Intumescent Coating Curing Rate via Polyester Polyol Reactivity

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Solution Overview

Problem

Intumescent coatings used for fire protection have slow curing rates, especially in low-temperature conditions, which limits overcoat time and return to service time, and can result in char cracking and reduced insulation properties.

Innovation Solution

An intumescent coating composition comprising a polyepoxy-functional compound, a beta-hydroxy ester of (meth)acrylic acid, a compound reactive with epoxy and acrylic groups, and an expansion gas, which increases curing rate without compromising char expansion or insulation properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If polyamine curing agents are used to cure polyepoxide resins in intumescent coating compositions, then the coating provides fire protection and char formation, but the curing rate is slow which limits overcoat time and return to service time

Engineering Contradiction:
Improvefire protectionVSAvoidcuring rate
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent changes the chemical parameters of the curing system by introducing alternative curing agents (polyester polyols, carboxylic acids, anhydrides) with different reactivity toward epoxy groups. This parameter change increases the curing rate while maintaining the fire protection function through proper selection of curing agent functionality and reactivity.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite curing system that combines multiple curing agents with different mechanisms and rates of reaction. This composite approach allows optimization of both curing speed and final coating performance including fire resistance and char formation properties.

Inventive Principle:
Principle #40Composite materials

2Productivity

If the curing rate is increased to improve productivity, then overcoat time and return to service time are reduced, but char expansion rate and insulation properties may be compromised

Engineering Contradiction:
Improvecuring rateVSAvoidchar expansion and insulation properties
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent carefully adjusts the parameters of the curing system by selecting curing agents with appropriate functionality and reactivity. The curing agent is chosen to have sufficient reactivity to increase curing rate while maintaining the chemical composition needed for proper char formation and insulation properties.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses curing agents with higher functionality than traditional polyamines, which provides excess reactivity for faster curing. However, the formulation is balanced to ensure that the excess reactivity does not compromise the char formation mechanism, achieving both faster curing and maintained fire protection.

Inventive Principle:
Principle #16Partial or excessive action

3Adaptability or versatility

If low temperature application conditions are used, then the coating can be applied in more environments, but the curing rate is slowed even further

Engineering Contradiction:
Improveapplication temperature rangeVSAvoidcuring rate
Core Design Contradiction:
Adaptability or versatilityVSProductivity

Solution Approach 1:

The patent changes the activation energy parameters of the curing system by selecting curing agents that maintain adequate reactivity at lower temperatures. The chosen curing agents have chemical properties that allow them to react effectively with epoxy groups even in cool conditions, thus improving adaptability without sacrificing curing rate.

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 composition achieves faster curing and improved char formation, reducing temperature rise in substrates during fires and preventing char cracking, thus enhancing fire resistance and protection.

Implementation Method 1

a compound bearing a plurality of functional groups that are reactive with the epoxy groups of the polyepoxy-functional compound (a) and the (meth)acrylic ester groups of the beta-hydroxy ester of (meth)acrylic acid comprising a plurality of beta-hydroxy (meth)acrylic ester groups (b)

Methodology Applied
Scientific EffectChemical reaction: Chemical Bonding

Implementation Method 2

a compound providing an expansion gas upon thermal decomposition

Methodology Applied
Scientific EffectThermal decomposition: Pyrolysis

Implementation Method 3

the coating contains additives called 'spumifics' that give off gas in a fire, which causes the char to swell into a foam

Methodology Applied
Scientific EffectGas expansion: Thermal Expansion

Implementation Method 4

If an epoxy resin is present in the binder, the binder also provides a source of carbon, which, in a fire, is converted to a char

Methodology Applied
Scientific EffectCarbonization: Pyrolysis

Data Source

PatentEP3658629B1Fast curing intumescent coating compositions
Publication Date: 2023.03.22 PPG COATINGS EURO BV

AI summary

The present invention relates to an intumescent coating composition comprising: (a) a polyepoxy-functional compound; (b) a beta-hydroxy ester of (meth)acrylic acid comprising a plurality of beta- hydroxy (meth)acrylic ester groups; (c) a compound bearing a plurality of functional groups that are reactive with the epoxy groups of the polyepoxy-functional compound (a) and the (meth)acrylic ester groups of the beta-hydroxy ester of (meth)acrylic acid comprising a plurality of beta-hydroxy (meth)acrylic ester groups; and (d) a compound providing an expansion gas upon thermal decomposition; wherein compounds (a) to (d) differ from each other, a method for coating a substrate with said intumescent coating composition and to a substrate at least partially coated with a coating deposited from said intumescent coating composition.