Polycarbonate Resin Composition UV Blocking Gas Generation
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Solution Overview
Problem
Current polycarbonate resin compositions fail to effectively block ultraviolet light at wavelengths of 400 to 420 nm while preventing gas generation during molding, which is crucial for protecting eyes from damage caused by sunlight and LED lighting.
Innovation Solution
A polycarbonate resin composition incorporating a sesamol group-containing benzotriazole ultraviolet absorber with a specific maximum absorption wavelength and a stabilizer, such as an aromatic phosphite or phenolic stabilizer, to block ultraviolet light and prevent gas generation during molding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If conventional ultraviolet absorbers are incorporated at large levels to block light at wavelengths of 400 to 420 nm, then the light-blocking capability is improved, but gas generation during molding increases
Solution Approach 1:
The patent changes the chemical structure parameters of the ultraviolet absorber by incorporating a sesamol group into the benzotriazole molecule. This structural modification enables the absorber to achieve effective light-blocking capability at lower concentrations, thereby preventing gas generation during molding while still blocking light at wavelengths of 400 to 420 nm
Solution Approach 2:
The patent creates a composite resin composition by combining polycarbonate resin with specifically designed sesamol group-containing benzotriazole ultraviolet absorbers and phosphorus-based stabilizers. This composite approach achieves synergistic effects where the unique molecular structure of the ultraviolet absorber provides both light-blocking capability and gas generation prevention
2Object-affected harmful factors
If conventional ultraviolet absorbers are used to block ultraviolet light, then ultraviolet protection is improved, but the ability to block visible light at 400 to 420 nm is insufficient
Solution Approach 1:
The patent modifies the absorption wavelength parameters of the ultraviolet absorber by incorporating the sesamol group, which extends the absorption spectrum to include visible light wavelengths of 400 to 420 nm. This enables the same substance to provide both ultraviolet protection and visible light blocking without requiring separate additives
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 composition effectively blocks ultraviolet light at wavelengths of 400 to 420 nm without gas generation, ensuring the mechanical and thermal properties of polycarbonate resins, making it suitable for applications like eyeglasses and automotive parts.
Implementation Method 1
a sesamol group-containing benzotriazole ultraviolet absorber (B1) having a maximum absorption wavelength of at least 375 nm in the absorption curve determined according to JIS K 7105
Data Source
Figure 1
AI summary
Provided is a polycarbonate resin composition that can block ultraviolet light as well as light on the visible light side therefrom at wavelengths of 400 to 420 nm, and that is free of the problem of gas generation during molding. The polycarbonate resin composition characteristically comprises, per 100 parts by mass of a polycarbonate resin (A), (i) 0.02 to 1 parts by mass of a sesamol group-containing benzotriazole ultraviolet absorber (B1) having a maximum absorption wavelength of at least 375 nm in the absorption curve determined according to JIS K 7105 using the following formula, or (ii) 0.08 to 1 parts by mass of a sesamol group-containing benzotriazole ultraviolet absorber (B2) having a maximum absorption wavelength of at least 360 nm and less than 375 nm in the absorption curve determined according to JIS K 7105 using the following formula; and 0.01 to 0.5 % by mass of a stabilizer (C).