Polycarbonate Resin Composition Flame Retardancy Flowability
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Solution Overview
Problem
Conventional polycarbonate resin compositions face challenges in achieving high rigidity, high flowability, high heat resistance, and excellent flame retardancy, particularly in thin-walled and complex-shaped molded articles for electric and electronic equipment, while also requiring environmental safety and reduced toxic gas emission during burning.
Innovation Solution
A polycarbonate resin composition is developed by blending a nonmetallic inorganic filler and a phosphate compound with a resin mixture comprising an aromatic polycarbonate resin and a fatty acid polyester in specific proportions, which includes a polycarbonate-polyorganosiloxane copolymer and polylactic acid, to enhance mechanical strength, heat resistance, and flame retardancy without compromising flowability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If conventional PC-polyester alloys are used to improve heat resistance and chemical resistance, then these properties are enhanced, but flowability deteriorates
Solution Approach 1:
The patent uses a composite material system consisting of polycarbonate, fatty acid polyester, and inorganic filler. This specific combination achieves both high heat resistance (maintaining PC properties) and improved flowability (through polyester and filler), resolving the contradiction between these two properties.
Solution Approach 2:
The patent optimizes the compositional parameters by controlling the ratio of polycarbonate to fatty acid polyester at 95:5 to 50:50 by mass, and adding 1-50 parts of inorganic filler per 100 parts of resin mixture. This parameter optimization enables simultaneous achievement of heat resistance and flowability.
2Productivity
If styrene type resins or plasticizers are added to increase flowability, then flowability is improved, but rigidity and flame retardancy deteriorate
Solution Approach 1:
The patent replaces conventional plasticizers with inorganic fillers that provide flowability improvement without the negative effects of organic plasticizers. The inorganic filler acts as a short-term processing aid that does not compromise long-term mechanical properties or flame retardancy.
Solution Approach 2:
The patent changes the approach from adding organic modifiers to using inorganic fillers in specific quantities (1-50 parts per 100 parts resin). This parameter change enables flowability improvement while maintaining rigidity and flame retardancy.
3Strength
If glass fibers are added to improve rigidity, then rigidity is enhanced, but flowability and heat resistance deteriorate
Solution Approach 1:
The patent optimizes the filler content to 1-50 parts per 100 parts of resin mixture, which is a lower range compared to conventional glass fiber reinforcements. This parameter optimization provides sufficient rigidity improvement while maintaining adequate flowability for complex-shaped molded articles.
Solution Approach 2:
The patent uses inorganic fillers with aspect ratios of 5 or more, which provide localized reinforcement in critical areas while maintaining overall flowability. The filler distribution creates local rigidity enhancement without compromising global processability.
4Object-affected harmful factors
If halogen type flame retardants are added to improve flame retardancy, then flame retardancy is enhanced, but environmental safety deteriorates
Solution Approach 1:
The patent converts the potential harm of flame retardants by selecting inorganic fillers that inherently provide flame retardancy without generating toxic gases. The inorganic filler serves a dual function: structural reinforcement and environmental-safe flame retardancy.
Solution Approach 2:
The patent changes the flame retardancy approach from chemical additives to physical barriers using inorganic fillers. This parameter change in the flame retardancy mechanism eliminates toxic gas emission while maintaining effective flame resistance.
5Object-affected harmful factors
If phosphate type flame retardants are added in large volumes to improve flame retardancy, then flame retardancy is enhanced, but heat resistance and impact strength deteriorate
Solution Approach 1:
The patent replaces large-volume phosphate flame retardants with inorganic fillers that provide flame retardancy at lower concentrations. The inorganic filler acts as a multifunctional additive that does not compromise heat resistance or mechanical properties.
Solution Approach 2:
The patent optimizes the filler content to 1-50 parts per 100 parts resin, which provides adequate flame retardancy without the excessive concentrations needed for phosphate flame retardants. This parameter optimization maintains heat resistance and impact strength.
Data Source
AI summary
Provided is a polycarbonate resin composition having high rigidity, high flowability, high heat resistance, and excellent flame retardancy and molded articles with good appearance using the polycarbonate resin composition. The polycarbonate resin composition comprises 4 to 50 parts by mass of a nonmetallic inorganic filler (B) and 0.01 to 1 part by mass of a phosphate compound (C) relative to 100 parts by mass of a resin mixture (A) which is composed of 60 to 97% by mass of an aromatic polycarbonate resin (a-1) and 40 to 3% by mass of a fatty acid polyester (a-2).