UV-LED Curing Cosmetic Compositions Using Composite Photoinitiators
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
UV-LED curing of cosmetic films for nails is limited by the deficiency of short wavelengths, leading to incomplete curing and tackiness, which existing methods like thicker coats or additional components fail to adequately address, resulting in unsatisfactory finishes and increased costs.
Innovation Solution
A cosmetic composition comprising ethylenically unsaturated polymerizable compounds and a photoinitiator system with photoinitiators having absorption wavelengths greater than 350 nm, where at least 60% of the photoinitiators have such wavelengths, allowing for effective curing with UV-LED radiation and reducing curing times.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If UV-LED radiation is used for curing cosmetic films, then curing time is reduced and power consumption is decreased, but the surface curing is incomplete and tackiness remains due to deficiency of short wavelengths
Solution Approach 1:
The patent uses a composite photoinitiator system containing multiple photoinitiators with different absorption characteristics. Specifically, it combines photoinitiators that absorb at longer wavelengths (380-450 nm) with those that absorb at shorter wavelengths (280-350 nm), creating a composite initiation system that works synergistically with UV-LED radiation to achieve complete surface curing while maintaining the energy efficiency of LED technology
Solution Approach 2:
The patent changes the parameters of the photoinitiator system by selecting photoinitiators with specific absorption wavelength ranges that match the UV-LED spectrum. By adjusting the types and proportions of photoinitiators (e.g., using acylphosphine oxides, benzophenones, or oxime esters with appropriate absorption characteristics), the system optimizes the utilization of UV-LED radiation across different wavelength regions to eliminate tackiness
2Reliability
If conventional UV lamps are used for curing, then surface curing is effective, but curing time is increased and damage to cosmetic film and nail bed occurs
Solution Approach 1:
The patent applies local quality by using photoinitiators with different absorption characteristics in specific proportions to target different wavelength regions. This creates a localized optimization where each photoinitiator component addresses specific curing needs at different depths and surfaces, enabling effective curing with reduced overall UV exposure and minimized damage to the cosmetic film and nail bed
Solution Approach 2:
The photoinitiator system acts as an intermediary that converts UV-LED radiation into chemical reactions for curing. By selecting photoinitiators with appropriate absorption wavelengths, the system mediates between the UV-LED light source and the polymerizable compounds, enabling efficient energy transfer and curing while reducing the need for high-intensity short-wavelength UV that causes damage
3Reliability
If thicker coats of polish are applied to compensate for UV-LED deficiency, then surface curing may improve, but production costs increase and additional components are required
Solution Approach 1:
The patent applies partial action by using a photoinitiator system that is specifically optimized for UV-LED wavelengths. Rather than attempting to cure all layers simultaneously with excessive thickness, the system uses photoinitiators with different absorption characteristics to ensure adequate initiation throughout the film thickness at appropriate coat weights, avoiding the need for thicker applications
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 achieves tack-free, thin cosmetic films with improved shine, adhesion, and long wear, while significantly reducing curing times and avoiding the drawbacks of traditional methods.
Implementation Method 1
cosmetic compositions comprising (1) at least one ethylenically unsaturated polymerizable compound, and (2) at least one photoinitiator system... exposing the film to UV-LED radiation
Implementation Method 2
at least one photoinitiator having an absorption wavelength greater than about 350 nm
Data Source
AI summary
Disclosed herein are cosmetic compositions comprising (a) at least one ethylenically unsaturated polymerizable compound and (b) at least one photoinitiator system comprising at least one photoinitiatorhaving at least one absorption wavelength greater than about 350 nm. Also disclosed herein are methods of making up and/or enhancing the appearance of a keratinous substrate comprising (1 ) forming at least one film on the keratinous substrate by applying said cosmetic composition to the keratinous substrate and (2) exposing the film to UV-LED radiation.