Polycarbonate Copolymer Molding Composition Flowability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing thermoplastic compositions for injection molding, particularly in the electrical and automotive industries, face challenges in achieving low viscosity without compromising mechanical properties such as impact resistance and flowability, as conventional methods either impair toughness or require costly reengineering and surface-active additives that can lead to adhesion issues.
Innovation Solution
A thermoplastic molding composition comprising 99.9 to 10 parts by weight of aromatic polycarbonate and 0.1 to 20 parts by weight of a copolymer of α-olefin with methacrylic or acrylic ester, where the Melt Flow Index (MFI) of the copolymer is no less than 100 g/10 min, enhancing both flowability and notched impact strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If low-molecular-weight polymer resins are used to reduce viscosity, then flowability is improved, but mechanical properties particularly toughness are impaired
Solution Approach 1:
The invention uses a composite system consisting of a base polymer resin combined with specific low-molecular-weight flow auxiliaries (fatty acid esters of polyols or amides of fatty acids and amines). This composite approach allows the base resin to maintain mechanical properties while the flow auxiliary reduces viscosity, resolving the contradiction between flowability and toughness.
Solution Approach 2:
The invention changes the molecular weight parameter of the additive (using low-molecular-weight compounds with specific molecular weights) to achieve reduced viscosity without significantly affecting the mechanical properties of the base polymer. The specific parameter range of the flow auxiliary molecular weight is optimized to balance flowability and mechanical strength.
2Ease of operation
If surface-active flow auxiliaries are used to reduce viscosity, then flowability is improved, but adhesion properties deteriorate due to migration to the surface
Solution Approach 1:
The invention extracts the surface-active properties from the flow auxiliary system by selecting compounds with specific chemical structures (fatty acid esters of polyols or amides of fatty acids and amines) that have reduced surface activity compared to conventional flow auxiliaries. This extraction of surface-active characteristics prevents migration to the moldings surface while maintaining the viscosity-reducing function.
Solution Approach 2:
The invention applies local quality by selecting flow auxiliaries with specific molecular structures that have different properties at different locations - the compounds are designed to remain compatible with the bulk polymer matrix while having minimal tendency to migrate to the surface, thus providing localized flow improvement without compromising surface adhesion.
3Ease of operation
If conventional flow auxiliaries are used, then viscosity is reduced, but mechanical properties are significantly impaired
Solution Approach 1:
The invention optimizes the molecular weight parameter of the flow auxiliary within a specific range (low-molecular-weight compounds) to achieve viscosity reduction while minimizing impact on mechanical properties. The specific molecular weight range is carefully selected to balance flowability improvement with mechanical property preservation.
Solution Approach 2:
The invention creates a composite system where the base polymer resin and the flow auxiliary work synergistically - the base resin provides the mechanical strength while the low-molecular-weight flow auxiliary provides viscosity reduction. This composite approach allows both requirements to be met simultaneously without significant compromise to mechanical properties.
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 improved flowability and maintains mechanical properties, allowing for the production of components with high notched impact strength and reduced injection pressures, suitable for thin-wall technology and multitooling systems without the drawbacks of lower-viscosity resins or surface-active additives.
Implementation Method 1
A) from 99.9 to 10 parts by weight, preferably from 99.0 to 40 parts by weight, particularly preferably from 80.0 to 50.0 parts by weight, of at least one thermoplastic polycarbonate... B) from 0.1 to 20 parts by weight, preferably from 0.25 to 15 parts by weight, particularly preferably from 1.0 to 10 parts by weight, of at least one copolymer... where the MFI (Melt Flow Index) of the copolymer B) is no less than 100 g/10 min
Data Source
AI summary
This invention relates to thermoplastic moulding compositions with improved flowability based on a thermoplastic polycarbonate and on a copolymer of at least one olefin with at least one methacrylic ester or acrylic ester of an aliphatic alcohol, where the MFI of the copolymer is no less than 100 g/10 min, to a process for preparation of these moulding compositions, and also to the use of these moulding compositions for production of mouldings for the electrical industry, electronics industry, telecommunications industry, motor vehicle industry, or computer industry, in sports, in medicine, in households, or in the entertainment industry.