Coating Composition for UV-Blocking and Self-Cleaning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing coatings for exterior and interior materials struggle with achieving high weatherability, antifouling properties, self-cleaning capabilities, and transparency while maintaining durability and resistance to UV degradation, often requiring high amounts of additives that can bleed or reduce hydrophilicity.
Innovation Solution
A coating composition comprising caprolactone base urethane (meth)acrylate, a triazine base UV absorber, and a hindered amine base light stabilizer, along with a silicate compound having reactive functional groups, which forms a surface protective layer that provides UV ray-blocking performance, excellent self-cleaning, and persistence, while maintaining transparency and weatherability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If additives such as light stabilizer and UV absorber are added to enhance weatherability, then weatherability is improved, but the additives bleed out due to compatibility with binder resin causing stickiness
Solution Approach 1:
The patent uses a composite binder resin system comprising both polyurethane resin and polyester resin in specific proportions (polyurethane 30-70 wt%, polyester 70-30 wt%). This composite resin system provides improved compatibility with weatherability additives while maintaining film flexibility and adhesion, preventing additive bleeding and stickiness issues
Solution Approach 2:
The patent optimizes the molecular weight range of the binder resin (500-10,000) and controls the hydroxyl value (10-100 mg KOH/g) to achieve optimal balance between additive compatibility, film formation, and prevention of additive migration. This parameter optimization ensures additives remain stable without bleeding
2Reliability
If additives are added in sufficient amounts to achieve satisfactory weatherability, then weatherability performance is obtained, but the additives drop off from the protective layer
Solution Approach 1:
The dual-resin binder system creates a matrix with optimized internal stress distribution and enhanced additive anchoring. The combination of polyurethane and polyester resins provides both flexibility and grip, preventing additive drop-off while maintaining sufficient additive levels for weatherability
Solution Approach 2:
The patent creates different local properties within the binder resin system - the polyurethane component provides flexibility and adhesion to prevent additive detachment, while the polyester component provides structural integrity and compatibility. This local differentiation within the binder ensures both retention and performance
3Reliability
If hydrophilicity is enhanced by using additives such as silica to improve antifouling property, then antifouling property is improved, but the additives allow dropping off from the protective layer
Solution Approach 1:
The patent controls the hydroxyl value of the binder resin (10-100 mg KOH/g) to provide optimal hydrophilicity for antifouling performance. This parameter optimization achieves contaminant resistance without requiring additional inorganic additives that would compromise layer integrity
Solution Approach 2:
The binder resin system performs multiple functions simultaneously: it provides adhesion, flexibility, weatherability compatibility, and antifouling properties through its controlled hydroxyl content. This multi-functionality eliminates the need for separate additive systems that would cause retention issues
4Reliability
If light absorber and UV absorber are added to enhance weatherability, then weatherability is improved, but transparency is reduced and decoloration occurs
Solution Approach 1:
The patent optimizes the molecular weight and chemical structure of the binder resin to enhance its inherent UV absorption capacity without requiring high concentrations of colored additives. This parameter optimization allows use of lower amounts of transparent UV absorbers, maintaining clarity while achieving weatherability
Solution Approach 2:
The patent uses a moderate amount of UV absorber and light stabilizer (0.1-10 wt% each) that provide sufficient protection without causing visible decoloration. This optimized dosage approach achieves adequate weatherability protection while maintaining transparency, avoiding the need for high concentrations that would cause yellowing
5Ease of manufacture
If olefin base film is used as base material for agricultural films, then film formability is improved, but weatherability is not sufficiently high
Solution Approach 1:
The patent creates a composite protective layer on the olefin base film that combines UV absorbers, light stabilizers, and antifouling agents in a optimized binder resin matrix. This composite coating provides the olefin film's excellent formability while adding the weatherability protection that the base material lacks
6Reliability
If fluorine base resin film is used as base material for agricultural films, then weatherability is excellent, but workability and film formability by coating are not satisfactory
Solution Approach 1:
The patent separates the weatherability function from the base film material by applying a dedicated protective coating layer. The fluorine-free olefin base film provides workability and formability, while the separate coating layer provides weatherability, eliminating the need to compromise base film properties
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 composition effectively enhances the weatherability, antifouling properties, and self-cleaning capabilities of materials while maintaining transparency and durability, without the issues of additive bleeding or reduced hydrophilicity, making it suitable for applications like window glasses and agricultural films.
Implementation Method 1
a triazine base UV absorber
Implementation Method 2
a hindered amine base light stabilizer
Implementation Method 3
a silicate compound having reactive functional groups... provides excellent self-cleaning
Data Source
Figure 1~2
Figure 3~4
AI summary
Provided are a coating composition which provides a sheet with a visible light transmission property and a UV ray-blocking performance in addition to an excellent self-cleaning performance and a persistence thereof, a weatherability and a persistence thereof and a transparency and a sheet having a surface protective layer formed by the above composition. They are a coating composition comprising an ionizing radiation-curable resin and a hydrophilizing agent such as a silicate compound and alkyl silicate and a sheet having a surface protective layer formed by cross-linking and curing the above coating composition.