Antifouling Coating Composition with Triorganosilyl Ester Copolymer
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Solution Overview
Problem
Conventional antifouling coating materials face challenges such as high temperature-dependent solubility, poor water resistance, and environmental concerns, leading to inefficient prevention of aquatic fouling organisms on ships and submerged structures.
Innovation Solution
A triorganosilyl ester-containing copolymer and copper salt-based antifouling coating composition with a specific monomer ratio and molecular weight range, which forms a coating film with stable solubility and low temperature dependency, ensuring effective antifouling performance over extended periods without environmental harm.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If triorganosilyl ester-containing copolymers are used as hydrolyzable copolymers to replace organic tin-containing copolymers, then environmental harm is reduced, but the dissolving rate becomes excessively high after a long period of time
Solution Approach 1:
The patent changes the chemical structure parameters of the copolymer by specifying precise monomer ratios (triorganosilyl methacrylate: 45-65 wt%, other methacrylate: 35-55 wt%) and molecular weight (20,000-70,000) to control the hydrolysis rate and dissolving characteristics of the coating film, achieving stable antifouling performance over time
Solution Approach 2:
The patent creates a composite coating system by combining triorganosilyl ester-containing copolymer with copper salt (rosin copper salt or copper salt of rosin derivative) and optionally cuprous oxide, where each component contributes specific properties to achieve balanced dissolving rate and antifouling effectiveness
2Productivity
If copolymers obtained by copolymerization of silyl monomers with straight-chain alkyl groups are used, then the dissolving rate increases, but water resistance deteriorates
Solution Approach 1:
The patent specifies using triorganosilyl methacrylate with branched alkyl groups (such as triisopropylsilyl methacrylate) rather than straight-chain alkyl groups, and controls the organosilyl group content at 2-10 mmol/g to optimize both dissolving rate and water resistance by adjusting the molecular structure parameters
3Reliability
If copolymers with branched alkyl groups are used, then water resistance improves, but the coating film becomes brittle and may be cracked or peeled
Solution Approach 1:
The patent optimizes the molecular weight of the copolymer to 20,000-70,000 and controls the ratio of branched alkyl group-containing monomer to balance the coating film's flexibility and water resistance, preventing brittleness while maintaining protective properties
Solution Approach 2:
The patent combines the copolymer with copper salt and rosin components to create a composite coating system where the interaction between components enhances coating film flexibility and adhesion, compensating for the potential brittleness introduced by branched alkyl groups
4Productivity
If the coating film dissolving amount is increased at high seawater temperature, then antifouling effect is enhanced, but coating film thickness design becomes difficult
Solution Approach 1:
The patent designs the copolymer with specific molecular weight (20,000-70,000) and monomer composition to achieve a temperature dependency coefficient of 1.3 or less, ensuring that the dissolving amount at 35°C is not more than 1.3 times that at 25°C, providing predictable coating performance across temperature variations
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 provides a stable and long-lasting antifouling effect with reduced temperature dependency, maintaining water resistance and preventing fouling organisms, even in high seawater temperatures, while being environmentally friendly and easy to recoat.
Implementation Method 1
a coating film formed by application of an antifouling coating material that contains a polymer with tributyltin groups gradually dissolves the polymer component into seawater
Implementation Method 2
the use of these antifouling coating materials has now been abandoned due to problems with marine pollution
Data Source
AI summary
An object of the present invention is to provide a composition for forming an environment friendly antifouling coating film that can effectively exhibit an antifouling effect in seawater for a long period of time and furthermore exhibits a small temperature dependency of the coating film dissolving amount. The present invention provides an antifouling coating composition comprising: (A) a triorganosilyl ester-containing copolymer obtained by a mixture of (a) a triorganosilyl methacrylate monomer represented by a general formula (1) in which R1, R2, and R3 are equal or different each other, and each represent an alkyl group having 3 to 6 carbons and branched on α-position or a phenyl group, and (b) a methoxyalkyl methacrylate monomer represented by a general formula (2) in which R4 represents an alkylene group having 2 to 4 carbons, wherein a content ratio of the monomer (a) in the mixture is 45 to 65 weight%, and a total content of the monomer (a) and the monomer (b) in the mixture is 80 weight% or more, and a copper salt that is at least one member selected from the group consisting of rosin copper salts and copper salts of rosin derivatives.