All-Aromatic Polyester Heat Resistance Moldability
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Solution Overview
Problem
Existing methods for producing all-aromatic polyesters struggle to achieve consistent quality, high heat resistance, high strength, and high solder heat resistance, which are critical for manufacturing minute electronic parts like connectors and relays.
Innovation Solution
A method involving prepolymerization of hydroxyl benzoic acid, benzoquinone, dihydroxybiphenyl, terephthalic acid, isophthalic acid, and acetic anhydride, followed by controlled particle size distribution and solid polymerization at specific temperatures to produce all-aromatic polyesters with optimal repeating unit ratios, ensuring excellent flowability and heat resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If liquid crystal polyesters are used for molding minute electronic parts, then heat resistance and mechanical properties are improved, but melt temperature becomes excessively high requiring inorganic fillers
Solution Approach 1:
The patent changes the chemical composition parameters of the polyester by incorporating specific aromatic components (hydroxyl benzoic acid, dihydroxybiphenyl, terephthalic acid, isophthalic acid) in controlled ratios. This chemical parameter modification achieves the dual goal of maintaining high heat resistance while reducing melt temperature to improve moldability, eliminating the need for inorganic fillers
Solution Approach 2:
The patent creates a composite polyester structure by combining multiple aromatic monomers (hydroxyl benzoic acid, dihydroxybiphenyl, terephthalic acid, isophthalic acid) in specific proportions. This composite approach allows the material to achieve both high heat resistance and improved flowability, resolving the contradiction between thermal performance and manufacturability
2Temperature
If inorganic fillers are added to liquid crystal polyesters, then heat resistance is improved, but manufacturing complexity and cost increase
Solution Approach 1:
The patent extracts and eliminates the need for inorganic fillers by fundamentally reformulating the polyester composition. Through careful selection and ratio control of aromatic monomers, the invention achieves high heat resistance inherently, removing the requirement for additional filler materials and simplifying the overall manufacturing process
3Reliability
If conventional polyester production methods are used, then production simplicity is maintained, but quality stability and performance consistency are insufficient
Solution Approach 1:
The patent applies preliminary action by carefully pre-determining and controlling the particle size distribution of the polyester powder before final processing. The invention specifies precise mesh distribution ranges (10-39 mesh: 5-20 wt%, 40-59 mesh: 20-40 wt%, 60-79 mesh: 40-70 wt%, 80-120 mesh: 0-15 wt%) to ensure consistent quality and performance, achieving quality stability through advance preparation
Solution Approach 2:
The patent changes multiple critical parameters including monomer ratios (a/(a+b+c)=0.35-0.70, b/(a+b+c)=0.15-0.35, c/(a+b+c)=0.90-1.10), particle size distribution, and processing temperatures. These parameter modifications work together to achieve both quality stability and manufacturing feasibility
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 method effectively produces all-aromatic polyesters with high quality stability, high flowability, and high solder heat resistance when combined with inorganic fillers, resulting in products with enhanced resistance, strength, and dimension precision.
Implementation Method 1
subjecting the prepolymer having the above particle size distribution to a solid polymerization to obtain all-aromatic polyesters
Implementation Method 2
increase the temperature from 140 ̃160° C. to 280 ̃320° C. at a heating rate of 0.3 ̃3° C./minute to collect distillate side products
Data Source
AI summary
The present invention relates to all-aromatic polyesters, a method for preparing the same, and a polyester composition containing the same. The present method is carried out in two stages of first carrying out a prepolymerization to obtain a prepolymer having a specific particle size distribution, then carrying out a solid polymerization.The present method can control the quality of polyester effectively and produce all-aromatic polyester exhibiting excellent flowability, high heat resistance, and high solder heat resistance.