Fluoropolymer Back Coating for Durable Solar Heat Reflectors

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing solar heat-collecting reflectors face issues with durability, weather resistance, scratch resistance, and impact resistance due to the detachment of anti-corrosive coating film layers caused by thermal expansion, moisture absorption, and exposure to outdoor conditions such as sunlight and sand.

Innovation Solution

A coating composition for back coating that forms a cured coating film layer using a fluoropolymer with units derived from fluoroolefins and crosslinkable groups, which reacts with a curing agent to create a crosslinked structure, enhancing heat resistance, water resistance, weather resistance, and impact resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional anti-corrosive coating materials (lead-free pigments with synthetic resin binders) are used, then environmental requirements are met, but durability and weather resistance are insufficient

Engineering Contradiction:
ImprovedurabilityVSAvoidenvironmental harm
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent uses composite coating materials comprising fluoropolymer resins (providing weather resistance and durability) combined with specific pigments and additives. This composite approach allows the coating to simultaneously achieve environmental compliance (no lead) and superior performance in withstanding outdoor conditions including heat, moisture, and UV exposure.

Inventive Principle:
Principle #40Composite materials

2Reliability

If the anti-corrosive coating film layer is made thicker to improve durability, then protection against corrosion improves, but detachment due to thermal expansion and moisture absorption worsens

Engineering Contradiction:
Improvecorrosion protectionVSAvoidcoating film stability
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent modifies the chemical composition parameters of the coating film by using fluoropolymer resins with specific molecular structures and crosslinking densities. This changes the thermal expansion coefficient and moisture absorption characteristics of the coating, allowing it to remain stable and adherent even when applied at sufficient thicknesses for corrosion protection.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If a fluororesin is used as synthetic resin binder to improve durability, then heat resistance and water resistance improve, but weather resistance, scratch resistance and impact resistance remain insufficient

Engineering Contradiction:
Improveheat resistanceVSAvoidscratch resistance
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent combines fluoropolymer resins (providing heat and water resistance) with other functional components including crosslinking agents and reinforcing pigments. This composite formulation maintains the excellent heat resistance of fluororesins while adding scratch resistance through crosslinked network structures and impact resistance through toughening mechanisms.

Inventive Principle:
Principle #40Composite materials

4Stability of the object's composition

If the coating film is made more resistant to thermal expansion and shrinkage, then detachment is prevented, but the coating becomes more complex in composition

Engineering Contradiction:
Improvethermal stabilityVSAvoidcoating composition complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The patent achieves thermal stability by selecting fluoropolymer resins with inherently low thermal expansion coefficients and specific glass transition temperatures. By carefully controlling the polymerization degree and molecular weight distribution, the coating achieves dimensional stability across temperature cycles without requiring overly complex multi-component formulations.

Inventive Principle:
Principle #35Parameter changes

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 forms a durable cured coating film layer that maintains performance under outdoor conditions, preventing peeling and maintaining reflectance, thus ensuring the longevity and efficiency of solar heat-collecting reflectors.

Implementation Method 1

a fluoropolymer with units derived from fluoroolefins and crosslinkable groups, which reacts with a curing agent to create a crosslinked structure

Methodology Applied
Scientific EffectCrosslinking: Chemical Bonding

Implementation Method 2

The cured coating film layer is excellent in durability such as heat resistance or water resistance

Methodology Applied
Scientific EffectHydrophobic effect: Hydrophobe

Implementation Method 3

The anti-corrosive coating film layer is detached from the reflective metal layer by expansion or shrinkage by heat

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 4

The reflective metal layer is oxidized by moisture absorption or water absorption of the anti-corrosive coating film layer

Methodology Applied
Scientific EffectOxidation: Oxidation

Data Source

PatentEP2540785B1Use of a coating composition for preparing a solar heat-collecting reflector, solar heat-collecting reflector and method for producing same
Publication Date: 2016.02.10 AGC INC
  • EP2540785B1 patent drawingFigure 1

AI summary

To provide a coating composition for back coating, by which, in a solar heat-collecting reflector, a cured coating film layer excellent in durability such as heat resistance or water resistance and excellent in weather resistance, scratch resistance and impact resistance, can be formed, and a solar heat-collecting reflector having such a cured coating film layer. A coating composition for back coating to be used for the production of a solar heat-collecting reflector, which comprises a fluoropolymer (A) having units (A1) derived from a fluoroolefin and units (A2) having a crosslinkable group. A solar heat-collecting reflector having a cured coating film layer formed by the coating composition.