Low-Temperature Intumescent Coating With Crack-Resistant Char

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Solution Overview

Problem

Existing intumescent coatings fail to maintain structural integrity and adherence to steel substrates at extremely low temperatures, such as -60°C, while also experiencing high water absorption and slow cure rates, leading to cracking and inadequate protection during hydrocarbon or jet fires.

Innovation Solution

A balanced epoxy resin and amine functional curing agent system, incorporating an internally flexibilised acetoacetoxy polyacetoacetate (AcAc) functional polymer, ensures flexibility and durability, allowing the coating to cure within 24 hours to a Shore D hardness of at least 5.0, withstand -60°C without cracking, and maintain low water absorption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional intumescent coatings are used to provide fire protection, then fire resistance is achieved, but the coatings crack and fail at extremely low temperatures below -40°C

Engineering Contradiction:
Improvefire protection reliabilityVSAvoidlow temperature resistance
Core Design Contradiction:
ReliabilityVSTemperature

Solution Approach 1:

The patent modifies the chemical composition parameters of the coating by incorporating specific flexible polymers (polyurethane, polyester, epoxy) in optimized ratios, and adjusts the glass transition temperature of the resin system to remain below -60°C. This parameter optimization allows the coating to maintain flexibility and prevent cracking at extreme low temperatures while preserving fire protection capabilities.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention creates a composite coating system combining multiple polymer types (polyurethane, polyester, epoxy) with intumescent ingredients. This composite structure provides both the flexibility needed for low-temperature performance and the fire-resistant properties required for hydrocarbon fire protection, resolving the contradiction between temperature resistance and fire reliability.

Inventive Principle:
Principle #40Composite materials

2Temperature

If the coating is made flexible to withstand low temperatures, then low temperature resistance improves, but water absorption increases

Engineering Contradiction:
Improvelow temperature resistanceVSAvoidwater absorption
Core Design Contradiction:
TemperatureVSQuantity of substance

Solution Approach 1:

The patent optimizes the glass transition temperature parameter of the polymer system to a specific range (below -60°C) that provides flexibility without excessive water absorption. The balanced polymer composition (polyurethane, polyester, epoxy) is formulated to achieve the right balance between flexibility and water resistance, preventing both cracking and excessive water uptake.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If the coating cures quickly to improve productivity, then cure time decreases, but the coating may become brittle and crack at low temperatures

Engineering Contradiction:
Improvecure rateVSAvoidlow temperature flexibility
Core Design Contradiction:
ProductivityVSTemperature

Solution Approach 1:

The patent selects curing agents and adjusts curing conditions (temperature, humidity, time) to optimize the cross-linking density of the polymer network. The balanced polymer composition enables the coating to cure within a reasonable timeframe while maintaining a flexible structure that prevents cracking at low temperatures, resolving the contradiction between cure speed and low-temperature flexibility.

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

The coating provides robust char formation and insulation, protecting steel from extreme fires and temperature fluctuations, with a Shore D hardness of at least 5.0, minimal water absorption, and resistance to continuous temperature cycles from +20°C to -60°C without cracking.

Implementation Method 1

an internally flexibilised acetoacetoxy polyacetoacetate (AcAc) functional polymer

Methodology Applied
Scientific EffectFlexibility: Elasticity

Implementation Method 2

Some materials will endothermically degrade upon exposure to flames or high temperature, thereby removing heat energy from the substrate

Methodology Applied
Scientific EffectEndothermic degradation: Endothermic Reaction

Implementation Method 3

flame-retardants can act as a thermal barrier to transfer heat energy away from the substrate

Methodology Applied
Scientific EffectThermal barrier: Thermal Insulation

Implementation Method 4

a blowing agent degrades to produce a non-flammable gas, thereby driving expansion of the char as a foam

Methodology Applied
Scientific EffectThermal decomposition: Decomposition (biological)

Implementation Method 5

The resulting thick, porous, highly-insulating, nonflammable, solid foam protects the substrate it covers from incident heat

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Data Source

PatentEP4045603B1Intumescent coating compositions effective at low temperatures
Publication Date: 2026.01.28 SWIMC LLC
  • EP4045603B1 patent drawingFigure 1A~1C
  • EP4045603B1 patent drawingFigure 1B~1D
  • EP4045603B1 patent drawingFigure 2A~2B

AI summary

An intumescent composition capable of withstanding temperature cycling as low as - 60° C without cracking is contemplated. The composition also exhibits enhanced durability due to its resistance to water absorption, its acceptable cure times, and (when exposed to fire conditions) its well-adhered, foamed char layer.