Flame retardant compositions with low formaldehyde content
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Solution Overview
Problem
Existing flame-retardant textile treatments using condensates of tetrakis (hydroxyorgano) phosphonium salts and (thio)urea contain high levels of formaldehyde, posing toxicity issues during storage, transportation, and handling.
Innovation Solution
Using tetrakis (hydroxyorgano) phosphonium sulfate (THPS) instead of tetrakis (hydroxyorgano) phosphonium chloride (THPC) to produce a condensate with a formaldehyde content of less than 0.1%, thereby reducing formaldehyde formation and odor during application.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If tetrakis (hydroxyorgano) phosphonium chloride (THPC) is used to produce flame-retardant condensate, then flame-retardant properties are achieved, but formaldehyde content exceeds 0.1% causing toxicity issues
Solution Approach 1:
The patent changes the chemical parameter of the phosphonium salt from chloride form (THPC) to sulfate form (THPS). This parameter change fundamentally alters the formaldehyde generation behavior during alkaline treatment, reducing formaldehyde content from >0.1% to <0.1% while preserving the flame-retardant functionality of the condensate.
2Ease of manufacture
If strong base (KOH or NaOH) is added to elevate pH for condensate formation, then condensate is produced, but formaldehyde formation increases
Solution Approach 1:
The patent changes the chemical parameter of the phosphonium salt from chloride to sulfate form. This parameter change fundamentally alters the formaldehyde generation behavior during alkaline treatment, reducing formaldehyde content from >0.1% to <0.1% while preserving the flame-retardant functionality of the condensate.
3Reliability
If conventional THP+ chloride condensate is used for textile treatment, then flame-retardant treatment is achieved, but odor increases during application
Solution Approach 1:
The patent changes the chemical parameter of the phosphonium salt from chloride form (THPC) to sulfate form (THPS). This parameter change fundamentally alters the formaldehyde generation behavior during alkaline treatment, reducing formaldehyde content from >0.1% to <0.1% while preserving the flame-retardant functionality of the condensate.
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 use of THPS in the condensate significantly reduces formaldehyde content to below 0.1%, making the precursor safer for handling and use, while also minimizing odor during textile application.
Implementation Method 1
the fabric is then dried and then cured with ammonia (NH3) whereby a phosphonium-based polymer is produced within the fibers of the fabric
Implementation Method 2
the obtained polymer is generally oxidized in order to convert at least a part of the trivalent phosphorus (carried by the phosphonium group) into a pentavalent phosphorous (an phosphine oxide group)
Data Source
AI summary
The instant invention relates to a composition useful as a precursor for imparting flame-retardant properties to textile articles, comprising a condensate of: (a) a tetrakis (hydroxyorgano) phosphonium sulfate THPS; (b) urea, or alternatively thiourea; (c) optionally, and preferably, an aliphatic hydroxyl-reactive compound, such an amine wherein said composition has a very low free formaldehyde content, namely of less than 0.1%.