Diaminostilbene Optical Brighteners for Polyester Fabric Deposition
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Solution Overview
Problem
Commercially available optical brighteners fail to effectively deposit on polyester-based fabrics, resulting in no improvement in whiteness index when used in laundry care compositions.
Innovation Solution
Development of novel optical brightener compounds derived from 4,4′-diaminostilbene-2,2′-disulfonic acid or 4,4′-diaminostilbene-2,2′-dicarboxylic acid with specific structural modifications, such as varying substituents and counterions, which are incorporated into laundry detergents to enhance deposition and whitening efficacy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If commercially available optical brighteners are used, then the whiteness of cellulosic fabrics is improved, but deposition on polyester-based fabrics is insufficient
Solution Approach 1:
The patent modifies the chemical structure of optical brighteners by changing parameters such as introducing polyethyleneimine substituents with specific molecular weights (200-20,000), adjusting the number of ethyleneimine units, and modifying the core diaminostilbene structure. These parameter changes enable the brightener to effectively deposit on polyester fabrics while maintaining whiteness enhancement capability.
Solution Approach 2:
The invention creates a composite structure by combining polyethyleneimine substituents with the diaminostilbene core structure. This composite molecular architecture provides both the affinity for polyester fabrics (through the polyethyleneimine component) and the optical brightening function (through the diaminostilbene fluorophore), resolving the contradiction between deposition effectiveness and whiteness improvement.
2Reliability
If optical brighteners are designed for effective deposition on polyester, then deposition effectiveness is improved, but compatibility with various fabric types may be reduced
Solution Approach 1:
The patent designs optical brighteners with polyethyleneimine substituents that provide universal deposition capability across different fabric types. The polyethyleneimine component can interact with various fabric surfaces (cellulosic, polyester, blends) through multiple mechanisms, while the diaminostilbene core maintains optical brightening function. This multi-functional design allows effective deposition on polyester without sacrificing compatibility with other fabric types.
Solution Approach 2:
The invention optimizes parameters such as the molecular weight of polyethyleneimine (200-20,000) and the number of ethyleneimine units to achieve broad fabric compatibility. By adjusting these parameters, the brightener can adapt to different fabric surfaces while maintaining effective deposition on polyester and whiteness enhancement on cellulosic fabrics.
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 novel optical brightener compounds effectively deposit on polyester-based fabrics, significantly improving the whiteness index of treated fabrics, as demonstrated by increased CIE Whiteness values and deposition efficiency compared to conventional optical brighteners.
Implementation Method 1
Optical brighteners are a class of fluorescent materials that absorb light in the ultraviolet regions of the electromagnetic spectrum (e.g., less than 400 nm) and re-emit light in the violet and blue regions of the electromagnetic spectrum (e.g., greater than 400 nm)
Data Source
AI summary
Novel compounds based on diaminostilbene are provided. The compounds conform to the general structuresThe compounds are useful as optical brighteners. Compositions, such as laundry compositions, containing such compounds are also provided.