Marine Coating Composition with Dehydrating Agent for Self-Polishing Control
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Solution Overview
Problem
Existing self-polishing antifouling coatings for marine applications face issues with hardness, self-polishing rates, and difficulty in accurately controlling these rates, often resulting in insufficient performance and uncontrollable metal resinate formation.
Innovation Solution
A coating composition is developed that includes a carboxylic acid, such as rosin or its hydrogenated derivative, combined with a metal oxide compound and a dehydrating agent, where the dehydrating agent is contacted with either the carboxylic acid or the metal oxide before their combination, reducing trace water and preventing metal resinate formation, thereby enhancing self-polishing rates and erosion consistency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If carboxylic acid and metal oxide are combined directly in the coating composition, then the coating provides antifouling properties, but metal resinate formation becomes uncontrollable and self-polishing rates are insufficient
Solution Approach 1:
The dehydrating agent is added to the coating composition before the carboxylic acid and metal oxide components are combined. This preliminary action removes trace water that would otherwise catalyze uncontrolled metal resinate formation, enabling precise control over the self-polishing rate while maintaining antifouling performance
Solution Approach 2:
The dehydrating agent acts as an intermediary substance that mediates between the carboxylic acid and metal oxide components. By selectively binding trace water, it prevents unwanted side reactions and controls the rate of metal resinate formation, thereby regulating the self-polishing process
2Duration of action of stationary object
If the coating is designed to degrade slowly over time, then organisms adhere less to the surface, but the erosion rate is not constant and performance is insufficient
Solution Approach 1:
The dehydrating agent creates a controlled feedback mechanism where trace water removal regulates the rate of metal resinate formation. This ensures a constant erosion rate as the coating degrades over time, maintaining both durability and consistent self-polishing performance throughout the coating's service life
3Reliability
If metal oxides are added in excess to form metal carboxylates, then antifouling properties are enhanced, but the coating hardness decreases and self-polishing rates become uncontrollable
Solution Approach 1:
The addition of the dehydrating agent changes the chemical parameters of the coating system by removing trace water. This parameter change prevents hydrolysis and uncontrolled metal resinate formation, allowing metal oxides to be added in excess for enhanced antifouling properties while maintaining coating hardness and controlling self-polishing rates
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 approach results in a coating with improved self-polishing rates, a faster and more constant erosion rate, higher volume solids, reduced solvent emission, and increased environmental friendliness, making it more economical and effective for use in tropical and low-operation marine vessels.
Implementation Method 1
a dehydrating agent wherein the dehydrating agent is selected from one or more of sylosiv, sylosiv A4, anhydrous gypsum (CaSO4), synthetic zeolite adsorbents; orthoesters such as methyl orthoformate and methyl orthoacetate; orthoboric esters; silicates and isocyanates
Implementation Method 2
it is known in the art that metal oxides react with carboxylic acids such as rosin to form metal carboxylates (in the case of rosin, metal rosinates, also known as metal resinates)
Implementation Method 3
The degradation is often caused by a slow hydrolysation of the coating (usually the binder within the coating)
Data Source
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AI summary
A coating composition comprising: i) a carboxylic acid; comprising one or more of rosin or a hydrogenated derivative thereof: ii) at least one metal oxide compound; iii) a dehydrating agent; and iv) one or more binder; characterised in that, in the production of the coating composition, the dehydrating agent iii) is contacted with either of component i) or ii), prior to the addition of the other of component i) or ii).