Photocurable White Ink Composition for LED Curing
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Solution Overview
Problem
Photocurable ink compositions for inkjet printing on polyvinyl chloride sheets face challenges with adhesion, cockling, and compatibility with low-energy light sources like LEDs, while also requiring solvent and scratch resistance and storage stability.
Innovation Solution
A photocurable white ink composition containing specific amounts of monofunctional and multifunctional monomers with ether and cyclic structures, an acyl phosphine oxide photopolymerization initiator, and titanium dioxide, optimized for use with LEDs, which minimizes vinyl formamide content and ensures excellent adhesion, curability, and stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a component that dissolves the base material is blended into the ink to improve adhesion, then adhesion to polyvinyl chloride sheet is improved, but the printed matter cockles easily
Solution Approach 1:
The patent changes the chemical parameters of the photopolymerizable component by specifying precise compositional ratios: 0.1-20 mass% monofunctional monomer with ether group, 35-70 mass% monofunctional monomer with cyclic structure, and 5-40 mass% multifunctional monomer. This parameter optimization achieves adhesion improvement without excessive base material dissolution, preventing cockling while maintaining bonding strength.
Solution Approach 2:
The patent creates a composite photopolymerizable system combining three types of monomers (ether-containing, cyclic structure-containing, and multifunctional) in specific proportions. This composite approach balances adhesion promotion through controlled base material interaction while maintaining film integrity and preventing cockling defects.
2Reliability
If conventional high-energy light sources like metal halide lamps are used for curing, then curability is achieved, but ozone is generated and equipment size increases
Solution Approach 1:
The patent substitutes conventional metal halide lamp curing with LED-based curing by incorporating photopolymerizable components that respond to LED emission wavelengths. This replacement eliminates ozone generation, reduces equipment size, and extends service life while maintaining effective curability through optimized monomer composition.
3Strength
If photocurable materials that form tough films are used, then film strength is improved, but adhesion to base material decreases
Solution Approach 1:
The patent optimizes the compositional parameters of the photopolymerizable component to achieve balanced performance: incorporating 0.1-20 mass% monofunctional monomer with ether group and 35-70 mass% monofunctional monomer with cyclic structure provides adequate adhesion, while 5-40 mass% multifunctional monomer ensures tough film formation. This parameter balance resolves the trade-off between film strength and adhesion.
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 composition achieves remarkable curability under UV light, strong adhesion to polyvinyl chloride sheets, solvent resistance, scratch resistance, discharge stability, and storage stability, while being safe and environmentally friendly.
Implementation Method 1
a photopolymerizable component that contains: virtually no vinyl formamide; 0.1 to 20 percent by mass of a monofunctional monomer containing an ether group relative to the total mass of the photopolymerizable component; 35 to 70 percent by mass of a monofunctional monomer containing a cyclic structure relative to the total mass of the photopolymerizable component; 5 to 40 percent by mass of a multifunctional monomer; and an acyl phosphine oxide photopolymerization initiator by 3 to 20 percent by mass relative to the total mass of the photopolymerizable component; and titanium dioxide
Data Source
AI summary
An object of the present invention is to provide a photocurable white ink composition for inkjet printing that exhibits good properties including curability in thin film form under ultraviolet light, especially ultraviolet light generated by a light source using light-emitting diodes (LEDs), adhesion to polyvinyl chloride sheets, etc., solvent resistance, scratch resistance, discharge stability, and storage stability. A photocurable white ink composition for inkjet printing that contains: a photopolymerizable compound that contains: virtually no vinyl formamide; 0.1 to 20 percent by mass of a monofunctional monomer containing an ether group relative to the total mass of the photopolymerizable component; 35 to 70 percent by mass of a monofunctional monomer containing a cyclic structure relative to the total mass of the photopolymerizable component; 5 to 40 percent by mass of a multifunctional monomer relative to the total mass of the photopolymerizable component; an acyl phosphine oxide photopolymerization initiator by 3 to 20 percent by mass relative to the total mass of the photopolymerizable component; and titanium dioxide; wherein, the viscosity of said photocurable white ink composition for inkjet printing is 100 mPa·s or less at 25°C.