Low-Temperature Multilayer Coatings for Class-A CFRP Finishes
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional multilayer coating systems on fiber reinforced plastic substrates, such as CFRP, suffer from telegraphing effects and uneven paint finishes due to low glass transition temperature and thermal expansion coefficient differences, which compromise the 'class-A appearance and packaging stability.
Innovation Solution
A multilayer coating system comprising a primer, basecoat, and clearcoat composition, where the primer contains a (meth)acrylic polymer modified with chlorinated polyolefin and a clearcoat with OH-functional (meth)acrylic polymer, cured at low temperatures to minimize telegraphing and ensure excellent paint finish.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional multilayer coating systems are applied on fiber reinforced plastic substrates, then the coating process can be completed, but telegraphing effects and uneven paint finishes occur due to low glass transition temperature and thermal expansion coefficient differences
Solution Approach 1:
The patent modifies the chemical composition parameters of the primer coating to achieve a glass transition temperature of at least 80°C and specific thermal expansion properties. This is accomplished by selecting polymers with appropriate Tg values and using plasticizers in controlled amounts to adjust the overall thermal and mechanical properties of the primer layer, thereby eliminating telegraphing effects while maintaining packaging stability
Solution Approach 2:
The patent employs a composite primer formulation combining multiple polymers (polyester, acrylic, vinyl acetate), plasticizers, and other additives in specific proportions. This composite approach allows optimization of both glass transition temperature and thermal expansion coefficient to match the substrate, resolving the contradiction between paint finish quality and packaging stability
2Reliability
If high curing temperatures are used to ensure complete curing of the coating system, then curing completeness is improved, but energy consumption and process time increase
Solution Approach 1:
The patent lowers the curing temperature parameter from conventional high temperatures to a range of 50-80°C by modifying the chemical composition of the primer system. The specific polymer selection and plasticizer content enable complete curing at these reduced temperatures, significantly decreasing energy consumption while maintaining curing completeness
Solution Approach 2:
The patent replaces thermal energy input (high temperature curing) with chemically optimized curing mechanisms. The modified primer composition enables self-curing or low-temperature curing through chemical reactions that proceed efficiently at lower temperatures, substituting the need for high thermal energy input
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 system achieves a 'class-A appearance with LW≤10 and SW≤20, maintaining packaging stability and reducing process time and energy consumption.
Implementation Method 1
a primer, basecoat and a clearcoat which have been cured jointly at low temperatures
Implementation Method 2
cured at low temperatures to minimize telegraphing and ensure excellent paint finish
Data Source
AI summary
Disclosed herein are a multilayer coating system present on a substrate including at least three layers L1 to L3, layer L1 being obtained from a primer coating composition, which is obtained from a primer coating system including at least two components A) and B) separated from each other, where component A) inter alia includes at least one constituent a2), which is at least one (meth)acrylic polymer, which has been modified with at least one chlorinated polyolefin, where the polymer contains functional groups, that are reactive towards NCO-groups, layer L2 being obtained from a basecoat composition, and layer L3 being obtained from a clearcoat composition, a method of preparing a multilayer coating system making use of the aforementioned primer coating system, and a kit-of-parts including separated from one another at least the primer coating system and a clearcoat composition or a clearcoat system.