Refrigerant Hose Resin Composition for Extrusion and Permeation
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Solution Overview
Problem
Refrigerant-transporting hoses made from semi-aromatic polyamide resins face issues with extrusion processability, flexibility, and refrigerant permeation resistance due to high crystallinity and rigidity, leading to potential cracking and reduced performance in high-temperature environments.
Innovation Solution
A resin composition combining a semi-aromatic polyamide resin with an aliphatic polyamide resin and an uncrosslinked elastomer, where the elastomer is finely dispersed in the aliphatic polyamide resin and incorporated as particles, improving compatibility and flexibility while maintaining refrigerant permeation resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If semi-aromatic polyamide resin is used to improve refrigerant permeation resistance and acid resistance, then extrusion processability deteriorates due to high crystallization rate and high melting point
Solution Approach 1:
The patent combines semi-aromatic polyamide resin (providing refrigerant permeation resistance and acid resistance) with aliphatic polyamide resin (improving extrusion processability and flexibility). This composite material approach allows the hose to simultaneously achieve high barrier properties and good processability during extrusion, resolving the contradiction between reliability and ease of manufacture.
2Reliability
If semi-aromatic polyamide resin is used to improve refrigerant permeation resistance, then flexibility deteriorates due to high rigidity
Solution Approach 1:
The patent creates a composite material system where semi-aromatic polyamide resin provides the necessary barrier properties while aliphatic polyamide resin and elastomer components provide flexibility. The synergistic combination allows the hose to maintain both high refrigerant permeation resistance and adequate flexibility for installation and operation.
Solution Approach 2:
The patent introduces an elastomer component that selectively provides flexibility and impact resistance at specific locations within the material structure, while the semi-aromatic polyamide resin maintains its barrier properties. This local quality differentiation allows the material to exhibit both rigidity and flexibility as needed.
3Reliability
If semi-aromatic polyamide resin is used to improve acid resistance, then impact resistance at low temperature deteriorates
Solution Approach 1:
The patent formulates a composite material where semi-aromatic polyamide resin provides acid resistance while elastomer components provide impact resistance at low temperatures. The combination ensures the hose can withstand both chemical degradation from refrigerant acids and mechanical impact under cold operating conditions.
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 resin composition enhances extrusion processability, flexibility, and refrigerant permeation resistance, reducing the occurrence of weld lines and thickness deviations, and maintaining acid resistance, resulting in improved performance of refrigerant-transporting hoses.
Implementation Method 1
kneading an aliphatic polyamide resin (B) and an elastomer (C) that is uncrosslinked to finely disperse the elastomer (C) in the aliphatic polyamide resin (B)
Implementation Method 2
when the semi-aromatic polyamide resin such as the PA9T is extruded upon production of the hose, the resin crystallizes (changes from a molten state to a solid state) immediately after the extrusion because the resin has a high melting point and a high crystallization rate
Data Source
AI summary
A resin composition for a refrigerant-transporting hose, including: a semi-aromatic polyamide resin (A) as a main component; an aliphatic polyamide resin (B); and an elastomer (C), in which the aliphatic polyamide resin (B) is dispersed in a phase formed of the semi-aromatic polyamide resin (A) and the elastomer (C), which is not crosslinked, is incorporated in the form of particles into the dispersed aliphatic polyamide resin (B). Thus, excellent refrigerant permeation resistance and acid resistance, and at the same time, for example, extrusion processability and flexibility, are obtained.