Color-Changing Composition for Absorbent Articles
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing color-changing compositions for personal care absorbent articles, such as disposable diapers, lack durability, retention, and rapid color change, especially when exposed to wetness, and are not suitable for application at room temperature or use with breathable outer cover materials.
Innovation Solution
A color-changing composition comprising a matrix-forming component, a pH indicator, and a surfactant, applied as an ink at room temperature, which forms a water-insoluble film on the substrate, preventing leaching and ensuring adherence, and includes a combination of low and high molecular weight organic acids to prevent premature color change when used with breathable materials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a color-changing composition is applied to indicate wetness in absorbent articles, then the indicator provides useful information to users, but the colorant tends to leach out into other components of the product
Solution Approach 1:
A binding agent is introduced as an intermediary substance between the colorant and the substrate. This binding agent immobilizes the colorant in both its initial and final color states, preventing leaching while maintaining the color change functionality. The binding agent acts as a mediator that holds the colorant in place without interfering with its pH-responsive color transformation.
Solution Approach 2:
The invention uses a composite material system consisting of multiple components: a colorant, a binding agent, and potentially other additives. This composite approach combines the color-changing properties of the pH indicator with the immobilizing properties of the binding agent, creating a material that both indicates wetness and remains retained on the substrate without leaching.
2Reliability
If a color indicator is used to detect wetness, then the indicator changes color in response to moisture, but the indicator loses color when dissolved by water
Solution Approach 1:
The binding agent serves as a protective intermediary that allows the colorant to respond to pH changes (indicating wetness) while preventing direct dissolution of the colorant by water. The binding agent creates a controlled environment where the colorant can undergo reversible color changes without being washed away or permanently dissolved.
Solution Approach 2:
The invention exploits parameter changes in the chemical environment, specifically pH changes that occur when moisture is present. The colorant is selected to change color in response to pH variations caused by wetness, providing a reliable visual indicator that distinguishes between dry and wet states without requiring the indicator itself to be water-soluble.
3Adaptability or versatility
If existing color-changing compositions are used in absorbent articles with breathable outer covers, then the articles provide comfort, but the color indicator undergoes premature color change before actual wetness occurs
Solution Approach 1:
The invention carefully selects and adjusts the parameters of the color-changing composition, including the specific pH indicator used and the pH buffer system employed. By controlling the pH transition range and buffer capacity, the composition is tuned to remain stable under normal breathable conditions while only changing color when actual wetness alters the pH beyond the buffer's capacity.
Solution Approach 2:
The composition is designed as a disposable indicator system specifically formulated for single-use absorbent articles. The indicator is engineered to have a defined lifespan and stability profile that matches the intended use duration, ensuring it remains stable during normal wear with breathable covers but activates reliably when wetness occurs.
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 provides a durable, water-resistant, and rapid color change indicator that maintains efficacy even with breathable outer cover materials, ensuring effective detection of fluid presence without premature activation, and can be easily applied to substrates without heating.
Implementation Method 1
The pH indicator undergoes a color change when in contact with urine
Implementation Method 2
a surfactant, wherein the surfactant reduces the surface tension of the color-changing composition
Implementation Method 3
The color-changing composition may be dissolved in an organic solvent that acts as a carrier and later evaporates after the color-changing composition is applied to the printed layer or forms the printed layer itself
Data Source
AI summary
The present invention relates to a multiple-component material including a substrate and a printed layer on the substrate. The printed layer includes a color- changing composition to indicate a change in condition, such as a change in pH. The color-changing composition includes a matrix-forming component, a colorant, a surfactant and a pH adjuster. The pH adjuster includes a low molecular weight organic acid and a high molecular weight organic acid.