Branched Polycarbonate Resin Silsesquioxane Branching Agent

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Solution Overview

Problem

The existing branched polycarbonate resins lack sufficient thermal stability and industrial advantages due to insolubility issues with branching agents in dichloromethane or polycarbonate oligomer solutions.

Innovation Solution

A branched polycarbonate resin is developed using a specific branching agent with a silsesquioxane structure, which is soluble in dichloromethane and its solutions, enhancing thermal stability and melt tension while being industrially accessible.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a hydrocarbon-based tetrafunctional branching agent is used, then the branched polycarbonate can be produced, but the branching agent is insoluble in dichloromethane or oligomer/dichloromethane solution requiring separate dissolution in alkaline solution

Engineering Contradiction:

Improvemanufacturing process simplicityVSAvoiddissolution process complexity

Core Design Contradiction:

Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent changes the chemical structure parameters of the branching agent by introducing siloxane bonds and aromatic rings, which fundamentally alters its solubility characteristics. This structural modification enables the branching agent to dissolve in dichloromethane without requiring separate dissolution steps in alkaline solutions, thereby simplifying the overall manufacturing process while maintaining the ability to produce branched polycarbonate.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The branching agent combines multiple functional groups and structural elements (siloxane bonds, aromatic rings, hydroxyl groups) into a composite molecular structure. This composite structure achieves both solubility in organic solvents like dichloromethane and reactivity with polycarbonate oligomers, eliminating the need for separate dissolution steps and streamlining the manufacturing process.

Inventive Principle:

Principle #40Composite materials

2Ease of manufacture

If a siloxane tetrabranched structure branching agent is used, then the branched polycarbonate can be produced, but the thermal stability is insufficient

Engineering Contradiction:

Improvebranching agent availabilityVSAvoidthermal stability

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent creates a composite molecular structure that combines siloxane bonds (for manufacturability and processability) with aromatic rings (for thermal stability). This composite structure integrates the advantages of both components: the siloxane portion enables easy manufacturing and dissolution, while the aromatic portions provide the necessary thermal stability, achieving both goals simultaneously.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

Different parts of the branching agent molecule are designed with different functional qualities: the siloxane bonds and alkyl chains provide solubility and processability, while the aromatic rings specifically provide thermal stability. This local differentiation of functional qualities within the single molecular structure allows the material to meet multiple performance requirements simultaneously.

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS10239993B2Branched polycarbonate resin and method for producing same

Publication Date: 2019.03.26 IDEMITSU KOSAN CO LTD

AI summary

Provided is a branched polycarbonate resin, including a constituent unit represented by the general formula (I′).