Amorphous Polyamide Resin Composition for Low-Fouling Color-Stable Molding
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Solution Overview
Problem
Amorphous polyamide resins formed from certain diamines and aliphatic dicarboxylic acids can suffer from color tone deterioration and mold fouling during injection molding.
Innovation Solution
A resin composition containing a specific amorphous polyamide resin with 70 mol% or more diamine-derived units from a compound represented by Formula (1) and 70 mol% or more dicarboxylic acid-derived units from α,ω-linear aliphatic dicarboxylic acids, with 3 to 100 mass ppm of the compound represented by Formula (1), which acts as an antioxidant to improve color tone and reduce mold fouling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If amorphous polyamide resin is molded using conventional diamines and aliphatic dicarboxylic acids, then transparency and versatility are improved, but color tone deteriorates and mold fouling occurs
Solution Approach 1:
The patent changes the chemical structure parameters of the diamine by introducing a specific cyclic structure with hindered amine groups. This structural modification alters the polymerization characteristics and thermal stability, thereby improving color tone while maintaining versatility. The specific diamine structure (with cyclic rings and hindered amine groups) prevents unwanted side reactions during molding that would otherwise cause yellowing.
Solution Approach 2:
The patent creates a composite resin system by combining the specifically structured diamine with aliphatic dicarboxylic acid and other additives in controlled proportions. This composite approach leverages the complementary properties of each component: the diamine provides structural framework and color stability, while the dicarboxylic acid contributes to polymerization and mechanical properties. The synergistic combination resolves the contradiction between versatility and color tone maintenance.
2Adaptability or versatility
If amorphous polyamide resin is molded using conventional diamines and aliphatic dicarboxylic acids, then transparency and versatility are improved, but mold fouling increases
Solution Approach 1:
The patent modifies the diamine molecular structure by incorporating cyclic arrangements and hindered amine groups, which changes the thermal and rheological parameters of the resin during molding. These parameter changes reduce the tendency of the resin to adhere to mold surfaces, thereby minimizing fouling while preserving the versatility provided by the amorphous polyamide structure.
Solution Approach 2:
The patent employs a diamine structure with hindered amine groups that acts as a self-limiting agent during molding. The molecular structure inherently prevents excessive adhesion to mold surfaces, effectively making the resin 'non-sticky' during the molding process. This approach eliminates the need for complex mold release mechanisms or extensive mold cleaning procedures.
3Object-affected harmful factors
If compound represented by Formula (1) is added to improve color tone, then color tone is improved, but volatilization and adhesion to mold increase
Solution Approach 1:
The patent optimizes the concentration parameter of the diamine compound by establishing a specific range (3-100 mass ppm). This parameter optimization ensures sufficient color tone improvement while preventing excessive amounts that would volatilize during molding. The hindered amine structure inherently has lower volatility, and the controlled concentration further suppresses evaporative loss, resolving the contradiction between color improvement and substance loss.
Solution Approach 2:
The patent applies the diamine compound at very low concentrations (trace amounts) rather than high concentrations. This local quality approach uses the compound's antioxidant properties efficiently at minimal levels, improving color tone without generating sufficient vapor pressure to cause fouling or adhesion issues. The hindered amine structure provides localized protection against oxidation and color degradation without bulk volatilization.
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 achieves excellent color tone and minimizes mold fouling, enhancing productivity by preventing volatilization and adhesion of the compound during molding.
Implementation Method 1
the compound represented by Formula (1) has a hindered amine structure, thus acts as an antioxidant and adjusts the color tone
Implementation Method 2
the compound represented by Formula (1) if contained in a large amount would volatilize during molding
Data Source
AI summary
To provide a polyamide resin composition preventing mold fouling during molding and capable of producing a molded product with an excellent color tone, as well as a molded product, a method for producing a molded product, and an antioxidant. The composition is a resin composition containing: a polyamide resin constituted of diamine-derived constituent units and dicarboxylic acid-derived constituent units, 70 mol% or more of the diamine-derived constituent units being derived from a compound represented by Formula (1), and 70 mol% or more of the dicarboxylic acid-derived constituent units being derived from an α,ω-linear aliphatic dicarboxylic acid having from 8 to 12 carbon atoms; and a compound represented by Formula (1), where R1 and R2 each independently represent an alkyl group having from 1 to 4 carbon atoms, and n1 and n2 are each independently an integer from 0 to 4, wherein a content of the compound represented by Formula (1) is from 3 to 100 mass ppm of the resin composition.