Polyamide Resin Composition Heat Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Polyamide resin compositions used in materials like gasoline tanks and molded containers face issues with heat stability, yellowing, and filter clogging due to heat deterioration, leading to increased filter back pressure and reduced productivity.
Innovation Solution
A polyamide resin composition containing mainly m-xylylenediamine and adipic acid, with specific phosphorus and sodium content ranges, and a back pressure increasing coefficient within certain limits, is developed to enhance heat stability, color tone, and reduce filter clogging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If polyamide is used to improve physical and mechanical characteristics, then strength and durability are improved, but heat stability deteriorates causing gelation and yellowing
Solution Approach 1:
A phosphorus compound is introduced as an intermediary substance to mediate between the polyamide and heat. The phosphorus compound acts as a heat stabilizer that protects the polyamide from thermal degradation, gelation, and yellowing while maintaining the polyamide's inherent strength and mechanical properties.
Solution Approach 2:
The invention changes the chemical composition parameters of the polyamide system by adding specific phosphorus compounds. This parameter change (addition of phosphorus stabilizer) fundamentally alters the thermal behavior of the polyamide, improving heat stability without compromising mechanical strength.
2Reliability
If conventional stabilizers are added to prevent heat deterioration, then heat stability is improved, but filter clogging increases and productivity decreases
Solution Approach 1:
The invention optimizes the concentration parameter of the phosphorus compound within a specific range (0.01-2% by weight). This precise parameter control ensures sufficient heat stabilization while minimizing the formation of gelled products that would clog filters and reduce productivity.
Solution Approach 2:
The phosphorus compound effectively copies or replaces the protective function of conventional stabilizers (such as hindered phenols and hindered amines) but with superior performance characteristics. It provides heat stability without the severe side effects of filter clogging and gelation that plague traditional stabilizer systems.
3Reliability
If phenylenediamine is added to suppress heat deterioration, then heat stability is improved, but filter back pressure increases due to gelation
Solution Approach 1:
The phosphorus compound serves as an intermediary that prevents the direct harmful interaction between heat and polyamide. It mediates the thermal stress by absorbing or dissipating thermal energy in a way that prevents gelation, thereby maintaining low filter back pressure while providing heat stability.
Solution Approach 2:
The phosphorus compound converts the potentially harmful effect of heat exposure into a beneficial protective mechanism. By adding the phosphorus stabilizer, the system gains heat resistance while avoiding the formation of gelled products that would increase filter back pressure, thus turning thermal stress from a harmful factor into a controlled parameter.
Data Source
AI summary
The present invention relates to such a polyamide resin composition that is suitably used as a material of a gasoline tank and a material of a molded article, such as a hollow molded container including a beverage bottle, a film and a sheet. A polyamide resin that is good in heat stability upon molding and suffers less increase in filter back pressure is provided by regulating a polyamide resin composition to have a phosphorus content of from 30 to 200 ppm (excluding 200 ppm), and a sodium content/phosphorus content ratio (molar ratio) of from 3 to 7 (excluding 3 and 7) or regulating it to have a phosphorus content less than 30 ppm and an alkali metal content less than 45 ppm.