Biaxially Oriented Polyester Film UV Hydrolysis Resistance
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Solution Overview
Problem
Existing transparent biaxially oriented polyester films lack sufficient UV and hydrolysis resistance, leading to degradation and increased haze, which is not cost-effectively addressed by prior art methods that require high concentrations of hydrolysis stabilizers or result in excessive organic volatiles and processing issues.
Innovation Solution
A biaxially oriented polyester film with a low carboxyl end group concentration, combined with extremely low concentrations of carbodiimide hydrolysis stabilizer and UV absorbers, providing superior UV and hydrolysis resistance while maintaining clarity and cost-effectiveness, achieved through a unique formulation and processing techniques such as solid state polymerization and masterbatch blending.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If high concentrations of hydrolysis stabilizers are used to achieve hydrolysis resistance, then hydrolysis resistance is improved, but excessive organic volatiles are generated and processing issues occur
Solution Approach 1:
The patent changes the concentration parameter of hydrolysis stabilizers from high (prior art) to extremely low (0.010-0.1 wt.%), achieving the same hydrolysis resistance through optimized formulation and processing conditions. This parameter change eliminates excessive organic volatile generation while maintaining reliability.
Solution Approach 2:
The patent creates a composite formulation combining polyester with specific ratios of hydrolysis stabilizers and UV absorbers. This composite approach allows synergistic effects where low concentrations of stabilizers work effectively with UV absorbers to provide both hydrolysis and UV resistance without generating harmful volatiles.
2Reliability
If high concentrations of hydrolysis stabilizers are used to achieve hydrolysis resistance, then hydrolysis resistance is improved, but processing complexity and cost increase
Solution Approach 1:
The patent simplifies the formulation by reducing stabilizer concentrations to 0.010-0.1 wt.% and optimizing processing parameters (solid state polymerization, masterbatch blending). This reduces formulation complexity while maintaining hydrolysis resistance through scientifically optimized conditions.
Solution Approach 2:
The patent uses exactly the right amount of stabilizers (0.010-0.1 wt.%) - not too little to fail, not too much to complicate. This partial action principle achieves sufficient hydrolysis resistance with minimal formulation complexity and cost.
3Illumination intensity
If conventional polyester films are used for outdoor applications, then basic transparency is maintained, but UV and hydrolysis resistance are insufficient leading to degradation
Solution Approach 1:
The patent creates a composite film combining polyester with UV absorbers (0.1-2 wt.%) and hydrolysis stabilizers (0.010-0.1 wt.%). This composite structure provides both transparency and superior UV/hydrolysis resistance, solving the degradation problem of conventional films.
Solution Approach 2:
The patent introduces UV absorbers as intermediary substances that intercept UV radiation before it can damage the polyester. These intermediaries protect the film from UV degradation while maintaining transparency, and work synergistically with hydrolysis stabilizers.
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 film exhibits high clarity, reduced haze, effective UV radiation interception, and long-term resistance to degradation, retaining 50% or more of its tensile strength after prolonged weathering and UV exposure, with improved processing stability and reduced environmental impact.
Implementation Method 1
0.010-0.1 wt. % of a carbodiimide hydrolysis stabilizer
Implementation Method 2
0.1-2 wt. % UV absorber
Implementation Method 3
biaxially oriented polyester film
Data Source
AI summary
Biaxially oriented polyester films including polyester polymer, a carbodiimide hydrolysis stabilizer, and a UV absorber are described. The polyester films have a carboxyl end group concentration of 5-20 equivalents per ton, and a haze value of 2% or less. The films exhibit superior transparency and possess stable light transmission characteristics. Methods of making the films and articles produced from the films are also described.