Polybutylene Terephthalate Resin Composition Flowability and Strength
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Polybutylene terephthalate resin compositions with inorganic fillers face challenges in maintaining mechanical strength and toughness while improving flowability, often resulting in insufficient molding and warping due to reduced flowability and surface bleeding issues when using traditional flowability-improving agents.
Innovation Solution
A polybutylene terephthalate resin composition combining 50-90% polybutylene terephthalate resin with 10-50% inorganic fillers and 0.05-5 parts by weight of a specific glycerin fatty acid ester, which enhances melt-flowability without compromising mechanical strength or causing bleeding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If inorganic filler such as glass fiber is blended in polybutylene terephthalate resin to improve mechanical characteristics, then mechanical strength and stiffness are improved, but flowability decreases causing insufficient molding and warping
Solution Approach 1:
A silane-modified polyethylene wax is introduced as an intermediary substance between the inorganic filler and the polybutylene terephthalate resin. This intermediary improves the interfacial compatibility and lubrication, allowing the resin to flow more smoothly even with high inorganic filler content, thus resolving the contradiction between mechanical strength enhancement and flowability maintenance
Solution Approach 2:
The invention changes the chemical structure parameters of the additive by using silane-modified polyethylene wax with specific molecular weight (10,000-50,000) and silane content (5-50 mass%). This parameter optimization enables the additive to provide both reinforcement compatibility and flow improvement, simultaneously achieving enhanced mechanical strength and maintained flowability
2Object-generated harmful factors
If traditional flowability-improving agents are added to improve flowability, then flowability is improved, but mechanical strength decreases and surface bleeding occurs
Solution Approach 1:
The invention uses a small amount (0.01-5 parts by weight per 100 parts resin) of silane-modified polyethylene wax that provides temporary flow improvement during molding, then stabilizes to maintain mechanical strength. The additive acts as a short-term flow enhancer during the molding process without causing long-term degradation of mechanical properties or surface bleeding
Solution Approach 2:
The invention creates a composite additive system combining polyethylene base material with silane modification, creating a material that exhibits both flow-improving properties and mechanical strength maintenance. The composite structure allows the additive to function as both a lubricant during flow and a strength-preserving agent in the final product
3Strength
If high-viscosity polybutylene terephthalate is used to improve toughness and elongation, then mechanical toughness is improved, but flowability deteriorates causing insufficient molding
Solution Approach 1:
The silane-modified polyethylene wax acts as a mediator that reduces the negative impact of high viscosity on flowability. It provides lubrication at the molecular level, enabling high-toughness resin to flow adequately during injection molding without sacrificing the toughness and elongation properties inherent in high-viscosity polybutylene terephthalate
Data Source
AI summary
A polybutylene terephthalate resin composition which is free from bleeding and other problems, and improves the flowability (melt-flowability) while maintaining the characteristics such as mechanical strength or toughness. To 100 parts by weight of a composition composed of 50 to 90% by weight of (A) a polybutylene terephthalate resin and 10 to 50% by weight of (B) inorganic filler, is blended 0.05 to 5 parts by weight of (C) a glycerin fatty acid ester being composed of glycerin and/or a dehydrated condensate thereof and a fatty acid having 12 or more carbon atoms and having 200 or more hydroxyl value determined by a method specified in the description.