Novolac Epoxy Coating for Thermal Shock and CUI Resistance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing corrosion protection coatings for insulated pipes and vessels fail to provide adequate thermal shock resistance and long-term protection against corrosion under insulation (CUI), especially when exposed to temperature fluctuations between 200 °C and ice water, leading to cracking and flaking.
Innovation Solution
A corrosion protection coating combining novolak epoxy resin with a specific amine of formula (I) and phosphorus-containing pigments, which offers high thermal shock resistance and effective adhesion, preventing corrosion even after prolonged moisture exposure and multiple temperature changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional epoxy resin coatings with highly functional novolak epoxy resins are used, then good corrosion protection is achieved, but the coating becomes brittle and susceptible to cracking under thermal shock
Solution Approach 1:
The patent modifies the chemical composition parameters of the epoxy coating by incorporating specific flexible chain polymers and adjusting the ratio of rigid to flexible components. This changes the physical properties of the coating to achieve both corrosion protection and thermal shock resistance simultaneously.
Solution Approach 2:
The patent creates a composite coating system combining epoxy resin with flexible chain polymers (such as polyesters, polyethers, or polyacrylates). This composite structure integrates the corrosion-resistant properties of epoxy with the flexibility and thermal shock resistance of the polymer chains.
2Manufacturing precision
If high-boiling thinners like benzyl alcohol are added to suppress blushing, then surface quality improves, but the coating becomes more brittle and damages insulation at high temperatures
Solution Approach 1:
The patent changes the chemical parameters by selecting thinners with specific boiling point ranges (below 150°C) and molecular characteristics. This modification allows the thinner to evaporate completely before the coating cures, preventing insulation damage while still suppressing blushing effects.
Solution Approach 2:
The patent uses low-boiling thinners that serve their purpose temporarily during application and then completely evaporate, leaving no residual harmful substances. These thinners are 'short-living' in the sense that they are present only during application and decomposition, not in the final cured coating.
3Productivity
If the coating is designed for quick curing at ambient temperature, then productivity improves, but thermal shock resistance deteriorates
Solution Approach 1:
The patent adjusts the curing parameters by selecting hardeners and catalysts that enable rapid ambient temperature curing while simultaneously incorporating flexible polymer chains that maintain thermal shock resistance. The chemical reaction kinetics are optimized to achieve fast curing without compromising the final coating's flexibility.
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 effectively withstands 20 cycles of thermal shock between 204 °C and ice water without damage, ensuring reliable corrosion protection and maintaining integrity over time.
Implementation Method 1
They consist of liquid resin and hardener components, which are mixed before application and harden to form a solid coating
Implementation Method 2
at least one phosphorus-containing corrosion protection pigment
Implementation Method 3
A coated steel sheet must go through 20 cycles between a circulating air oven at 204 °C and ice water without the coating being destroyed or cracks, flaking or steel corrosion occurring
Data Source
AI summary
The invention relates to a corrosion protection coating comprising: - at least one novolac epoxy resin with an average functionality of at least 2.3, - at least one amine of formula (I), Z-NH-A-NH-CH2-Y (I) where A represents a divalent alkylene or cycloalkylene residue with 2 to 8 carbon atoms, Z represents H or ---CH2-Y, and Y represents an optionally substituted phenyl residue with 6 to 12 carbon atoms or a naphthyl residue, wherein the two nitrogen atoms to which residue A is bonded are separated from each other by at least two carbon atoms, and - at least one phosphorus-containing corrosion protection pigment. The corrosion protection coating is suitable for high service temperatures up to 230 °C and has high thermal shock resistance.It is preferably used for the protection of insulated metal pipes or vessels that are in contact with hot and/or cold media, in particular preventing metal corrosion under the insulation.