Amorphous Polyamide Resin for Humidity Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Amorphous polyamide resins face challenges in maintaining a good appearance and dimensional stability under hot and humid conditions, with existing materials prone to weight change and deformation.
Innovation Solution
An amorphous polyamide resin composition comprising at least 70 mol % isophoronediamine-derived units and a combination of α,ω-straight chain aliphatic dicarboxylic acids and aromatic dicarboxylic acids, with specific ratios and types, such as sebacic acid, dodecanedioic acid, 2,6-naphthalene dicarboxylic acid, and isophthalic acid, to achieve low water absorption and high glass transition temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional amorphous polyamide resins are used, then transparency and chemical resistance are achieved, but weight change and deformation occur under hot and humid conditions
Solution Approach 1:
The patent changes the compositional parameters of the polyamide resin by specifying precise molar ratios of diamine and dicarboxylic acid constituents. The resin comprises 60-80 mol% of units from isophoronediamine and aliphatic dicarboxylic acids combined with 20-40 mol% of units from aromatic dicarboxylic acids, creating a specific molecular structure that reduces water absorption and maintains dimensional stability under hot and humid conditions
Solution Approach 2:
The patent creates a composite polyamide resin system by combining multiple diamine components (isophoronediamine with other diamines) and multiple dicarboxylic acid components (aliphatic and aromatic types). This composite approach at the molecular level achieves both amorphous transparency and improved resistance to weight change and deformation through the synergistic effects of different monomer units
2Manufacturing precision
If amorphous polyamide resin is formed into molded articles, then burr formation is reduced, but appearance degradation occurs under hot and humid conditions
Solution Approach 1:
The patent modifies the chemical composition parameters to achieve a glass transition temperature of 140-200°C, which provides thermal stability that prevents deformation and appearance degradation of molded articles under hot and humid service conditions while preserving the amorphous structure that reduces burr formation during molding
Data Source
AI summary
Provided is an amorphous polyamide resin that has a small weight change rate under hot and humid conditions and that can maintain a good appearance even when formed into a molded article and placed under hot and humid conditions. Also provided is a molded article including the amorphous polyamide resin. An amorphous polyamide resin includes: constituent units derived from a diamine and constituent units derived from a dicarboxylic acid, not less than 70 mol % of the constituent units derived from a diamine being constituent units derived from isophoronediamine, the constituent units derived from a dicarboxylic acid including constituent units derived from an α,ω-straight chain aliphatic dicarboxylic acid having from 8 to 14 carbons and constituent units derived from an aromatic dicarboxylic acid.