Water-Based Ink Emulsion Core-Shell Structure for Adhesion and Blocking
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Solution Overview
Problem
Existing water-based inks for inkjet printing face challenges in achieving excellent image uniformity, adhesion, and blocking resistance, particularly when printed on non-absorbent media such as resin films like PET and OPP, where traditional formulations often fall short in ensuring stable ejection and preventing media blocking.
Innovation Solution
A water-based ink emulsion comprising core-shell structured particles with specific glass transition temperatures and acid values, where the core portion has a glass transition temperature of 90°C or more and the shell portion has a temperature of 25°C or less, along with a predetermined acid value derived from carboxyl groups, enhancing both adhesion and blocking resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If water-based inks are used for environmental considerations, then environmental compatibility is improved, but image uniformity and adhesion are insufficient
Solution Approach 1:
The invention changes the chemical parameters of the emulsion by controlling the acid value within 0-6 mg KOH/g and adjusting the glass transition temperatures of polymer components (core: 55-200°C, shell: -50-55°C). This parameter optimization enables water-based inks to achieve both environmental compatibility and reliable image uniformity/adhesion on non-absorbent media
Solution Approach 2:
The invention uses composite emulsion particles with a core-shell structure combining different polymer components. The core contains high Tg polymers for blocking resistance, while the shell contains low Tg polymers for adhesion and image uniformity. This composite structure allows water-based inks to simultaneously achieve environmental friendliness and printing performance
2Reliability
If inks are formulated for adhesion on non-absorbent media, then adhesion is improved, but blocking resistance deteriorates
Solution Approach 1:
The invention applies local quality by creating a core-shell structure where different regions of the emulsion particle have different properties. The core portion (high Tg ≥55°C) provides blocking resistance, while the shell portion (low Tg <55°C) provides adhesion. This spatial differentiation of properties allows simultaneous achievement of adhesion and blocking resistance
Solution Approach 2:
The invention optimizes the glass transition temperature parameter of polymer components within specific ranges (core: 55-200°C, shell: -50-55°C) to balance adhesion and blocking resistance. By controlling this thermal parameter, the emulsion achieves proper flexibility for adhesion while maintaining structural integrity to prevent blocking
3Object-generated harmful factors
If emulsion particles are designed for blocking resistance, then blocking resistance is improved, but image uniformity deteriorates
Solution Approach 1:
The core-shell structure creates local quality differentiation where the core (high Tg) provides blocking resistance and the shell (low Tg) ensures image uniformity. This localized functional distribution allows the emulsion to simultaneously achieve both properties
Solution Approach 2:
The composite emulsion structure combines polymers with different glass transition temperatures in a core-shell configuration. This material composition enables the emulsion to exhibit both blocking resistance (from high Tg core) and image uniformity (from low Tg shell)
4Object-generated harmful factors
If polymer components with high glass transition temperature are used, then blocking resistance is improved, but adhesion deteriorates
Solution Approach 1:
The invention places high Tg polymer components specifically in the core region for blocking resistance, while low Tg polymer components are placed in the shell region for adhesion. This spatial separation of polymer types with different Tg values resolves the contradiction between blocking resistance and adhesion
Solution Approach 2:
The emulsion particle is segmented into core and shell portions with different polymer compositions and glass transition temperatures. This segmentation allows each portion to independently fulfill its function (core: blocking resistance, shell: adhesion) without compromising the other
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 emulsion and ink composition demonstrate improved image uniformity, adhesion, and blocking resistance, making them suitable for printing on non-absorbent media like PET and OPP films, ensuring stable ejection and preventing media blocking.
Implementation Method 1
an emulsion which contains two or more kinds of polymer components each having a specific glass transition temperature respectively
Data Source
AI summary
The emulsion for water-based inks of the present invention comprises an emulsion particle containing a polymer component having a glass transition temperature of 55° C. or more and a polymer component having a glass transition temperature of less than 55° C., and the emulsion particle having an acid value derived from carboxyl groups of 0 to 6. Further, the ink composition for water based inks of the present invention comprises the above-mentioned emulsion for water-based inks.