Infrared-Shielding Laminated Sheet With Balanced Color and Weather Resistance
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Solution Overview
Problem
Existing infrared shielding materials for window applications, such as those using polycarbonate resins, face challenges with high production costs, thermal processing issues, and undesirable color tones, which affect their weather resistance and performance.
Innovation Solution
A laminated sheet structure comprising a polycarbonate resin substrate layer with a methacrylic resin surface layer, incorporating colorants and infrared absorbing agents to achieve balanced light shielding, transmission, and color tone, while ensuring excellent weather resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a heat reflecting film with Ag film and transparent metal oxide films is used for infrared shielding, then infrared shielding performance is improved, but production cost increases due to sputtering method requirement
Solution Approach 1:
The patent changes the material composition parameters by using polycarbonate resin with specific infrared absorbing additives instead of metal oxide films, and applies surface treatment to achieve the desired infrared shielding effect at lower cost
Solution Approach 2:
The patent replaces expensive sputtered metal oxide films with more economical organic infrared absorbing additives and surface treatments that can be applied through conventional coating methods
2Reliability
If a multilayered polymer film with crystalline naphthalene dicarboxylic acid polyester is used for infrared shielding, then infrared energy reflection is improved, but production cost increases and thermal processing performance deteriorates
Solution Approach 1:
The patent modifies the resin composition by incorporating specific infrared absorbing additives into polycarbonate resin and controls the surface treatment parameters to achieve infrared shielding without requiring complex multilayer structures
Solution Approach 2:
The patent creates a composite material system combining polycarbonate resin with infrared absorbing additives and surface treatment layers, achieving multiple functions in a simpler structure
3Ease of manufacture
If carbon black is added to polycarbonate resin for infrared shielding, then production cost decreases, but color tone becomes reddish black and weather resistance deteriorates
Solution Approach 1:
The patent changes the type of infrared absorbing additive from carbon black to organic infrared absorbing dyes or pigments that provide better color tone and weather resistance while maintaining infrared shielding performance
Solution Approach 2:
The patent applies surface treatment specifically to the polycarbonate resin surface to enhance weather resistance and color stability without affecting the bulk material 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 laminated sheet provides effective infrared shielding, maintains a desirable color tone close to jet black, and enhances weather resistance, reducing material costs and thermal processing issues.
Implementation Method 1
a laminated sheet having a good color tone, good infrared shielding properties
Data Source
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AI summary
The present invention provides a laminated sheet having a good color tone, good infrared shielding properties, and excellent weather resistance. The present invention relates to a laminated sheet (10X) including surface layers (12A, 12B) containing a methacrylic resin laminated on at least one surface of the substrate layer (11) containing a polycarbonate resin. The substrate layer (11) contains a colorant. The total thickness is 3.0 to 10.0 mm, and T1 > T2 is satisfied wherein T1 represents the thickness of the substrate layer (11) and T2 represents the total thickness of the surface layer (12A, 12B). The total light transmittance is 3 to 60%, and the transmittance at a wavelength of 1,500 nm is 60% or less. The absolute value of a* value is 10.0 or less and the absolute value of b* is 10.0 or less in the L*a*b* color space defined by JIS Z 8781-4.