Phosphine Oxide Polymer Coating for Wash-Durable Flame-Resistant Textiles

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Solution Overview

Problem

Existing flame retardant, phosphorus-containing polymers used in cellulose-containing fabrics release formaldehyde over time, leading to efficacy loss after washing, and existing solutions fail to provide a long-term solution.

Innovation Solution

A phosphorus-containing polymer with 75% or more of its phosphorus atoms in phosphine oxide moieties, produced through a process involving a phosphonium compound, a nitrogen-containing cross-linking compound, and exposure to a Bronsted base and oxidizing agent, which enhances durability and thermal protective performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional phosphorus-containing polymers are used to impart flame resistance to cellulose fabrics, then flame retardant performance is achieved, but formaldehyde is released over time causing efficacy loss after washing

Engineering Contradiction:
Improveflame resistanceVSAvoidformaldehyde release
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The invention changes the chemical composition parameters of the polymer by incorporating specific phosphorus-containing moieties (phosphine oxide, phosphonate, or phosphate groups) with controlled ratios. This parameter change eliminates formaldehyde release while maintaining flame resistance, as the stable phosphorus structures do not decompose to release formaldehyde like conventional polymers

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention creates a composite polymer structure combining cellulose with specific phosphorus-containing compounds (tetrahydroxymethyl phosphonium compound and crosslinking agent) that form a coordinated system. This composite structure provides both flame resistance and eliminates formaldehyde release through the synergistic interaction between the phosphorus compounds and cellulose

Inventive Principle:
Principle #40Composite materials

2Object-generated harmful factors

If existing solutions are applied to reduce formaldehyde generation, then formaldehyde release is reduced, but the solutions lose efficacy after a couple of washes

Engineering Contradiction:
Improveformaldehyde generationVSAvoiddurability after washing
Core Design Contradiction:
Object-generated harmful factorsVSDuration of action of stationary object

Solution Approach 1:

The invention performs preliminary crosslinking of the phosphorus-containing polymer with the cellulose substrate through specific chemical reactions (condensation between phosphorus compounds and hydroxyl groups on cellulose). This preliminary bonding action creates durable attachment that withstands washing, preventing both formaldehyde release and efficacy loss over time

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention uses a crosslinking agent as an intermediary substance that mediates between the phosphorus-containing compound and the cellulose substrate. This intermediary forms stable crosslinks that anchor the flame retardant polymer to the fabric, ensuring long-term durability and preventing wash-off while maintaining low formaldehyde generation

Inventive Principle:
Principle #24Intermediary (Mediator)

3Temperature

If polymer is applied to impart flame resistance, then thermal protection is achieved, but the polymer releases formaldehyde leading to efficacy loss

Engineering Contradiction:
Improvethermal protective performanceVSAvoidlong term flame resistance
Core Design Contradiction:
TemperatureVSDuration of action of moving object

Solution Approach 1:

The invention changes the thermal stability parameters of the polymer by using phosphorus compounds with high thermal stability (phosphine oxide, phosphonate, or phosphate groups). These stable structures maintain thermal protective performance while resisting decomposition that would otherwise release formaldehyde and reduce long-term efficacy

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention replaces unstable, short-lived conventional phosphorus polymers that release formaldehyde with stable, long-lasting phosphorus-containing structures. The new polymer structures are designed to be durable and long-term effective, eliminating the need for frequent reapplication while maintaining flame resistance

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

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 significantly reduces formaldehyde release and maintains long-term flame resistance and thermal protection, even under industrial washing conditions, with improved durability and thermal protective performance compared to conventional polymers.

Implementation Method 1

reacting the phosphorus-containing compound and the nitrogen-containing cross-linking compound in a condensation reaction to produce a first intermediate polymer

Methodology Applied
Scientific EffectCondensation reaction: Chemical Bonding

Implementation Method 2

exposing the first intermediate polymer to a Bronsted base under conditions sufficient to convert at least a portion of the phosphonium moieties to phosphine moieties

Methodology Applied
Scientific EffectDeprotonation: Chemical Bonding

Implementation Method 3

oxidizing the second intermediate polymer by exposing the second intermediate polymer to a suitable oxidizing agent under conditions sufficient to oxidize at least a portion of the phosphorus atoms in the polymer to a pentavalent state

Methodology Applied
Scientific EffectOxidation: Oxidation

Data Source

PatentEP3003580A1Phosphorus-containing polymer, article, and processes for producing the same
Publication Date: 2016.04.13 MILLIKEN & CO

AI summary

A phosphorus-containing polymer comprises a plurality of phosphorus atoms, wherein about 75% or more of the phosphorus atoms in the phosphorus-containing polymer are present in phosphine oxide moieties. An article comprises a textile material having at least one surface and a phosphorus-containing polymer disposed on a least a portion of the surface, wherein the phosphorus-containing polymer comprises a plurality of phosphorus atoms, and wherein about 75% or more of the phosphorus atoms in the phosphorus-containing polymer are present in phosphine oxide moieties.