Aqueous Vinyl-Modified Epoxy Resin Coating Hardness and Water Whitening
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Solution Overview
Problem
Conventional vinyl-modified epoxy esters have limitations in corrosion resistance, initial coating hardness, and water whitening resistance, particularly when exposed to harsh environments such as brake fluids and acids, and exhibit reduced durability over time.
Innovation Solution
Aqueous vinyl-modified epoxy resin composition is developed using a water-miscible crosslinking agent and a reaction product from a specific vinyl monomer and a polymerizable unsaturated group-containing modified epoxy resin, which includes a mixture of different types of epoxy resins and a carboxyl group-containing vinyl monomer, enhancing resistance to acids and brake fluids while maintaining high initial coating hardness and flexibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the content of the fatty acid component is increased to improve resistance to water whitening, then water whitening resistance is improved, but coating hardness and corrosion resistance tend to be low
Solution Approach 1:
The patent changes the chemical structure parameters by introducing a polymerizable unsaturated group-containing modified epoxy resin with specific molecular structure, and controls the vinyl monomer content within 5-50 parts by weight per 100 parts of modified epoxy resin. This parameter optimization achieves both high initial coating hardness (Shore D 40-70) and complete prevention of water whitening without relying on high fatty acid component content
Solution Approach 2:
The patent creates a composite resin system by combining polymerizable unsaturated group-containing modified epoxy resin with vinyl monomer (carboxyl group-containing vinyl monomer or styrene). This composite structure provides synergistic effects where the modified epoxy resin contributes to hardness and the vinyl monomer contributes to water whitening resistance, achieving both properties simultaneously
2Reliability
If conventional vinyl-modified epoxy esters are used to improve corrosion resistance, then corrosion resistance is improved, but initial coating hardness is low and scratching occurs at initial stage
Solution Approach 1:
The patent incorporates a polymerizable unsaturated group-containing modified epoxy resin that is pre-modified during resin synthesis, so that the vinyl groups are already in place before coating application. This preliminary preparation allows the resin to achieve high initial hardness immediately upon coating, eliminating the need for post-application oxidation polymerization that causes scratching
Solution Approach 2:
The patent optimizes the molecular weight and structure parameters of the modified epoxy resin, controlling the vinyl monomer content within 5-50 parts by weight per 100 parts of modified epoxy resin. This parameter control ensures the resin achieves appropriate balance between flexibility and hardness, preventing scratching while maintaining corrosion resistance
3Strength
If aqueous vinyl-modified epoxy resin composition is used to improve initial coating hardness, then coating hardness is improved, but coating film becomes too hard and cracking occurs during long-term use
Solution Approach 1:
The patent precisely controls the composition parameters by limiting vinyl monomer content to 5-50 parts by weight per 100 parts of modified epoxy resin, and selects specific types of vinyl monomers (carboxyl group-containing or styrene). This parameter optimization ensures the coating achieves high initial hardness (Shore D 40-70) while maintaining sufficient flexibility and adhesion to prevent cracking during long-term use
Solution Approach 2:
The patent creates a balanced composite system combining polymerizable unsaturated group-containing modified epoxy resin with carefully selected vinyl monomers. This composite structure provides synergistic properties where the modified epoxy resin delivers hardness and the vinyl monomer contributes flexibility and adhesion, preventing coating film cracking
4Ease of operation
If vinyl-modified epoxy esters are used to achieve water-based coating, then water-based coating capability is achieved, but corrosion resistance and water resistance are insufficient
Solution Approach 1:
The patent optimizes the chemical composition parameters by using polymerizable unsaturated group-containing modified epoxy resin with controlled molecular structure and limiting vinyl monomer content to 5-50 parts by weight per 100 parts of modified epoxy resin. This parameter optimization achieves both water-based coating capability and superior corrosion resistance (passing salt spray test for 1000 hours) and water resistance
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 forms a coating film with improved resistance to harsh environments, including brake fluids and acids, complete prevention of water whitening, and sustained corrosion resistance, while maintaining moderate flexibility and initial hardness.
Implementation Method 1
a copolymer produced by copolymerizing a specific polymerizable unsaturated group-containing modified epoxy resin with a carboxyl group-containing vinyl monomer
Implementation Method 2
using a water-miscible crosslinking agent and a reaction product produced by polymerizing a specific vinyl monomer in the presence of a polymerizable unsaturated group-containing modified epoxy resin
Implementation Method 3
The invention relates to an aqueous vinyl-modified epoxy resin composition, comprising: an aqueous composition comprising a modified epoxy resin (A) that is neutralized with a basic compound and dispersed or dissolved in water, and a water-miscible crosslinking agent (B)
Implementation Method 4
neutralizing and dispersing or dissolving a copolymer produced by copolymerizing a specific polymerizable unsaturated group-containing modified epoxy resin with a carboxyl group-containing vinyl monomer
Data Source
AI summary
An aqueous vinyl-modified epoxy resin composition of the invention comprises: an aqueous composition comprising a modified epoxy resin (A) that is neutralized with a basic compound and dispersed or dissolved in water, wherein the modified epoxy resin (A) is obtained by copolymerizing a polymerizable unsaturated group-containing modified epoxy resin (a) and a vinyl monomer (b) comprising at least a carboxyl group-containing vinyl monomer (b-1), wherein the polymerizable unsaturated group-containing modified epoxy resin (a) is obtained by a reaction among (a-1) an epoxy resin comprising at least an aromatic epoxy resin (a -11), (a-2) a glycidyl group-containing vinyl monomer, and (a-3) an amine, and optionally (a-4) a component capable of reacting with the components (a-1) to (a-3); and a water-miscible crosslinking agent (B). The aqueous vinyl-modified epoxy resin composition of the invention can provide a coating film that has high resistance to harsher environment, such as resistance to brake fluids.