Flame-Retardant Fabric Composition for Thick Char Layer Formation

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Solution Overview

Problem

Existing flame-retardant fabrics using modacrylic fibers with antimony compounds face environmental and health concerns, and zinc stannate compounds offer inferior flame retardancy compared to antimony compounds.

Innovation Solution

A flame-retardant fabric comprising modacrylic fibers with a compound containing tin and zinc, and cellulose fibers with a magnesium compound, where the modacrylic fibers are substantially free of magnesium and zinc, respectively, achieving a char layer thickness of 4.0 mm or more during flammability tests, enhancing both gas-phase and solid-phase flame retardancy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If an antimony compound is used as a flame retardant in modacrylic fibers, then flame retardancy is improved, but environmental and health safety deteriorates

Engineering Contradiction:

Improveflame retardancyVSAvoidenvironmental and health impact

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The invention changes the chemical composition parameters by replacing antimony compounds with a combination of zinc stannate compound and magnesium compound in modacrylic fibers, maintaining flame retardancy while eliminating environmental and health hazards associated with antimony

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention uses a composite flame retardant system combining zinc stannate compound and magnesium compound together in modacrylic fibers, creating synergistic effects that achieve superior flame retardancy comparable to or better than antimony compounds without the associated environmental problems

Inventive Principle:

Principle #40Composite materials

2Object-affected harmful factors

If a zinc stannate compound is used as a flame retardant in modacrylic fibers, then environmental friendliness is improved, but flame retardancy deteriorates

Engineering Contradiction:

Improveenvironmental impactVSAvoidflame retardancy

Core Design Contradiction:

Object-affected harmful factorsVSReliability

Solution Approach 1:

The invention merges zinc stannate compound and magnesium compound into a combined flame retardant system within modacrylic fibers, where the two compounds work synergistically to achieve flame retardancy that compensates for and exceeds the performance of zinc stannate alone

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The invention creates a composite flame retardant material system using zinc stannate compound and magnesium compound in specific combinations, producing synergistic effects that enhance flame retardancy while maintaining environmental friendliness

Inventive Principle:

Principle #40Composite materials

3Ease of manufacture

If a single type of flame retardant compound is used in modacrylic fibers, then manufacturing simplicity is improved, but flame retardancy performance deteriorates

Engineering Contradiction:

Improvemanufacturing simplicityVSAvoidflame retardancy

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The invention segments the flame retardant function into two distinct compounds (zinc stannate and magnesium compound) with different mechanisms of action, allowing each to contribute uniquely to overall flame retardancy while maintaining relatively simple manufacturing processes

Inventive Principle:

Principle #1Segmentation

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 fabric achieves superior flame retardancy with reduced environmental impact by forming a thick char layer, shortening afterflame and afterglow times, and providing effective body protection in work clothing.

Implementation Method 1

the flame-retardant fabric forms a char layer with a thickness of 4.0 mm or more after a flammability test according to ISO 15025

Methodology Applied

Scientific EffectChar layer formation:

Implementation Method 2

the synergistic effect of the gas-phase flame retardancy of the compound containing tin and zinc in the modacrylic fiber A and the solid-phase flame retardancy of the magnesium compound in the modacrylic fiber B

Methodology Applied

Scientific EffectGas-phase flame retardancy:

Implementation Method 3

Methodology Applied

Scientific EffectSolid-phase flame retardancy:

Data Source

PatentEP4667636A1Flame-retardant fabric, and flame-retardant work clothes comprising same

Publication Date: 2025.12.24 KANEKA CORP

AI summary

The present invention relates to a flame-retardant fabric including a modacrylic fiber A, a modacrylic fiber B, and a cellulose fiber. The modacrylic fiber A includes a compound containing tin and zinc, and is substantially free of a magnesium compound, and the modacrylic fiber B comprises a magnesium compound, and is substantially free of a compound containing tin and zinc. The flame-retardant fabric comprises the compound containing tin and zinc derived from the modacrylic fiber A in an amount of 2.0 mass% or more, and the flame-retardant fabric forms a char layer with a thickness of 4.0 mm or more after a flammability test according to ISO 15025.