Two-Component Curable Coating Agent for Weather and Acid Resistance
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Solution Overview
Problem
Surface-treated articles exposed to outdoor conditions suffer from unevenness, discoloration, acid resistance issues, and low elongation properties in their protective layers, leading to appearance defects and potential cracking.
Innovation Solution
A two-component curable coating agent comprising a polyol with an alicyclic acrylic polyol and an alkyl polyol, reacting with a polyisocyanate to form a surface protective layer with enhanced weather resistance, acid resistance, fouling resistance, and elongation properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a polyol with high hydroxyl value is used to improve crosslinking density and durability, then the surface protective layer shows improved weather resistance and acid resistance, but gelation occurs and elongation properties deteriorate
Solution Approach 1:
The invention changes the parameter of hydroxyl value from the conventional limit of 35 mgKOH/g to a higher range of 36-200 mgKOH/g, enabling improved crosslinking density and weather resistance while avoiding gelation through the specific two-component formulation approach
Solution Approach 2:
The invention uses a composite polyol system combining acrylic polyol with other polyols (polyester polyol, polycarbonate polyol, or polyether polyol) in specific ratios, creating a composite material that achieves both high crosslinking density and maintained elongation properties
2Reliability
If the surface protective layer is made more resistant to environmental degradation, then weather resistance and acid resistance improve, but the layer becomes more prone to cracking under tensile force
Solution Approach 1:
The invention creates a composite polyol system that combines the benefits of different polyol types, achieving a balance between crosslinking density (for acid resistance) and chain flexibility (for cracking resistance), with the acrylic polyol providing crosslinking sites and the additional polyols providing flexibility
3Ease of manufacture
If conventional urethane modified acrylic resin is used, then the coating process is simple, but the surface protective layer shows poor weather resistance and acid resistance
Solution Approach 1:
The invention changes the chemical composition parameters by using high hydroxyl value acrylic polyol (36-200 mgKOH/g) instead of conventional low hydroxyl value resins, enabling improved fouling resistance and weather resistance while maintaining the simplicity of the two-component coating process
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 agent forms a protective layer that maintains a visually favorable appearance over time, withstands tensile forces, and reduces cracking, ensuring excellent weather, acid, and fouling resistance while maintaining flexibility.
Implementation Method 1
a surface protective layer containing a polyurethane obtained by a reaction of an acrylic polymer having a hydroxyl group with a polyisocyanate
Data Source
AI summary
Provided are a two-component curable coating agent capable of forming a surface protective layer having excellent weather resistance, acid resistance, fouling resistance, and elongation properties, and a multilayer film including a surface protective layer that is a cured film of the two-component curable coating agent. The two-component curable coating agent of the present invention includes: a main agent that contains a polyol containing an acrylic polyol having an alicyclic structure and a hydroxyl value of 36 mgKOH/g or more and 125 mgKOH/g or less, and an alkyl polyol; and a curing agent that contains a polyisocyanate. The multilayer film of the present invention includes: a substrate layer; and a surface protective layer that is integrally layered on a first surface of the substrate layer and is a cured film of the two-component curable coating agent.