UV-Absorbing Polymer Material Resolving Precipitation and Bleed-Out
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current ultraviolet absorbents face challenges in long-term stability, precipitation, and skin irritation, while also requiring high concentrations to effectively block long-wavelength UV light, which can lead to limited application in polymer materials.
Innovation Solution
A polymer material incorporating a specific compound with a particular structure, such as represented by formula (2), which is kneaded with polymers or dissolved in solvents, providing resistance to precipitation and bleeding, and maintaining high ultraviolet absorption capacity and lightfastness over time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If high concentration of ultraviolet absorbent is added to block long-wavelength UV light, then UV absorption capacity is improved, but precipitation and bleed-out occur during long-term use
Solution Approach 1:
The patent modifies the chemical structure of the ultraviolet absorbent by introducing specific substituents (Y21, Y22) with Hammett substituent constants σp ≥ 0.2, which changes the electronic properties and intermolecular interactions of the compound. This structural parameter change enhances both UV absorption capacity and resistance to precipitation/bleed-out, resolving the contradiction between absorption performance and stability.
Solution Approach 2:
The patent creates a composite system by combining the specifically structured ultraviolet absorbent compound with polymer substances (acrylic acid-based polymers, polyester-based polymers, or polycarbonate-based polymers). This composite approach allows the absorbent to be dispersed within the polymer matrix, maintaining high UV absorption capacity while preventing precipitation and bleed-out through the stabilizing effect of the polymer carrier.
2Reliability
If benzophenone- and benzotriazole-based ultraviolet absorbents are used to block long-wavelength UV light, then light stability is improved, but film thickness is limited to several tens of μm and high concentration causes precipitation
Solution Approach 1:
The patent introduces specific structural parameters (substituents Y21, Y22 with σp ≥ 0.2) that modify the molecular properties of the ultraviolet absorbent. These parameter changes enable the compound to maintain effectiveness at lower concentrations and thinner film thicknesses while preserving light stability, overcoming the film thickness limitation of conventional benzophenone and benzotriazole-based absorbents.
3Reliability
If conventional ultraviolet absorbents are used, then UV absorption is achieved, but skin irritation and accumulation in body occur
Solution Approach 1:
The patent systematically modifies the molecular structure of the ultraviolet absorbent by introducing specific substituents with defined Hammett constants. These parameter changes alter the chemical properties to reduce skin irritation and body accumulation while maintaining UV absorption functionality, addressing the harmful effects of conventional absorbents.
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 polymer material effectively absorbs long-wavelength UV light without precipitation or bleeding, ensuring long-term stability and lightfastness, addressing the limitations of existing ultraviolet absorbents.
Implementation Method 1
a compound represented by formula (2) contained in the polymer substance... superior in long-wavelength ultraviolet absorption capacity
Data Source
AI summary
A polymer material, containing at least one kind of polymer substance selected from the group consisting of acrylic acid-based polymers, polyester-based polymers, and polycarbonate-based polymers; and a compound represented by formula (2) contained in the polymer substance:wherein A21 and A22 each independently represent an atom other than hydrogen atom and carbon atom; Y21 and Y22 each independently represent a hydrogen atom or a monovalent substituent; at least one of Y21 and Y22 represents a substituent having a Hammett substituent constant σp of 0.2 or more; Y21 and Y22 may bind to each other to form a ring; and (B) represents a group of atoms necessary for forming a five- or six-membered ring with A21, A22 and the carbon atom.