IR Reflective Paint Using Iron Oxide and Phthalocyanine Blue
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Solution Overview
Problem
Existing architectural paints, especially those with deep pastel and dark colors, absorb infrared radiation leading to significant temperature rises on building surfaces, limiting the palette available and increasing energy consumption for cooling, as they often contain carbon black pigments that absorb IR radiation.
Innovation Solution
A solar IR reflective paint composition using red iron oxide, phthalocyanine blue, and titanium dioxide pigments, free of IR-absorptive and IR-reflective black pigments, with a lightness value of 38 to 88, which reflects IR radiation and maintains a non-metallic sheen, reducing the need for additional IR reflective layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If carbon black pigment is used to achieve deep pastel and dark colors, then color palette is expanded, but infrared radiation absorption increases leading to temperature rise
Solution Approach 1:
The invention extracts and removes carbon black pigment from the paint composition entirely, replacing it with alternative pigments (red iron oxide and phthalocyanine blue) that do not absorb infrared radiation. This extraction eliminates the harmful IR absorption effect while maintaining the ability to produce deep pastel and dark colors through alternative means.
Solution Approach 2:
The invention changes the chemical composition parameters of the pigment system by substituting carbon black with specific inorganic pigments having different optical properties. The red iron oxide and phthalocyanine blue pigments are selected for their specific reflectance characteristics in the infrared region, fundamentally altering how the paint interacts with solar radiation.
2Temperature
If light colors are used to reflect infrared radiation, then temperature rise is reduced, but color palette is limited
Solution Approach 1:
The invention removes the limitation imposed by carbon black by extracting it from the formulation. This allows the use of alternative pigments that can create deep pastel and dark colors without the harmful IR absorption, thereby expanding the usable color palette beyond traditional light colors.
Solution Approach 2:
The invention uses a composite pigment system combining red iron oxide and phthalocyanine blue in specific proportions. This composite approach allows the creation of various deep pastel and dark hues while maintaining infrared reflectance, as the combination of these two pigments achieves color depth without carbon black's IR absorption.
3Object-affected harmful factors
If titanium dioxide is used to reflect infrared radiation, then IR reflectance is improved, but paint formulation complexity increases
Solution Approach 1:
The invention extracts and removes the need for additional IR-reflective additives by using a simplified pigment system of red iron oxide and phthalocyanine blue. This extraction of complexity eliminates the need for specialized IR-reflective titanium dioxide formulations while maintaining effective infrared reflectance through the inherent optical properties of the selected pigments.
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 paint composition effectively reduces the temperature rise on building surfaces by reflecting IR radiation, achieving lower surface temperatures compared to traditional paints, even when exposed to direct sunlight, while offering a broader color range without the use of carbon black.
Implementation Method 1
the infra-red (IR) portion of the solar radiation (of wavelength from 700-2500nm) being absorbed by the exterior surfaces... titanium dioxide is a good reflector of IR radiation... the paint composition effectively reduces the temperature rise on building surfaces by reflecting IR radiation
Implementation Method 2
the infra-red (IR) portion of the solar radiation (of wavelength from 700-2500nm) being absorbed by the exterior surfaces and thence transmitted to the interior surface of the wall
Data Source
AI summary
An Infra Red-reflective architectural paint composition comprising: i. red iron oxide pigment ii. phthalocyanine blue pigment iii. titanium dioxide and optionally yellow iron oxide wherein the composition is free of Infra Red-absorptive black pigments, Infra Red- transparent black pigments and Infra Red-reflective black pigments, has a lightness value, L*, when dry, of from 38 to 88 and the weight ratio of i:ii is from 3 : 1 to 15: 1.