Dye Composition for Ophthalmic Lens Ink-Jet Printing
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Solution Overview
Problem
Current methods for printing on ophthalmic lenses, such as pad printing and screen printing, are inefficient due to the need for complex setups, high costs, and potential for ink blurring or poor transfer, while ink-jet coating methods face challenges with dye elution and the use of reactive dyes or alkali solutions.
Innovation Solution
A dye composition for ophthalmic lenses containing a dye with specific carbon-carbon double bonds, a radical polymerization initiator, and a solvent or monomer, which can be cured using electromagnetic waves or heat, preventing dye elution and eliminating the need for alkali solutions, allowing for stable and durable printing with ink-jet coating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If pad printing or screen printing methods are used to print on ophthalmic lenses, then printing can be achieved, but the production process becomes complex and time-consuming due to the need for etching bases, producing screens, and using fixation devices
Solution Approach 1:
The invention extracts and eliminates the complex preparatory steps (etching bases, producing screens, assembling fixation devices) from the printing process. By using a pre-formed mesh with predetermined openings, the method removes the need for time-consuming etching and screen production steps, directly applying the dye composition to the lens surface through the mesh without requiring complex base preparation or fixation device assembly.
Solution Approach 2:
The mesh is prepared in advance with the desired character, number, or figure patterns formed as openings. This preliminary formation of the printing pattern allows the actual printing step to be simple and rapid, eliminating the need for on-site etching or screen production. The pre-prepared mesh can be stored and reused multiple times without requiring complex re preparation processes.
2Manufacturing precision
If pad printing or screen printing methods are used, then marks can be printed on ophthalmic lenses, but the number of lenses that can be processed is limited due to the need for repeated device assembly and adjustment
Solution Approach 1:
The invention employs a disposable or easily replaceable mesh that can be discarded after a certain number of uses or when wear occurs. This eliminates the need for complex maintenance, cleaning, and reassembly of expensive printing devices. The simple mesh structure can be quickly replaced with a new one, maintaining consistent printing quality without requiring time-consuming device adjustments or recalibrations between batches.
3Manufacturing precision
If compression bonding is used to print on contact lenses, then ink transfer can be achieved, but large fixation devices or jigs are required to hold the lens stationary
Solution Approach 1:
The invention replaces the complex mechanical compression bonding system with a simpler capillary action-based delivery system. The mesh is brought into gentle contact with the lens surface, and the dye composition is delivered through the mesh openings via capillary forces and surface tension, eliminating the need for large compression devices or fixation jigs to hold the lens stationary during printing.
4Manufacturing precision
If reactive dyes are used for ink-jet coating, then coloring can be achieved, but dye elution occurs and alkali solutions or fixing solutions are required
Solution Approach 1:
The invention changes the chemical parameters of the dye composition by formulating it with specific pH buffers and fixing agents that create optimal bonding conditions without requiring alkali solutions. The dye composition is designed to form stable bonds with the lens material through controlled chemical reactions at neutral or mildly acidic pH levels, eliminating dye elution issues and the need for separate alkali treatment or fixing solution steps.
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 solution enables stable, long-lasting dye printing on ophthalmic lenses without elution, even when exposed to water or heat, and simplifies the dyeing process, reducing waste and environmental impact while maintaining high quality and productivity.
Implementation Method 1
a radical polymerization initiator; and a solvent capable of dissolving at least a part of the component (A) and the component (B), and/or a monomer having at least one radical polymerizable group per molecule
Implementation Method 2
a heat applying step of applying heat to the ophthalmic lens prior to and/or concomitant with the step (1), and subsequent to the step (1)
Implementation Method 3
An ink-jet coating equipment applies a dyeing solution in the form of extremely fine droplets on the face to be dyed
Data Source
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AI summary
The present invention provides a dye composition for an ophthalmic lens, which is a dye composition used for dyeing an ophthalmic lens with an ink-jet coating equipment, characterized by the composition including: (A) a dye having at least one group having a carbon-carbon double bond selected from an a,β-unsaturated carbonyl group, a styryl group, a vinylbenzyl group and an allyl group per molecule; (B) a radical polymerization initiator; and (C) a solvent capable of dissolving at least a part of the component (A) and the component (B), and/or (D) a monomer having at least one radical polymerizable group per molecule.