Polyester resin composition and molded article for capacitor housing manufactured using the same
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional capacitor housing materials face challenges in achieving high adhesion to epoxy potting materials, dimensional stability, and hydrolysis resistance, particularly with polybutylene terephthalate (PBT)-based materials, which limit their mechanical strength and filler content due to high viscosity and poor hydrolysis resistance.
Innovation Solution
A polyester resin composition comprising 40-50% polybutylene terephthalate resin, 18-20% acrylic styrene acrylonitrile resin, 25-35% glass fiber, 1-3% epoxy resin, 0.01-1% carbodiimide-based anti-hydrolysis agent, and 0.01-1% epoxy silane, which enhances adhesion, dimensional stability, and hydrolysis resistance, while maintaining mechanical properties and moldability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If polybutylene terephthalate (PBT)-based materials are used for capacitor housing, then adhesion to epoxy potting material can be improved, but hydrolysis resistance deteriorates
Solution Approach 1:
The patent uses a composite material system consisting of PBT resin as the base polymer combined with ASA resin (acrylic styrene acrylonitrile) and glass fiber reinforcements. This composite approach allows the PBT to provide adhesion to epoxy potting material while the ASA and glass fiber components compensate for hydrolysis resistance deficiencies, achieving both adhesion and hydrolytic stability in the final molded article.
2Stability of the object's composition
If a large amount of minerals is added to improve dimensional stability, then adhesion to epoxy can be enhanced, but viscosity increases making it difficult to include high content of filler
Solution Approach 1:
The patent controls the viscosity parameter by carefully selecting the PBT resin with specific intrinsic viscosity (0.70-1.20 dl/g) and adjusting the processing temperature (230-280°C). The resin composition parameters are optimized to maintain viscosity at levels that allow high filler content (20-40 wt% minerals) while achieving the desired dimensional stability through the combined effect of minerals and glass fiber (10-30 wt%).
3Stability of the object's composition
If high content of filler is included to improve dimensional stability, then mechanical strength can be enhanced, but adhesion to epoxy potting material deteriorates
Solution Approach 1:
The patent employs a multi-component composite system where PBT resin provides the adhesive matrix for epoxy potting material, while minerals (20-40 wt%) contribute to dimensional stability. The glass fiber (10-30 wt%) acts as a bridging element that maintains structural integrity and adhesion properties even with high filler content. The ASA resin (5-20 wt%) further enhances the composite's overall performance, ensuring that adhesion is maintained despite the high mineral loading.
4Stability of the object's composition
If polyphenylene sulfide (PPS)-based resin with high content of filler is used, then dimensional stability can be achieved, but adhesion to epoxy potting material and hydrolysis resistance deteriorate
Solution Approach 1:
The patent changes the base polymer parameter from PPS to PBT, which has inherently better adhesion properties to epoxy potting material. The PBT resin's chemical structure provides superior epoxy compatibility while maintaining dimensional stability through the added minerals and glass fiber. This parameter change in the base polymer selection resolves the adhesion problem while the filler system maintains dimensional stability.
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 solution provides a capacitor housing with high initial adhesive strength, sustained adhesion under harsh environmental conditions, and excellent mechanical properties, including a low coefficient of linear expansion and high comparative tracking index, ensuring reliable insulation and mechanical integrity.
Implementation Method 1
0.01 to 1% by weight of a carbodiimide-based anti-hydrolysis agent
Implementation Method 2
0.01 to 1% by weight of epoxy silane
Data Source
AI summary
A polyester resin composition that has excellent adhesion to an epoxy potting material and can simultaneously satisfy dimensional stability and hydrolysis resistance, and a molded article for capacitor housing, which is manufactured using the polyester resin composition. The polyester resin composition including 40 to 50% by weight of polybutylene terephthalate resin, 18 to 20% by weight of acrylic styrene acrylonitrile resin, 25 to 35% by weight of glass fiber, 1 to 3% by weight of epoxy resin, 0.01 to 1% by weight of a carbodiimide-based anti-hydrolysis agent, and 0.01 to 1% by weight of epoxy silane.