Overprint Varnish Non-Aqueous Dispersion Drying
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Solution Overview
Problem
Current overprint varnishes do not provide sufficient setting and drying properties, such as rub resistance, protection from yellowing, and desirable gloss levels on substrates after coating, which limits the ability to process coated substrates quickly and maintain appearance.
Innovation Solution
Incorporating an essentially non-aqueous dispersion (NAD) containing acrylic core/shell polymers in a non-aqueous organic solvent, like mineral oil, into overprint varnishes to enhance setting, drying, and aging properties, including increased rub resistance and resistance to yellowing, while maintaining high gloss levels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If traditional overprint varnishes are used, then the coating process is simple, but the setting and drying speed is slow and rub resistance is insufficient
Solution Approach 1:
The patent changes the chemical parameters of the varnish by incorporating NAD (non-aqueous dispersion) containing acrylic core/shell polymers in a non-aqueous organic solvent. This chemical parameter change enables faster setting and drying speeds while improving rub resistance, as the NAD particles provide rapid water evaporation and film formation capabilities.
Solution Approach 2:
The patent uses a composite material system combining NAD (non-aqueous dispersion) with traditional overprint varnish components. The NAD contains acrylic core/shell polymers dispersed in a non-aqueous organic solvent like mineral oil, creating a composite formulation that achieves both fast drying and high rub resistance while maintaining coating simplicity.
2Reliability
If traditional overprint varnishes are used, then the formulation is straightforward, but resistance to yellowing and gloss retention is insufficient
Solution Approach 1:
The patent modifies the chemical composition parameters by incorporating NAD with specific acrylic core/shell polymer structures. The core/shell architecture and non-aqueous solvent system provide inherent resistance to yellowing and maintain gloss retention, as these polymer structures are more stable against oxidation and environmental degradation compared to traditional varnish formulations.
Solution Approach 2:
The patent employs a composite formulation where NAD (non-aqueous dispersion) is integrated with traditional overprint varnish. The NAD component, containing acrylic core/shell polymers in a non-aqueous organic solvent, provides enhanced reliability through its stable polymer structure that resists yellowing and maintains gloss, while the overall formulation remains straightforward to apply.
3Reliability
If NAD is incorporated into overprint varnishes, then setting, drying, and aging properties are enhanced, but the viscosity of the varnish increases
Solution Approach 1:
The patent optimizes the concentration parameter of NAD in the overprint varnish formulation. By controlling the amount of NAD added and selecting appropriate non-aqueous solvents with suitable viscosity characteristics, the formulation achieves enhanced setting, drying, and aging properties while keeping the overall viscosity within acceptable ranges for coating application.
Solution Approach 2:
The patent utilizes the local quality of the NAD particles, where the acrylic core/shell polymer structure provides localized functional benefits (fast setting, good aging) while the non-aqueous solvent matrix maintains overall fluidity. This allows different regions of the varnish to have different properties: the NAD particles provide reliability enhancement while the continuous phase maintains workable viscosity.
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 use of NAD in overprint varnishes results in faster setting and drying, improved rub resistance, and resistance to yellowing, allowing substrates to be processed soon after coating while maintaining high gloss and contrast, thus addressing the limitations of existing varnishes.
Implementation Method 1
The OPVs provided herein allow for a substrate, such as a printed substrate, to be subject to further processing, such as cutting, stacking, etc. soon after printing, without compromising on marring, scuffing or rub-off properties
Implementation Method 2
The OPVs provided herein provide higher gloss, better resistance to yellowing and improved rub resistance properties soon after printing on a substrate
Data Source
AI summary
Provided are overprint varnish (OPV) compositions containing high viscosity essentially non-aqueous dispersions that include acrylic core/shell polymer particles in a non-aqueous solvent such as mineral oil. Also provided are methods of coating a substrate with an OPV containing the non-aqueous dispersions to improve the properties of the OPV when used to coat a substrate, such as improved rub resistance, resistance to yellowing, and desirable gloss values.