Polyimide Resin Moldability Heat Resistance
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Solution Overview
Problem
Current polyimide resins face challenges in being easily processed by molding while maintaining high heat resistance and low colorability or flame resistance, with existing materials often having high melting points and requiring costly processing conditions, and struggling to balance heat resistance with moldability and color suppression.
Innovation Solution
A polyimide resin composition incorporating specific repeating structural units at particular ratios, including alicyclic hydrocarbon and aromatic ring-containing groups, which reduces melting point and enhances glass transition temperature, crystallization rate, and flame resistance, allowing for easier processing and improved properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a polyimide resin is designed to have high heat resistance and low colorability, then the resin maintains excellent thermal stability and flame resistance, but the resin becomes difficult to process by molding due to very low flowability even at high temperatures
Solution Approach 1:
The invention changes the chemical structure parameters of the polyimide resin by introducing specific repeating structural units (formulae 1 and 2) with particular ratios. This modifies the molecular chain flexibility and intermolecular forces, thereby changing the flowability parameter while maintaining heat resistance, resolving the contradiction between processability and thermal stability
Solution Approach 2:
The invention creates a composite molecular structure within the polyimide resin by combining different repeating structural units (formula 1 with alicyclic hydrocarbon and formula 2 with aromatic rings) in specific ratios. This composite approach allows the resin to exhibit both the heat resistance of aromatic structures and the improved flowability from alicyclic units
2Reliability
If a polyimide resin is designed to have high heat resistance and low colorability, then the resin maintains excellent thermal stability and flame resistance, but prolonged molding under high temperature and high pressure is required, increasing manufacturing cost
Solution Approach 1:
The invention changes the processing temperature parameter by reducing the resin's melting point through structural modification. The specific repeating units enable the resin to be processed at lower temperatures and shorter times, directly improving molding efficiency while maintaining the heat resistance property through the inherent stability of the polyimide molecular structure
3Ease of manufacture
If flexible ether bonds and meta structures are introduced to create a melting point, then the resin achieves thermoplasticity and easier molding, but the glass transition temperature remains very high at 250°C, limiting further heat resistance optimization
Solution Approach 1:
The invention applies local quality by introducing flexible structures (ether bonds) only in specific repeating units (formula 1 with alicyclic hydrocarbon) while maintaining rigid aromatic structures (formula 2) in other portions. This localized flexibility provides thermoplasticity for easy molding, while the distributed aromatic units maintain high heat resistance and appropriate glass transition temperature
4Ease of manufacture
If long linear aliphatic diamine is used as raw material to decrease melting point, then the resin achieves better molding processability, but the rigidity decreases and the glass transition temperature is reduced, compromising high temperature strength
Solution Approach 1:
The invention uses local quality by incorporating alicyclic hydrocarbon structures (formula 1) that provide moderate flexibility for improved processability, while combining them with rigid aromatic ring structures (formula 2) that maintain high temperature strength. The specific ratio balance ensures neither flexibility nor rigidity is excessive, resolving the contradiction between moldability and high temperature performance
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 achieves easy moldability with high heat resistance, low colorability, and enhanced flame resistance, making it suitable for various applications without the need for high-temperature processing, and can be processed into articles with improved mechanical and thermal properties.
Implementation Method 1
The polyimide resin has a melting point of 360°C. or lower and a glass transition temperature of 170°C. or higher, and thus may be heat-molded
Implementation Method 2
The polyimide resin may have a melting point of 360° C. or lower and a glass transition temperature of 170° C. or higher
Data Source
AI summary
A polyimide resin containing a repeating structural unit of the following formula (1), a repeating structural unit of the following formula (2), and a repeating structural unit of the following formula (A) or a repeating structural unit of the following formula (B), a content ratio of formula (1) with respect to the total of formula (1) and formula (2) being from 40 to 70 mol %, and a content ratio of formula (A) or formula (B) with respect to the total of formula (1) and formula (2) being more than 0 mol % and 25 mol % or less:wherein R1 represents a divalent group having from 6 to 22 carbon atoms containing at least one alicyclic hydrocarbon structure; R2 represents a divalent chain aliphatic group having from 5 to 20 carbon atoms; Ra represents a divalent group containing at least one aromatic ring which is bonded to a monovalent or divalent electron-attracting group; Rb represents a divalent group containing —SO2— or —Si(Rx)(Ry)O— wherein Rx and Ry each independently represent a chain aliphatic group having from 1 to 3 carbon atoms, or a phenyl group; and X1, X2, Xa, and Xb each independently represent a tetravalent group having from 6 to 22 carbon atoms containing at least one aromatic ring.