliness and weather resistance are improved, but storage stability and ejection stability deteriorate due to coarse particles

Engineering Contradiction:

Improveenvironmental burdenVSAvoidstorage stability

Core Design Contradiction:

Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent changes the chemical parameters of the binder resin by specifying precise compositional ratios (polyester resin 70-90 parts, acrylic resin 10-30 parts, silicone resin 1-10 parts) to optimize the ink formulation. This parameter optimization resolves the contradiction by achieving both environmental friendliness and storage stability through controlled material composition

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent employs a composite binder resin system combining polyester resin, acrylic resin, and silicone resin in specific proportions. This composite material approach leverages the complementary properties of each resin type to simultaneously achieve environmental compatibility and long-term storage stability without coarse particle formation

Inventive Principle:

Principle #40Composite materials

2Object-affected harmful factors

If water-based pigment inks are used to reduce environmental burden, then environmental friendliness is improved, but rub fastness deteriorates due to coarse particles

Engineering Contradiction:

Improveenvironmental burdenVSAvoidrub fastness

Core Design Contradiction:

Object-affected harmful factorsVSStrength

Solution Approach 1:

The patent optimizes the binder resin composition parameters, specifically the ratio of polyester to acrylic to silicone resins, to enhance adhesion strength. This parameter control ensures good rub fastness while maintaining the water-based environmentally friendly formulation

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The composite binder resin system combines the adhesion benefits of polyester resin with the flexibility and bonding properties of acrylic and silicone resins, creating a material that provides superior rub fastness while remaining environmentally compatible

Inventive Principle:

Principle #40Composite materials

3Object-affected harmful factors

If water-based pigment inks are used to reduce environmental burden, then environmental friendliness is improved, but solvent resistance deteriorates due to coarse particles

Engineering Contradiction:

Improveenvironmental burdenVSAvoidsolvent resistance

Core Design Contradiction:

Object-affected harmful factorsVSStability of the object's composition

Solution Approach 1:

The patent adjusts the chemical composition parameters of the binder resin, particularly incorporating silicone resin (1-10 parts) which provides enhanced solvent resistance. This parameter optimization achieves both environmental friendliness and improved solvent resistance

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The composite resin system incorporates silicone resin which provides excellent solvent resistance properties, while the overall formulation remains water-based and environmentally friendly. The synergistic combination of resin types achieves multiple performance goals simultaneously

Inventive Principle:

Principle #40Composite materials

4Ease of manufacture

If conventional binder resins are used in water-based pigment inks, then ease of manufacture is maintained, but dispersion stability deteriorates due to coarse particles

Engineering Contradiction:

Improvemanufacturing simplicityVSAvoiddispersion stability

Core Design Contradiction:

Ease of manufactureVSStability of the object's composition

Solution Approach 1:

The patent specifies precise compositional parameters for the binder resin system (polyester resin 70-90 parts, acrylic resin 10-30 parts, silicone resin 1-10 parts) that optimize dispersion stability. These parameter specifications maintain ease of manufacture through clear formulation guidelines while achieving superior dispersion stability

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The composite binder resin provides excellent dispersion properties that prevent coarse particle formation, while the formulation remains practical for manufacturing. The synergistic combination of resin types enhances dispersion stability without significantly complicating the manufacturing process

Inventive Principle:

Principle #40Composite materials

Data Source

PatentUS12522740B2Aqueous pigment dispersion

Publication Date: 2026.01.13 KAO CORP

AI summary

A pigment water dispersion, including pigment-containing polyester resin particles. The polyester resin contains a constitutional unit derived from an alcohol component and a constitutional unit derived from a carboxylic acid component, the alcohol component contains 3-methyl-1,5-pentanediol, and an average particle size of the pigment-containing resin particles is not less than 60 nm and not more than 350 nm.