Crystalline Polyamide Resin Composition for Automotive Door Checkers
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Solution Overview
Problem
Highly viscous polyamide resins with high molecular weight improve sliding characteristics but compromise moldability and mechanical strength, while low-molecular compounds enhance moldability at the cost of mechanical strength, limiting their use in automotive parts requiring both properties.
Innovation Solution
A crystalline polyamide-type resin composition combining two polyamides with different viscosities and a modified polyolefin resin with reactive functional groups, improving miscibility and maintaining mechanical strength and moldability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a highly viscous polyamide resin with high molecular weight is used, then sliding characteristic is improved, but moldability becomes bad
Solution Approach 1:
The invention divides the polyamide resin system into two separate resins with different viscosities: a highly viscous polyamide resin (A) with relative viscosity of 3.5 or more providing sliding characteristics, and a less viscous polyamide resin (B) with relative viscosity of 2.0 to 3.4 providing moldability. This segmentation allows each resin to fulfill its specific function without compromising the other.
Solution Approach 2:
The invention creates a composite resin composition by combining two different polyamide resins with complementary properties. The composition includes polyamide resin (A) with high viscosity for sliding resistance and polyamide resin (B) with lower viscosity for good moldability, achieving a balance between conflicting requirements through material composition.
2Reliability
If a highly viscous polyamide resin with high molecular weight is used, then sliding characteristic is improved, but mechanical strength becomes bad
Solution Approach 1:
The invention segments the mechanical strength function from the sliding characteristic function by assigning them to different resin components. Polyamide resin (A) with high viscosity handles sliding characteristics, while polyamide resin (B) with controlled viscosity and specific molecular weight (average molecular weight of 10,000 to 50,000) provides mechanical strength, allowing both requirements to be satisfied simultaneously.
Solution Approach 2:
The composite resin composition combines polyamide resin (A) providing sliding resistance with polyamide resin (B) providing mechanical strength. The specific composition ratio and molecular weight control ensure that the final product achieves both good sliding characteristics and adequate mechanical strength, resolving the contradiction between these properties.
3Ease of manufacture
If low-molecular compound such as higher fatty acid is compounded for improving moldability, then moldability becomes better, but mechanical strength significantly lowers
Solution Approach 1:
The invention uses polyamide resin (B) as an intermediary material that provides moldability without the need for low-molecular compounds. Resin (B) acts as a mediator between the high-viscosity resin (A) and the molding process, enabling good moldability while maintaining mechanical strength through its controlled molecular weight and viscosity characteristics.
Solution Approach 2:
The invention changes the viscosity parameter by using a blend of two resins with different viscosities rather than adding chemical additives. By adjusting the composition ratio of resin (A) and resin (B), the invention achieves optimal moldability through physical parameter control rather than chemical modification, thereby preserving mechanical strength.
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 durability against sliding and shock resistance with enhanced moldability, suitable for automotive parts like door checkers and gears, where mechanical strength and sliding characteristics are crucial.
Implementation Method 1
a modified polyolefin resin (C) having a reactive functional group being able to react with the terminal group and/or main-chain amide group of the polyamide resin
Data Source
AI summary
The invention provides a crystalline polyamide-type resin composition comprises (a) a crystalline polyamide resin composition comprising (i) 50 to 90% by weight of crystalline polyamide resin (A) having a relative viscosity in 96% sulfuric acid of not less than 3.5 and (ii) 50 to 10% by weight of a crystalline polyamide resin (B) having a melting point lower than the melting point of polyamide resin (A) by 20° C. or more and a relative viscosity dissolved in 96% sulfuric acid of not more than 3.6, and (b) 1 to 10 part(s) by weight of a modified polyolefin resin (C) having a reactive functional group being able to react with the terminal group and/or main-chain amide group of the polyamide resin. The invention also provides a door checker for automobiles prepared from the crystalline polyamide-type resin composition.