Fluorescent Brightener FB #71 for High-Brightness Paper Without Yellowing

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Solution Overview

Problem

Conventional optical brightener agents (OBA) and fluorescent whitening agents (FWA) face challenges such as yellowing due to overdosage, low retention rates, and high costs in achieving ultra-bright paper products with high stability, especially in papermaking processes involving mechanical pulp.

Innovation Solution

The new generation fluorescent brightener FB #71, with a distinct molecular structure, is used at optimized dosages and temperatures to achieve high brightness and stability, offering a higher retention rate and cost-effectiveness by avoiding yellowing and plateauing in brightness gain, even at higher dosages.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If conventional optical brightener agents (OBA) or fluorescent whitening agents (FWA) are used to achieve ultra-bright paper products, then brightness is improved, but yellowing occurs due to overdosage and low retention rates

Engineering Contradiction:
ImprovebrightnessVSAvoidyellowing
Core Design Contradiction:
Illumination intensityVSObject-generated harmful factors

Solution Approach 1:

The patent changes the chemical structure parameters of the fluorescent whitening agent by introducing a morpholino group at the 6-position of the triazin ring in FB #71. This structural modification alters the agent's properties to prevent yellowing while maintaining high brightness, resolving the contradiction between achieving ultra-bright paper and avoiding yellowing effects

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs FB #71 which provides high brightness gain without the long-term yellowing issues associated with conventional OBAs and FWA's. The agent delivers its brightening effect efficiently without persistent harmful residues, addressing the retention rate and yellowing problems

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

2Illumination intensity

If higher dosages of conventional FWA are added to increase brightness, then brightness gain is improved, but cost increases and yellowing occurs

Engineering Contradiction:
Improvebrightness gainVSAvoiddosage
Core Design Contradiction:
Illumination intensityVSQuantity of substance

Solution Approach 1:

The patent modifies the chemical structure of FWA by adding a morpholino group, which changes the agent's efficiency characteristics. This allows FB #71 to achieve higher brightness gain per unit dosage compared to conventional FWA's, reducing the total quantity needed while avoiding yellowing

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses FB #71 which combines the beneficial properties of high brightness capability with the yellowing-prevention feature. This composite chemical structure achieves superior performance at lower dosages, resolving the contradiction between brightness gain and dosage quantity

Inventive Principle:
Principle #40Composite materials

3Illumination intensity

If conventional OBA/FWA is used to achieve high brightness, then brightness is improved, but retention rate is low

Engineering Contradiction:
ImprovebrightnessVSAvoidretention rate
Core Design Contradiction:
Illumination intensityVSReliability

Solution Approach 1:

The patent changes the chemical parameters of the brightening agent by incorporating a morpholino group, which improves the agent's performance characteristics. This structural modification enhances brightness delivery while preventing the low retention and yellowing issues associated with conventional agents

Inventive Principle:
Principle #35Parameter changes

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

FB #71 enables the production of high-brightness paper with increased retention rates and lower costs, preventing yellowing and maintaining brightness without the need for excessive addition, thereby expanding market applications and reducing brightness reversion.

Implementation Method 1

OBA's or FWA's have chemical properties that absorb light in the ultra-violet region (340-370 nm) and then re-emitting it back into the visible spectrum, usually in the color blue or indigo (420-470 nm). The absorption and re-emission happen at a rapid pace unlike the slow phosphorescence behaviour.

Methodology Applied
Scientific EffectFluorescence: Fluorescence

Data Source

PatentUS9109331B2Fluorescent brighter #71 used for the papermaking process
Publication Date: 2015.08.18 LI MENG JUN

AI summary

Fluorescent whitening agent 71 (FB #71) 4,4′-bis[4-anilino-6-morpholino-1,3,5-triazin-2-yl]amino-2,2′-stilbene disodium salt (CAS #16090-02-1) is used on the wet-end papermaking process and coating papermaking process to increase the brightness of paper.