Flame-Retardant Textile Treatment With Low-Phosphorus Effluent

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Solution Overview

Problem

Existing methods for flame-retardant treatment of textile materials using poly(hydroxyorgano)phosphonium compounds result in effluent with significant levels of water-soluble phosphorus species, which are hazardous and require costly and complex removal processes.

Innovation Solution

The method involves impregnating textile materials with a poly(hydroxyorgano)phosphonium compound, drying, curing with ammonia to increase the atomic ratio of N:P by 0.8 or more, and oxidizing the polymer to convert trivalent phosphorus to pentavalent phosphorus, resulting in an effluent predominantly containing 1,3,5-triaza-7-phosphaadamantane and derivatives, which can be more easily removed using ion exchange or other techniques.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If poly(hydroxyorgano)phosphonium compound is used for flame-retardant treatment, then flame-retardant properties are achieved, but water-soluble phosphorus species are generated in effluent which are hazardous and costly to remove

Engineering Contradiction:
Improveflame-retardant propertiesVSAvoidwater-soluble phosphorus species in effluent
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The invention changes the chemical parameters of the effluent by controlling the curing process to increase atomic ratio of N:P by 0.8 or more, which transforms the form of phosphorus species from water-soluble THPO to less soluble forms, thereby reducing environmental hazard while maintaining flame-retardant effectiveness

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention converts the harmful water-soluble phosphorus species into less harmful forms by optimizing the curing conditions, thereby transforming an environmental problem into a beneficial outcome where the same treatment process produces effluent that is easier and cheaper to treat

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

2Loss of substance

If harsh oxidation treatments are used to remove water-soluble phosphorus species, then phosphorus removal is achieved, but treatment cost and complexity increase

Engineering Contradiction:
Improvewater-soluble phosphorus speciesVSAvoideffluent treatment process
Core Design Contradiction:
Loss of substanceVSDevice complexity

Solution Approach 1:

The invention performs preliminary action during the curing step by controlling the atomic ratio of N:P increase, which pre-transforms the phosphorus species into less soluble forms before effluent treatment, thereby simplifying subsequent treatment processes and reducing overall complexity

Inventive Principle:
Principle #10Preliminary action

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

This approach significantly reduces the amount of water-soluble phosphorus in the effluent, allowing for easier and less harsh removal processes, thereby reducing treatment costs and complexity while maintaining flame-retardant properties in the treated textiles.

Implementation Method 1

curing the dried impregnated material with ammonia to produce a cured, water-insoluble polymer

Methodology Applied
Scientific EffectCuring reaction: Chemical Bonding

Implementation Method 2

oxidising the cured polymer to convert trivalent phosphorus to pentavalent phosphorus

Methodology Applied
Scientific EffectOxidation: Oxidation

Data Source

PatentUS8580348B2Treatment of textile materials
Publication Date: 2013.11.12 ENERGY SOLUTIONS US LLC

AI summary

The present invention provides a method for treating textile material to confer flame retardant properties, the method comprising the steps of impregnating the material with an aqueous solution of a treatment agent which is a poly(hydroxyorgano)phosphonium compound; drying the impregnated material; curing the dried impregnated material with ammonia to produce a cured, water-insoluble polymer which is mechanically fixed within the fibers of the material; oxidizing the cured polymer to convert trivalent phosphorus to pentavalent phosphorus; and washing and drying the material; wherein one or both of steps (d) and (e) result in the co-production of an aqueous effluent; and wherein the conditions are controlled such that the atomic ratio of N:P present on the material increases during step (c) by 0.8 or more.